lib/webos/plugin/webos/filereader.js

/*
 *
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 *
*/

var FileError = require('cordova/plugin/FileError'),
    ProgressEvent = require('cordova/plugin/ProgressEvent');

var FileReader = function() {
    this.fileName = "";

    this.readyState = 0; // FileReader.EMPTY

    // File data
    this.result = null;

    // Error
    this.error = null;

    // Event handlers
    this.onloadstart = null;    // When the read starts.
    this.onprogress = null;     // While reading (and decoding) file or fileBlob data, and reporting partial file data (progess.loaded/progress.total)
    this.onload = null;         // When the read has successfully completed.
    this.onerror = null;        // When the read has failed (see errors).
    this.onloadend = null;      // When the request has completed (either in success or failure).
    this.onabort = null;        // When the read has been aborted. For instance, by invoking the abort() method.
};

FileReader.prototype.readAsText = function(file, encoding) {
    console.error("webos plugin filereader readastext:" + file);
    //Mojo has no file i/o yet, so we use an xhr. very limited

    // Already loading something
    if (this.readyState == FileReader.LOADING) {
        throw new FileError(FileError.INVALID_STATE_ERR);
    }

    // LOADING state
    this.readyState = FileReader.LOADING;

    // If loadstart callback
    if (typeof this.onloadstart === "function") {
        this.onloadstart(new ProgressEvent("loadstart", {target:this}));
    }

    // Default encoding is UTF-8
    var enc = encoding ? encoding : "UTF-8";

    var me = this;

    var xhr = new XMLHttpRequest();
    xhr.onreadystatechange = function() {
        console.error("onreadystatechange:"+xhr.readyState+" "+xhr.status);
        if (xhr.readyState == 4) {
            if (xhr.status == 200 && xhr.responseText) {
                console.error("file read completed");
                // Save result
                me.result = xhr.responseText;

                // If onload callback
                if (typeof me.onload === "function") {
                    me.onload(new ProgressEvent("load", {target:me}));
                }

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

                // If onloadend callback
                if (typeof me.onloadend === "function") {
                    me.onloadend(new ProgressEvent("loadend", {target:me}));
                }

            } else {
                // If DONE (cancelled), then don't do anything
                if (me.readyState === FileReader.DONE) {
                    return;
                }

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

                me.result = null;

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

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

                // If onloadend callback
                if (typeof me.onloadend === "function") {
                    me.onloadend(new ProgressEvent("loadend", {target:me}));
                }
            }
        }
    };
    xhr.open("GET", file, true);
    xhr.send();
};

module.exports = FileReader;