Develop Reference

Simulate cut function with JavaScript?

I'm working on a chrome extension and I want to do something with the text that is selected (highlighted by the user) on the page. For that, I need a way to remove the selected text, for example text inside an input field.
I found a way to "clear" the selected text, meaning it will be unselected:
Clear Text Selection with JavaScript But it doesn't seem to be what I'm looking for.
This just removes the highlighting from the text:
window.getSelection().empty();
I want to remove the text that is selected, if it's editable text. Is this possible with JavaScript?

You can use the deleteFromDocument method:
window.getSelection().deleteFromDocument()
This will immediately remove the selected content from the document, and as such also clear the selection.
As described formally in the MDN web docs:
The deleteFromDocument() method of the Selection interface deletes the selected text from the document's DOM.
If you'd like to be able to delete text from input elements instead, you need to use different APIs:
var activeEl = document.activeElement;
var text = activeEl.value;
activeEl.value = text.slice(0, activeEl.selectionStart) + text.slice(activeEl.selectionEnd);
Edit from me, Synn Ko: to cover input fields, textareas and contenteditables, use this:
var selection = window.getSelection();
var actElem = document.activeElement;
var actTagName = actElem.tagName;
if(actTagName == "DIV") {
var isContentEditable = actElem.getAttribute("contenteditable"); // true or false
if(isContentEditable) {
selection.deleteFromDocument();
}
}
if (actTagName == "INPUT" || actTagName == "TEXTAREA") {
var actText = actElem.value;
actElem.value = actText.slice(0, actElem.selectionStart) + actText.slice(actElem.selectionEnd);
}

JavaScript selected text entirely within node

I'm looking into text selection and ranges in JavaScript.
I need to get any nodes that surround the selected text exactly, for example:
<div>this is <span>some simple</span> text</div>
When the user selects the words 'some simple' i need to know that it sits entirely within the node .
Yet if they select just 'some' then this is not entirely within the node as the word 'simple' is NOT selected.
The end requirement is to be able to amend the class on the node only if the whole text within the node is selected.
jquery is also viable. thanks
To add some more context to this, when a user selects some text we add some sytling to it, let's say 'bold'. the user can edit the text in the parent div as often as they wish so each edit could add a new span enclosing the selected text. We could end up with something like this:
<div><span class="text-bold">Hi</span>, <span class="text-red">this <span class="text-italic">is</span></span> a sample text item</div>
So the spans can come and go dependant on what the user wants.

You are looking to get the DOM each time. So you can set id to your HTML Element Objects and get the value from them. For example:
<span id="f_span">some simple</span>
<script>
var x = document.getElementById("f_span");
</script>
Then you can check if x value equals with the value that user had selected.

You can use setInterval to get the selected text every x second. With the joined function you can get the selected text.
For the selection of user :
function getSelected() {
if(window.getSelection) { return window.getSelection(); }
else if(document.getSelection) { return document.getSelection(); }
else {
var selection = document.selection && document.selection.createRange();
if(selection.text) { return selection.text; }
return false;
}
return false;
}
It return an object that give you the offset of the selection. If result.anchorOffset = 0 and result.focusOffset = result.anchorNode.length (if it start at the begining of the node and it have the length of the whole node), then the user selected all your node.

Thanks for your replies, it allowed me to cobble together my solution:
function applyTextFormatClass(className) {
var selection = getSelected();
var parent = selection.getRangeAt(0).commonAncestorContainer; //see comment and link below
if (parent.nodeType !== 1) {
parent = parent.parentNode; //we want the parent node
}
var tagText = parent.innerText;
var selectText = selection.toString();
if (tagText.length !== selectText.length) {
addNodeAroundSelectedText(selection, className); //create new node
} else {
addClass(parent, className); //add class to existing node
}
}
commonAncestorContainer: https://developer.mozilla.org/en-US/docs/Web/API/Range/commonAncestorContainer

Replace text with link with chrome extension

I am trying to replace text on a webpage with links. When I try this it just replaces the text with the tag and not a link. For example this code will replace "river" with:
asdf
This is what I have so far:
function handleText(textNode)
{
var v = textNode.nodeValue;
v = v.replace(/\briver\b/g, 'asdf');
textNode.nodeValue = v;
}

If all you wanted to do was change the text to other plain text, then you could change the contents of the text nodes directly. However, you are wanting to add an <a> element. For each <a> element you want to add, you are effectively wanting to add a child element. Text nodes can not have children. Thus, to do this you have to actually replace the text node with a more complicated structure. In doing so, you will want to make as little impact on the DOM as possible, in order to not disturb other scripts which rely on the current structure of the DOM. The simplest way to make little impact is to replace the text node with a <span> which contains the new text nodes (the text will split around the new <a>) and any new <a> elements.
The code below should do what you desire. It replaces the textNode with a <span> containing the new text nodes and the created <a> elements. It only makes the replacement when one or more <a> elements need to be inserted.
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 <script> or <style>.
return;
}
let origText = textNode.textContent;
let newHtml=origText.replace(/\briver\b/g,'asdf');
//Only change the DOM if we actually made a replacement in the text.
//Compare the strings, as it should be faster than a second RegExp operation and
// lets us use the RegExp in only one place for maintainability.
if( newHtml !== origText) {
let newSpan = document.createElement('span');
newSpan.innerHTML = newHtml;
textNode.parentNode.replaceChild(newSpan,textNode);
}
}
//Testing: Walk the DOM of the <body> handling all non-empty text nodes
function processDocument() {
//Create the TreeWalker
let treeWalker = document.createTreeWalker(document.body, NodeFilter.SHOW_TEXT,{
acceptNode: function(node) {
if(node.textContent.length === 0) {
//Alternately, could filter out the <script> and <style> text nodes here.
return NodeFilter.FILTER_SKIP; //Skip empty text nodes
} //else
return NodeFilter.FILTER_ACCEPT;
}
}, false );
//Make a list of the text nodes prior to modifying the DOM. Once the DOM is
// modified the TreeWalker will become invalid (i.e. the TreeWalker will stop
// traversing the DOM after the first modification).
let nodeList=[];
while(treeWalker.nextNode()){
nodeList.push(treeWalker.currentNode);
}
//Iterate over all text nodes, calling handleTextNode on each node in the list.
nodeList.forEach(function(el){
handleTextNode(el);
});
}
document.getElementById('clickTo').addEventListener('click',processDocument,false);
<input type="button" id="clickTo" value="Click to process"/>
<div id="testDiv">This text should change to a link -->river<--.</div>
The TreeWalker code was taken from my answer here.

Replacing contenteditable characters on the fly with (or without) rangy

I'm working on a little experimental editor where I would like to visualize the time between typed characters. Therefore I'm using javascript and a contenteditable div to wrap every character with a SPAN and a timestamp attribute. I build a little function with the help of rangy:
function insertAtCursor(char, timestamp) {
var sel = rangy.getSelection();
var range = sel.rangeCount ? sel.getRangeAt(0) : null;
if (range) {
var el = document.createElement("span");
$(el).attr('time', timestamp);
el.appendChild(document.createTextNode(char));
range.insertNode(el);
range.setStartAfter(el);
rangy.getSelection().setSingleRange(range);
}
}
Now I'm facing two problems with this concept where I would appreciate some help:
a. With the above function the output ends in nested span's like seen here:
<span time="12345">a
<span time="12345">b
<span time="12345">c</span>
</span>
</span>
b. Even if I could get the above function running, a copy&paste or drag&drop action would possibly also end in some nested span's ... and I wonder if there is a way to avoid that at all?
Thanks,
Andreas

I'm not convinced this a good idea overall, particularly if the text could get large. A couple of improvements:
time should probably be data-time to validate as HTML5
you need to handle the case where some content is selected (adding range.deleteContents() would do).
However, if you are going to do this, I would suggest checking if the cursor is at the end of a text node inside an existing <span> and appending the new <span> after the text node's parent. Something like this:
Live demo: http://jsfiddle.net/kWL82/1/
Code:
function insertAtCursor(char, timestamp) {
var sel = rangy.getSelection();
var range = sel.rangeCount ? sel.getRangeAt(0) : null;
var parent;
if (range) {
var el = document.createElement("span");
$(el).attr('data-time', timestamp);
el.appendChild(document.createTextNode(char));
// Check if the cursor is at the end of the text in an existing span
if (range.endContainer.nodeType == 3
&& (parent = range.endContainer.parentNode)
&& (parent.tagName == "SPAN")) {
range.setStartAfter(parent);
}
range.insertNode(el);
range.setStartAfter(el);
rangy.getSelection().setSingleRange(range);
}
}

Tag-like autocompletion and caret/cursor movement in contenteditable elements

I'm working on a jQuery plugin that will allow you to do #username style tags, like Facebook does in their status update input box.
My problem is, that even after hours of researching and experimenting, it seems REALLY hard to simply move the caret. I've managed to inject the <a> tag with someone's name, but placing the caret after it seems like rocket science, specially if it's supposed work in all browsers.
And I haven't even looked into replacing the typed #username text with the tag yet, rather than just injecting it as I'm doing right now... lol
There's a ton of questions about working with contenteditable here on Stack Overflow, and I think I've read all of them, but they don't really cover properly what I need. So any more information anyone can provide would be great :)

You could use my Rangy library, which attempts with some success to normalize browser range and selection implementations. If you've managed to insert the <a> as you say and you've got it in a variable called aElement, you can do the following:
var range = rangy.createRange();
range.setStartAfter(aElement);
range.collapse(true);
var sel = rangy.getSelection();
sel.removeAllRanges();
sel.addRange(range);

I got interested in this, so I've written the starting point for a full solution. The following uses my Rangy library with its selection save/restore module to save and restore the selection and normalize cross browser issues. It surrounds all matching text (#whatever in this case) with a link element and positions the selection where it had been previously. This is triggered after there has been no keyboard activity for one second. It should be quite reusable.
function createLink(matchedTextNode) {
var el = document.createElement("a");
el.style.backgroundColor = "yellow";
el.style.padding = "2px";
el.contentEditable = false;
var matchedName = matchedTextNode.data.slice(1); // Remove the leading #
el.href = "http://www.example.com/?name=" + matchedName;
matchedTextNode.data = matchedName;
el.appendChild(matchedTextNode);
return el;
}
function shouldLinkifyContents(el) {
return el.tagName != "A";
}
function surroundInElement(el, regex, surrounderCreateFunc, shouldSurroundFunc) {
var child = el.lastChild;
while (child) {
if (child.nodeType == 1 && shouldSurroundFunc(el)) {
surroundInElement(child, regex, surrounderCreateFunc, shouldSurroundFunc);
} else if (child.nodeType == 3) {
surroundMatchingText(child, regex, surrounderCreateFunc);
}
child = child.previousSibling;
}
}
function surroundMatchingText(textNode, regex, surrounderCreateFunc) {
var parent = textNode.parentNode;
var result, surroundingNode, matchedTextNode, matchLength, matchedText;
while ( textNode && (result = regex.exec(textNode.data)) ) {
matchedTextNode = textNode.splitText(result.index);
matchedText = result[0];
matchLength = matchedText.length;
textNode = (matchedTextNode.length > matchLength) ?
matchedTextNode.splitText(matchLength) : null;
surroundingNode = surrounderCreateFunc(matchedTextNode.cloneNode(true));
parent.insertBefore(surroundingNode, matchedTextNode);
parent.removeChild(matchedTextNode);
}
}
function updateLinks() {
var el = document.getElementById("editable");
var savedSelection = rangy.saveSelection();
surroundInElement(el, /#\w+/, createLink, shouldLinkifyContents);
rangy.restoreSelection(savedSelection);
}
var keyTimer = null, keyDelay = 1000;
function keyUpLinkifyHandler() {
if (keyTimer) {
window.clearTimeout(keyTimer);
}
keyTimer = window.setTimeout(function() {
updateLinks();
keyTimer = null;
}, keyDelay);
}
HTML:
<p contenteditable="true" id="editable" onkeyup="keyUpLinkifyHandler()">
Some editable content for #someone or other
</p>

As you say you can already insert an tag at the caret, I'm going to start from there. The first thing to do is to give your tag an id when you insert it. You should then have something like this:
<div contenteditable='true' id='status'>I went shopping with <a href='#' id='atagid'>Jane</a></div>
Here is a function that should place the cursor just after the tag.
function setCursorAfterA()
{
var atag = document.getElementById("atagid");
var parentdiv = document.getElementById("status");
var range,selection;
if(window.getSelection) //FF,Chrome,Opera,Safari,IE9+
{
parentdiv.appendChild(document.createTextNode(""));//FF wont allow cursor to be placed directly between <a> tag and the end of the div, so a space is added at the end (this can be trimmed later)
range = document.createRange();//create range object (like an invisible selection)
range.setEndAfter(atag);//set end of range selection to just after the <a> tag
range.setStartAfter(atag);//set start of range selection to just after the <a> tag
selection = window.getSelection();//get selection object (list of current selections/ranges)
selection.removeAllRanges();//remove any current selections (FF can have more than one)
parentdiv.focus();//Focuses contenteditable div (necessary for opera)
selection.addRange(range);//add our range object to the selection list (make our range visible)
}
else if(document.selection)//IE 8 and lower
{
range = document.body.createRange();//create a "Text Range" object (like an invisible selection)
range.moveToElementText(atag);//select the contents of the a tag (i.e. "Jane")
range.collapse(false);//collapse selection to end of range (between "e" and "</a>").
while(range.parentElement() == atag)//while ranges cursor is still inside <a> tag
{
range.move("character",1);//move cursor 1 character to the right
}
range.move("character",-1);//move cursor 1 character to the left
range.select()//move the actual cursor to the position of the ranges cursor
}
/*OPTIONAL:
atag.id = ""; //remove id from a tag
*/
}
EDIT:
Tested and fixed script. It definitely works in IE6, chrome 8, firefox 4, and opera 11. Don't have other browsers on hand to test, but it doesn't use any functions that have changed recently so it should work in anything that supports contenteditable.
This button is handy for testing:
<input type='button' onclick='setCursorAfterA()' value='Place Cursor After <a/> tag' >
Nico