node_helper.js

/* global Module */

/* node_helper.js
 * 
 * Magic Mirror
 * Module: MMM-ImageSlideshow
 * 
 * Magic Mirror By Michael Teeuw http://michaelteeuw.nl
 * MIT Licensed.
 * 
 * MMM-PenPlotter.js by Jason Bamford https://jbamford.github.io/
 * MIT Licensed.
 * 
 * Derivate work of
 * Module MMM-ImageSlideshow By Adam Moses http://adammoses.com
 * MIT Licensed.
 */

// call in the required classes
var NodeHelper = require("node_helper");
var FileSystemPenPlotter = require("fs");

// the main module helper create
module.exports = NodeHelper.create({
    // subclass start method, clears the initial config array
    start: function() {
        this.moduleConfigs = [];
    },
    // shuffles an array at random and returns it
    shuffleArray: function(array) {
      var currentIndex = array.length, temporaryValue, randomIndex;
      while (0 !== currentIndex) {
        randomIndex = Math.floor(Math.random() * currentIndex);
        currentIndex -= 1;
        temporaryValue = array[currentIndex];
        array[currentIndex] = array[randomIndex];
        array[randomIndex] = temporaryValue;
      }
      return array;
    },
    // sort by filename attribute
    sortByFilename: function (a, b) {
        aL = a.filename.toLowerCase();
        bL = b.filename.toLowerCase();
        if (aL > bL) 
			return 1;
		else 
			return -1;
    },
    // checks there's a valid image file extension
    checkValidImageFileExtension: function(filename, extensions) {
        var extList = extensions.split(',');
        for (var extIndex = 0; extIndex < extList.length; extIndex++) {
            if (filename.toLowerCase().endsWith(extList[extIndex]))
                return true;
        }
        return false;
    },
    // gathers the image list
    gatherImageList: function(config) {
        var self = this;
        // create an empty main image list
        var imageList = [];
        // for each of the paths specified
        for (var pathIndex = 0; pathIndex < config.imagePaths.length; pathIndex++) {
            var currentPath = config.imagePaths[pathIndex];
            var currentPathImageList = FileSystemPenPlotter.readdirSync(path = currentPath);
            // for each file in the current path
            if (currentPathImageList.length > 0) {
                // create an empty list for images in the current path
                var currentImageList = [];
                // for each file
                for (var imageIndex = 0; imageIndex < currentPathImageList.length; imageIndex++) {
                    // seperate into path and filename
                    var currentImage = {path: currentPath, filename: currentPathImageList[imageIndex]};
                    // check if file has a valid image file extension
                    var isValidImageFileExtension = this.checkValidImageFileExtension(
                                currentImage.filename, 
                                config.validImageFileExtensions);
                    //  if file is valid, add it to the list
                    if (isValidImageFileExtension)
                        currentImageList.push(currentImage);
                }
                // if not set to combine all paths, do random or alphabetical sort
                if (!config.treatAllPathsAsOne) {
                    if (config.randomizeImageOrder)
                        currentImageList = this.shuffleArray(currentImageList);
                    else
                        currentImageList = currentImageList.sort(this.sortByFilename);
                }
                // add current list main list
                imageList = imageList.concat(currentImageList);
            }
        }
        // if set to combine all paths, sort all images randomly or alphabetically by filename
        if (config.treatAllPathsAsOne) {
            if (config.randomizeImageOrder)
                imageList = this.shuffleArray(imageList);
            else
                imageList = imageList.sort(this.sortByFilename);
        }
        // create a file image list combining paths and filenames
        var imageListComplete = [];
        for (var index = 0; index < imageList.length; index++) {
            imageListComplete.push(imageList[index].path + '/' + imageList[index].filename);
		}
        // return final list
        return imageListComplete;
    },
    // subclass socketNotificationReceived, received notification from module
    socketNotificationReceived: function(notification, payload) {
        if (notification === "PENPLOTTER_REGISTER_CONFIG") {
            // add the current config to an array of all configs used by the helper
            this.moduleConfigs.push(payload);
            // this to self
            var self = this;
            // get the image list
            var imageList = this.gatherImageList(payload);
            // build the return payload
            var returnPayload = { identifier: payload.identifier, imageList: imageList };
            // send the image list back
            self.sendSocketNotification('PENPLOTTER_FILELIST', returnPayload );
        }
    },     
});

//------------ end -------------