includes/search/SearchIndexField.php

   1 <?php
   2 /**
   3  * Definition of a mapping for the search index field.
   4  * @since 1.28
   5  */
   6 interface SearchIndexField {
   7         /*
   8          * Field types
   9          */
  10         /**
  11          * TEXT fields are suitable for natural language and may be subject to
  12          * analysis such as stemming.
  13          *
  14          * Read more:
  15          * https://wikimediafoundation.org/2018/08/07/anatomy-search-token-affection/
  16          * https://wikimediafoundation.org/2018/09/13/anatomy-search-variation-under-nature/
  17          */
  18         const INDEX_TYPE_TEXT = 'text';
  19         /**
  20          * KEYWORD fields are indexed without any processing, so are appropriate
  21          * for e.g. URLs.  The content will often consist of a single token.
  22          */
  23         const INDEX_TYPE_KEYWORD = 'keyword';
  24         const INDEX_TYPE_INTEGER = 'integer';
  25         const INDEX_TYPE_NUMBER = 'number';
  26         const INDEX_TYPE_DATETIME = 'datetime';
  27         const INDEX_TYPE_NESTED = 'nested';
  28         const INDEX_TYPE_BOOL = 'bool';
  29
  30         /**
  31          * SHORT_TEXT is meant to be used with short text made of mostly ascii
  32          * technical information. Generally a language agnostic analysis chain
  33          * is used and aggressive splitting to increase recall.
  34          * E.g suited for mime/type
  35          */
  36         const INDEX_TYPE_SHORT_TEXT = 'short_text';
  37
  38         /**
  39          * Generic field flags.
  40          */
  41         /**
  42          * This field is case-insensitive.
  43          */
  44         const FLAG_CASEFOLD = 1;
  45
  46         /**
  47          * This field contains secondary information, which is
  48          * already present in other fields, but can be used for
  49          * scoring.
  50          */
  51         const FLAG_SCORING = 2;
  52
  53         /**
  54          * This field does not need highlight handling.
  55          */
  56         const FLAG_NO_HIGHLIGHT = 4;
  57
  58         /**
  59          * Do not index this field, just store it.
  60          */
  61         const FLAG_NO_INDEX = 8;
  62
  63         /**
  64          * Get mapping for specific search engine
  65          * @param SearchEngine $engine
  66          * @return array|null Null means this field does not map to anything
  67          */
  68         public function getMapping( SearchEngine $engine );
  69
  70         /**
  71          * Set global flag for this field.
  72          *
  73          * @param int $flag Bit flag to set/unset
  74          * @param bool $unset True if flag should be unset, false by default
  75          * @return $this
  76          */
  77         public function setFlag( $flag, $unset = false );
  78
  79         /**
  80          * Check if flag is set.
  81          * @param int $flag
  82          * @return int 0 if unset, !=0 if set
  83          */
  84         public function checkFlag( $flag );
  85
  86         /**
  87          * Merge two field definitions if possible.
  88          *
  89          * @param SearchIndexField $that
  90          * @return SearchIndexField|false New definition or false if not mergeable.
  91          */
  92         public function merge( SearchIndexField $that );
  93
  94         /**
  95          * A list of search engine hints for this field.
  96          * Hints are usually specific to a search engine implementation
  97          * and allow to fine control how the search engine will handle this
  98          * particular field.
  99          *
 100          * For example some search engine permits some optimizations
 101          * at index time by ignoring an update if the updated value
 102          * does not change by more than X% on a numeric value.
 103          *
 104          * @param SearchEngine $engine
 105          * @return array an array of hints generally indexed by hint name. The type of
 106          * values is search engine specific
 107          * @since 1.30
 108          */
 109         public function getEngineHints( SearchEngine $engine );
 110 }