承诺和上传数据
Promises and uploading data
我在在线发送表单或将其保存在本地时遇到了一些问题。我有一个Phonegap应用程序，它只是一个简单的形式，可以保存到数据库中，或者如果失败，则在本地保存。
我只设置了这个功能。首先，我想，我只是用布尔人做，运行功能，如果一切顺利，则返回 True。但这不起作用，因为代码只是在我有一个值要比较之前执行，这意味着该值将始终为 false。
这是现在的代码：
if(uploadDataAndImage(formData))
{
//Its true, do my things
}
else
{
//Its false
}
这是布尔函数：
function uploadDataAndImage(dataForm) {
var localURL = dataForm.cardurl;
console.log(localURL);
if(localURL == "")
{
$$.ajax({
type: "POST",
url: "upload.php",
crossDomain: true,
data: dataForm,
success:function(data)
{
console.log("Upload to server without card");
return true;
},
error: function()
{
console.log("Form couldn't upload to the server");
//alert("Couldnt upload to server, saving locally");
return false;
}
});
}
else{
//set upload options
var options = new FileUploadOptions();
options.chunkedMode = false;
console.log("Start upload picture");
var ft = new FileTransfer();
ft.upload(deLokaleURL, encodeURI("uploaderino.php"), win, fail, options);
function win(r) {
console.log("Code = " + r.responseCode);
console.log("R" + r.response);
console.log("Sent = " + r.bytesSent);
dataForm.cardurl = r.response;
var dataString = JSON.stringify(dataForm);
$$.ajax({
type: "POST",
url: "upload.php",
crossDomain: true,
data: dataForm,
success:function(data)
{
console.log("Upload to server with card");
return true;
},
error: function()
{
console.log("Form couldn't upload to the server, do nothing");
return false;
}
});
}
function fail(error) {
//alert("An error has occurred: Code = " + error.code);
console.log("An error has occurred: Code = " + error.code);
console.log("upload error source " + error.source);
console.log("upload error target " + error.target);
showMessage("Image upload has failed, get a better internet connection and try again!" , function(){console.log("Upload van de form is mislukt!")});
return false;
}
}
}
但这显然是行不通的。现在我做了一些研究，问了一些问题，我找到了承诺。但我似乎无法理解如何使用它。
我是这样想的：
var deferred = $.Deferred();
deferred.resolve(uploadDataAndImage(formData));
deferred.done(function(value) {
//Upload went well so do my things
});
但这不是它的工作原理，对吧/？
在 uploadDataAndImage 中使用 deferred 返回一个承诺。然后，您可以使用 then（） 和 catch（） 在 ajax 调用完成时执行某些操作。
function uploadDataAndImage() {
var deferred = $.Deferred();
$$.ajax({
type: "POST",
url: "upload.php",
crossDomain: true,
data: dataForm,
success:function(data) {
deferred.resolve();
}, error: function(e) {
deferred.reject(e);
}
});
return deferred.promise;
}
uploadDataAndImage(formData).then(function() {
//Its true, do my things
}).catch(function() {
//Its false
});
我只是将其设置为使用回调函数。也许是这样的东西
uploadDataAndImage(formData, function(data){
console.log(data);
if(data){
//do something in here that needs doing as the ajax call was true
}
else
{
//Do something after the ajax returned an error...
}
})
function uploadDataAndImage(dataForm, callBack) {
var localURL = dataForm.cardurl;
console.log(localURL);
if(localURL == "")
{
$$.ajax({
type: "POST",
url: "upload.php",
crossDomain: true,
data: dataForm,
success:function(data)
{
console.log("Upload to server without card");
callBack(true);
},
error: function()
{
callBack(false);
}
});
}
else{
//set upload options
var options = new FileUploadOptions();
options.chunkedMode = false;
console.log("Start upload picture");
var ft = new FileTransfer();
ft.upload(deLokaleURL, encodeURI("uploaderino.php"), win, fail, options);
function win(r) {
console.log("Code = " + r.responseCode);
console.log("R" + r.response);
console.log("Sent = " + r.bytesSent);
dataForm.cardurl = r.response;
var dataString = JSON.stringify(dataForm);
$$.ajax({
type: "POST",
url: "upload.php",
crossDomain: true,
data: dataForm,
success:function(data)
{
callBack(true);
},
error: function()
{
callBack(false);
}
});
}
function fail(error) {
//alert("An error has occurred: Code = " + error.code);
console.log("An error has occurred: Code = " + error.code);
console.log("upload error source " + error.source);
console.log("upload error target " + error.target);
showMessage("Image upload has failed, get a better internet connection and try again!" , function(){console.log("Upload van de form is mislukt!")});
return false;
}
}
}
你可以玩弄你想要函数做什么，我不是 100% 确定你想要什么:)但是，无论您放入函数中的内容，都将在进行 ajax 调用后执行。
你可以使用promises，像这样：
uploadDataAndImage(formData)
.done(function(){
// Its true, do my things
}).fail(function(){
//Its false
});
function uploadDataAndImage(dataForm) {
var deferred = $.Deferred();
var localURL = dataForm.cardurl;
console.log(localURL);
if (localURL == "") {
$$.ajax({
type: "POST",
url: "upload.php",
crossDomain: true,
data: dataForm,
success: function(data) {
console.log("Upload to server without card");
deferred.resolve();
},
error: function() {
console.log("Form couldn't upload to the server");
//alert("Couldnt upload to server, saving locally");
deferred.reject();
}
});
} else {
//set upload options
var options = new FileUploadOptions();
options.chunkedMode = false;
console.log("Start upload picture");
var ft = new FileTransfer();
ft.upload(deLokaleURL, encodeURI("uploaderino.php"), win, fail, options);
function win(r) {
console.log("Code = " + r.responseCode);
console.log("R" + r.response);
console.log("Sent = " + r.bytesSent);
dataForm.cardurl = r.response;
var dataString = JSON.stringify(dataForm);
$$.ajax({
type: "POST",
url: "upload.php",
crossDomain: true,
data: dataForm,
success: function(data) {
console.log("Upload to server with card");
deferred.resolve();
},
error: function() {
console.log("Form couldn't upload to the server, do nothing");
deferred.reject();
}
});
}
function fail(error) {
//alert("An error has occurred: Code = " + error.code);
console.log("An error has occurred: Code = " + error.code);
console.log("upload error source " + error.source);
console.log("upload error target " + error.target);
showMessage("Image upload has failed, get a better internet connection and try again!", function() {
console.log("Upload van de form is mislukt!")
});
deferred.reject();
}
}
return deferred.promise();
}
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