Views Contextual Filter Validator: Regular Expression (regex)

About
Views Contextual Filter Validator: Regular Expression adds a Views contextual filter validator that can evaluate an argument based on user-supplied regular expression pattern.

Requirements
This module does not require any additional modules outside of Drupal core.

Installation
Install as you would normally install a contributed Drupal module. See: https://drupal.org/documentation/install/modules-themes/modules-8 for further information.

Configuration
The module has no menu or modifiable settings. There is no configuration.

Use
Add a Regular express (regex) validator to a View's contextual filter to use this module. E.g. --


* Create a new View with a page display.
* Add a contextual filter (Advanced -> Contextual Filters -> Add).
* From the "Add contextual filters" popup:
* Select "Global" from the Category menu.
* Enable the checkbox for the "Null" filter.
* Click Add and configure contextual filters.


* Under When the filter value IS available or a default is provided, select Specify validation criteria and set the following options:
* Validator: Regular expression (regex)
* Regular expression: /^\d{4}$/
* Action to take if filter value does not validate: Show Page not found


* Click Apply.
* Click Save for the full view.

This example ensures that the first contextual filter is exactly four digits. If the filter contains any non-digits or is not exactly four characters, the View page will give a "Page not found" error.