Allowed Values Function

(and "Default value function" too!)

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This module allows you to populate a list field's options (and default value(s)) with the results of calling a custom function.

Once enabled, in the Field UI, add a new list (ex: List (text)). You will now see a box to enter a value for "Allowed values function". Likewise you can enter a function name for "default_value_function". These should be a function name only (no parenthesis), which returns an associative array of values.

Usage

On the Configure field screen you will see a new box for the Allowed values function. Let's say you enter "my_module_test":

Allowed values function: my_module_test

Then, in your module your function should look like so, including the expected arguments:

function my_module_test($field, $instance, $entity_type, $entity = NULL, $cacheable = FALSE) {
  return ['a' => 'Apple', 'ban' => 'Banana'];
}

To configure a Default value function, on the Configure field screen:

Default value function: my_module_get_default

Then, in your module, the function should look like so (notice the expected arguments are different!)

function my_module_get_default($entity_type, $entity, $field, $instance, $langcode) {
  return array(
                0 => array('value' => "my_value_goes_here")
               );
}

Take note of what is being returned; it is not a simple value, but rather a nested array.

Installation

• Install this module using the official Backdrop CMS instructions at https://backdropcms.org/guide/modules

Current Maintainers

• Richard Peacock (original creator for Backdrop CMS)
• Seeking additional maintainers.

License

This project is GPL v2 software. See the LICENSE.txt file in this directory for complete text.