HTML5 WebSQL: how to know when a db transaction finishes?

Ok, this is my fifth revision, but I liked this question and I keep coming up with better ideas. This one uses jquery deferred objects and I think it finally covers all cases and works the way it should.

function tableInsert(url) {    var dfd = $.Deferred();    var arr = [];    $.getJSON(url, function(json) {        $.each(json.results, function(i, res) {            var dfd = $.Deferred();            arr.push(dfd.promise());             db.transaction(function(tx) {                tx.executeSql(                    "INSERT INTO table1 (A, B, C, D) VALUES (?,?,?,?) ",                     [res.A, res.B, res.C, res.D],                     function(){                        onSuccess(dfd.resolve);                    },                     function(){                        onError(dfd.resolve);                    }                );            });        });        $.when.apply(this, arr).then(dfd.resolve);    });    return dfd.promise();}function databaseSync() {    $.when( tableInsert("http://192.168.1.40:8888/iOS/mobilesrv/index.php?ACT=one"),            tableInsert("http://192.168.1.40:8888/iOS/mobilesrv/index.php?ACT=two"),             tableInsert("http://192.168.1.40:8888/iOS/mobilesrv/index.php?ACT=three"))        .then(function(){            console.log( 'All processing complete' );        });}

For this to work you'll need to change onSuccess and onError to execute the resolve function as a callback function after doing whatever else it is they do and then this should work for you. I hope you find this useful.

Alternately, you can use one transaction for the bulk insert and use callback function to get notified about completion of the transaction

function doSync(){  databaseSync(function(){    console.log('database sync is completed')  });}function databaseSync(onTrxSuccess) {  db.transaction(function(tx) {  // table one  $.getJSON("http://192.168.1.40:8888/iOS/mobilesrv/index.php?ACT=one", function(json) {        $.each(json.results, function(i, res) {                                tx.executeSql("INSERT INTO table1 (A, B, C, D) VALUES (?,?,?,?) ", [res.A, res.B, res.C, res.D], onSuccess, onError);            });        });    // table two    $.getJSON("http://192.168.1.40:8888/iOS/mobilesrv/index.php?ACT=two", function(json) {        $.each(json.results, function(i, res) {                tx.executeSql("INSERT INTO table1 (A, B, C, D) VALUES (?,?,?,?) ", [res.A, res.B, res.C, res.D], onSuccess, onError);            });    });    // table three    $.getJSON("http://192.168.1.40:8888/iOS/mobilesrv/index.php?ACT=three", function(json) {        $.each(json.results, function(i, res) {                tx.executeSql("INSERT INTO table1 (A, B, C, D) VALUES (?,?,?,?) ", [res.A, res.B, res.C, res.D], onSuccess, onError);            });        });    }, null, onTrxSuccess);}