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highlight the .replace() word in javascript

function handleTextNode(textNode) {
if(textNode.nodeName !== '#text'
|| textNode.parentNode.nodeName === 'SCRIPT'
|| textNode.parentNode.nodeName === 'STYLE'
) {
//Don't do anything except on text nodes, which are not children
// of or .
return;
}
var find = ["build", "add", "Fast"];
var replace = ["Develope", "add", "Fast"];
let origText = textNode.textContent;
let newHtml = origText.replace(new RegExp("(" + find.map(function(i){return i.replace(/[.?*+^$[\]\\(){}|-]/g, "\\$&")}).join("|") + ")", "g"),function(s){ return replace[ find.indexOf(s)]});
if( newHtml !== origText) {
let newSpan = document.createElement('span');
newSpan.innerHTML = newHtml;
textNode.parentNode.replaceChild(newSpan,textNode);
}
// <span title="Dyslexia is a learning disorder that involves difficulty reading due to problems identifying speech sounds. " style="background-color: yellow"></span>
}
let textNodes = [];
//Create a NodeIterator to get the text nodes in the body of the document
let nodeIter = document.createNodeIterator(document.body,NodeFilter.SHOW_TEXT);
let currentNode;
//Add the text nodes found to the list of text nodes to process.
while(currentNode = nodeIter.nextNode()) {
textNodes.push(currentNode);
}
//Process each text node
textNodes.forEach(function(el){
handleTextNode(el);
});
i want to make the replaced word highlighted. this code will run only for web pages. like i am building a adblocker with a functionality that help dyslexia Student. At the moment it only replace words correctly. can any body help?

Random Kerning in text area (input) for each letter

I'm all new to this, but after spending a week trying to find an answer, I thought I would try asking directly.
I am building a text editor using javascript and jquery. I have a textarea (with contenteditable), a stylesheet and a js script. What I want is that for each letter pressed, the kerning will be random. I achieved that with a simple function, but I don't want ALL textarea text to have this kerning, only the last letter pressed and so on and so on, so this type of thing would be the result:
simulation
There is what I have so far in my js file:
$(document).ready(
function() {
$('#textarea').keypress(function(){
var KerningRandom = Math.floor((Math.random()*90)-20);
$(this).css('letter-spacing',KerningRandom);
});
Here is my jsfiddle that actually doesn't work in jsfiddle and I don't get why as it works fine in local...?
Thanks!

You cannot address individual characters ( and so glyphs ) in CSS. Only ::first-letter.
Options you have:
convert all characters to individual spans. That's too much I think.
use <canvas> to render text and so to implement text flow layout from scratch.

You can find a working plunker of what you want to achieve there (I forked yours).
https://jsfiddle.net/1gesLgsa/2/
Full code :
//Code from https://stackoverflow.com/questions/1125292/how-to-move-cursor-to-end-of-contenteditable-entity
//Namespace management idea from http://enterprisejquery.com/2010/10/how-good-c-habits-can-encourage-bad-javascript-habits-part-1/
(function( cursorManager ) {
//From: http://www.w3.org/TR/html-markup/syntax.html#syntax-elements
var voidNodeTags = ['AREA', 'BASE', 'BR', 'COL', 'EMBED', 'HR', 'IMG', 'INPUT', 'KEYGEN', 'LINK', 'MENUITEM', 'META', 'PARAM', 'SOURCE', 'TRACK', 'WBR', 'BASEFONT', 'BGSOUND', 'FRAME', 'ISINDEX'];
//From: https://stackoverflow.com/questions/237104/array-containsobj-in-javascript
Array.prototype.contains = function(obj) {
var i = this.length;
while (i--) {
if (this[i] === obj) {
return true;
}
}
return false;
}
//Basic idea from: https://stackoverflow.com/questions/19790442/test-if-an-element-can-contain-text
function canContainText(node) {
if(node.nodeType == 1) { //is an element node
return !voidNodeTags.contains(node.nodeName);
} else { //is not an element node
return false;
}
};
function getLastChildElement(el){
var lc = el.lastChild;
while(lc && lc.nodeType != 1) {
if(lc.previousSibling)
lc = lc.previousSibling;
else
break;
}
return lc;
}
//Based on Nico Burns's answer
cursorManager.setEndOfContenteditable = function(contentEditableElement)
{
while(getLastChildElement(contentEditableElement) &&
canContainText(getLastChildElement(contentEditableElement))) {
contentEditableElement = getLastChildElement(contentEditableElement);
}
var range,selection;
if(document.createRange)//Firefox, Chrome, Opera, Safari, IE 9+
{
range = document.createRange();//Create a range (a range is a like the selection but invisible)
range.selectNodeContents(contentEditableElement);//Select the entire contents of the element with the range
range.collapse(false);//collapse the range to the end point. false means collapse to end rather than the start
selection = window.getSelection();//get the selection object (allows you to change selection)
selection.removeAllRanges();//remove any selections already made
selection.addRange(range);//make the range you have just created the visible selection
}
else if(document.selection)//IE 8 and lower
{
range = document.body.createTextRange();//Create a range (a range is a like the selection but invisible)
range.moveToElementText(contentEditableElement);//Select the entire contents of the element with the range
range.collapse(false);//collapse the range to the end point. false means collapse to end rather than the start
range.select();//Select the range (make it the visible selection
}
}
}( window.cursorManager = window.cursorManager || {}));
// ACTUAL CODE MADE FOR THIS ANSWER
$('#textarea').keypress(function(event) {
event.preventDefault();
var KerningRandom = Math.floor((Math.random() * 90));
if ($("#last").length > 0)
{
var previousLast = $("#textarea #last").html();
$("#textarea #last").remove();
}
else
var previousLast = "";
$("#textarea").html($("#textarea").html().slice() + previousLast + "<span id='last'>" + String.fromCharCode(event.which) + "</span>")
$("#last").css('margin-left', KerningRandom + "px");
var editableDiv = document.getElementById("textarea");
cursorManager.setEndOfContenteditable(editableDiv)
});
var editableDiv = document.getElementById("textarea");
cursorManager.setEndOfContenteditable(editableDiv)
Point by point explanation :
$('#textarea').keypress(function(event) {
event.preventDefault();
var KerningRandom = Math.floor((Math.random() * 90));
if ($("#last").length > 0)
{
var previousLast = $("#textarea #last").html();
$("#textarea #last").remove();
}
else
var previousLast = "";
$("#textarea").html($("#textarea").html() + previousLast + "<span id='last'>" + String.fromCharCode(event.which) + "</span>")
$("#last").css('margin-left', KerningRandom + "px");
var editableDiv = document.getElementById("textarea");
cursorManager.setEndOfContenteditable(editableDiv)
});
The event.preventDefault() prevent the letter to be added when pressing a key.
Then, we calculate our left margin value, save the previous last letter we had and remove the span that contains the last letter as it's not the last letter anymore.
We append the previous last letter , and the span that has a random left margin (to simulate the kerning) and the value of the pressed key (thanks to
How to find out what character key is pressed?) to the actual content.
After that, we needed to move the carret at the end of the textarea manually, because it would stay at the beginning otherwise.
For that, I used the code from
How to move cursor to end of contenteditable entity so goes there for explanation.

How to replace selected text in a textarea with Javascript?

I have a textarea and a button which adds the following text to the textarea:
" - List Item "
If there is some text which is selected in the textarea, I would rather the text added to appear as so:
" - (selected text) "
So, the way to go about this would be to use an if function to see if there is text selected within the textarea and then if that is true, then receive the highlighted text so that it can be appended to the text in the textarea.
The appending part can simply be done by using document.getElementById(textarea).value += string but I'm unsure on checking if some of the text in the textarea is selected and receiving it.

For non IE browsers you can do something like this using selectionStart and SelectionEnd properties of textarea object:
function createListElement() {
if(document.activeElement === textarea) {
if(typeof textarea.selectionStart == 'number' && typeof textarea.selectionEnd == 'number') {
// All browsers except IE
var start = textarea.selectionStart;
var end = textarea.selectionEnd;
var selectedText = textarea.value.slice(start, end);
var before = textarea.value.slice(0, start);
var after = textarea.value.slice(end);
var text = before + '- ' + selectedText + after;
textarea.value = text;
}
}
}
But such a trivial manipulation is getting much harder for IE, you can find more here.
I hope this will help you :)

javascript not changing the text color

I have a function that I want to change the font color of the user entered string if it is equal to a certain word located in an array.. So far when I step through it it says that it changes the font color but it actually never updates it to the screen and I don't know why. Here is what I have so far
function getLastWord() {
var input = document.getElementById("my_text");
//var input = document.getElementById(textArea.value);
//var lineIn = document.getElementById(my_text).innerHTML;
var inputValue = input.value;
var lastWordTyped
var changeColorOfWord;
if (input == null) {
input == " ";
}
//lastWordTyped = input.substr(input.trim().lastIndexOf(" ") + 1);
lastWordTyped = inputValue.substr(inputValue.trim().lastIndexOf(" ") + 1);
if (input != null) {
for (var i = 0; i < reservedKeyWords.length; i++) {
if (reservedKeyWords[i] === lastWordTyped) {
lastWordTyped = lastWordTyped.fontcolor("blue");
my_text.replace(inputValue, lastWordTyped);
} else {
}
}
}
}

I see two issues with the code thus far.
You are using 'fontcolor("blue")' parameter on the lastWordTyped. The proper syntax to change color is element.style.color="#CCC".
You will need to wrap the last typed word in a span so you can target it and apply the color to just that word.

string.fontcolor is legacy, and should not be used even though I could see it as a viable option in this case
Essentially, what you are doing is adding font tags around the word:
var txt = 'hello world';
txt = txt.fontcolor('blue');
//txt = '<font color="blue">hello world</font>';
You do not show what you do with the result, but if you actually put it in an HTML element it should work, even though instead of using fontcolor, I'd rather use element.style.color. This would require slightly more work though:
var ele = document.querySelector('#my_text');
ele.style.color = 'blue';
ele.innerHTML = lastWordTyped;
If you still want to go with the .fontcolor method, you could just keep what you have in the question and add
input.innerHTML = my_text;

How to wrap highlighted text with a span and place a div positioned relative to it in javascript?

My end goal is for the user to be able to :
select text from a paragraph
wrap the text in a span
place an action button / div at the end of the selection that they could click to take further action
Here is my code so far:
function Discussion(){
var $this = this;
$(document).bind("mouseup",function(){
$this.selectText($this);
});
}
Discussion.prototype.selectText = function($this){
var selection = $this.getSelectedText();
if(selection.length > 3){
console.log(selection);
var spn = '<span class="selected">' + selection + '</span>';
$(this).html($(this).html().replace(selection, spn));
//ERROR here; it says that it can't replace() on undefined $(this).html()
}
}
Discussion.prototype.getSelectedText = function(){
if(window.getSelection){
return window.getSelection().toString();
}
else if(document.getSelection){
return document.getSelection();
}
else if(document.selection){
return document.selection.createRange().text;
}
}
As you might expect, so far I can get the text of the selection with window.getSelection().toString(). If I remove the .toString(), I get a Selection object. With this I can use window.getSelection().anchorNode.parentNode to get most of the information I need.
I also see that Selection.anchorOffset and Selection.extentOffset will give me the range of characters I've selected. Is there a way I can use this information to place the span?
I guess my questions would be:
Why isn't this code wrapping the selection in divs?
Will this fail with multiple instances of the same text?
After wrapping the selection with a span or inline-block div or something, will I be able to get (and use) its position for positioning an additional button / div?
Phew, thanks for your time!
Edit: I added a JS fiddle here : http://jsfiddle.net/nn62G/

I'm going to post my js fiddle here with the solution for posterity. Thanks for all the help, everyone!
http://jsfiddle.net/prodikl/mP8KT/
function Discussion(){
var $this = this;
$(document).bind("mouseup",function(){
$this.selectText($this);
});
}
Discussion.prototype.selectText = function($this){
$("mark").contents().unwrap();
$("mark").remove();
var selection = $this.getSelection();
var range = selection.getRangeAt(0);
var cssclass = $(selection.anchorNode.parentNode).attr("class");
if(selection.toString().length > 2){
$this.startPoint = selection.anchorOffset;
$this.endPoint = selection.extentOffset;
var newNode = document.createElement("mark");
range.surroundContents(newNode);
$("mark").attr('title', ' ');
$("mark").tooltip({
content : "<a class='content' href='http://www.google.com' target='_blank'>Here's a link.</a>"
});
$("mark").on('mouseleave',function(event){
event.stopImmediatePropagation();
}).tooltip("open");
}
}
Discussion.prototype.getSelection = function(){
if(window.getSelection){
return window.getSelection();
}
else if(document.getSelection){
return document.getSelection();
}
else if(document.selection){
return document.selection.createRange().text;
}
}
var discussion = new Discussion();

The value returned by getSelectedText is a selection not an element in the DOM. That is why your cal to the html function is failing, selection has no such property.
You can do what you want as follows, set the part of the document you want to process as contentEditable for example a <p> or <div>. When you select within that area then you can get the HTML element using document.activeElement. If you select outside a contentEdiatble area then activeElement returns the body element. The activeElement you CAN process :
document.activeElement.innerHTML =
document.activeElement.innerHTML.replace (selection, spn);
However, if you make parts of your document editable other things happen which you may not want. More seriously, if the selected text occurs multiple times you cannot determine which one has actually been selected so this may not be a solution to your problem.
Updated fiddle here

Ok well, a possible solution could be to find the element that contains the current selection and replace it's html something like:
// this get's you all the elements (including the top parent) that contain the selection
var existsInElements = $('*:contains("' + selection + '")');
// the exact element match is in the last one
var exactElement = existsInElements[existsInElements.length - 1];
Here is a fiddle that works.