localforage/src/utils/createBlob.js

Offline storage, improved.

// Abstracts constructing a Blob object, so it also works in older
// browsers that don't support the native Blob constructor. (i.e.
// old QtWebKit versions, at least).
// Abstracts constructing a Blob object, so it also works in older
// browsers that don't support the native Blob constructor. (i.e.
// old QtWebKit versions, at least).
function createBlob(parts, properties) {
    /* global BlobBuilder,MSBlobBuilder,MozBlobBuilder,WebKitBlobBuilder */
    parts = parts || [];
    properties = properties || {};
    try {
        return new Blob(parts, properties);
    } catch (e) {
        if (e.name !== 'TypeError') {
            throw e;
        }
        var Builder =
            typeof BlobBuilder !== 'undefined'
                ? BlobBuilder
                : typeof MSBlobBuilder !== 'undefined'
                  ? MSBlobBuilder
                  : typeof MozBlobBuilder !== 'undefined'
                    ? MozBlobBuilder
                    : WebKitBlobBuilder;
        var builder = new Builder();
        for (var i = 0; i < parts.length; i += 1) {
            builder.append(parts[i]);
        }
        return builder.getBlob(properties.type);
    }
}

export default createBlob;