通过PHP触发javascript函数

Question

I'm trying to call a JavaScript function through PHP and have met some problems. I have got three code snippets for your understanding:

1) My javascript function:

function addPoints(radiobutton){
    //code
}

The parameter is an actual button and inside the function is a lot of code reading button value and name and taking care of checked status of the button.

2) My php-code creating the button looks like this. Notice that i send 'this' to the function.

echo "<input type=\"radio\" name=\"X\" value=\"Y\" onClick=\"addPoints(this)\"/>";

3) Finally I have this code at the very end of the document for triggering the javascript function when page is loaded.

echo "<SCRIPT LANGUAGE='javascript'>addPoints();</SCRIPT>";

If addPoints only consisted of an alert, this would work. But my problem is that I need to send an actual button as parameter to the function. I need both triggering the function on page load (to load some data from a database) and the normal button onClick-event.

Is there any solution for this if I don't use another server request to catch the desired button? It's important that I get the button created above (in fact I've got a lot of buttons, but let's think of is as one) and send it as parameter.

Answer 1

Give the button to pass to the function on load an id="initial_radio_button" attribute, and then make your last snippet:

echo "<script type='text/javascript'>addPoints(document.getElementById('initial_radio_button')‌​);</script>";