adminhtml fields dependency

Question

I'm learning the Magento form generation feature and I have an question related to system.xml file. Here's the code example:

 <days translate="label">
 <label>Days</label>
 <frontend_type>multiselect</frontend_type>
 <source_model>adminhtml/system_config_source_locale_weekdays</source_model>
 <sort_order>10</sort_order>
 <show_in_default>1</show_in_default>
 <show_in_website>1</show_in_website>
 <show_in_store>1</show_in_store>
 <comment>Days</comment>
 </days>
 <sunday translate="label">
 <label>Sunday</label>
 <frontend_type>multiselect</frontend_type>
 <source_model>xxx_xxx_Model_System_Config_Source_Hours</source_model>
 <sort_order>100</sort_order>
 <show_in_default>1</show_in_default>
 <show_in_website>1</show_in_website>
 <show_in_store>1</show_in_store>
 <comment>Hours in Sunday</comment>
 <depends>
 <days>0</days>
 </depends>
 </sunday>
 <monday translate="label">
 <label>Monday</label>
 <frontend_type>multiselect</frontend_type>
 <source_model>xxx_xxx_Model_System_Config_Source_Hours</source_model>
 <sort_order>110</sort_order>
 <show_in_default>1</show_in_default>
 <show_in_website>1</show_in_website>
 <show_in_store>1</show_in_store>
 <comment>Hours in Monday</comment>
 <depends>
 <days>1</days>
 </depends>
 </monday>

The source model returns list of hours - from 0 to 23.

Why when I select Sunday and Monday only Sunday dependency appears, but when I select only Monday, the Monday dependency appears as it should, but how to get working multiple dependences with multiselect field?

Answer 1

Why when I select Sunday and Monday only Sunday dependency appears, but when I select only Monday, the Monday dependency appears as it should

In PrototypeJS/JavaScript, $('multiselect').value will always return, in order of appearance, the first selected option only. This first selected option is then compared with the value given as dependecy:

• Sunday + Monday = Sunday
• Monday = Monday
• Monday + Tuesday + Wednesday = Monday

how to get working multiple dependences with multiselect field?

The only solution I can think of is replacing the original JavaScript function that is used to handle dependencies. Currently, it cannot determine multiple selected values.