FileWriter.prototype.write = function()

in www/FileWriter.js [111:223]
25 lines of code
11 McCabe index (conditional complexity)

FileWriter.prototype.write = function (data, isPendingBlobReadResult) {
    const that = this;
    const supportsBinary = (typeof window.Blob !== 'undefined' && typeof window.ArrayBuffer !== 'undefined');
    /* eslint-disable no-undef */
    const isProxySupportBlobNatively = cordova.platformId === 'windows';

    // Check to see if the incoming data is a blob
    if (data instanceof File || (!isProxySupportBlobNatively && supportsBinary && data instanceof Blob)) {
        const fileReader = new FileReader();
        /* eslint-enable no-undef */
        fileReader.onload = function () {
            // Call this method again, with the arraybuffer as argument
            FileWriter.prototype.write.call(that, this.result, true /* isPendingBlobReadResult */);
        };
        fileReader.onerror = function () {
            // DONE state
            that.readyState = FileWriter.DONE;

            // Save error
            that.error = this.error;

            // If onerror callback
            if (typeof that.onerror === 'function') {
                that.onerror(new ProgressEvent('error', { target: that }));
            }

            // If onwriteend callback
            if (typeof that.onwriteend === 'function') {
                that.onwriteend(new ProgressEvent('writeend', { target: that }));
            }
        };

        // WRITING state
        this.readyState = FileWriter.WRITING;

        if (supportsBinary) {
            fileReader.readAsArrayBuffer(data);
        } else {
            fileReader.readAsText(data);
        }
        return;
    }

    // Mark data type for safer transport over the binary bridge
    const isBinary = supportsBinary && (data instanceof ArrayBuffer);

    // Throw an exception if we are already writing a file
    if (this.readyState === FileWriter.WRITING && !isPendingBlobReadResult) {
        throw new FileError(FileError.INVALID_STATE_ERR);
    }

    // WRITING state
    this.readyState = FileWriter.WRITING;

    const me = this;

    // If onwritestart callback
    if (typeof me.onwritestart === 'function') {
        me.onwritestart(new ProgressEvent('writestart', { target: me }));
    }

    // Write file
    exec(
        // Success callback
        function (r) {
            // If DONE (cancelled), then don't do anything
            if (me.readyState === FileWriter.DONE) {
                return;
            }

            // position always increases by bytes written because file would be extended
            me.position += r;
            // The length of the file is now where we are done writing.

            me.length = me.position;

            // DONE state
            me.readyState = FileWriter.DONE;

            // If onwrite callback
            if (typeof me.onwrite === 'function') {
                me.onwrite(new ProgressEvent('write', { target: me }));
            }

            // If onwriteend callback
            if (typeof me.onwriteend === 'function') {
                me.onwriteend(new ProgressEvent('writeend', { target: me }));
            }
        },
        // Error callback
        function (e) {
            // If DONE (cancelled), then don't do anything
            if (me.readyState === FileWriter.DONE) {
                return;
            }

            // DONE state
            me.readyState = FileWriter.DONE;

            // Save error
            me.error = new FileError(e);

            // If onerror callback
            if (typeof me.onerror === 'function') {
                me.onerror(new ProgressEvent('error', { target: me }));
            }

            // If onwriteend callback
            if (typeof me.onwriteend === 'function') {
                me.onwriteend(new ProgressEvent('writeend', { target: me }));
            }
        }, 'File', 'write', [this.localURL, data, this.position, isBinary]);
};