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javascriptappenddynamically-generatedcodemirror

Dynamically Append DIV into CodeMirror (Without Replacing Initial Code)

I can dynamically embed a DIV into CodeMirror like so. However I don't want my initial code replaced with the following. Is there anyway I can append this without it clearing my initial code?

Example - http://liveweave.com/nJthjR

$("a#div").click(function() {
    editor.setValue('<div class="gendiv">gendiv</div>');
});

JavaScript

var delay;

// Initialize CodeMirror editor
var editor = CodeMirror.fromTextArea(document.getElementById('code'), {
    mode: 'text/html',
    tabMode: 'indent',
    lineNumbers: true,
    lineWrapping: true,
    autoCloseTags: true
});

// Live preview
editor.on("change", function() {
    clearTimeout(delay);
    delay = setTimeout(updatePreview, 300);
});

function updatePreview() {
    var previewFrame = document.getElementById('preview');
    var preview =  previewFrame.contentDocument ||  previewFrame.contentWindow.document;
    preview.open();
    preview.write(editor.getValue());
    preview.close();
}
setTimeout(updatePreview, 300);

Full Code

<!Doctype html>
<html>
<head>
<meta charset="utf-8">
<title>CodeMirror: HTML5 preview</title>
<script src=http://codemirror.net/lib/codemirror.js></script>
<script src=http://codemirror.net/mode/xml/xml.js></script>
<script src=http://codemirror.net/mode/javascript/javascript.js></script>
<script src=http://codemirror.net/mode/css/css.js></script>
<script src=http://codemirror.net/mode/htmlmixed/htmlmixed.js></script>
<link rel=stylesheet href=http://codemirror.net/lib/codemirror.css>
<link rel=stylesheet href=http://codemirror.net/doc/docs.css>
<style type=text/css>
.CodeMirror {
    float: left;
    width: 50%;
    border: 1px solid black;}

iframe {
    width: 49%;
    float: left;
    height: 300px;
    border: 1px solid black;
    border-left: 0px;}
</style>
</head>
<body>
<h1>CodeMirror: HTML5 preview</h1>
<textarea id=code name=code><!doctype html>
<html>
  <head>
    <meta charset=utf-8>
    <title>HTML5 canvas demo</title>
    <style>p {font-family: monospace;}</style>
  </head>
  <body>
    <p>Canvas pane goes here:</p>
    <canvas id=pane width=300 height=200></canvas>
    <script>
      var canvas = document.getElementById('pane');
      var context = canvas.getContext('2d');

      context.fillStyle = 'rgb(250,0,0)';
      context.fillRect(10, 10, 55, 50);

      context.fillStyle = 'rgba(0, 0, 250, 0.5)';
      context.fillRect(30, 30, 55, 50);
    </script>
  </body>
</html></textarea>
    <iframe id=preview></iframe>
    <a href="#my-header" onclick='DivGen()'>Generate DIV</a>

<script>
var delay;

// Initialize CodeMirror editor
var editor = CodeMirror.fromTextArea(document.getElementById('code'), {
    mode: 'text/html',
    tabMode: 'indent',
    lineNumbers: true,
    lineWrapping: true,
    autoCloseTags: true
});

// Live preview
editor.on("change", function() {
    clearTimeout(delay);
    delay = setTimeout(updatePreview, 300);
});

function updatePreview() {
    var previewFrame = document.getElementById('preview');
    var preview =  previewFrame.contentDocument ||  previewFrame.contentWindow.document;
    preview.open();
    preview.write(editor.getValue());
    preview.close();
}
setTimeout(updatePreview, 300);

function destroyClickedElement(event) {
    document.body.removeChild(event.target);}

function DivGen() {
    editor.setValue('<div class="gendiv">gendiv</div>');}
</script>
</body>
</html>
Solution

  • Use replaceRange():

    function DivGen() { 
    editor.replaceRange(
        '<div class="gendiv">gendiv</div>\n', {line: 9,ch: 0}, {line: 9,ch: 0});
}

    You can also base that on cursor location: 

    function DivGen() {
    editor.replaceRange(
        '<div class="gendiv">gendiv</div>\n', editor.getCursor());
}