SproutCMS

source of /sprout/Helpers/DisplayConditions/DisplayCondition.php

<?php
/*
 * Copyright (C) 2017 Karmabunny Pty Ltd.
 *
 * This file is a part of SproutCMS.
 *
 * SproutCMS is free software: you can redistribute it and/or modify it under the terms
 * of the GNU General Public License as published by the Free Software Foundation, either
 * version 2 of the License, or (at your option) any later version.
 *
 * For more information, visit <http://getsproutcms.com>.
 */
 
namespace Sprout\Helpers\DisplayConditions;
 
 
/**
 * Base class for display conditions
 *
 * This is known as the Context Engine, and is a set of display rules which affect
 * which widgets (content blocks) are shown or hidden on the page
 */
abstract class DisplayCondition
{
 
    /**
     * Return the list of operators for the condition value
     * Common values would be 'equals', 'not equals', 'less than', 'contains', etc
     *
     * @return array Key is internal value (e.g. '=') and value is the label (e.g. 'Equals')
     */
    abstract public function getOperators();
 
 
    /**
     * Return the type of parameter for UI display
     * Only two types are supported - 'text' or 'dropdown'
     *
     * @return string
     */
    abstract public function getParamType();
 
 
    /**
     * Return the available values for dropdowns
     *
     * @return array Key is internal value (e.g. 'desktop') and value is the label (e.g. 'Desktop')
     */
    public function getParamValues()
    {
        return [];
    }
 
 
    /**
     * Does a given condition match?
     *
     * @param array $env Environment, such as page id etc
     * @param string $op string One of the keys from the array returned by {@see DisplayCondition::getOperators}
     * @param string $val string Entered value OR one of the keys from {@see DisplayCondition::getParamValues}
     * @return bool True of condition matches, false if it does not
     */
    abstract public function match(array $env, $op, $val);
 
}