javascript - How to simulate typing in input field using jQuery?

Question

What I want is to simulate typing in <input> field using javascript.

I have the following code:

var press = jQuery.Event("keydown");
press.ctrlKey = false;
press.which = 65;
$("#test").trigger(press);

But when I load the page, the #test input field has no typed characters, the keycode of '65' represents 'A', but there is no 'A' input.

Basically what I want is to automatically typing in the website using Greasemonkey.

Please give me some ideas or some library with which I can use to do this.
Thanks a lot!

Answer 1

You can send key events, and anything listening for them will get them, but they will not change the input, so you will not see the letter A appear, for example. This is mostly a security thing; see "Manually firing events" for a discussion about that.

So, if you want the letter to appear, you must alter the input's value as you send the key event. There is a jQuery plugin for that, see "The $.fn.sendkeys Plugin".

You can see how an <input> reacts with user-applied keys, key events, and that plugin at this jsFiddle.

For reference, this is the key piece of code from that jsFiddle:

$("button").click ( function (zEvent) {
    if (zEvent.target.id == "simA_plain") {
        console.log ("Send Plain key event");
        var keyVal = 65;
        $("#eventTarg").trigger ( {
            type: 'keypress', keyCode: keyVal, which: keyVal, charCode: keyVal
        } );
    }
    else {
        console.log ("Use the Plugin to simulate a keystroke");
        $("#eventTarg").sendkeys ("B") ;
    }
} );

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That plugin should be sufficient if you are just trying to "simulate typing on an <input>". However, depending on what you are really trying to do, you may need to do one or more of the following:

1. Just set the text to what you want it to be.
2. Send a keydown event, if the page's javascript triggers off of that.
3. Likewise, send a change event, etc., if the page's javascript triggers off of that.
4. Just find and call the page's javascript directly. Use script injection, the location hack, unsafeWindow, and/or @grant none mode to do that.
5. Something else? State your true objective and link to the target page.