From f4fc53fa193f7fe3fc9c1328c0c4d677f754826d Mon Sep 17 00:00:00 2001
From: Edward Shen <6173958+edward-shen@users.noreply.github.com>
Date: Mon, 7 May 2018 13:05:52 -0400
Subject: [PATCH] added support for changing by a certain amount of pages

---
 MMM-pages.js | 13 ++++++++++---
 readme.md    |  7 ++++---
 2 files changed, 14 insertions(+), 6 deletions(-)

diff --git a/MMM-pages.js b/MMM-pages.js
index 713f6b1..ea9097c 100644
--- a/MMM-pages.js
+++ b/MMM-pages.js
@@ -55,11 +55,12 @@ Module.register('MMM-pages', {
    * @param {number} payload the page to change to
    */
   notificationReceived: function(notification, payload) {
+    const isValidPayload = typeof payload === 'number';
     switch (notification) {
       case 'PAGE_CHANGED':
         Log.log(`${this.name} recieved a notification`
           + `to change to page ${payload} of type ${typeof payload}`);
-        if (typeof payload === 'number') {
+        if (isValidPayload) {
           this.curPage = payload;
         } else {
           Log.error('Was asked to change to an invalid number!');
@@ -70,12 +71,18 @@ Module.register('MMM-pages', {
         break;
       case 'PAGE_INCREMENT':
         Log.log(`${this.name} recieved a notification to increment pages!`);
-        this.curPage = this.mod(this.curPage + 1, this.config.modules.length);
+        this.curPage = this.mod(
+          this.curPage + (isValidPayload) ? payload : 1,
+          this.config.modules.length
+        );
         this.updatePages(true);
         break;
       case 'PAGE_DECREMENT':
         Log.log(`${this.name} recieved a notification to decrement pages!`);
-        this.curPage = this.mod(this.curPage - 1, this.config.modules.length);
+        this.curPage = this.mod(
+          this.curPage - (isValidPayload) ? payload : 1,
+          this.config.modules.length
+        );
         this.updatePages(true);
         break;
       case 'DOM_OBJECTS_CREATED':
diff --git a/readme.md b/readme.md
index 6832b05..cbc11c8 100644
--- a/readme.md
+++ b/readme.md
@@ -76,9 +76,10 @@ this.sendNotification("PAGE_CHANGED", 2);
 ```
 This would cause the module to change show that you are on page 3.
 
-You can also just send `PAGE_INCREMENT` or `PAGE_DECREMENT` without any payloads
- (or with, but it will be ignored) to have the module change the displayed page 
- by one.
+Sending a `PAGE_INCREMENT` or `PAGE_DECREMENT` without any parameters will
+increase or decrease the page by one. Attaching a valid payload to the
+aforementioned notifications will increase or decrease the pages by that amount.
+Remember that this module **strictly checks** for a number.
 
 This module keeps internal track of how many pages you have, defined by your 
 config in the config file. There is no way to dynamically change the pages you