snipe-it/bower_components/jquery.iframe-transport/jquery.iframe-transport.js

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2017-01-11 03:05:06 -08:00
// This [jQuery](https://jquery.com/) plugin implements an `<iframe>`
// [transport](https://api.jquery.com/jQuery.ajax/#extending-ajax) so that
// `$.ajax()` calls support the uploading of files using standard HTML file
// input fields. This is done by switching the exchange from `XMLHttpRequest`
// to a hidden `iframe` element containing a form that is submitted.
// The [source for the plugin](https://github.com/cmlenz/jquery-iframe-transport)
// is available on [Github](https://github.com/) and licensed under the [MIT
// license](https://github.com/cmlenz/jquery-iframe-transport/blob/master/LICENSE).
// ## Usage
// To use this plugin, you simply add an `iframe` option with the value `true`
// to the Ajax settings an `$.ajax()` call, and specify the file fields to
// include in the submssion using the `files` option, which can be a selector,
// jQuery object, or a list of DOM elements containing one or more
// `<input type="file">` elements:
// $("#myform").submit(function() {
// $.ajax(this.action, {
// files: $(":file", this),
// iframe: true
// }).complete(function(data) {
// console.log(data);
// });
// });
// The plugin will construct hidden `<iframe>` and `<form>` elements, add the
// file field(s) to that form, submit the form, and process the response.
// If you want to include other form fields in the form submission, include
// them in the `data` option, and set the `processData` option to `false`:
// $("#myform").submit(function() {
// $.ajax(this.action, {
// data: $(":text", this).serializeArray(),
// files: $(":file", this),
// iframe: true,
// processData: false
// }).complete(function(data) {
// console.log(data);
// });
// });
// ### Response Data Types
// As the transport does not have access to the HTTP headers of the server
// response, it is not as simple to make use of the automatic content type
// detection provided by jQuery as with regular XHR. If you can't set the
// expected response data type (for example because it may vary depending on
// the outcome of processing by the server), you will need to employ a
// workaround on the server side: Send back an HTML document containing just a
// `<textarea>` element with a `data-type` attribute that specifies the MIME
// type, and put the actual payload in the textarea:
// <textarea data-type="application/json">
// {"ok": true, "message": "Thanks so much"}
// </textarea>
// The iframe transport plugin will detect this and pass the value of the
// `data-type` attribute on to jQuery as if it was the "Content-Type" response
// header, thereby enabling the same kind of conversions that jQuery applies
// to regular responses. For the example above you should get a Javascript
// object as the `data` parameter of the `complete` callback, with the
// properties `ok: true` and `message: "Thanks so much"`.
// ### Handling Server Errors
// Another problem with using an `iframe` for file uploads is that it is
// impossible for the javascript code to determine the HTTP status code of the
// servers response. Effectively, all of the calls you make will look like they
// are getting successful responses, and thus invoke the `done()` or
// `complete()` callbacks. You can only communicate problems using the content
// of the response payload. For example, consider using a JSON response such as
// the following to indicate a problem with an uploaded file:
// <textarea data-type="application/json">
// {"ok": false, "message": "Please only upload reasonably sized files."}
// </textarea>
// ### Compatibility
// This plugin has primarily been tested on Safari 5 (or later), Firefox 4 (or
// later), and Internet Explorer (all the way back to version 6). While I
// haven't found any issues with it so far, I'm fairly sure it still doesn't
// work around all the quirks in all different browsers. But the code is still
// pretty simple overall, so you should be able to fix it and contribute a
// patch :)
// ## Annotated Source
(function($, undefined) {
"use strict";
// Register a prefilter that checks whether the `iframe` option is set, and
// switches to the "iframe" data type if it is `true`.
$.ajaxPrefilter(function(options, origOptions, jqXHR) {
if (options.iframe) {
options.originalURL = options.url;
return "iframe";
}
});
// Register a transport for the "iframe" data type. It will only activate
// when the "files" option has been set to a non-empty list of enabled file
// inputs.
$.ajaxTransport("iframe", function(options, origOptions, jqXHR) {
var form = null,
iframe = null,
name = "iframe-" + $.now(),
files = $(options.files).filter(":file:enabled"),
markers = null,
accepts = null;
// This function gets called after a successful submission or an abortion
// and should revert all changes made to the page to enable the
// submission via this transport.
function cleanUp() {
files.each(function(i, file) {
var $file = $(file);
$file.data("clone").replaceWith($file);
});
form.remove();
iframe.one("load", function() { iframe.remove(); });
iframe.attr("src", "about:blank");
}
// Remove "iframe" from the data types list so that further processing is
// based on the content type returned by the server, without attempting an
// (unsupported) conversion from "iframe" to the actual type.
options.dataTypes.shift();
// Use the data from the original AJAX options, as it doesn't seem to be
// copied over since jQuery 1.7.
// See https://github.com/cmlenz/jquery-iframe-transport/issues/6
options.data = origOptions.data;
if (files.length) {
form = $("<form enctype='multipart/form-data' method='post'></form>").
hide().attr({action: options.originalURL, target: name});
// If there is any additional data specified via the `data` option,
// we add it as hidden fields to the form. This (currently) requires
// the `processData` option to be set to false so that the data doesn't
// get serialized to a string.
if (typeof(options.data) === "string" && options.data.length > 0) {
$.error("data must not be serialized");
}
$.each(options.data || {}, function(name, value) {
if ($.isPlainObject(value)) {
name = value.name;
value = value.value;
}
$("<input type='hidden' />").attr({name: name, value: value}).
appendTo(form);
});
// Add a hidden `X-Requested-With` field with the value `IFrame` to the
// field, to help server-side code to determine that the upload happened
// through this transport.
$("<input type='hidden' value='IFrame' name='X-Requested-With' />").
appendTo(form);
// Borrowed straight from the JQuery source.
// Provides a way of specifying the accepted data type similar to the
// HTTP "Accept" header
if (options.dataTypes[0] && options.accepts[options.dataTypes[0]]) {
accepts = options.accepts[options.dataTypes[0]] +
(options.dataTypes[0] !== "*" ? ", */*; q=0.01" : "");
} else {
accepts = options.accepts["*"];
}
$("<input type='hidden' name='X-HTTP-Accept'>").
attr("value", accepts).appendTo(form);
// Move the file fields into the hidden form, but first remember their
// original locations in the document by replacing them with disabled
// clones. This should also avoid introducing unwanted changes to the
// page layout during submission.
markers = files.after(function(idx) {
var $this = $(this),
$clone = $this.clone().prop("disabled", true);
$this.data("clone", $clone);
return $clone;
}).next();
files.appendTo(form);
return {
// The `send` function is called by jQuery when the request should be
// sent.
send: function(headers, completeCallback) {
iframe = $("<iframe src='about:blank' name='" + name +
"' id='" + name + "' style='display:none'></iframe>");
// The first load event gets fired after the iframe has been injected
// into the DOM, and is used to prepare the actual submission.
iframe.one("load", function() {
// The second load event gets fired when the response to the form
// submission is received. The implementation detects whether the
// actual payload is embedded in a `<textarea>` element, and
// prepares the required conversions to be made in that case.
iframe.one("load", function() {
var doc = this.contentWindow ? this.contentWindow.document :
(this.contentDocument ? this.contentDocument : this.document),
root = doc.documentElement ? doc.documentElement : doc.body,
textarea = root.getElementsByTagName("textarea")[0],
type = textarea && textarea.getAttribute("data-type") || null,
status = textarea && textarea.getAttribute("data-status") || 200,
statusText = textarea && textarea.getAttribute("data-statusText") || "OK",
content = {
html: root.innerHTML,
text: type ?
textarea.value :
root ? (root.textContent || root.innerText) : null
};
cleanUp();
completeCallback(status, statusText, content, type ?
("Content-Type: " + type) :
null);
});
// Now that the load handler has been set up, submit the form.
form[0].submit();
});
// After everything has been set up correctly, the form and iframe
// get injected into the DOM so that the submission can be
// initiated.
$("body").append(form, iframe);
},
// The `abort` function is called by jQuery when the request should be
// aborted.
abort: function() {
if (iframe !== null) {
iframe.unbind("load").attr("src", "about:blank");
cleanUp();
}
}
};
}
});
})(jQuery);