This is a little hacky, but it's how I did it. I have a bunch of forms that I wanted to force the user to unlock in order to edit (to prevent accidental edits). The gist of it is using jquery.find to loop through a collection of DOM elements with the selector and call a function on them.
This is the function that the form onLoad calls to make sure all the field elements are disabled initially:
function disableForm(which) {
var form = $('#' + which + '_Form');
var btn = $('#' + which + '_Toggle');
var lock = $('#' + which + '_Locked');
btn.linkbutton({
text: 'Unlock <span class="offset-up" uk-icon="icon:lock"></span>'
});
lock.val(1);
form.find('.easyui-textbox').each(function() {
$(this).textbox('readonly', true);
});
form.find('.easyui-combobox').each(function() {
$(this).combobox('readonly', true)
});
form.find('.easyui-datebox').each(function() {
$(this).datebox('readonly', true)
});
form.find('.easyui-numberbox').each(function() {
$(this).numberbox('readonly', true)
});
}