我有一個similar question here,但我想我會問一個不同的方式來建立更廣泛的網絡。我還沒有遇到可行的解決方案(我知道)。
我希望XCode發出JavaScript命令並從executeSql回調中獲取返回值。
從我一直在閱讀的研究中,我無法發出同步executeSql命令。我最近來到的是試圖旋轉鎖定,直到我得到回調。但那還沒有奏效。也許我的紡紗沒有給回調機會回來(見下面的代碼)。
問:jQuery如何在Ajax中使用async = false參數? XHR和executeSql命令有什麼不同嗎?
這是我證明了概念至今:(大家不要笑)
// First define any dom elements that are referenced more than once.
var dom = {};
dom.TestID = $('#TestID'); // <input id="TestID">
dom.msg = $('#msg'); // <div id="msg"></div>
window.dbo = openDatabase('POC','1.0','Proof-Of-Concept', 1024*1024); // 1MB
!function($, window, undefined) {
var Variables = {}; // Variables that are to be passed from one function to another.
Variables.Ready = new $.Deferred();
Variables.DropTableDeferred = new $.Deferred();
Variables.CreateTableDeferred = new $.Deferred();
window.dbo.transaction(function(myTrans) {
myTrans.executeSql(
'drop table Test;',
[],
Variables.DropTableDeferred.resolve()
// ,WebSqlError
);
});
$.when(Variables.DropTableDeferred).done(function() {
window.dbo.transaction(function(myTrans) {
myTrans.executeSql(
'CREATE TABLE IF NOT EXISTS Test'
+ '(TestID Integer NOT NULL PRIMARY KEY'
+ ',TestSort Int'
+ ');',
[],
Variables.CreateTableDeferred.resolve(),
WebSqlError
);
});
});
$.when(Variables.CreateTableDeferred).done(function() {
for (var i=0;i < 10;i++) {
myFunction(i);
};
Variables.Ready.resolve();
function myFunction(i) {
window.dbo.transaction(function(myTrans) {
myTrans.executeSql(
'INSERT INTO Test(TestID,TestSort) VALUES(?,?)',
[
i
,i+100000
]
,function() {}
,WebSqlError
)
});
};
});
$.when(Variables.Ready).done(function() {
$('#Save').removeAttr('disabled');
});
}(jQuery, window);
!function($, window, undefined) {
var Variables = {};
$(document).on('click','#Save',function() {
var local = {};
local.result = barcode.Scan(dom.TestID.val());
console.log(local.result);
});
var mySuccess = function(transaction, argument) {
var local = {};
for (local.i=0; local.i < argument.rows.length; local.i++) {
local.qry = argument.rows.item(local.i);
Variables.result = local.qry.TestSort;
}
Variables.Return = true;
};
var myError = function(transaction, argument) {
dom.msg.text(argument.message);
Variables.result = '';
Variables.Return = true;
}
var barcode = {};
barcode.Scan = function(argument) {
var local = {};
Variables.result = '';
Variables.Return = false;
window.dbo.transaction(function(myTrans) {
myTrans.executeSql(
'SELECT * FROM Test WHERE TestID=?'
,[argument]
,mySuccess
,myError
)
});
for (local.I = 0;local.I < 3; local.I++) { // Try a bunch of times.
if (Variables.Return) break; // Gets set in mySuccess and myError
SpinLock(250);
}
return Variables.result;
}
var SpinLock = function(milliseconds) {
var local = {};
local.StartTime = Date.now();
do {
} while (Date.now() < local.StartTime + milliseconds);
}
function WebSqlError(tx,result) {
if (dom.msg.text()) {
dom.msg.append('<br>');
}
dom.msg.append(result.message);
}
}(jQuery, window);
我覺得'不需要new $ .Deferred()''。$ .Deferred()'就夠了 – 2013-03-12 05:12:37
好的,Arun,謝謝。 – 2013-03-12 05:58:09