How to get selected text from a textbox control with JavaScript

Viewed 73452

I have a textbox and a link button. When I write some text, select some of it and then click the link button, the selected text from textbox must be show with a message box.

How can I do it?


When I click the submit button for the textbox below, the message box must show Lorem ipsum. Because "Lorem ipsum" is selected in the area.


If I select any text from the page and click the submit button it is working, but if I write a text to textbox and make it, it's not. Because when I click to another space, the selection of textbox is canceled.

Now problem is that, when I select text from textbox and click any other control or space, the text, which is selected, must still be selected.

How is it to be done?

6 Answers

OK, here is the code I have:

function ShowSelection()
{
  var textComponent = document.getElementById('Editor');
  var selectedText;

  if (textComponent.selectionStart !== undefined)
  { // Standards-compliant version
    var startPos = textComponent.selectionStart;
    var endPos = textComponent.selectionEnd;
    selectedText = textComponent.value.substring(startPos, endPos);
  }
  else if (document.selection !== undefined)
  { // Internet Explorer version
    textComponent.focus();
    var sel = document.selection.createRange();
    selectedText = sel.text;
  }

  alert("You selected: " + selectedText);
}

The problem is, although the code I give for Internet Explorer is given on a lot of sites, I cannot make it work on my copy of Internet Explorer 6 on my current system. Perhaps it will work for you, and that's why I give it.

The trick you look for is probably the .focus() call to give the focus back to the textarea, so the selection is reactivated.

I got the right result (the selection content) with the onKeyDown event:

document.onkeydown = function (e) { ShowSelection(); }

So the code is correct. Again, the issue is to get the selection on click on a button... I continue to search.

I didn't have any success with a button drawn with a li tag, because when we click on it, Internet Explorer deselects the previous selection. The above code works with a simple input button, though...

For Opera, Firefox and Safari, you can use the following function:

function getTextFieldSelection(textField) {
    return textField.value.substring(textField.selectionStart, textField.selectionEnd);
}

Then, you just pass a reference to a text field element (like a textarea or input element) to the function:

alert(getTextFieldSelection(document.getElementsByTagName("textarea")[0]));

Or, if you want <textarea> and <input> to have a getSelection() function of their own:

HTMLTextAreaElement.prototype.getSelection = HTMLInputElement.prototype.getSelection = function() {
    var ss = this.selectionStart;
    var se = this.selectionEnd;
    if (typeof ss === "number" && typeof se === "number") {
        return this.value.substring(this.selectionStart, this.selectionEnd);
    }
    return "";
};

Then, you'd just do:

alert(document.getElementsByTagName("textarea")[0].getSelection());
alert(document.getElementsByTagName("input")[0].getSelection());

for example.

// jQuery
var textarea = $('#post-content');
var selectionStart = textarea.prop('selectionStart');
var selectionEnd = textarea.prop('selectionEnd');
var selection = (textarea.val()).substring(selectionStart, selectionEnd);

// JavaScript
var textarea = document.getElementById("post-content");
var selection = (textarea.value).substring(textarea.selectionStart, textarea.selectionEnd);
Related