hellojs-xiaotian
Version:
A clientside Javascript library for standardizing requests to OAuth2 web services (and OAuth1 - with a shim)
190 lines (182 loc) • 5.49 kB
JavaScript
/**
* Blob.js
* A Blob implementation.
* 2013-06-20
*
* By Eli Grey, http://eligrey.com
* By Devin Samarin, https://github.com/eboyjr
* License: X11/MIT
* See LICENSE.md
*/
/*global unescape */
/*jslint bitwise: true, regexp: true, confusion: true, es5: true, vars: true, white: true,
plusplus: true */
/*! @source http://purl.eligrey.com/github/Blob.js/blob/master/Blob.js */
if ((typeof Blob !== "function" && typeof Blob !== "object") || (Blob && Blob.toString() === '[object BlobConstructor]'))
this.Blob = (function(view) {
"use strict";
var BlobBuilder = view.BlobBuilder || view.WebKitBlobBuilder || view.MozBlobBuilder || view.MSBlobBuilder || (function(view) {
var
get_class = function(object) {
return Object.prototype.toString.call(object).match(/^\[object\s(.*)\]$/)[1];
}
, FakeBlobBuilder = function BlobBuilder() {
this.data = [];
}
, FakeBlob = function Blob(data, type, encoding) {
this.data = data;
this.size = data.length;
this.type = type;
this.encoding = encoding;
}
, FBB_proto = FakeBlobBuilder.prototype
, FB_proto = FakeBlob.prototype
, FileReaderSync = view.FileReaderSync
, FileException = function(type) {
this.code = this[this.name = type];
}
, file_ex_codes = (
"NOT_FOUND_ERR SECURITY_ERR ABORT_ERR NOT_READABLE_ERR ENCODING_ERR "
+ "NO_MODIFICATION_ALLOWED_ERR INVALID_STATE_ERR SYNTAX_ERR"
).split(" ")
, file_ex_code = file_ex_codes.length
, real_URL = view.URL || view.webkitURL || view
, real_create_object_URL = real_URL.createObjectURL
, real_revoke_object_URL = real_URL.revokeObjectURL
, URL = real_URL
, btoa = view.btoa
, atob = view.atob
, ArrayBuffer = view.ArrayBuffer
, Uint8Array = view.Uint8Array
;
FakeBlob.fake = FB_proto.fake = true;
while (file_ex_code--) {
FileException.prototype[file_ex_codes[file_ex_code]] = file_ex_code + 1;
}
if (!real_URL.createObjectURL) {
URL = view.URL = {};
}
URL.createObjectURL = function(blob) {
var
type = blob.type
, data_URI_header
;
if (type === null) {
type = "application/octet-stream";
}
if (blob instanceof FakeBlob) {
data_URI_header = "data:" + type;
if (blob.encoding === "base64") {
return data_URI_header + ";base64," + blob.data;
} else if (blob.encoding === "URI") {
return data_URI_header + "," + decodeURIComponent(blob.data);
} if (btoa) {
return data_URI_header + ";base64," + btoa(blob.data);
} else {
return data_URI_header + "," + encodeURIComponent(blob.data);
}
} else if (real_create_object_URL) {
return real_create_object_URL.call(real_URL, blob);
}
};
URL.revokeObjectURL = function(object_URL) {
if (object_URL.substring(0, 5) !== "data:" && real_revoke_object_URL) {
real_revoke_object_URL.call(real_URL, object_URL);
}
};
FBB_proto.append = function(data/*, endings*/) {
var bb = this.data;
// Decode data to a binary string
if (Uint8Array && (data instanceof ArrayBuffer || data instanceof Uint8Array)) {
var
str = ""
, buf = new Uint8Array(data)
, i = 0
, buf_len = buf.length
;
for (; i < buf_len; i++) {
str += String.fromCharCode(buf[i]);
}
bb.push(str);
} else if (get_class(data) === "Blob" || get_class(data) === "File") {
if (FileReaderSync) {
var fr = new FileReaderSync;
bb.push(fr.readAsBinaryString(data));
} else {
// Async FileReader won't work as BlobBuilder is sync
throw new FileException("NOT_READABLE_ERR");
}
} else if (data instanceof FakeBlob) {
if (data.encoding === "base64" && atob) {
bb.push(atob(data.data));
} else if (data.encoding === "URI") {
bb.push(decodeURIComponent(data.data));
} else if (data.encoding === "raw") {
bb.push(data.data);
}
} else {
if (typeof data !== "string") {
data += ""; // Convert unsupported types to strings
}
// Decode UTF-16 to binary string
bb.push(unescape(encodeURIComponent(data)));
}
};
FBB_proto.getBlob = function(type) {
if (!arguments.length) {
type = null;
}
return new FakeBlob(this.data.join(""), type, "raw");
};
FBB_proto.toString = function() {
return "[object BlobBuilder]";
};
FB_proto.slice = function(start, end, type) {
var args = arguments.length;
if (args < 3) {
type = null;
}
return new FakeBlob(
this.data.slice(start, args > 1 ? end : this.data.length)
, type
, this.encoding
);
};
FB_proto.toString = function() {
return "[object Blob]";
};
return FakeBlobBuilder;
}(view));
var Blob = function(blobParts, options) {
var type = options ? (options.type || "") : "";
var builder = new BlobBuilder();
if (blobParts) {
for (var i = 0, len = blobParts.length; i < len; i++) {
if (Uint8Array && blobParts[i] instanceof Uint8Array) {
builder.append(blobParts[i].buffer);
}
else {
builder.append(blobParts[i]);
}
}
}
var blob = builder.getBlob(type);
if (!blob.slice && blob.webkitSlice) {
blob.slice = blob.webkitSlice;
}
return blob;
};
var getPrototypeOf = Object.getPrototypeOf || function(object) {
return object.__proto__;
};
Blob.prototype = getPrototypeOf(new Blob());
return Blob;
}(this));
var supportsBlob = false;
if (this.Blob) {
try{
new Blob([new Int8Array([17, -45.3])], {type: 'image/jpeg'});
supportsBlob = true;
}
catch(e) {}
}