| 1 |  |  | <?php | 
            
                                                                                                            
                            
            
                                    
            
            
                | 2 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 3 |  |  | namespace Saxulum\PaginationProvider\Twig; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 4 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 5 |  |  | use Saxulum\PaginationProvider\Helper\Processor; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 6 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 7 |  |  | class PaginationExtension extends \Twig_Extension | 
            
                                                                                                            
                            
            
                                    
            
            
                | 8 |  |  | { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 9 |  |  |     /** | 
            
                                                                                                            
                            
            
                                    
            
            
                | 10 |  |  |      * @var \Twig_Environment | 
            
                                                                                                            
                            
            
                                    
            
            
                | 11 |  |  |      */ | 
            
                                                                                                            
                            
            
                                    
            
            
                | 12 |  |  |     protected $environment; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 13 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 14 |  |  |     /** | 
            
                                                                                                            
                            
            
                                    
            
            
                | 15 |  |  |      * @var Processor | 
            
                                                                                                            
                            
            
                                    
            
            
                | 16 |  |  |      */ | 
            
                                                                                                            
                            
            
                                    
            
            
                | 17 |  |  |     protected $processor; | 
            
                                                                                                            
                                                                
            
                                    
            
            
                | 18 |  |  |  | 
            
                                                                        
                            
            
                                    
            
            
                | 19 |  |  |     public function __construct(Processor $processor) | 
            
                                                                        
                            
            
                                    
            
            
                | 20 |  |  |     { | 
            
                                                                        
                            
            
                                    
            
            
                | 21 |  |  |         $this->processor = $processor; | 
            
                                                                        
                            
            
                                    
            
            
                | 22 |  |  |     } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 23 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 24 |  |  |     /** | 
            
                                                                                                            
                            
            
                                    
            
            
                | 25 |  |  |      * {@inheritDoc} | 
            
                                                                                                            
                            
            
                                    
            
            
                | 26 |  |  |      */ | 
            
                                                                                                            
                            
            
                                    
            
            
                | 27 |  |  |     public function initRuntime(\Twig_Environment $environment) | 
            
                                                                                                            
                            
            
                                    
            
            
                | 28 |  |  |     { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 29 |  |  |         $this->environment = $environment; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 30 |  |  |     } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 31 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 32 |  |  |     /** | 
            
                                                                                                            
                            
            
                                    
            
            
                | 33 |  |  |      * {@inheritDoc} | 
            
                                                                                                            
                            
            
                                    
            
            
                | 34 |  |  |      */ | 
            
                                                                                                            
                            
            
                                    
            
            
                | 35 |  |  |     public function getFunctions() | 
            
                                                                                                            
                            
            
                                    
            
            
                | 36 |  |  |     { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 37 |  |  |         return array( | 
                            
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                | 38 |  |  |             'knp_pagination_render' => new \Twig_Function_Method($this, 'render', array('is_safe' => array('html'))), | 
                            
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                | 39 |  |  |             'knp_pagination_sortable' => new \Twig_Function_Method($this, 'sortable', array('is_safe' => array('html'))), | 
                            
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                | 40 |  |  |             'knp_pagination_filter' => new \Twig_Function_Method($this, 'filter', array('is_safe' => array('html'))), | 
                            
                    |  |  |  | 
                                                                                        
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                | 41 |  |  |         ); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 42 |  |  |     } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 43 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 44 |  |  |     /** | 
            
                                                                                                            
                            
            
                                    
            
            
                | 45 |  |  |      * Renders the pagination template | 
            
                                                                                                            
                            
            
                                    
            
            
                | 46 |  |  |      * | 
            
                                                                                                            
                            
            
                                    
            
            
                | 47 |  |  |      * @param string $template | 
            
                                                                                                            
                            
            
                                    
            
            
                | 48 |  |  |      * @param array  $queryParams | 
            
                                                                                                            
                            
            
                                    
            
            
                | 49 |  |  |      * @param array  $viewParams | 
            
                                                                                                            
                            
            
                                    
            
            
                | 50 |  |  |      * | 
            
                                                                                                            
                            
            
                                    
            
            
                | 51 |  |  |      * @return string | 
            
                                                                                                            
                            
            
                                    
            
            
                | 52 |  |  |      */ | 
            
                                                                                                            
                            
            
                                    
            
            
                | 53 |  |  |     public function render($pagination, $template = null, array $queryParams = array(), array $viewParams = array()) | 
            
                                                                                                            
                            
            
                                    
            
            
                | 54 |  |  |     { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 55 |  |  |         return $this->environment->render( | 
            
                                                                                                            
                            
            
                                    
            
            
                | 56 |  |  |             $template ?: $pagination->getTemplate(), | 
            
                                                                                                            
                            
            
                                    
            
            
                | 57 |  |  |             $this->processor->render($pagination, $queryParams, $viewParams) | 
            
                                                                                                            
                            
            
                                    
            
            
                | 58 |  |  |         ); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 59 |  |  |     } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 60 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 61 |  |  |     /** | 
            
                                                                                                            
                            
            
                                    
            
            
                | 62 |  |  |      * Create a sort url for the field named $title | 
            
                                                                                                            
                            
            
                                    
            
            
                | 63 |  |  |      * and identified by $key which consists of | 
            
                                                                                                            
                            
            
                                    
            
            
                | 64 |  |  |      * alias and field. $options holds all link | 
            
                                                                                                            
                            
            
                                    
            
            
                | 65 |  |  |      * parameters like "alt, class" and so on. | 
            
                                                                                                            
                            
            
                                    
            
            
                | 66 |  |  |      * | 
            
                                                                                                            
                            
            
                                    
            
            
                | 67 |  |  |      * $key example: "article.title" | 
            
                                                                                                            
                            
            
                                    
            
            
                | 68 |  |  |      * | 
            
                                                                                                            
                            
            
                                    
            
            
                | 69 |  |  |      * @param  string $title | 
            
                                                                                                            
                            
            
                                    
            
            
                | 70 |  |  |      * @param  string $key | 
            
                                                                                                            
                            
            
                                    
            
            
                | 71 |  |  |      * @param  array  $options | 
            
                                                                                                            
                            
            
                                    
            
            
                | 72 |  |  |      * @param  array  $params | 
            
                                                                                                            
                            
            
                                    
            
            
                | 73 |  |  |      * @param  string $template | 
            
                                                                                                            
                            
            
                                    
            
            
                | 74 |  |  |      * @return string | 
            
                                                                                                            
                            
            
                                    
            
            
                | 75 |  |  |      */ | 
            
                                                                                                            
                            
            
                                    
            
            
                | 76 |  |  |     public function sortable($pagination, $title, $key, $options = array(), $params = array(), $template = null) | 
            
                                                                                                            
                            
            
                                    
            
            
                | 77 |  |  |     { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 78 |  |  |         return $this->environment->render( | 
            
                                                                                                            
                            
            
                                    
            
            
                | 79 |  |  |             $template ?: $pagination->getSortableTemplate(), | 
            
                                                                                                            
                            
            
                                    
            
            
                | 80 |  |  |             $this->processor->sortable($pagination, $title, $key, $options, $params) | 
            
                                                                                                            
                            
            
                                    
            
            
                | 81 |  |  |         ); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 82 |  |  |     } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 83 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 84 |  |  |     /** | 
            
                                                                                                            
                            
            
                                    
            
            
                | 85 |  |  |      * Create a filter url for the field named $title | 
            
                                                                                                            
                            
            
                                    
            
            
                | 86 |  |  |      * and identified by $key which consists of | 
            
                                                                                                            
                            
            
                                    
            
            
                | 87 |  |  |      * alias and field. $options holds all link | 
            
                                                                                                            
                            
            
                                    
            
            
                | 88 |  |  |      * parameters like "alt, class" and so on. | 
            
                                                                                                            
                            
            
                                    
            
            
                | 89 |  |  |      * | 
            
                                                                                                            
                            
            
                                    
            
            
                | 90 |  |  |      * $key example: "article.title" | 
            
                                                                                                            
                            
            
                                    
            
            
                | 91 |  |  |      * | 
            
                                                                                                            
                            
            
                                    
            
            
                | 92 |  |  |      * @param  string $title | 
                            
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                | 93 |  |  |      * @param  string $key | 
                            
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                | 94 |  |  |      * @param  array  $options | 
            
                                                                                                            
                            
            
                                    
            
            
                | 95 |  |  |      * @param  array  $params | 
            
                                                                                                            
                            
            
                                    
            
            
                | 96 |  |  |      * @param  string $template | 
            
                                                                                                            
                            
            
                                    
            
            
                | 97 |  |  |      * @return string | 
            
                                                                                                            
                            
            
                                    
            
            
                | 98 |  |  |      */ | 
            
                                                                                                            
                            
            
                                    
            
            
                | 99 |  |  |     public function filter($pagination, array $fields, $options = array(), $params = array(), $template = null) | 
            
                                                                                                            
                            
            
                                    
            
            
                | 100 |  |  |     { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 101 |  |  |         return $this->environment->render( | 
            
                                                                                                            
                            
            
                                    
            
            
                | 102 |  |  |             $template ?: $pagination->getFiltrationTemplate(), | 
            
                                                                                                            
                            
            
                                    
            
            
                | 103 |  |  |             $this->processor->filter($pagination, $fields, $options, $params) | 
            
                                                                                                            
                            
            
                                    
            
            
                | 104 |  |  |         ); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 105 |  |  |     } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 106 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 107 |  |  |     /** | 
            
                                                                                                            
                            
            
                                    
            
            
                | 108 |  |  |      * Get name | 
            
                                                                                                            
                            
            
                                    
            
            
                | 109 |  |  |      * | 
            
                                                                                                            
                            
            
                                    
            
            
                | 110 |  |  |      * @return string | 
            
                                                                                                            
                            
            
                                    
            
            
                | 111 |  |  |      */ | 
            
                                                                                                            
                            
            
                                    
            
            
                | 112 |  |  |     public function getName() | 
            
                                                                                                            
                            
            
                                    
            
            
                | 113 |  |  |     { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 114 |  |  |         return 'knp_pagination'; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 115 |  |  |     } | 
            
                                                                                                            
                                                                
            
                                    
            
            
                | 116 |  |  | } | 
            
                                                        
            
                                    
            
            
                | 117 |  |  |  | 
            
                        
If you return a value from a function or method, it should be a sub-type of the type that is given by the parent type f.e. an interface, or abstract method. This is more formally defined by the Lizkov substitution principle, and guarantees that classes that depend on the parent type can use any instance of a child type interchangably. This principle also belongs to the SOLID principles for object oriented design.
Let’s take a look at an example:
Our function
my_functionexpects aPostobject, and outputs the author of the post. The base classPostreturns a simple string and outputting a simple string will work just fine. However, the child classBlogPostwhich is a sub-type ofPostinstead decided to return anobject, and is therefore violating the SOLID principles. If aBlogPostwere passed tomy_function, PHP would not complain, but ultimately fail when executing thestrtouppercall in its body.