Surya's Sandbox

Studies Skepticism

2018-06-08T10:30:00-04:00

Studies/Research Skepticism

Who did the study/research.
Who is backing them or funding the group.
Is there a conflict of interest.
If the study fails or succeeds, what are the implications (financially or otherwise) to the entity who funded them

Comparing products

2018-02-27T15:54:00-05:00

Comparing two or more products and choosing the right one for the task.

What problem are they trying to solve.
How many people are using them.
Who made it and what is their track record.
How many contributors/and release cycle till date.
Be wary of marketing on the item, cause they don't tell what is missing or wrong.

How to improve Javascript coding

2015-03-11T22:47:00-04:00

Advantages

Modern browsers are way faster to process JS.
Trend – clients are doing what servers used to do
Server is used only to generate data like json
Client is used only to generate/render html
Speed/efficient (no redundant data transfer between server client)

Disadvantage

No compile time error checking
Once a project becomes big, it is hard to upgrade libraries/framework
without breaking something (at runtime)
Not properly organized (global methods, big script file)

Solution

Enclose functions in namespace
Modularize code (this way big file can be split)
“use strict” (reason)
Write unit test (to solve compile time checking)

here is an example -

(function (nsr, $, undefined) {
     "use strict"
     nsr.Module1 = nsr.Module1 || {};
     nsr.Module1.variable1 = 'test';
     nsr.Module1.function1 = function(){}
} (window.nsr = window.nsr || {}, jQuery));

Using and working with IndexedDB

2012-05-17T12:32:00-04:00

Below is a sample example code for IndexedDB

//nsr is namespace
(function (nsr, $, undefined) {
    //private variables
    nsr.myTvQ.indexedDB = nsr.myTvQ.indexedDB || {};
    nsr.myTvQ.indexedDB.db = null;
    nsr.myTvQ.indexedDB.version = "1.0";

    //saving webkitIndexedDB in global namespace
    if ('webkitIndexedDB' in window) {
        window.indexedDB = window.webkitIndexedDB;
        window.IDBTransaction = window.webkitIDBTransaction;
        window.IDBKeyRange = window.webkitIDBKeyRange;
        window.IDBCursor = window.webkitIDBCursor;
    }
    //global error handler
    nsr.myTvQ.indexedDB.onerror = function (e) {
        console.log("myError: ", e);        
    };
    // callback param in integer, -1 error, 0 exiting, 1 new
    nsr.myTvQ.indexedDB.Open = function (callback) {
        if (nsr.myTvQ.indexedDB.db) {
            if (callback) {
                callback(0);//opened but present
            }
            return;
        }
        var request = indexedDB.open("myTvQDB", "comments bla blah database v1.0");

        request.onsuccess = function (e) {
            var v = nsr.myTvQ.indexedDB.version;
            nsr.myTvQ.indexedDB.db = e.target.result;
            var db = nsr.myTvQ.indexedDB.db;
            console.log('opened indexedDB myTvQDB v:' + db.version);

            // We can only create Object stores in a setVersion transaction;
            // so if version not found update or create new db
            if (v != db.version) {
                console.log('setting new v ',v, db.version);
                var setVrequest = db.setVersion(v);

                // onsuccess is the only place we can create Object Stores
                setVrequest.onfailure = request.onfailure =  function (e) 
                {        
                    console.log("myError: ", e); 
                    if (callback) {                        
                        callback(-1);
                    }
                };
                setVrequest.onsuccess = function (e) {
                    //create this at last, since update_time is stored in end
                    nsr.myTvQ.indexedDB.DropObjectStore("settings");
                    nsr.myTvQ.indexedDB.CreateSettingsStore();

                    nsr.myTvQ.indexedDB.DropObjectStore("listings");
                    nsr.myTvQ.indexedDB.listing.CreateListingsStore();         
                    if (callback) {
                        callback(1);//created                        
                    }
                };
            } else {
                if (callback) {
                    callback(0);//opened but present
                }
                console.log('object stores are present');
            }
        };

        request.onfailure =  function (e) 
        {        
            console.log("myError: ", e); 
            if (callback) {
                callback(-1);//error
            }
        };
    }

    //helper methods
    nsr.myTvQ.indexedDB.Close = function(){
        try {
            var db = nsr.myTvQ.indexedDB.db;
            if (db) {
                db.close();
                nsr.myTvQ.indexedDB.db = null;
                if (callback) {
                    callback(1);
                }
            }   
        } catch (ex) {
            if (callback) {
                callback(-1);
            }
            console.log("Exception in Close() - " + ex.message);
        }
    } 
    nsr.myTvQ.indexedDB.DeleteDatabase = function(callback){
        try {
            var db = nsr.myTvQ.indexedDB.db;
            if (db) {
                db.close();
            }   
            var request =  window.indexedDB.deleteDatabase('myTvQDB');
            request.onsuccess = function (e) {
                nsr.myTvQ.indexedDB.db = null;
                if (callback) {
                    callback(1);
                }
                console.log('Database successfully deleted');
            };
            request.onfailure = function (e) 
            {        
                console.log("myError: ", e); 
                if (callback) {
                    callback(-1);
                }
            };    
        } catch (ex) {
            if (callback) {
                callback(-1);
            }
            console.log("Exception in DeleteDatabase() - " + ex.message);
        }
    }

    nsr.myTvQ.indexedDB.DropObjectStore = function (storeName) {
        var db = nsr.myTvQ.indexedDB.db;
        if (db.objectStoreNames.contains(storeName)) {
            db.deleteObjectStore(storeName);
            console.log('objectstore ' + storeName + ' dropped');
        }
    }

    nsr.myTvQ.indexedDB.ForceDropObjectStore = function (storeName) {
        var db = nsr.myTvQ.indexedDB.db;
        var setVrequest = db.setVersion(Math.random());
        setVrequest.onfailure = nsr.myTvQ.indexedDB.onerror;
        setVrequest.onsuccess = function (e) {
            console.log('db.version ', db.version);
            nsr.myTvQ.indexedDB.DropObjectStore(storeName);
        }
    };

    //can use to re-create empty ObjectStore
    nsr.myTvQ.indexedDB.ForceCreateObjectStore = function (storeName) {
        console.log('ForceCreateObjectStore', storeName);
        var db = nsr.myTvQ.indexedDB.db;
        var setVrequest = db.setVersion(Math.random());
        setVrequest.onfailure = nsr.myTvQ.indexedDB.onerror;
        setVrequest.onsuccess = function (e) {
            console.log('db.version ', db.version);
            nsr.myTvQ.indexedDB.DropObjectStore(storeName);
            switch(storeName){
                case "listings":
                    nsr.myTvQ.indexedDB.listing.CreateListingsStore();
                    break;  
                case "settings":
                    nsr.myTvQ.indexedDB.listing.CreateSettingsStore();
                    break;     
                default:
                    break;
                }
            nsr.myTvQ.indexedDB.ResetVersion();
        }
    };

    //set version back to old version
    nsr.myTvQ.indexedDB.ResetVersion = function () {
        var db = nsr.myTvQ.indexedDB.db;
        var setVrequest = db.setVersion(nsr.myTvQ.indexedDB.version);
        setVrequest.onfailure = nsr.myTvQ.indexedDB.onerror;
        setVrequest.onsuccess = function (e) {
            console.log('reset db.version ', db.version);
        }
    };

    //empty or truncate table
    nsr.myTvQ.indexedDB.ClearAll = function(storeName, callback){
        var db = nsr.myTvQ.indexedDB.db;
        if (db.objectStoreNames.contains(storeName)) {
            var clearTransaction = db.transaction([storeName], IDBTransaction.READ_WRITE);
            var clearRequest = clearTransaction.objectStore(storeName).clear();
            clearRequest.onsuccess = function(event){
                 //event.target.result contains undefined
                 if (callback) {
                    callback(true);
                 }                 
            };
            clearRequest.onerror = function(event){            
                 console.log("myError: ", event);
                 if (callback) {
                    callback(false);
                 }                                  
            };
        }else {
            console.log(storeName+ " doesnot exist ");
            if (callback) {
                    callback(false);
            }                 
        }
    }
    //nsr.myTvQ.indexedDB.ListAll('','store_id',function(l1){console.log(l1);});
    nsr.myTvQ.indexedDB.ListAll = function(storeName, objOrArray, callback){
        var db = nsr.myTvQ.indexedDB.db;
        if (db.objectStoreNames.contains(storeName)) {
            var transaction = db.transaction(storeName, IDBTransaction.READ_ONLY);
            var list = objOrArray ? {} : [] ;
            transaction.oncomplete = function(event) {
                if(callback){
                    //console.log(results);
                    callback(list);
                }
            };
            transaction.onerror = nsr.myTvQ.indexedDB.onerror;
            var cursorRequest = transaction.objectStore(storeName).openCursor();

            cursorRequest.onsuccess = function(ev) {
                var cursor = cursorRequest.result || ev.target.result;
                if(!!cursor == false)
                    return;
                if(objOrArray){
                    list[cursor.value[objOrArray]] = cursor.value;
                }
                else{
                    list.push(cursor.value);                
                }
                cursor.continue();
            };      
        }else {
            console.log(storeName+ " doesnot exist ");
            if (callback) {
                    callback(false);
            }                 
        }            
    }

    nsr.myTvQ.indexedDB.Delete = function(storeName, key, callback){
        var db = nsr.myTvQ.indexedDB.db;
        var request = db.transaction(storeName, IDBTransaction.READ_WRITE)  
                .objectStore(storeName)  
                .delete(key);  
        request.onsuccess = function(event) {  
          if(callback){
                //console.log(results);
                callback(true);
            }  
        };
        request.onerror = function(event) {  
          if(callback){
                callback(false);
            }  
        };
    }

    nsr.myTvQ.indexedDB.CreateSettingsStore = function(callback){
        var db = nsr.myTvQ.indexedDB.db;
        if(!db.objectStoreNames.contains("settings")) {
            //will be used by background to get all past dates and run operations on them
            db.createObjectStore("settings",{keyPath:"Name"});
            console.log('objectstore settings created');

            nsr.myTvQ.indexedDB.SetAllSettings(undefined,callback);
        }
    };



    nsr.myTvQ.indexedDB.GetAllSettings = function(callback){
        var db = nsr.myTvQ.indexedDB.db;        
        var settings = {};
        var transaction = db.transaction(["settings"], IDBTransaction.READ_ONLY);
        transaction.oncomplete = function(event) {  
          if(callback){
            callback(settings);
          }
        }; 
        transaction.onerror = nsr.myTvQ.indexedDB.onerror;
        var store = transaction.objectStore("settings");
        var cursorRequest = store.openCursor(IDBKeyRange.lowerBound(0));
        cursorRequest.onsuccess = function(ev) {
            var cursor = cursorRequest.result || ev.target.result;
            if(!!cursor == false)
                return;
            //console.log(cursor.value);
            settings[cursor.value.Name] = cursor.value.Value;
            cursor.continue();
        };          
    }

    nsr.myTvQ.indexedDB.SetAllSettings = function(settings, callback){
         var db = nsr.myTvQ.indexedDB.db; 
         var transaction = db.transaction(["settings"], IDBTransaction.READ_WRITE);
         var store = transaction.objectStore("settings");
         transaction.oncomplete = function(event) {  
            if(callback){
                console.log('SetAllSettings Initialized');
                callback();
            }
         }; 
         transaction.onerror = nsr.myTvQ.indexedDB.onerror;
         settings = settings || {};
         var init_list = [{"Name":"update_time","Value":settings.update_time || (new Date()).getTime() }                          
                            ,{"Name":"enable_notification","Value":settings.enable_notification || 1}
                            ,{"Name":"default_country","Value":settings.default_country || 'US'}];

         $.each(init_list, function (index0, item0) {
                var request = store.put(item0);
                request.onsuccess = function(event) {};
                request.onerror = function(event) {
                    console.log(event);
                }; 
         });
    }

    nsr.myTvQ.indexedDB.GetSettingsFor = function(name, callback){
        var db = nsr.myTvQ.indexedDB.db;
        var resultset = null;
        var transaction = db.transaction(["settings"], IDBTransaction.READ_ONLY);
        transaction.oncomplete = function(event) {  
          if(callback){
            callback(resultset);
          }
        }; 
        transaction.onerror = nsr.myTvQ.indexedDB.onerror;
        var store = transaction.objectStore("settings");
        var request = store.get(name);  
        request.onerror = function(event) {  
          console.log(event);
        };  
        request.onsuccess = function(event) {  
          resultset = request.result ? request.result.Value : undefined ;  
        };
    }

    nsr.myTvQ.indexedDB.SetSettingsFor = function(name, value, callback){
        var db = nsr.myTvQ.indexedDB.db;
        var transaction = db.transaction(["settings"], IDBTransaction.READ_WRITE);
        transaction.oncomplete = function(event) {  
          if(callback){
            callback(true);
          }
        }; 
        transaction.onerror = function(event) {  
          if(callback){
            callback(false);
          }
        }; 
        var store = transaction.objectStore("settings");
        var request = store.put({"Name":name,"Value":value});  
        request.onerror = function(event) {  
          console.log(event);
        };  
        request.onsuccess = function(event) {};
    }

    ///Show Listings
    nsr.myTvQ.indexedDB.listing.CreateListingsStore = function(callback){
        var db = nsr.myTvQ.indexedDB.db;
        if(!db.objectStoreNames.contains("listings")) {
            var store = db.createObjectStore("listings", { keyPath: "show_id" });
            store.createIndex("countryIndex", "country", { unique: false });
            store.createIndex("country_statusIndex", "country_status", { unique: false });
            store.createIndex("show_name_Index", "show_name", { unique: false });
            console.log('objectstore listing created');  
            if(callback){
                callback(true);
            }          
        }else {
            if(callback){
                console.log('CreateListingsStore already exits');
                callback(true);
            }
        }
    };

    nsr.myTvQ.indexedDB.listing.AddListings = function (x2j_list_new, index, callback) {
        //no need to clear, since its add or update.        
        var db = nsr.myTvQ.indexedDB.db;
        var transaction = db.transaction(["listings"], IDBTransaction.READ_WRITE);
        var count = 0;
        transaction.oncomplete = function (event) {
            if (callback) {
                console.log('x2jShowListing Added ' + count + '/' + x2j_list_new.length);
                callback([index, count, x2j_list_new.length]);
            }
        };
        transaction.onerror = nsr.myTvQ.indexedDB.onerror;
        var store = transaction.objectStore("listings");
        console.log('AddListings looping'+index);
        $.each(x2j_list_new, function (index0, item0) {
            var request = store.put(item0);
            request.onsuccess = function (event) {
                count++;
                // event.target.result == show_id  
            };
        });        
    };

    nsr.myTvQ.listing.AddListingsInChunks = function (progressElemId, callback) {
        $(progressElemId).html('(Listing is older than 14 days, fetching latest from server)');
        nsr.myTvQ.listing.GetListingsFromTvRage(function (x2j_list_new) {
            if (!x2j_list_new) {
                if (callback) {
                    $(progressElemId).html('(Encountered Error while fetching, please try again later.)');
                    callback(false);
                    return;
                }
            }
            console.log('x2j_list_new now calling AddListings');

            //http://stackoverflow.com/questions/8495687/split-array-into-chunks      
            var i = 0, j = x2j_list_new.length, temp_array, chunk = 500;
            $(progressElemId).html('(Got a total of '+j+' Shows)');
            //http://www.kryogenix.org/days/2009/07/03/not-blocking-the-ui-in-tight-javascript-loops
            function doWork() {
                temp_array = x2j_list_new.slice(i, i + chunk);
                nsr.myTvQ.indexedDB.listing.AddListings(temp_array, i, function (cnt) {
                    if (cnt[0] >= j - chunk) {
                        console.log('AddListings ALL DONE', cnt);
                        if (callback) {
                            $(progressElemId).html('(Saving Shows locally 100% Comlepete. Now generating screen. Almost there... )');
                            callback(true);
                            return;
                        }
                    }
                    $(progressElemId).html('(Saving '+j+' Shows locally, '+(((i + chunk >=j ? j: i + chunk)/j)*100).toFixed(2) +'% Done.)');
                    console.log(cnt);
                });
                i += chunk;
                if (i < j) {
                    setTimeout(doWork, 100);
                }
            };
            setTimeout(doWork, 100);            
        });
    }

    nsr.myTvQ.indexedDB.listing.GetAllCountries = function (callback) {
        var db = nsr.myTvQ.indexedDB.db;
        var resultset = [];
        var transaction = db.transaction(["listings"], IDBTransaction.READ_ONLY);
        transaction.oncomplete = function(event) {  
          if(callback){
            callback(resultset);
          }
        }; 
        transaction.onerror = nsr.myTvQ.indexedDB.onerror;
        var store = transaction.objectStore("listings");

        var countryIndex = store.index("countryIndex");

        var cursorRequest = countryIndex.openKeyCursor(null, IDBCursor.NEXT_NO_DUPLICATE);
        cursorRequest.onsuccess = function(ev) {
          var cursor = cursorRequest.result;
          if (cursor) {
            resultset.push(cursor.key);
            //console.log(cursor.value);//undefined
            cursor.continue();
          }
        };
    };

    nsr.myTvQ.indexedDB.listing.GetListingByCountry = function (country, callback) {
        console.log("GetListingBy country");
        var resultset = [];
        var db = nsr.myTvQ.indexedDB.db;
        var transaction = db.transaction(["listings"], IDBTransaction.READ_ONLY);
        transaction.oncomplete = function(event) {  
            if(callback){
            callback(resultset);
            }
        }; 
        transaction.onerror = nsr.myTvQ.indexedDB.onerror;
        var store = transaction.objectStore("listings");

        var countryIndex = store.index("countryIndex");

        var cursorRequest = countryIndex.openCursor(new IDBKeyRange.only(country));
        cursorRequest.onsuccess = function(ev) {
            var cursor = cursorRequest.result;
            if (cursor) {
            resultset.push(cursor.value);

            cursor.continue();
            }
        };
    };

    nsr.myTvQ.indexedDB.listing.GetListingByCountryStatus = function (country, status, callback) {
        var resultset = [];
        var db = nsr.myTvQ.indexedDB.db;
        var transaction = db.transaction(["listings"], IDBTransaction.READ_ONLY);
        transaction.oncomplete = function(event) {  
          if(callback){
            callback(resultset);
          }
        }; 
        transaction.onerror = nsr.myTvQ.indexedDB.onerror;
        var store = transaction.objectStore("listings");

        var country_statusIndex = store.index("country_statusIndex");
        var cursorRequest = country_statusIndex.openCursor(new IDBKeyRange.only(country +'_'+ status));
        cursorRequest.onsuccess = function(ev) {
          var cursor = cursorRequest.result;
          if (cursor) {
            resultset.push(cursor.value);
            //console.log(cursor.value);
            cursor.continue();
          }          
        };
    };

    //from ="A", to="B"
    nsr.myTvQ.indexedDB.listing.GetCountryByRange = function (from, to) {
        var db = nsr.myTvQ.indexedDB.db;
        var resultset = [];
        var transaction = db.transaction(["listings"], IDBTransaction.READ_ONLY);
        transaction.oncomplete = function(event) {  
            console.log(resultset);
        }; 
        transaction.onerror = nsr.myTvQ.indexedDB.onerror;
        var store = transaction.objectStore("listings");

        var countryIndex = store.index("countryIndex");

        var cursorRequest = countryIndex.openKeyCursor(IDBKeyRange.bound(from,to,false,true), IDBCursor.NEXT_NO_DUPLICATE);
        cursorRequest.onsuccess = function(ev) {
          var cursor = cursorRequest.result;
          if (cursor) {
            resultset.push(cursor.key);
            //console.log(cursor.value);//undefined
            cursor.continue();
          }
        };
    };

    //chrome doesnot support count yet.
    nsr.myTvQ.indexedDB.listing.CountListing = function (callback) {        
        var db = nsr.myTvQ.indexedDB.db;
        var transaction = db.transaction(["listings"], IDBTransaction.READ_ONLY);
        var count = 0;
        transaction.oncomplete = function(event) {  
          if(callback){
            callback(count);
          }
        };
        transaction.onerror = nsr.myTvQ.indexedDB.onerror;
        var store = transaction.objectStore("listings");

        var keyRange = IDBKeyRange.lowerBound(0);
        var showidRequest  = store.openCursor(keyRange);
        showidRequest.onsuccess = function(ev) {
          var result = ev.target.result;
          if(!!result == false)
            return;

            count++;
            result.continue();          
        };
    }

    nsr.myTvQ.indexedDB.listing.CountListingBy = function (country, callback) {        
        var db = nsr.myTvQ.indexedDB.db;
        var transaction = db.transaction(["listings"], IDBTransaction.READ_ONLY);
        var count=0;
        transaction.oncomplete = function(event) {  
          if(callback){
            //console.log(count);
            callback(count);
          }
        };
        transaction.onerror = nsr.myTvQ.indexedDB.onerror;
        var store = transaction.objectStore("listings");

        var countryIndex = store.index("countryIndex");

        var cursorRequest = countryIndex.openCursor(new IDBKeyRange.only(country));
        cursorRequest.onsuccess = function(ev) {
          var cursor = cursorRequest.result;
          if(!!cursor == false)
            return;

          count++;
          cursor.continue();
        };        
    }

} (window.nsr = window.nsr || {}, jQuery));

Convert xml to json or JavaScript object

2012-05-11T12:46:00-04:00

For my Google chrome extension TV WatchList, I needed to save TVRage.com's xml feed in indexedDB. Since it only takes json object,I decided to make a small library which can convert xml to JavaScript xml2json. Existing solutions did not work for me due various reasons like node with url was giving me blank values, console.log would throw circular exeptions during debugging, and couple of other things i dont remember right now.

This library is 100% javascript with no third party library dependency.
Also This is only tested in chrome browser.This should work in other browsers too (maybe with minor tweaks)
Anyway lets start with some code

Sample XML - shows.xml

<?xml version="1.0" encoding="UTF-8" ?>
<Results>
    <show>
        <name>One Piece (JP)</name>
        <link>http://www.tvrage.com/One_Piece_JP</link>
        <country>JP</country>
        <started>Oct/20/1999</started>
        <ended></ended>
        <genres><genre>Anime</genre><genre>Action</genre><genre>Adventure</genre><genre>Comedy</genre><genre>Fantasy</genre></genres>
        <network country="JP">Fuji TV</network>
        <akas><aka country="JP">&#12527;&#12531;&#12500;&#12540;&#12473;</aka></akas>
    </show>
    <show>
        <name>One Piece (US)</name>
        <link>http://www.tvrage.com/One_Piece_US</link>
        <country>AJ</country>
        <started>Sep/18/2004</started>
        <ended>Mar/15/2008</ended>
        <genres><genre>Anime</genre><genre>Children</genre></genres>
        <network country="US">Cartoon Network</network>
    </show>
</Results>

Usage:

var x2jObj = null;
$.get('shows.xml', function (xmlDocument) {
    x2jObj = X2J.parseXml(xmlDocument); //X2J.parseXml(xmlDocument, '/');
    //x2jObj is called jNode
    console.log('x2jObj populated', x2jObj);
    //...
});

Above code will read and parse xml into X2J object or jNode. Note: here I am just using jquery to read xml. (You can use your favourite method/framework to read xml).
Under chrome open console (press F12 key), You should be able to see the object after 'x2jObj populated'. expand it to see in full details. its usefull in debugging.
In subsequent examples i will work on x2jObj object.

UseCase: get value/attribute part 1

console.log('To get name "One Piece (US)"', x2jObj[0].Results[0].show[1].name[0].jValue);
console.log('Get aka for country="JP"', x2jObj[0].Results[0].show[0].akas[0].aka[0].jValue);
console.log('Get genre for Adventure', X2J.getValue(x2jObj[0].Results[0].show[0].genres[0].genre[2].jValue));

console.log('Get country US attribute for network ', x2jObj[0].Results[0].show[1].network[0].jAttr["country"]);

UseCase: get value/attribute part 2

console.log('To get name "One Piece (US)"', X2J.getValue(x2jObj[0].Results[0].show[1], 'name', 0, ''));
console.log('Get aka for country="JP"', X2J.getValue(x2jObj[0].Results[0].show[0].akas[0], 'aka'));
console.log('Get genre for Adventure', X2J.getValue(x2jObj[0].Results[0].show[0].genres[0], 'genre',2));
console.log('Get country US attribute for network ', X2J.getAttr(x2jObj[0].Results[0].show[1].network[0], 'country'));

In part 2 getValue can be used when unsure of an element existance, so its a safe way to get value

UseCase: convert xml to json

console.log('X2J Object in json string:\n' + X2J.getJson(x2jObj));

You will notice, there are some extra fields(not part of original xml). Those are X2J meta data to preserve order, attributes, indexes etc

UseCase: convert X2J object back to xml

console.log('X2J Object to xml string:\n' + X2J.getXml(x2jObj));

This should recreate the xml exactly as the original(with order) except for whitespaces

UseCase: print jNode to console

X2J.printJNode(x2jObject[0], function (name, value, attr, level) {
    var strAttr = X2J.printJAttribute(attr);
    console.log(spaces(level), name, typeof value === 'string' ? value : '', strAttr ? ', ' + strAttr : '');
});
function spaces(no) {
        if (no === 0) {
            return '';
        }
        var space = ' ';
        for (var i = 0; i < no; i++) {
            space += ' ';
        }
        return space;
}

To make a calculator from scratch

2011-12-22T14:24:00-05:00

Near May 2011, as a personal challenge, I made a very basic calculator from scratch using C#.NET. My goals were to avoid any CLR's arithmetic operations and integers, And to only use memory.

I first came up with a very basic counter, this was the building block for Addition, Which in turn was the building block for Multiplication. I actually have two version of addition and multiplication. The second version has better performance as it caches intermediary results.

One of the cool side effect of using this technique is the results can be bigger than Integer's Max value.
For example it can easily calculate
(5492012742638447789741521173787972956681294295296 * 22867376956627844231881057173787972956681294295296)
and return full result without the E Notation :)

partial class FastCalculator
{
    static LinkedList<Char> numbers = new LinkedList<Char>(new Char[] { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9' });
    static Dictionary<Char, LinkedListNode<Char>> fastNumbers = new Dictionary<Char,LinkedListNode<Char>>();
    static Dictionary<string, LinkedList<char>> operationCache = new Dictionary<string, LinkedList<char>>();

    static FastCalculator()
    {
        LinkedListNode<Char> zero = numbers.First;
        while (zero != null)
        {
            fastNumbers[zero.Value] = zero;
            zero = zero.Next;
        }
    }

    static void Main(string[] args)
    {
        try
        {
            System.Diagnostics.Stopwatch watch = new System.Diagnostics.Stopwatch();
            watch.Start();
    //        System.Diagnostics.Debug.WriteLine(0 + " PlusOne is " + PlusOne("0"));
    //        System.Diagnostics.Debug.WriteLine(5 + " PlusOne is " + PlusOne("5"));
    //        System.Diagnostics.Debug.WriteLine(9 + " PlusOne is " + PlusOne("9"));
    //        System.Diagnostics.Debug.WriteLine(10 + " PlusOne is " + PlusOne("10"));
    //        System.Diagnostics.Debug.WriteLine(999 + " PlusOne is " + PlusOne("999"));
    //        System.Diagnostics.Debug.WriteLine(256 + " PlusOne is " + PlusOne("256"));
    //        System.Diagnostics.Debug.WriteLine("Multiply 999*256 =" + Multiply("999", "256"));
            System.Diagnostics.Debug.WriteLine(MultiplyVer2("5492012742638447789741521173787972956681294295296", "22867376956627844231881057173787972956681294295296"));
            watch.Stop();
            TimeSpan ts = watch.Elapsed;
            string elapsedTime = String.Format("{0:00}h:{1:00}m:{2:00}s.{3:00}ms",
                                    ts.Hours, ts.Minutes, ts.Seconds,
                                    ts.Milliseconds / 10);
            System.Diagnostics.Debug.WriteLine("elapsedTime " + elapsedTime);
        }
        catch (Exception ex)
        {
            System.Diagnostics.Debug.WriteLine(ex.Message);
        }
    }

    static string PlusOne(string num)
    {
        if (!string.IsNullOrEmpty(num))
        {
            LinkedList<Char> input = new LinkedList<Char>(num.ToCharArray());
            if (input.Last.Value != numbers.Last.Value)// not 9
            {
                input.Last.Value = fastNumbers[input.Last.Value].Next.Value;
                return LinkedListToString(input);
            }
            else // if 9
            {
                LinkedListNode<Char> in_last = input.Last;
                bool doCarryOver = true;
                while (in_last != null)
                {
                    if (in_last.Value == numbers.Last.Value)
                    {
                        if (doCarryOver)
                        {
                            in_last.Value = numbers.First.Value;
                            doCarryOver = true;
                        }
                    }
                    else
                    {
                        if (doCarryOver)
                        {
                            in_last.Value = fastNumbers[in_last.Value].Next.Value;
                            doCarryOver = false;
                        }                            
                    }
                    in_last = in_last.Previous;
                }
                if (doCarryOver)
                {
                    input.AddFirst(numbers.First.Next.Value);//1
                }
                return LinkedListToString(input);
            }            
        }

        return "0";
    }

    static string Add(string left, string right)
    {
        string zero = numbers.First.Value.ToString();
        if (string.IsNullOrEmpty(left) && string.IsNullOrEmpty(right))
        {
            return zero;
        }

        while (zero != right)
        {
            left = PlusOne(left);
            zero = PlusOne(zero);
        }
        return left;
    }

    static string AddVer2(string left, string right)
    {
        string zero = numbers.First.Value.ToString();
        if (string.IsNullOrEmpty(left))
        {
            left = zero;
        }

        if (string.IsNullOrEmpty(right))
        {
            right = zero;
        }

        if (LengthLessThan(left, right)) //(left.Length < right.Length),make sure left is always greater
        {
            string tmp = left;
            left = right;
            right = tmp;
        }

        LinkedList<Char> rightIn = new LinkedList<Char>(right.ToCharArray());
        LinkedList<Char> leftIn = new LinkedList<Char>(left.ToCharArray());
        var leftInLast = leftIn.Last;
        var rightInLast = rightIn.Last;
        bool doCarryOver = false;

        while (leftInLast != null)
        {
            if (rightInLast != null)
            {
                LinkedList<Char> add = AddSymbols(leftInLast.Value, rightInLast.Value);
                if (doCarryOver)
                {   //since carry is always 1, we will do PlusOne
                    add = new LinkedList<Char>(PlusOne(LinkedListToString(add)).ToCharArray());
                }
                leftInLast.Value = add.Last.Value;
                if (add.Last.Previous != null)
                {
                    doCarryOver = true;
                }
                else
                {
                    doCarryOver = false;
                }
                rightInLast = rightInLast.Previous;
            }
            else
            {
                LinkedList<Char> add = AddSymbols(leftInLast.Value, numbers.First.Value);
                if (doCarryOver)
                {   //since carry is always 1, we will do PlusOne
                    add = new LinkedList<Char>(PlusOne(LinkedListToString(add)).ToCharArray());
                }
                leftInLast.Value = add.Last.Value;
                if (add.Last.Previous != null)
                {
                    doCarryOver = true;
                }
                else
                {
                    doCarryOver = false;
                }
            }

            leftInLast = leftInLast.Previous;
        }
        if (doCarryOver)
        {
            leftIn.AddFirst(numbers.First.Next.Value);//1
        }
        return LinkedListToString(leftIn);
    }

    static string Multiply(string left, string right)
    {
        string zero = numbers.First.Value.ToString();
        if (string.IsNullOrEmpty(left) && string.IsNullOrEmpty(right))
        {
            return zero;
        }

        string rtn = zero;

        while (zero != right)
        {
            rtn = Add(rtn, left);
            zero = PlusOne(zero);
        }

        return rtn;
    }

    static string MultiplyVer2(string left, string right)
    {
        string zero = numbers.First.Value.ToString();
        if (string.IsNullOrEmpty(left) || string.IsNullOrEmpty(right))
        {
            return zero;
        }

        if (LengthLessThan(left, right))//(left.length < right.length) make sure left is always greater
        {
            var tmp = left;
            left = right;
            right = tmp;
            System.Diagnostics.Debug.WriteLine("swapped");
        }

        string rtn = zero;
        LinkedList<Char> rightIn = new LinkedList<Char>(right.ToCharArray());
        LinkedList<Char> leftIn = new LinkedList<Char>(left.ToCharArray());
        LinkedList<string> result2sum = new LinkedList<string>();
        var rightInLast = rightIn.Last;
        while (rightInLast != null)
        {
            var leftInLast = leftIn.Last;
            System.Diagnostics.Debug.WriteLine("right symbol " + rightInLast.Value);
            LinkedList<Char> temp = new LinkedList<char>();
            String carry = string.Empty;
            while (leftInLast != null)
            {
                System.Diagnostics.Debug.WriteLine("left symbol " + leftInLast.Value);
                LinkedList<Char> mult = MultiplySymbols(leftInLast.Value, rightInLast.Value);
                if (!string.IsNullOrEmpty(carry))
                {
                    mult = new LinkedList<Char>(AddVer2(LinkedListToString(mult), carry).ToCharArray());
                    carry = string.Empty;
                }
                temp.AddFirst(mult.Last.Value);
                if (mult.Last.Previous != null)
                {
                    carry = mult.Last.Previous.Value.ToString();
                }

                leftInLast = leftInLast.Previous;
            }
            if (!string.IsNullOrEmpty(carry))
            {
                temp.AddFirst(Convert.ToChar(carry));
            }
            result2sum.AddFirst(LinkedListToString(temp));
            rightInLast = rightInLast.Previous;
        }
        var result = result2sum.Last;
        string sum = numbers.First.Value.ToString();//0
        string sumShift = string.Empty;
        while (result != null)
        {
            //string r = result.Value;
            System.Diagnostics.Debug.WriteLine("sum " + sum + " with " + result.Value + sumShift);
            sum = AddVer2(sum, result.Value + sumShift);
            sumShift = sumShift + numbers.First.Value.ToString();
            result = result.Previous;
        }
        return sum;
    }

    static LinkedList<char> AddSymbols(char left, char right)
    {
        string inputStr = left + "+" + right;
        if (operationCache.ContainsKey(inputStr))
        {
            return operationCache[inputStr];
        }

        string zero = numbers.First.Value.ToString();
        string rightStr = right.ToString();
        string leftStr = left.ToString();
        while (zero != rightStr)
        {
            leftStr = PlusOne(leftStr);
            zero = PlusOne(zero);
        }
        operationCache[inputStr] = new LinkedList<Char>(leftStr.ToCharArray());
        return operationCache[inputStr];
    }

    static LinkedList<char> MultiplySymbols(char left, char right)
    {
        string inputStr = left + "*" + right;
        if (operationCache.ContainsKey(inputStr))
        {
            return operationCache[inputStr];
        }
        string zero = numbers.First.Value.ToString();
        string rightStr = right.ToString();
        string leftStr = left.ToString();
        string rtn = zero;
        while (zero != rightStr)
        {
            rtn = AddVer2(rtn, leftStr);
            zero = PlusOne(zero);
        }

        operationCache[inputStr] = new LinkedList<Char>(rtn.ToCharArray());
        return operationCache[inputStr];
    }

    static bool LengthLessThan(string left, string right)
    {
        LinkedList<Char> rightIn = new LinkedList<Char>(right.ToCharArray());
        LinkedList<Char> leftIn = new LinkedList<Char>(left.ToCharArray());
        var leftInLast = leftIn.Last;
        var rightInLast = rightIn.Last;
        while (leftInLast != null && rightInLast != null)
        {
            leftInLast = leftInLast.Previous;
            rightInLast = rightInLast.Previous;
        }
        if (leftInLast == null && rightInLast == null)
        {
            return false;
        }

        if (leftInLast != null && rightInLast == null)
        {
            return false;
        }

        if (leftInLast == null && rightInLast != null)
        {
            return true;
        }

        return false;
    }

    private static string LinkedListToString(LinkedList<Char> num)
    {
        StringBuilder sb = new StringBuilder();
        if (num != null)
        {
            LinkedListNode<Char> first = num.First;
            while (first != null)
            {
                sb.Append(first.Value);
                first = first.Next;
            }
        }

        return sb.ToString();
    }  
}

VisualSVN pre-commit hook

2011-06-03T14:33:00-04:00

1.Start VisualSVN Server Manager
2.Under Repositories, Select your repository and then Open Properties
3.Select Hooks tab
4.double click the pre-commit hook

Edit: As of VisualSVN version 2.5 use below code

setlocal enabledelayedexpansion

set REPOS=%1
set TXN=%2

set SVNLOOK="%VISUALSVN_SERVER%\bin\svnlook.exe"

SET M=

REM Concatenate all the lines in the commit message
FOR /F "usebackq delims==" %%g IN (`%SVNLOOK% log -t %TXN% %REPOS%`) DO SET M=!M!%%g

REM Make sure M is defined
SET M=0%M%

REM Here the 6 is the length we require
IF NOT "%M:~6,1%"=="" goto NORMAL_EXIT

:ERROR_TOO_SHORT
echo "Commit note must be at least 6 letters" >&2
goto ERROR_EXIT

:ERROR_EXIT
exit /b 1

REM All checks passed, so allow the commit.
:NORMAL_EXIT
exit 0

If using VisualSVN \< 2.5

setlocal

set REPOS=%1
set TXN=%2

set SVNLOOK="C:\Program Files\VisualSVN Server\bin\svnlook.exe"

REM Make sure that the log message contains some text.
FOR /F "usebackq delims==" %%g IN (`%SVNLOOK% log -t %TXN% %REPOS% FINDSTR /R /C:......`) DO goto NORMAL_EXIT

:ERROR_TOO_SHORT
echo "Comment must be at least 6 letters" >&2
goto ERROR_EXIT

:ERROR_EXIT
exit /b 1

REM All checks passed, so allow the commit.
:NORMAL_EXIT
exit 0

The above code will make the comment of at least 6 letters mandatory.

My Experience with SQL Azure

2011-05-09T01:09:00-04:00

We are in the process of developing a prototype for Windows Azure.
Since its a fairly a new technology not many online help/discussions
are available. and if there are, then they are obsolete (as these steps would become in couple of months)
the reason being, Microsoft comes out with updates for major/minor versions pretty quickly.
Anyway these are the challenges we faced until now and maybe would face some more in future. Most of them are
due to our ignorance or lack of knowledge on how it could be done in a certain way (thats one more problem with new tech, where
nobody knows what`s the standard way until you make errors).
Now Azure requires latest and greatest. Hence, we decided to use virtual machine to make Win 7 images and install azure sdk
and sql server 2008 (big mistake for sql server...as we painfully found out later that we needed SQL server 2008 R2 CTP!).
So during R\&D, we realized that we could use Windows Azure with Storage as our backend. But, it turned out to be a
Hash Table, which is only used to save key value pair, where value can be anything from blob to complex objects etc. However again, we needed a RDBMS. On further research, we found a service called SQL Azure which was exactly what we required for Storage.
And now when we tried to open it with Management Studio, we could only do scripts and not objects.. Bummer!! I am more
used to the GUI aspect of sqlserver then scripts, which made us search for different alternatives in codeplex i.e.
http://hanssens.org/tools/sqlazuremanager/ which were all buggy or mostly incomplete! Turns out we had to install
SQL server 2008 R2 CTP. sigh!!! Who knew??
Once everything was set, we now had to move our existing data from oracle to Azure. We used Microsoft's tool \<???> to migrate data, which was slow but worked fine. Finally, it was a success...Yippee!!

Simple OS A designers dream, a programmers pride

2011-05-09T00:10:00-04:00

I would like an Operating System which is open source.
Which has two options when its started for the first time.(Basic, Advanced)
Basic:my mother can use.Advanced: something a hardcore programmer hacker can use
which behaves like iPhoneOS/android i.e desktop with icons only(apps)/ no tray or task bar or menus or right clicks
apps can do what ever they want.
everything set to optimal default, plug and play, like boxee, xbmc (even they are a little complicated/clunky)
A single place to store documents,music,videos,settings,app store (with repository can use windows,linux apps).
A Closed App Ecosystem (only through repos like cydia)
no need of c drive,program files.

should have good games and social apps to appeal masses
In short, i want everything which iPad has and also the things it lacks.(multitasking,flash,plugins etc)
I guess future ChromeOS would be pretty close to what i want. There is also Jolicloud

I Love Innovation

2011-05-09T00:06:00-04:00

Google, Apple, Microsoft... big names you get to hear about them almost everyday and lot of flamewar going around with brand loyalty...like X company blows or Y company is awesome!! For me its the products these big names produce which i love and not the brand, i have macbookpro with windows 7 installed and use google search and alternatively use bing. My mouth waters if i see any cool innovative gadget/software which is a game changer. For me i dont care if its closed or opensource as long as its easy on the wallet (free is good too), easy to use and looks cool and if there is competition it definitely helps

Hello world!

2010-02-07T22:53:00-05:00

Hello! I recently changed from Drupal to Wordpress, Why? Cause, I was hearing a lot of buzz and I had nothing better to do this weekend ^_^.

I am happy i did, and my inital reaction is... Wordpress is made by designers and Drupal is made by programmers. Why do i say this? 'Cause, Wordpress is a very user friendly and easy to manage application and at the same time powerful too, for example you can extend it using plugins and themes, especially themes. You can also make changes if you want. where as Drupal is little complex and intimidating but very powerful and extensible at the same time. Stick with it if you know your way around it.

HOWTO export/copy ADODB recordset to excel spreadsheet via IronPython

2009-06-25T23:19:00-04:00

"""
Export or Copy ADODB Recordset to Excel Spreadsheet
@Author Surya Nyayapati
@Date Jun-25-2009
"""

import clr

from System.Reflection import Assembly
from System.Reflection import Missing

#From C:\WINDOWS\assembly Copied the Display name for ADODB
clr.AddReferenceByName('ADODB, Version=7.0.3300.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a')
from ADODB import ConnectionClass, RecordsetClass, CursorLocationEnum

connString = "DSN=myDsn;Uid=myUsername;Pwd=myPassword;"

conn = ConnectionClass()
rs = RecordsetClass()
conn.Open(connString)

conn.CursorLocation = CursorLocationEnum.adUseClient
query = "SELECT * FROM user_group" # Any SELECT SQL
rs = conn.Execute(query)
"""
#To iterate over Recordset
while rs.EOF <> True:   
    print "%s - %s" %(rs[0].Item[0].Name.ToString(),rs[0].Item[0].Value.ToString())
    print "%s - %s" %(rs[0].Item[1].Name.ToString(),rs[0].Item[1].Value.ToString()) 
        # ...
    rs.MoveNext()
"""

#Start a New Excel Instance
VSTOpath = "C:\\Program Files\\Microsoft Visual Studio 9.0\\Visual Studio Tools for Office\\PIA\\Office11\\"

#Load and add reference to Excel dll
excelAssemblyPath = "%sMicrosoft.Office.Interop.Excel.dll" % VSTOpath
excelAssembly = Assembly.LoadFile(excelAssemblyPath)
clr.AddReference(excelAssembly)
from Microsoft.Office.Interop import Excel

import System.IO.Directory
excelApp = Excel.ApplicationClass()   
excelApp.DefaultFilePath = System.IO.Directory.GetCurrentDirectory()
excelApp.Visible = True
excelApp.ScreenUpdating = False;
excelApp.DisplayAlerts = False   
excelApp.UserControl = False;
try:
    book1 = excelApp.Workbooks.Add(Excel.XlWBATemplate.xlWBATWorksheet)
    sheet1 = book1.ActiveSheet

        headRange = sheet1.Range("A1", "D1")

    #Python does not provide built-in support for multi-dimensional arrays
    from System import Array
    array2D = Array.CreateInstance(object, 2, 4)
    array2D[0,0] = "HEADER 1"
    array2D[0,1] = "HEADER 2"
    array2D[0,2] = "HEADER 3"
    array2D[0,3] = "HEADER 4"

    headRange.Value2 = array2D
    headRange.Font.Bold = True
    sheet1.Range("A2").CopyFromRecordset(rs, Missing.Value, Missing.Value)

except StandardError, (ErrorMessage):
    print "something wrong (%s)" % ErrorMessage

finally:
    excelApp.ScreenUpdating = True;
        excelApp.DisplayAlerts = True;
        excelApp.UserControl = True;
    #excelApp.Quit()

Howto create a dev server

2009-05-19T23:26:00-04:00

From childhood i have always been fascinated by computers and my first box was a 386 machine with a monochrome monitor. Whereas now i have a powerful Quad core machine ^_^ I have a home network which connects couple of wired desktops, XBox (which is now a media center with XBMC) and also wireless iPhone and Macbook pro. I have dedicated a box which is not publicly accessible to be a Dev server, and i recommend you doing the same. In this box i have Windows XP and the first thing i installed were Avira AntiVir (best free antivirus), SuperAntiSpyware and Microsoft BitDefender.

Installing XAMPP as WAMP Server

Moving on, i installed XAMPP in c:\xampp because it makes your life easier to install Apache Web Server 2.x with Openssl, PHP 5.x, MySQL 5.x, phpmyadmin, FTP server and a Mail server in one go. I installed all except FTP and mail server as a service. And if you want you can configure each piece separately by changing their ini files once installed. So this takes care of Webserver with php Scripting, Database with Web based GUI (BTW phpmyadmin is the web based GUI if you haven't already figured it out ^_~ ). After installing go to http://localhost and by default you will see xampp's page its due to index.php which redirects the browser to xampp's folder. its recommended to change all of the default settings i.e change password because sometimes people forget to change it and a hackers first attempt is to try the default password. its pretty simple, click security and follow instructions. one more advantage of using xampp is that you can also plugin other components perl, python if you want.Also it comes with a cool control panel from which you can control turning on and off the server.i will show apache+php configuration when i start a project

Installing Tomcat as app server

Now lets install tomcat, a servlet container which will act as app server for now. but first you have to install the latest stable JDK. My preference is to create a folder called c:\java and keep all my java related software and library there so its easy to organize and find java related stuff, plus i don't like spaces in my folder names i.e. C:\Program Files , since there are few programmes out there which fails due to this reason alone O_O. make sure to change the path in the wizard for both jdk and jre its installed as C:\java\jdk1.6.0_13 and C:\java\jre6 also in your environment variable set JAVA_HOME value to C:\java\jdk1.6.0_13. Once that's done get the latest tomcat's windows service installer and install tomcat as a service. so i installed it as C:\java\apache-tomcat-6.0.18. During install it will confirm for new port (8080 by default) and admin password. I will show tomcat configuration when i start a project

Installing Subversion as server for revision control system

Next step is to install revision control system, I choose subversion cause i feel this is the next generation of cvs, and they have a good number of quality and easy to use clients like Tortoisesvn (windows GUI client), Slik subersion (command line client), Subclipse (Eclipse), Anksvn (visual studio) i have installed all four. On my server i installed CollabNet Subversion (Certified binary for subversion) because it was easy and i just followed its readme for the setup. Couple of things to note, you have register for free at collabnet before downloading and there are multiple ways of installing and since i am using it for internal dev only i am installing the svnserve (svn:// protocol) instead of apache as svn server(http:// protocol)

svnserve's readme





svnserve's readme


A. Using svnserve
      ==============

   To use svnserve as your server, follow these steps:

     1. Open a new terminal (command prompt).

        NOTE: If you have an old command prompt open (prior to the Subversion
              installation), remember to open a brand new command prompt.

     2. Create a subversion repository.

        cd
        svnadmin create 

        For example:
        cd \repositories
        svnadmin create my-first-repos

     3. Setup a password database.

        Using notepad, edit the svnserve.conf file inside the conf directory of your
        repository.

        For example:
        If your repository is C:\repositories\my-first-repos
        svnserve.conf is:
        C:\repositories\my-first-repos\conf\svnserve.conf

        Inside svnserve.conf, you see the following information:

         ### The password-db option controls the location of the password
         ### database file.  Unless you specify a path starting with a /,
         ### the file's location is relative to the conf directory.
         ### Uncomment the line below to use the default password file.
         #password-db = passwd

       Follow the above instructions, and uncomment the "password-db=passwd"
       line, so that it simply says:

          password-db = passwd

     4. Setup usernames and passwords.

       Next, edit the passwd file. This passwd file is located in the
       same directory as svnserve.conf.

       Inside the passwd file, you see the following information:

       ### This file is an example password file for svnserve.
       ### Its format is similar to that of svnserve.conf. As shown in the
       ### example below it contains one section labelled [users].
       ### The name and password for each user follow, one account per line.

       [users]
       #harry = harryssecret
       #sally = sallyssecret

       To add a new user account, add your own username and password
       inside the [users] section. For example, if your name is "joe",
       and you want to set your password to "super-secret", add a
       new line like this:

         joe = super-secret

       Add as many users as you like.

     5. Open Port on Windows firewall.

        Before starting the server, the firewall must be notified that
        this particular port is going to be used. To enable this port in the
        Windows firewall, follow the instructions found here:

    http://www.microsoft.com/windowsxp/using/security/internet/sp2_wfexcepti...

        Note: svnserve.exe is the program name which needs to be added to the
        exceptions list. Alternatively, you can also use the port where
        you decide to run the server. By default, svnserve runs on 3690.

     6. Start svnserve.

        If you elected to have the installer setup svnserve as a service, then open
        the Services application, find the entry for the Subversion server, and take
        the Start option. The service has been configured to start automatically
        on reboot. You can also run this command from the command line:

        net start svnserve

        If you did not install svnserve as a service and want to start the server
        manually, run this command:

        svnserve -d -r 

        For example: svnserve -d -r C:\repositories

     7. To provide read and write access to anonymous users, modify the
        conf/svnserve.conf file inside the repository.

        anon-access = write

        To restrict an anonymous user from the repository:

        anon-access = none

     8. Check out the repository.

        svn co svn://localhost/

        For example: svn co svn://localhost/my-first-repos

     Tip: If you check out your Subversion repository from a different computer,
     replace 'localhost' with the IP address or hostname of the machine which
     hosts the Subversion repository.

Installing Hudson, A Continuous Integration Server

Download Hudson, if it downloads as a zip rename the extension as war(basically jar, war and ear are just zip files) and place it under tomcats webapps folder i.e. C:\java\apache-tomcat-6.0.18\webapps. Start tomcat and thats it you have installed Hudson.

Installing Maven

For Java using Ant is old school. You should use maven instead. Why? because its so much better for project/dependency management and its plugin system adds so much more functionality than ant, for example take a look at apache's plugins and codehaus plugins. So we are going to create a Maven repository. First Download maven2 extract the zip to say c:\java\apache-maven-2.1.0 then set the environment variable M2_HOME to c:\java\apache-maven-2.1.0 and Path as %Path%;c:\java\apache-maven-2.1.0\bin open c:\java\apache-maven-2.1.0\conf\settings.xml uncomment localrepository and change the path to C:\java\maven-repo create a folder .m2 in your home folder which would be C:\Documents and Settings\\.m2 you can do this by command prompt C:\Documents and Settings\surya>mkdir .m2 then create settings.xml and copy paste Example 3.1 (make sure to change the port) I also installed Nexus a Maven Repository Manager (due to m2eclipse supports nexus) Downloaded the open source war renamed to nexus.war and placed it inside tomcats webapp folder. logged in as administrator with username/password as admin/admin123 If you can see the repo that means its successfully installed.

Installing Trac

Under Construction...

In Conclusion

Right now in this article i am focused on installing the dev system. Whenever i start working on my project, i will configure each system individually and will write about it. You might have noticed, i am big fan of prepackaged binaries or wizard based software since they save time and do most of the work for you. Power user prefer to compile the source or extract from zip and manually configure it, the pros is, it increases your understanding and knowledge of the product , the cons would be it takes time, learning and going through documentation (which is not necessarily a bad thing ^_^). So personally (since i am developer and not administrator) if i can find a good wizard based software i will use that, otherwise i will use the zip version. (Under Construction...,Jira)

Maven: a lot better then Ant

2008-04-04T22:53:00-04:00

Maven is a software tool for Java project management and build automation similar in functionality to the Apache Ant. Now a days a lot of open source java project are using Maven.
Some of the main features are:-

Making the build process easy and it is network-ready
A way to share JARs across several projects
Providing guidelines for best practices development i.e. to write unit test
Creates common configuration for eclipse for users of same project.
more...

To get started go here http://maven.apache.org/guides/getting-started/index.html
also checkout http://en.wikipedia.org/wiki/Apache_Maven

A sample web project would look like
/project-name
/project-name/src/main/java
/project-name/src/main/resources
/project-name/src/test/java
/project-name/src/test/resources
/project-name/pom.xml
/project-name/src/main/webapp/project-name/src/main/webapp/WEB-INF

Some of the commands i use

mvn eclipse:eclipse
mvn clean
mvn install
more ...