Inserting text into an editable IFRAME at the caret position (IE)

I'm struggling with an actually straighforward problem: In Internet Explorer I want to insert plain text at the current caret position. This works really fine for simple TEXTAREA elements but it doesn't entirely work for editable IFRAMEs, which is what I have.

In the script I use I am creating a TextRange object from the document of the IFRAME which I use to paste the text as HTML at the cursor position.

<iframe id="editable">
  <html>
    <body>
      Some really boring text.
    </body>
  </html>
</iframe>
<script type="text/javascript">

    window.onload = function() {
        var iframe = document.getElementById('editable');
        var doc = iframe.contentDocument || iframe.contentWindow.document;

        doc.body.innerHTML = iframe.textContent || iframe.innerHTML;

        // Make IFRAME editable
        if (doc.body.contentEditable) {
            doc.body.contentEditable = true;
        } 
    }

    function insert(text) {
        var iframe = document.getElementById('editable');
        var doc = iframe.contentDocument || iframe.contentWindow.document;
        iframe.focus();
      if(typeof doc.selection != 'undefined') {
            var range = doc.selection.createRange();
            range.pasteHTML(text);
      }
}
</script>
<input type="button" value="Insert" onClick="insert('foo');"/>

When I select some text in the IFRAME, the selection will be replaced with "foo" - this is expected behaviour. But when I just place the caret somewhere in the text, the insertion won't work.

Is this common behaviour, as there is "no real selection" for the case that I just place the cursor somewhere or is it a bug with editable IFRAMEs in IE, since it works pretty well with simple TEXTAREA elements?

Is there a workaround?

You may find it works if you use onmousedown rather than onclick in your button.

UPDATE

The reason why this makes a difference is that the click event fires after the iframe has lost focus (which destroys a collapsed selection in IE) whereas mousedown fires before.

FURTHER UPDATE

You could also try fixing this in IE by saving/restoring the selected TextRange as the iframe loses/receives focus. Something like this should work:

function fixIframeCaret(iframe) {
    if (iframe.attachEvent) {
        var selectedRange = null;
        iframe.attachEvent("onbeforedeactivate", function() {
            var sel = iframe.contentWindow.document.selection;
            if (sel.type != "None") {
                selectedRange = sel.createRange();
            }
        });
        iframe.contentWindow.attachEvent("onfocus", function() {
            if (selectedRange) {
                selectedRange.select();
            }
        });
    }
}

window.onload = function() {
    var iframe = document.getElementById('editable');
    fixIframeCaret(iframe);
};

来源：https://stackoverflow.com/questions/5337752/inserting-text-into-an-editable-iframe-at-the-caret-position-ie

标签

javascript

internet-explorer

iframe

textrange