CODEWITHSUNDEEP
jqueryhtmldom
Georg Schölly
Georg Schölly

Reputation: 126135

How can I modify pasted text?

Is it possible to intercept and modify text that gets pasted into a textarea?

If intercepting isn't possible, can I modify it after being pasted? (Without modifying the already present text in the textarea.)

Upvotes: 4

Views: 10497

Answers (4)

Avatar
Avatar

Reputation: 15186

You prevent the default paste of the browser using event.preventDefault();.

Then you read the clipboard data.

Then you modify the clipboard data and paste it yourself setting the textarea (or input) value.

    <textarea id="myTextarea" placeholder="Paste text here..."></textarea>

    <script>
        document.getElementById('myTextarea').addEventListener('paste', function (event) 
        {
            // Prevent the default paste behavior
            event.preventDefault();

            // Get the clipboard data
            const clipboardData = (event.clipboardData || window.clipboardData);
            let pastedText = clipboardData.getData('text/plain');

            // Modify the pasted text as needed
            // Example: Convert to uppercase
            pastedText = pastedText.toUpperCase(); 

            // Insert the modified text into the textarea
            let textarea = event.target;
            let currentText = textarea.value;
            let selectionStart = textarea.selectionStart;
            let selectionEnd = textarea.selectionEnd;

            const newText = currentText.slice(0, selectionStart) + pastedText + currentText.slice(selectionEnd);

            textarea.value = newText;
        });
    </script>

Upvotes: 1

Carlos
Carlos

Reputation: 840

With jQuery:

    jQuery(function($){
      $('#your_element').bind('paste', function(event){
        event.preventDefault();
        var clipboardData = event.originalEvent.clipboardData.getData('text/plain');
        console.log(clipboardData);
      }); 
     }      
    });

Works in IE and Webkit. With Firefox you might have to use this:

http://intridea.com/2007/12/16/faking-onpaste-in-firefox?blog=company

Upvotes: 1

user396404
user396404

Reputation: 2819

The best way I know of how to do this is to wait for the content to the text field to be pasted then wait for a keyup or a keydown trigger. This is shown in the code below:

<script language="javascript">

function testfunction()
{

 // This function will execute whenever the content of 

}
</script>

<textarea onkeyup="testfunction()" onkeydown="testfunction()"></textarea>

If you want to monitor a textarea for any changes, the following code would do that. It checks the value of the textarea every 1/10th of a second for any updates.

<textarea id="testfield"></textarea>

<script language="javascript">

var textarea = document.getElementById('testfield');
var textval = '';

function monitor()
{

 if(textval != textarea.value)
 {

  textval = textarea.value;
  testfunction();

 }

 setTimeout('monitor()', 100);

}

function testfunction()
{

 // This function will get executed whenever the value of the text area is altered (at most within 1/10th of a second)

}

monitor();
</script>

In both cases, you can modify the value of the textarea when testfunction() then update the value of the textarea with the updated value.

Upvotes: 0

aularon
aularon

Reputation: 11110

Maybe intercept keypresses, to know when CTRL+C is pressed, cache current text, then at CTRL+C's keyup, check current value against cached one, with simple text processing you can know the new text, and do whatever you want with, and update accordingly.

Upvotes: 1

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