KnockoutJS: How to update view model after a user copy'n'paste into a text field?

Question

I am working on a website that auto populates search result in a table after user entered some text in the input text box (similar to google instant search).

I managed to get knockout js to update view model as user enters information by adding

valueUpdate: 'afterkeydown'

into my data-bind attribute, however, I also need to handle the case where user right click and paste some text into the textbox so I tried:

valueUpdate: ['afterkeydown','mouseup']

but that didn't work and when I tried to read the value of the text box through the view model I kept getting the old value until I tab out of the input text box.

Anyone know how can I fix this?

Oscar

Answer 1

You can use valueUpdate:'input'. I have testet it to work in Opera, Firefox and Chrome. I'm on a Linux box, so I can't test it in IE. Check this fiddle

UPDATE: I have now testet it in IE8, and it doesn't work. But using the following seems to work.

valueUpdate:['afterkeydown','propertychange','input']

Thanks to Michael Best for his comment about this :) I have updated the fiddle

UPDATE okt 2014: As kzh mention in a comment below, in one of the later versions of Knockout.js the textInput binding was added. This binding handles this scenario and has build in browser quirks handling http://knockoutjs.com/documentation/textinput-binding.html

Answer 2

New Way

Instead of:

data-bind="value: myValue, valueUpdate: ['input', 'textchange']"

One can now use the textInput binding:

data-bind="textInput: myValue"

From the documentation:

The textInput binding links a text box (<input>) or text area (<textarea>) with a viewmodel property, providing two-way updates between the viewmodel property and the element’s value. Unlike the value binding, textInput provides instant updates from the DOM for all types of user input, including autocomplete, drag-and-drop, and clipboard events.

Old Way

valueUpdate: ['afterkeydown','propertychange','input']

Does not work in IE9 if you want to support RightMouseClick → Delete or RightMouseClick → Cut.

The solution I came up with involves using jQuery and a jQuery plugin called jQuery Splendid Textchange. After you have both the jQuery and the plugin scripts loaded, you can happily use the 'textchange' event.

valueUpdate: 'textchange'

But, I may one day stop supporting bad browsers, so I have this:

valueUpdate: ['input', 'textchange']

Here is a fiddle I made for testing this and other events: http://jsfiddle.net/kaleb/w3ErR/

N.B. If you are using requirejs, jquery may have to be a hard dependency of knockout for this to work properly all the time.