Develop Reference

Next/Prev buttons to step through div contents

First of all a disclaimer, I'm not a dev. I'm halfway through The Odin Project and have covered some HTML and CSS, but, have not yet started on JS. In order to help with my learning I've created my own blog. My aim is for each blog post to have its own stylesheet (so with each new post I learn a little more about CSS).
Anyway, I plan to write a post about the benefits of using an eReader, specifically the Kindle. I've styled the page to look like a Kindle Oasis, and I'd like the reader to be able to step through the article contents via the Kindle's next/prev buttons, but, as I'm not a dev, this is where I'm stuck. Via Stack overflow I've managed to add some JS that will display page 1, 2 and 3 via dedicated buttons for each dive element, but, what I really need is to step through x number of pages via the prev/next buttons.
Here's what I have so far: https://codepen.io/dbssticky/pen/yLVoORO. Any help would be much appreciated. What I should do of course is finish The Odin Project and come up with a solution on my own, but, I'd really like to get this Kindle article published sooner rather than later. Hence my rather cheeky request for assistance.
Here's the JS I'm currently using:
function swapContent(id) {
const main = document.getElementById("main_place");
const div = document.getElementById(id);
const clone = div.cloneNode(true);
while (main.firstChild) main.firstChild.remove();
main.appendChild(clone);
}

You have the right idea and it just needs a few adjustments to get the previous/next functionality.
Currently your div IDs are following the format operation1, operation2, and so on. Since you want the previous/next functionality you'll need to change your 'swapping' function, which currently takes the full ID, to use the numeric portion only.
Add a new function which appends the number to 'operation' instead of using the whole thing:
function goToPage(pageNumber){
const main = document.getElementById("main_place");
const div = document.getElementById("operation" + pageNumber);
const clone = div.cloneNode(true);
while (main.firstChild) main.firstChild.remove();
main.appendChild(clone);
}
And then change your Page 1/2/3 buttons to use goToPage(1), goToPage(2) and so on.
Now for the previous/next functionality you'll need a way to track which page you're on, so that you can figure out which page to load.
Add a variable at the top (outside functions)
var currentPage = 0;
Then add a line in your goToPage function to track the page you're on.
currentPage = pageNumber;
Now that you're tracking you can add a previous and next function.
function goNextPage(){
goToPage(currentPage-1);
}
function goPreviousPage(){
goToPage(currentPage+1);
}
Then call it from the previous and next buttons.
<button onClick="goNextPage()" class="next-button"></button>
<button onClick="goPreviousPage()" class="previous-button"></button>
Here's a codepen: https://codepen.io/srirachapen/pen/WNZOXQZ
It's barebones and you may have to handle things like non existent div IDs.

HTML
<button class="next-button" onclick="nextContent()"></button>
<button class="previous-button" onclick="prevContent()"></button>
JS
var pageid = 0;
var maxpage = 3;
function nextContent() {
if(pageid == maxpage) return
pageid++
swapContent(`operation${pageid}`)
}
function prevContent() {
if(pageid == 1) return
pageid--
swapContent(`operation${pageid}`)
}
you can try this to switch between pages. But you may need to edit the "swapContent" method more sensibly.

Track the Current Page
Whatever solution you use to render pages & links (manual hardcoded links & content vs externally-stored & auto-generated), one thing is unavoidable: You need to track the current page!
var currentPage = 0
Then, any time there's a page change event, you update that variable.
With the current page being tracked, you can now perform operations relative to it (e.g. +1 or -1)
I'd suggest making a goToPage(page) function that does high-level paging logic, and keep your swapContent() function specifically for the literal act of swapping div content. In the future, you may find you'd want to use swapContent() for non-page content, like showing a "Welcome" or "Help" screen.
Example:
function goToPage(page) {
// Update `currentPage`
currentPage = page
// ... other logic, like a tracking event or anything else you want you occur when pages change
// Do the actual content swap, which could be your existing swapContent()
swapContent('operation'+page)
}
You'd invoke the function like so:
goToPage(3) // Jump to a specific page
goToPage(currentPage + 1) // Go to the next page
goToPage(currentPage - 1) // Go to the prev page
You can make separate helper functions like "goToNextPage()" if you desire, but for sure you start with a fundamental page-change function first.

How to find the end of node in tinymce?

I want to insert a text after the end of next closing tag in tinymce. For ex. <p>This is <span>This is a s|pan</span>paragraph</p>. '|' shows my cursor position, I need to place my cursor after '</span>|'.

Here's an outline for what you need to do:
// get a reference to the Editor instance
// (depending on your scenario, this may come from a different place)
var editor = tinymce.activeEditor;
// get the node your cursor is in - the one you want to insert after
var endNode = editor.selection.getEnd();
// move the selection after the current node
editor.selection.select(endNode).collapse(false);
// insert your content
editor.selection.setContent("abc");
You can use the API docs to actually make it work. What I wrote above is based strictly on the docs - as I don't have the time now to test it -, so it probably won't be plug and play.

Compiling the previous answer and comments into one block of code...
// Get a reference to the Editor instance
// (depending on your scenario, this may come from a different place)
var editor = tinymce.activeEditor;
// get the node your cursor is in - the one you want to insert after
var endNode = editor.selection.getEnd();
// move the selection after the current node
editor.selection.select(endNode);
editor.selection.collapse(false);
// insert your content
editor.selection.setContent("abc");

Display category name inside image with Javascript

I'm using Magazine Pro Child Theme for the Genesis Framework. This theme displays the Entry Date inside the featured images at the home page. As far as I know (not a programmer) it uses an apparently simple javascript code to do so:
jQuery(function( $ ){
// add js body class
$('body').addClass('js');
// find time for each entry and move it inside the image link
$('.home-middle article, .home-top article').each(function(){
var $time = $(this).find('.entry-time');
$(this).find('a.alignleft, a.alignnone, a.alignright').append($time);
});
I would like to replace the Entry Date for the Entry Category of each post. Is it possible just customizing the Javascript file?
Thank you for your help.

Do you mean replace A with B by saying replace A for B? If so, the following should do that.
The only changed part is the code block added to the middle of the each's function.
Note: I guess you want to replace the red tooltips in both the top and middle widget area, the following code only does the middle part because I can't find the category for the top featured article on the page(as you can see, the if statement ensures only middle ones are filled with category). Also, new texts filling the red tooltips should be Leadercaptalized, change the line between {} to $time.text($widgetArea.find('.widget-title').text().toUpperCase()); if you want wholly captalized ones, or toLowerCase for lowercased ones.
jQuery(function( $ ){
// add js body class
$('body').addClass('js');
// find time for each entry and move it inside the image link
$('.home-middle article, .home-top article').each(function(){
var $time = $(this).find('.entry-time');
var $widgetArea = $time.parents('.home-middle, .home-top');
if($widgetArea.hasClass('home-middle')) {
$time.text($widgetArea.find('.widget-title').text());
}
$(this).find('a.alignleft, a.alignnone, a.alignright').append($time);
});

Counting classes on another page and displaying them

To save me a lot of work editing a number in when adding a document to a site I decided to use javascript to count the number of elements with a class doc .
I am two main problems:
There is trouble displaying the variable. I initially thought this was because I hadn't added function, however when I tried adding this the variable was still not displayed.
The elements with the class I want to count are on another page and I have no idea how to link to it. For this I have tried var x = $('URL: /*pageURL*/ .doc').length; which hasn't worked.
Essentially I want the total elements with said class name and this to be displayed in a span element.
Currently I have something similar to what's displayed below:
<script>
var Items = $('.doc').length;
document.getElementById("display").innerHTML=Items;
</script>
<span id="display"></span>
Found an example of something similar here where the total numbers of articles are displayed.
Edit:
#ian
This code will be added to the homepage, domain.net/home.html. I want to link to the page containing this documents, domain.net/documents.html. I've seen this done somewhere before and if I remember correctly they used url:domainname.com/count somewhere in their code. Hope this helps.

Here is a jQuery call to retrieve the url "./" (this page) and parse the resulting data for all elements with class "lsep" "$('.lsep', data)". You should get back a number greater than 5 or so if you run this from within your debug console of your browser.
$.get("./", function(data, textStatus, jqXHR)
{
console.log("Instances of class: " + $('.lsep', data).length)
});
One important thing to remember is that you will run into issues if the URL your are trying to call is not in the same origin.
Here's an updated snippet of code to do what you're describing:
$(document).ready(
function ()
{
//var url = "/document.html" //this is what you'd have for url
//var container = $("#display"); //this is what you'd have for container
//var className = '.data'; //this is what you'd have for className
var url = "./"; //the document you want to parse
var container = $("#question-header"); //the container to update
var className = '.lsep'; //the class to search for
$.get(url, function (data, textStatus, jqXHR) {
$(container).html($(className, data).length);
});
}
);
If you run the above code from your browser's debug console it will replace the question header text of "Counting classes on another page and displaying them" with the count of instances the class name ".lsep" is used.

First, you have to wait until the document is ready before manipulating DOM elements, unless your code is placed after the definition of the elements you manipulate, wich is not the case in your example. You can pass a function to the $ and it will run it only when the document is ready.
$(function () {
//html() allows to set the innerHTML property of an element
$('#display').html($('.doc').length);
});
Now, if your elements belongs to another document, that obviously won't work. However, if you have used window.open to open another window wich holds the document that contains the .doc elements, you could put the above script in that page, and rely on window.opener to reference the span in the parent's window.
$('#display', opener.document.body).html($('.doc').length);
Another alternative would be to use ajax to access the content of the other page. Here, data will contain the HTML of the your_other_page.html document, wich you can then manipulate like a DOM structure using jQuery.
$.get('your_other_page.html', function(data) {
$('#display').html($('.doc', data).length);
});

Tree Menu? In JS?

I need a tree menu. But instead of a listview where you expand/collapse i need a dropdown box with the list and when you click on a element i need the box to update (with the first entry being 'Back') so the menu stays in a neat little dialog.
Does this menu have a name? Does anyone know where i can get code to do this?

I can think of several jQuery plugins which would soot your purposes. However, I would recommend jQuery iPod Style Drilldown Menu (Newer Version), which is exactly what it sounds like. The dropdown box updates in place, uses a cool sideways slide animation, and includes a "Back" button (as you desired). Finally, if you don't want any animation, you can try tweaking the plugin's many options. Setting crossSpeed to 0 may work, for example.

Adam is right, jQuery offers an assortment of menu's which you could use. Really though, this is a somewhat trivial problem, the code to write it would take up about 1/10th the space that jQuery's code will. So if possible I would say write it without jQuery.
The most effective method would be to do it JS OOP (Javascript Object-Oriented), but understandably this is a confusing topic.
Basically you just want something like:
function drillDown(){
//Any code that multiple drilldowns
// might need on the same page goes here
//Every instance of a drillDown will
// instantiate a new set of all functions/variables
// which are contained here
//A reference to the parent node the dropdown is placed in
this.parent;
//A reference to the div the dropdown is incased in
this.object;
//Returns a reference to this object so it can be
// stored/referenced from a variable in it's
// superclass
return this;
}
//Prototype Functions
//prototypes are shared by all
// instances so as to not double up code
//this function will build the dropdown
drillDown.prototype.build = function(parent){
//Too lazy to write all this, but build a div and your select box
// Add the select box to the div,
// Add the div to the parent (which is in your document somewhere)
var divEle = document.createElement('div');
var inputBox = document.createElement('input');
//code code code
divEle.appendChild(inputBox);
parent.appendChild(divEle);
}
//this function loads the newest dataset of
drillDown.prototype.loadNewDataSet = function(data){
//first clear out the old list
// remember we have a reference to both the
// 'object' and 'parent' by using
// this.object and this.parent
//load the data, we are going to use the text from
// the select boxes to load each new dataset, woo eval();
// If you didn't know, eval() turns a string into JS code,
// in this case referencing an array somewhere
var dataSet = eval(data);
//then loop through your list adding each new item
for(item in dataSet){
//add item to the list
//change the .onClick() of each one to load the next data set
// a la ->
selectItem.onClick = function(){this.loadNewDataSet(item);};
//if you name your datasets intelligently,
// say a bunch of arrays named for their respective selectors,
// this is mad easy
}
}
//Then you can just build it
var drillDownBox = new drillDown();
drillDownBox.build(document.getElementsByTagName('body')[0]);
drillDownBox.loadNewDataSet("start");
//assuming your first dataset array is named "start",
// it should just go
And by the way, Adam also said it, but wasn't explicit, this is refered to as a drill-down.