How get the zk element id from js

Question

I am working with ZK and I want to get the id of the a zk element from js. I have used differents ways:

Declaring the component like native html and it gets the id from js but it isn't correct. I have declared the element using the html tags of ZK but isn't correct too. I have seen some functions like Component.getFellow('component_name') and finally I have read about the UUID and use some example codes but I can't the element id for example:

<label id=titleBook/>

from javaScript.

any idea? Thank you.

Answer 1

The problem you're running into is that the id you assign an element in ZUL (ZK markup) is not one-to-one with the rendered DOM element id. ZK does this for a number of reasons, but the take away is that you need to reference the DOM elements without knowing their id.

ZK makes this easy by giving you a JavaScript framework also, they refer to it as 'Client Side Programming' a lot.

Have a look at ZK's documentation on Client Side Programming, specifically the paragraph on "How to Get Widget Reference in JavaScript".

Here you'll see that the ZK JavaScript APIs provide

<zk xmlns:w="http://www.zkoss.org/2005/zk/client">
    <label id="titleBook"/>
    <button label="button"
            w:onClick="this.$f('titleBook').setValue('sean is cool')" />
</zk>

Note that I am defining the w namespace to be ZK's client library just to fire the client side onClick event where I have access to this, the Button widget.

It sounds like you are probably working in vanilla JS would do something more like..

<zk>
    <script defer="true">
        jq("$titleBook").css('color', 'green');
        zk("$titleBook").setValue('sean is cool');
    </script>
    <label id="titleBook"/>
</zk>

Here we're leveraging the jq() and zk() globals in the ZK JavaScript APIs. The former is just jQuery's $() and the latter is the ZK counterpart. The difference is that the jQuery function returns a jQuery object while the latter returns a ZK widget. Both are extended to support the new $ CSS style selector which references the ZK widget id (what you assigned in ZUL/Java).