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define(["jQuery","BrowserEngines/sqlite_driver"], function ($,SQLite_driver) {
var WebSQL_driver = function(){
this.db = null;
this.ddl = [];
this.nativeSQLite = (window.openDatabase !== undefined);
return this;
};
$.extend(WebSQL_driver.prototype,SQLite_driver.prototype); // inherit from parent class
WebSQL_driver.prototype.buildSchema = function (args) {
var _this = this; // preserve reference to current object through local closures
try {
if (_this.nativeSQLite)
{
_this.db = openDatabase(args["short_code"], '1.0', args["short_code"], args["ddl"].length * 1024);
_this.db.transaction(function(tx){
var statements = _this.splitStatement(args["ddl"],args["statement_separator"]);
_this.ddl = statements;
var currentStatement = 0;
var statement = statements[currentStatement];
var sequentiallyExecute = function(tx2, result){
if (currentStatement < statements.length-1)
{
do {
currentStatement++;
statement = statements[currentStatement];
} while (currentStatement < statements.length-1 && statement.match(/^\s*$/));
if (!statement.match(/^\s*$/)) {
tx.executeSql(statement, [], sequentiallyExecute, handleFailure);
}
else
{
tx.executeSql("intentional failure used to rollback transaction");
args["success"]();
}
}
else
{
tx.executeSql("intentional failure used to rollback transaction");
args["success"]();
}
};
var handleFailure = function (tx2, result) {
if (result.message != "not an error") // thank you safari, for this
{
args["error"](result.message);
}
else
{
args["success"]();
}
return true; // roll back transaction
};
if (statement) {
tx.executeSql(statement, [], sequentiallyExecute, handleFailure);
}
else {
args["success"]();
}
});
}
else
{
args["error"]("SQLite (WebSQL) not available in your browser. Try either using a webkit-based browser (such as Safari or Chrome) or using the SQLite (SQL.js) database type.")
}
}
catch (e)
{
args["error"](e);
}
}
WebSQL_driver.prototype.executeQuery = function (args) {
var _this = this; // preserve reference to current object through local closures
try {
if (_this.db == null ) {
throw("You need to build the schema before you can run a query.");
}
var returnSets = [];
_this.db.transaction(function(tx){
var sequentiallyExecute = function(tx2, result) {
var thisSet = {
"STATEMENT": statement,
"SUCCEEDED": true,
"EXECUTIONTIME": (new Date()) - startTime,
"RESULTS": {
"COLUMNS": [],
"DATA": []
},
"EXECUTIONPLAN": {
"COLUMNS": [],
"DATA": []
}
};
for (var i = 0; i < result.rows.length; i++) {
var rowVals = [];
var item = result.rows.item(i);
/* We can't be sure about the order of the columns returned, since they are returned as
* a simple unordered structure. So, we'll just take the order returned the from the first
* request, then just use that order for each row.
*/
if (i == 0) {
for (col in item) {
thisSet["RESULTS"]["COLUMNS"].push(col);
}
}
for (var j = 0; j < thisSet["RESULTS"]["COLUMNS"].length; j++) {
if (item[thisSet["RESULTS"]["COLUMNS"][j]] === null) {
rowVals.push("(null)");
} else {
rowVals.push(item[thisSet["RESULTS"]["COLUMNS"][j]]);
}
}
thisSet["RESULTS"]["DATA"].push(rowVals);
}
tx.executeSql("EXPLAIN QUERY PLAN " + statement, [], function (tx3, executionPlanResult) {
for (var l = 0; l < executionPlanResult.rows.length; l++) {
var rowVals = [];
var item = executionPlanResult.rows.item(l);
/* We can't be sure about the order of the columns returned, since they are returned as
* a simple unordered structure. So, we'll just take the order returned the from the first
* request, then just use that order for each row.
*/
if (l == 0) {
for (col in item) {
thisSet["EXECUTIONPLAN"]["COLUMNS"].push(col);
}
}
for (var j = 0; j < thisSet["EXECUTIONPLAN"]["COLUMNS"].length; j++) {
rowVals.push(item[thisSet["EXECUTIONPLAN"]["COLUMNS"][j]]);
}
thisSet["EXECUTIONPLAN"]["DATA"].push(rowVals);
}
if (currentStatement > _this.ddl.length-1)
returnSets.push(thisSet);
// executeSQL runs asynchronously, so we have to make recursive calls to handle subsequent queries in order.
if (currentStatement < (statements.length - 1))
{
do {
currentStatement++;
statement = statements[currentStatement];
} while (currentStatement < statements.length-1 && statement.match(/^\s*$/));
if (! statement.match(/^\s*$/))
tx.executeSql(statement, [], sequentiallyExecute, handleFailure);
else
{
tx.executeSql("intentional failure used to rollback transaction");
args["success"](returnSets);
}
}
else
{
tx.executeSql("intentional failure used to rollback transaction");
args["success"](returnSets);
}
},
function(tx3, executionPlanResult){
// if the explain failed, then just append the base set to the result and move on....
if (currentStatement > _this.ddl.length-1)
returnSets.push(thisSet);
// executeSQL runs asynchronously, so we have to make recursive calls to handle subsequent queries in order.
if (currentStatement < (statements.length - 1))
{
do {
currentStatement++;
statement = statements[currentStatement];
} while (currentStatement < statements.length-1 && statement.match(/^\s*$/));
if (! statement.match(/^\s*$/))
tx.executeSql(statement, [], sequentiallyExecute, handleFailure);
else
{
tx.executeSql("intentional failure used to rollback transaction");
args["success"](returnSets);
}
}
else
{
tx.executeSql("intentional failure used to rollback transaction");
args["success"](returnSets);
}
});
}
var handleFailure = function (tx, result) {
if (result.message != "not an error") // thank you safari, for this
{
var thisSet = {
"SUCCEEDED": false,
"EXECUTIONTIME": (new Date()) - startTime,
"ERRORMESSAGE": result.message
};
returnSets.push(thisSet);
}
args["success"](returnSets); // 'success' - slightly confusing here, but in this context a failed query is still a valid result from the database
return true; // roll back transaction
}
var setArray = [], k, stop = false;
var statements = _this.ddl.slice(0);
$.each(_this.splitStatement(args["sql"],args["statement_separator"]), function (i, stmt) { statements.push(stmt); });
var currentStatement = 0;
var statement = statements[currentStatement];
var startTime = new Date();
/*
* executeSql runs asynchronously, so I impose a semblance of synchronous-ness via recursive calls
*/
tx.executeSql(statement, [], sequentiallyExecute, handleFailure);
});
}
catch (e)
{
args["error"](e);
}
}
return WebSQL_driver;
});
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