Custom Configuration with Unknown Number of Fields

Question

I've created my own module and custom configuration, and I want the user to be able to add as many fields as they need in the custom config.

Here's a mock up of what I'm after:

I want the user to be able to add as many users as they like to this list by clicking the Plus button.

Is this possible or is there a pattern I'm missing? I want the user to be able to add N sections, each following the pattern of taking in User Id and User Title so I hopefully end up with something like this JSON:

[{userId: 15, title: "Product Admin"}, {userId: 16, title: "Chat Moderator"}]

Thanks,
Harry

Answer 1

@Marius wrote a blog post about this

To sum this up, you need a new block:

<?php 
class Easylife_Configsection_Block_Adminhtml_System_Config_Form_Fieldset_Customer_Groups extends 
 Mage_Adminhtml_Block_System_Config_Form_Fieldset{
 protected $_dummyElement;
    protected $_fieldRenderer;
    protected $_values;

    public function render(Varien_Data_Form_Element_Abstract $element)
    {
        $html = $this->_getHeaderHtml($element);
 //here you cand loop through all the fields you want to add
 //for each element you neet to call $this->_getFieldHtml($element, $group);
        $groups = Mage::getModel('customer/group')->getCollection();

        foreach ($groups as $group) {
            $html.= $this->_getFieldHtml($element, $group);
        }
        $html .= $this->_getFooterHtml($element);

        return $html;
    }
    //this creates a dummy element so you can say if your config fields are available on default and website level - you can skip this and add the scope for each element in _getFieldHtml method
    protected function _getDummyElement()
    {
        if (empty($this->_dummyElement)) {
            $this->_dummyElement = new Varien_Object(array('show_in_default'=>1, 'show_in_website'=>1));
        }
        return $this->_dummyElement;
    }
    //this sets the fields renderer. If you have a custom renderer tou can change this. 
    protected function _getFieldRenderer()
    {
        if (empty($this->_fieldRenderer)) {
            $this->_fieldRenderer = Mage::getBlockSingleton('adminhtml/system_config_form_field');
        }
        return $this->_fieldRenderer;
    }
    //this is usefull in case you need to create a config field with type dropdown or multiselect. For text and texareaa you can skip it.
    protected function _getValues()
    {
        if (empty($this->_values)) {
            $this->_values = array(
                array('label'=>Mage::helper('adminhtml')->__('No'), 'value'=>0),
                array('label'=>Mage::helper('adminhtml')->__('Yes'), 'value'=>1),
            );
        }
        return $this->_values;
    }
    //this actually gets the html for a field
    protected function _getFieldHtml($fieldset, $group)
    {
        $configData = $this->getConfigData();
        $path = 'customer_groups_demo/demo/group_'.$group->getId();//this value is composed by the section name, group name and field name. The field name must not be numerical (that's why I added 'group_' in front of it)
        if (isset($configData[$path])) {
            $data = $configData[$path];
            $inherit = false;
        } else {
            $data = (int)(string)$this->getForm()->getConfigRoot()->descend($path);
            $inherit = true;
        }

        $e = $this->_getDummyElement();//get the dummy element

        $field = $fieldset->addField($group->getId(), 'select',//this is the type of the element (can be text, textarea, select, multiselect, ...)
            array(
                'name'          => 'groups[demo][fields][group_'.$group->getId().'][value]',//this is groups[group name][fields][field name][value]
                'label'         => $group->getCustomerGroupCode(),//this is the label of the element
                'value'         => $data,//this is the current value
                'values'        => $this->_getValues(),//this is necessary if the type is select or multiselect
                'inherit'       => $inherit,
                'can_use_default_value' => $this->getForm()->canUseDefaultValue($e),//sets if it can be changed on the default level
                'can_use_website_value' => $this->getForm()->canUseWebsiteValue($e),//sets if can be changed on website level
            ))->setRenderer($this->_getFieldRenderer());

        return $field->toHtml();
    }
}

And then you use it:

<frontend_model>configsection/adminhtml_system_config_form_fieldset_customer_groups</frontend_model>
<-- this is the model that renders all the fields -->

You can access the fields via:

$groupId = 1;
$val = Mage::getStoreConfig('customer_groups_demo/demo/group_'.$groupId);
//section_name/group/field