node_helper.js

/**
 * Magic Mirror
 * Node Helper: MMM-CoinMarketCap
 *
 * By David Dearden
 * MIT Licensed.
 */

/**
 * Load resources required by this module.
 */
var NodeHelper = require("node_helper");
var express = require("express");
var request = require("request");
var fs = require("fs");

/**
 * Use NodeHelper to create a module.
 */
module.exports = NodeHelper.create({
  /**
   * The minimum version of magic mirror that is required for this module to run.
   */
  requiresVersion: "2.2.1",

  /**
   * Override the start function to run when the module is started up.
   * Used to provide initialization information to the console and to map
   * additional routes.
   */
  start: function () {
    var self = this;
    console.log(self.name + ": module loaded! Path: " + this.path);
    try {
      self.expressApp.use(
        "/" + self.name + "/logos",
        express.static(self.path + "/logos")
      );
      console.log(self.name + ': Path "/logos" configured successfully.');
    } catch (err) {
      console.log(self.name + ": Error configuring additional routes: " + err);
    }
  },

  /**
   * Override the socketNotificationReceived function to handle notifications sent from the client script.
   *
   * @param notification (string) The type of notification sent
   * @param payload (any) The data sent with the notification
   */
  socketNotificationReceived: function (notification, payload) {
    var self = this;
    if (payload.developerMode) {
      console.log(
        self.name + ': Socket Notification Received: "' + notification + '".'
      );
    }
    if (notification === "GET_LISTINGS") {
      self.getAndReturnJSON(payload);
    } else if (notification === "GET_CURRENCY_DETAILS") {
      self.getAndReturnJSON(payload);
    } else if (notification === "DOWNLOAD_FILE") {
      self.downloadFile(payload);
    } else if (notification === "INIT") {
      self.sendSocketNotification("LOG", {
        original: payload,
        message: "INIT received from: " + payload.instanceID + ".",
        messageType: "dev",
      });
      self.sendSocketNotification("LOG", {
        original: payload,
        message: "node_helper.js loaded successfully.",
        messageType: "dev",
      });
    }
  },

  /**
   * The getAndReturnJSON function gets a JSON document from a URL and send it to the client.
   *
   * @param payload (object) Contains the data required for getting the JSON document
   */
  getAndReturnJSON: function (payload) {
    var self = this;
    var config = {
      url: payload.url,
      method: "GET",
    };
    if (payload.apiKey) {
      config.headers = { "X-CMC_PRO_API_KEY": payload.apiKey };
    }
    request(config, function (error, response, body) {
      var result;
      if (!error && response.statusCode === 200) {
        result = {
          original: payload,
          isSuccessful: true,
          response: response,
          data: JSON.parse(body),
        };
      } else {
        result = {
          original: payload,
          isSuccessful: false,
          response: response,
          data: error,
        };
      }
      if (typeof payload.notification === "string") {
        self.sendSocketNotification(payload.notification, result);
      }
    });
  },

  /**
   * The downloadFile function saves a file from a URL to the local file system.
   *
   * @param payload (object) Contains the data required for downloading and saving the file
   */
  downloadFile: function (payload) {
    var self = this;
    request(
      { url: payload.url, encoding: "binary", method: "GET" },
      function (error, response, body) {
        var result;
        if (!error && response.statusCode === 200) {
          result = {
            original: payload,
            isSuccessful: true,
            response: response,
            data: body,
          };
        } else {
          result = {
            original: payload,
            isSuccessful: false,
            response: response,
            data: error,
          };
        }
        if (typeof payload.notification === "string") {
          self.sendSocketNotification(payload.notification, result);
        }
        // If the download was successful, try to save the file
        if (result.isSuccessful) {
          fs.writeFile(
            payload.saveToFileName,
            response.body,
            { encoding: "binary" },
            function (err) {
              if (err) {
                self.sendSocketNotification("LOG", {
                  original: payload,
                  translate: true,
                  message: "LOGO_SAVE_FAILURE",
                  translateVars: {
                    sourceFilename: payload.url,
                    destinationFilename: payload.saveToFileName,
                  },
                });
              } else {
                self.sendSocketNotification("LOG", {
                  original: payload,
                  translate: true,
                  message: "LOGO_SAVE_SUCCESS",
                  translateVars: {
                    sourceFilename: payload.url,
                    destinationFilename: payload.saveToFileName,
                  },
                });
              }
            }
          );
        }
      }
    );
  },
});