How can I add an object to a form?

Question

How can I add an object to a form array to make it available to make it available to the hook_form_alter() implementations?

I have an object I pass to a form, which may have new property. I would like to implement hook_form_alter() in another module to add/change form items based on that property.

There is no need for the item to be available after submission. I would like to avoid the overhead of using a value form element.

Answer 1

You don't have to add the entire object to the $form array: You can just add the property you need to share with the hook_form_alter() implementations, for example with the following code.

$form['#mymodule_new'] = $object->new;

You don't have to worry about adding overhead because the values submitted in a form are transient by design. This means that, if none of the submission handlers store the submitted values, they will be lost anyway.