Extension:Semantic Forms Select

The Semantic Forms Select extension generates a select form element which option values are from semantic query or parser function. Semantic Forms provides useful input type for select elements such as dropdown, combobox, and listbox. Their option values can be derived from a static list, pages in a category, concept, property's allowed values, etc. However, it is still limited. This extension provides these features
 * The option values for select element is from an SMW query or parser function.
 * If the SMW query or parser function is not parametrized, its optioned values are loaded at form generation time.
 * If the SMW query or parser function is parametrized, in another word, its values depend on another form field. Its values are loaded through ajax call when trigger field changes.

Usage
Two form fields are involved. The first one is the form field we are trying to define. It is termed as Select field. The second one is the field the Select field depends on. It is termed as Value field. A change of Value field will trigger the loading of Select field.

Query And Function parameters
The input type from this extension is SF_Select. Field parameters are shown in the table below.

Query And Function format
In the above example, the query is |format=list|sep=,|link=none|headers=hide|limit=5000. To avoid parsing and text transform, we have to convert [ to (, = to ~ and | to ; in the query.

Parser function follows the same rule. The parser function is ask in example above. We can of course use other valid parser function. To fit a parser function into field definition, Strip the at the beginning and the end of normal parser function format.

The result from query or parser function should be a list of string separated by comma.

Example 1: Static query
Values are retrieved when form is loaded.

Example 2: Static function
Values are retrieved when form is loaded. Here the getallusers is a custom parser function which gives all users in current installation.

Example 3: Parametrized query/function
The parameter is the special character string @@@@. In this example, the Select field is P2Protocols3. The Value field is Project1. Both Select field and Value field are in the same template since we have sametemplate in field definition. If Value field is from another template, the template parameter should be used. When Project1 field changes, the @@@@ will be replaced by the value of Project1's value. The query is then sent to server through ajax call. The results will be the option values for P2Protocols3 field. if the current template is multiple, the P2Protocols3 only depends on the Project1 in the same instance.

In this case above, when adding a property to be shown (Has Name) and an extra  parameter, the property value is shown instead of the resulting page name.

Parser functions can be parametrized in the same way. In this example, we list all users in the selected group of Group field.

In case the queried results contain a comma as a separator one has to choose another separator like e.g. an asterisk (*). Use it both in the query and in the parser fuction.

Example 4: rmdiv
In this example, the Endpoint field depends on P2Protocols4 field in study template. The current template is also a multiple template. Endpoint's value is reloaded after P2Protocols4 changes. After reloading, Endpoint may not have any selected values and it is left in an invalid state. In this case, we may want to automatically remove the current instance. This is what rmdir parameter is for.

Installation
The extensions Semantic MediaWiki and Page Forms are required for this extension to work.


 * To install this extension:
 * 1) Use composer:
 * 2) Add the following line to your "LocalSettings.php" file after invoking the extensions Semantic MediaWiki and Page Forms:
 * 3) Done!

Acknowledgement
This project was sponsored by BioTeam and flexdms.

For support, please send email to the user mailing list of Semantic Mediawiki.