source: gs3-extensions/web-audio/trunk/js-mad/sink.js-master/src/core/dyn-url.js@ 28388

void function (Sink) {

var _Blob, _BlobBuilder, _URL, _btoa;

void function (prefixes, urlPrefixes) {
    function find (name, prefixes) {
        var b, a = prefixes.slice();

        for (b=a.shift(); typeof b !== 'undefined'; b=a.shift()) {
            b = Function('return typeof ' + b + name + 
                '=== "undefined" ? undefined : ' +
                b + name)();

            if (b) return b;
        }
    }

    _Blob = find('Blob', prefixes);
    _BlobBuilder = find('BlobBuilder', prefixes);
    _URL = find('URL', urlPrefixes);
    _btoa = find('btoa', ['']);
}([
    '',
    'Moz',
    'WebKit',
    'MS'
], [
    '',
    'webkit'
]);

var createBlob = _Blob && _URL && function (content, type) {
    return _URL.createObjectURL(new _Blob([content], { type: type }));
};

var createBlobBuilder = _BlobBuilder && _URL && function (content, type) {
    var bb = new _BlobBuilder();
    bb.append(content);

    return _URL.createObjectURL(bb.getBlob(type));
};

var createData = _btoa && function (content, type) {
    return 'data:' + type + ';base64,' + _btoa(content);
};

var createDynURL =
    createBlob ||
    createBlobBuilder ||
    createData;

if (!createDynURL) return;

if (createBlob) createDynURL.createBlob = createBlob;
if (createBlobBuilder) createDynURL.createBlobBuilder = createBlobBuilder;
if (createData) createDynURL.createData = createData;

if (_Blob) createDynURL.Blob = _Blob;
if (_BlobBuilder) createDynURL.BlobBuilder = _BlobBuilder;
if (_URL) createDynURL.URL = _URL;

Sink.createDynURL = createDynURL;

Sink.revokeDynURL = function (url) {
    if (typeof url === 'string' && url.indexOf('data:') === 0) {
        return false;
    } else {
        return _URL.revokeObjectURL(url);
    }
};

}(this.Sink);