Disable the button depending on the value
In case we need to make a button available or disable it based on the value of a certain field in the list, Let's consider describing the buttons of an arbitrary list:
<metadata name="list" type="list" key="id">
<toolbar>
<toolbtn func="list.new" type="new" img="t-new" name="newelem" default="yes"/>
<toolbtn func="list.hide" type="new" img="t-lock" name="hideelem">
<show name="active" value="on"/>
</toolbtn>
<toolbtn func="list.show" type="new" img="t-lock" name="showelem">
<hide name="active" value="on"/>
</toolbtn>
</toolbar>
...
</metadata>In this example, the showelem button will appear active for list items with the active column set to off. And hideelem for those with the value on.