Replace specific word in contenteditable

Question

I have a contenteditable div

I need to get the last word from caret position and on certai

Answer 1

To work with Ranges we need to keep in mind that we are working with Nodes, not only the text that is rendered. The structure you want to manipulate is:

 <-- Element Node
    "some text" <-- TextNode

But it also could be:

 <-- Element Node
    "some text" <-- TextNode
    "more text" <-- TextNode
    "" <-- TextNode

To solve your problem is simplier to handle only one TextNode, I propose to use the normalize() function to join all of them into a single one.

Then you only need to set the Range to the word's bounds before deleteContents(). Once deleted, you can insert a new TextNode with the substitution using insertNode().

var wordStart = range.toString().lastIndexOf(lastWord);
var wordEnd = wordStart + lastWord.length;

/* containerEl.firstChild refers to the div's TextNode */                   
range.setStart(containerEl.firstChild, wordStart);
range.setEnd(containerEl.firstChild, wordEnd);
range.deleteContents();
range.insertNode(document.createTextNode(resultValue));

For this to work, you need that the text is in a single TextNode. But after ìnsertNode the div will contain multiple text nodes. To fix this simply call normalize() to join all TextNode elements.

containerEl.normalize();

Edit:

As Basj points out, the original solution fails for multiline. That's because when hitting ENTER the structure changes from:

 <-- Element Node
    "some text" <-- TextNode

to something like:

 <-- Element Node
    
"some text"
    
"more text"

I've updated this answer, but it's also worth to read Basj's answer at this question: Replace word before cursor, when multiple lines in contenteditable

JSFiddle demo or runnable code snippet:

document.getElementById('divTest').onkeyup = function (e) {
    if (e.keyCode == 32) {
        getWordPrecedingCaret(this);
    }
};

function getWordPrecedingCaret(containerEl) {
    var preceding = "",
        sel,
        range,
        precedingRange;
    if (window.getSelection) {
        sel = window.getSelection();
        if (sel.rangeCount > 0) {
            range = sel.getRangeAt(0).cloneRange();
            range.collapse(true);
            range.setStart(containerEl, 0);
            preceding = range.toString();
        }
    } else if ((sel = document.selection) && sel.type != "Control") {
        range = sel.createRange();
        precedingRange = range.duplicate();
        precedingRange.moveToElementText(containerEl);
        precedingRange.setEndPoint("EndToStart", range);
        preceding = precedingRange.text;
    }

    var words = range.toString().trim().split(' '),
        lastWord = words[words.length - 1];
        
    if (lastWord) {
        var resultValue = 'some'; // this value is coming from some other function
        if (resultValue == lastWord) {
            console.log('do nothing: ' + lastWord);
            // do nothing
        } else {
            console.log('replace word ' + lastWord);
            
            /* Find word start and end */
            var wordStart = range.endContainer.data.lastIndexOf(lastWord);
            var wordEnd = wordStart + lastWord.length;
            console.log("pos: (" + wordStart + ", " + wordEnd + ")");
                           
            range.setStart(range.endContainer, wordStart);
            range.setEnd(range.endContainer, wordEnd);
            range.deleteContents();
            range.insertNode(document.createTextNode(resultValue));
            // delete That specific word and replace if with resultValue

            /* Merge multiple text nodes */            
            containerEl.normalize();
        }
        return lastWord;
    }
}

Write words here and hit SPACE BAR