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127 lines
3.9 KiB
JavaScript
127 lines
3.9 KiB
JavaScript
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/* BlobBuilder.js
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* A complete BlobBuilder shim
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* By Eli Grey
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* License: MIT/X11
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*/
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self.BlobBuilder || self.WebKitBlobBuilder || self.MozBlobBuilder || function (view) {
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"use strict";
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var
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get_class = function (object) {
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return Object.prototype.toString.call(object).match(/^\[object\s(.*)\]$/)[1];
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},
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FakeBlobBuilder = view.BlobBuilder = function () {},
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FakeBlob = view.Blob = function (data, type) {
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this.data = data;
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this.size = data.length;
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this.type = type;
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},
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FBB_proto = FakeBlobBuilder.prototype = [],
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FB_proto = FakeBlob.prototype,
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FileReaderSync = view.FileReaderSync,
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FileException = function (type) {
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this.code = this[this.name = type];
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},
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file_ex_codes = (
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"NOT_FOUND_ERR SECURITY_ERR ABORT_ERR NOT_READABLE_ERR ENCODING_ERR " +
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"NO_MODIFICATION_ALLOWED_ERR INVALID_STATE_ERR SYNTAX_ERR"
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).split(" "),
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file_ex_code = file_ex_codes.length,
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URL = view.URL = view.URL || view.webkitURL || view,
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real_create_object_url, real_revoke_object_url, btoa = view.btoa,
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ArrayBuffer = view.ArrayBuffer,
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can_apply_typed_arrays = false,
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can_apply_typed_arrays_test = function (pass) {
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can_apply_typed_arrays = !pass;
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};
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while (file_ex_code--) {
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FileException.prototype[file_ex_codes[file_ex_code]] = file_ex_code + 1;
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}
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try {
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if (ArrayBuffer) {
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can_apply_typed_arrays_test.apply(0, new Uint8Array(1));
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}
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} catch (ex) {}
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if (!URL.createObjectURL) {
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URL = {};
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}
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real_create_object_url = URL.createObjectURL;
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real_revoke_object_url = URL.revokeObjectURL;
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URL.createObjectURL = function (blob) {
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var type = blob.type;
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if (type === null) {
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type = "application/octet-stream";
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}
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if (blob instanceof FakeBlob) {
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if (btoa) {
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return "data:" + type + ";base64," + btoa(blob.data);
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} else {
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return "data:" + type + "," + encodeURIComponent(blob.data);
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}
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} else if (real_create_object_url) {
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return real_create_object_url.call(URL, blob);
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}
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};
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URL.revokeObjectURL = function (object_url) {
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if (object_url.substring(0, 5) !== "data:" && real_revoke_object_url) {
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real_revoke_object_url.call(URL, object_url);
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}
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};
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FBB_proto.append = function (data /*, endings*/ ) {
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var bb = this;
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// decode data to a binary string
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if (ArrayBuffer && data instanceof ArrayBuffer) {
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if (can_apply_typed_arrays) {
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bb.push(String.fromCharCode.apply(String, new Uint8Array(data)));
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} else {
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var
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str = "",
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buf = new Uint8Array(data),
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i = 0,
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buf_len = buf.length;
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for (; i < buf_len; i++) {
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str += String.fromCharCode(buf[i]);
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}
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}
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} else if (get_class(data) === "Blob" || get_class(data) === "File") {
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if (FileReaderSync) {
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var fr = new FileReaderSync;
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bb.push(fr.readAsBinaryString(data));
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} else {
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// async FileReader won't work as BlobBuilder is sync
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throw new FileException("NOT_READABLE_ERR");
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}
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} else if (data instanceof FakeBlob) {
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bb.push(data.data);
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} else {
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if (typeof data !== "string") {
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data += ""; // convert unsupported types to strings
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}
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// decode UTF-16 to binary string
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bb.push(unescape(encodeURIComponent(data)));
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}
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};
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FBB_proto.getBlob = function (type) {
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if (!arguments.length) {
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type = null;
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}
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return new FakeBlob(this.join(""), type);
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};
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FBB_proto.toString = function () {
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return "[object BlobBuilder]";
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};
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FB_proto.slice = function (start, end, type) {
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var args = arguments.length;
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if (args < 3) {
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type = null;
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}
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return new FakeBlob(
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this.data.slice(start, args > 1 ? end : this.data.length), type
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);
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};
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FB_proto.toString = function () {
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return "[object Blob]";
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};
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return FakeBlobBuilder;
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}(self);
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