Chris@13: <?php
Chris@13: namespace Consolidation\OutputFormatters\StructuredData;
Chris@13: 
Chris@13: /**
Chris@13:  * A structured data object may contains some elements that
Chris@13:  * are actually metadata. Metadata is not included in the
Chris@13:  * output of tabular data formatters (e.g. table, csv), although
Chris@13:  * some of these (e.g. table) may render the metadata alongside
Chris@13:  * the data. Raw data formatters (e.g. yaml, json) will render
Chris@13:  * both the data and the metadata.
Chris@13:  *
Chris@13:  * There are two possible options for the data format; either the
Chris@13:  * data is nested inside some element, and ever other item is
Chris@13:  * metadata, or the metadata may be nested inside some element,
Chris@13:  * and every other item is the data rows.
Chris@13:  *
Chris@13:  * Example 1: nested data
Chris@13:  *
Chris@13:  * [
Chris@13:  *     'data' => [ ... rows of field data ... ],
Chris@13:  *     'metadata1' => '...',
Chris@13:  *     'metadata2' => '...',
Chris@13:  * ]
Chris@13:  *
Chris@13:  * Example 2: nested metadata
Chris@13:  *
Chris@13:  * [
Chris@13:  *      'metadata' => [ ... metadata items ... ],
Chris@13:  *      'rowid1' => [ ... ],
Chris@13:  *      'rowid2' => [ ... ],
Chris@13:  * ]
Chris@13:  *
Chris@13:  * It is, of course, also possible that both the data and
Chris@13:  * the metadata may be nested inside subelements.
Chris@13:  */
Chris@13: trait MetadataHolderTrait
Chris@13: {
Chris@13:     protected $dataKey = false;
Chris@13:     protected $metadataKey = false;
Chris@13: 
Chris@13:     public function getDataKey()
Chris@13:     {
Chris@13:         return $this->dataKey;
Chris@13:     }
Chris@13: 
Chris@13:     public function setDataKey($key)
Chris@13:     {
Chris@13:         $this->dataKey = $key;
Chris@13:         return $this;
Chris@13:     }
Chris@13: 
Chris@13:     public function getMetadataKey()
Chris@13:     {
Chris@13:         return $this->metadataKey;
Chris@13:     }
Chris@13: 
Chris@13:     public function setMetadataKey($key)
Chris@13:     {
Chris@13:         $this->metadataKey = $key;
Chris@13:         return $this;
Chris@13:     }
Chris@13: 
Chris@13:     public function extractData($data)
Chris@13:     {
Chris@13:         if ($this->metadataKey) {
Chris@13:             unset($data[$this->metadataKey]);
Chris@13:         }
Chris@13:         if ($this->dataKey) {
Chris@13:             if (!isset($data[$this->dataKey])) {
Chris@13:                 return [];
Chris@13:             }
Chris@13:             return $data[$this->dataKey];
Chris@13:         }
Chris@13:         return $data;
Chris@13:     }
Chris@13: 
Chris@13:     public function extractMetadata($data)
Chris@13:     {
Chris@13:         if (!$this->dataKey && !$this->metadataKey) {
Chris@13:             return [];
Chris@13:         }
Chris@13:         if ($this->dataKey) {
Chris@13:             unset($data[$this->dataKey]);
Chris@13:         }
Chris@13:         if ($this->metadataKey) {
Chris@13:             if (!isset($data[$this->metadataKey])) {
Chris@13:                 return [];
Chris@13:             }
Chris@13:             return $data[$this->metadataKey];
Chris@13:         }
Chris@13:         return $data;
Chris@13:     }
Chris@13: 
Chris@13:     public function reconstruct($data, $metadata)
Chris@13:     {
Chris@13:         $reconstructedData = ($this->dataKey) ? [$this->dataKey => $data] : $data;
Chris@13:         $reconstructedMetadata = ($this->metadataKey) ? [$this->metadataKey => $metadata] : $metadata;
Chris@13: 
Chris@13:         return $reconstructedData + $reconstructedMetadata;
Chris@13:     }
Chris@13: }