I was recently trying to write some tests for some Javascript code that looked something like this (using
prototype):
function watch_keys(evt) {
if ((evt.keyCode >= 32) && (evt.keyCode < 127)) {
//other work...
Event.stop(evt);
}
}
Event.observe(window, 'load', function() {
Event.observe($('some_input_id'), 'keypress', watch_keys);
}
I simplified it down to just the basics. This code is attaching a key press handler to an input field. If the key being pressed is a printable character then the handler will do some work on it and then stop its propagation. The work being done isn't to important.
My initial attempts at testing this using
Watir (version 1.5.3) used the set method didn't work. The key press event was fired but it never activated the code because regardless of what character was sent the key code was always 0.
No big deal, I decided to use the send_keys method of Watir::IE. Using this method I was able to craft some code that worked some of the time. It turned out that it never worked on our CI system and it was very sensitive to any screen/mouse movement that occurred on the PC that was running the tests. I've experienced the same problems using send_keys in the past and this wasn't going to work for the long term.
Digging into the Watir source and why the set method didn't work revealed this code at the heart of the set method (input_elements.rb):
def doKeyPress(value)
value = limit_to_maxlength(value)
for i in 0 .. value.length - 1
sleep @container.typingspeed
c = value[i,1]
@o.value = @o.value.to_s + c
@o.fireEvent("onKeyDown")
@o.fireEvent("onKeyPress")
@o.fireEvent("onKeyUp")
end
end
Not very hard to see why this doesn't work with any event handlers that are actually checking key codes.... Though the key press event is fired it doesn't have any event information in it. I'm guessing that by default IE will generate an event with a 0 key code if nothing was provided.
I ended up monkey patching IE with a custom implementation of send keys that seems to work for my purposes.
module Watir
class IE
def run_script(js)
ie.Document.parentWindow.execScript(js)
end
def send_some_keys(ele, text)
ele.focus
run_script("var wtr_evt=document.createEventObject();"+
"var wtr_ele=$('#ele.id}');");
text.scan(/./) do |char|
run_script("wtr_evt.keyCode='#{char}'.charCodeAt(0);"+
"wtr_ele.fireEvent('onkeypress', wtr_evt);");
end
end
end
This code injects several pieces of JavaScript into the DOM. It creates new event object which represents the key stroke that is incoming. It then manually fires the event on the element in question.
Note that the element must have a valid ID to work and that the injected JavaScript uses the a Prototype method to locate the element. It shouldn't be hard to customize the code to work with pure JavaScript methods or a different event type.
So far it is working well in development and CI environments.
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