Civi/Api4/Query/SqlFunction.php

   1 <?php
   2 /*
   3  +--------------------------------------------------------------------+
   4  | Copyright CiviCRM LLC. All rights reserved.                        |
   5  |                                                                    |
   6  | This work is published under the GNU AGPLv3 license with some      |
   7  | permitted exceptions and without any warranty. For full license    |
   8  | and copyright information, see https://civicrm.org/licensing       |
   9  +--------------------------------------------------------------------+
  10  */
  11
  12 namespace Civi\Api4\Query;
  13
  14 /**
  15  * Base class for all Sql functions.
  16  *
  17  * @package Civi\Api4\Query
  18  */
  19 abstract class SqlFunction extends SqlExpression {
  20
  21   /**
  22    * @var array[]
  23    */
  24   protected $args = [];
  25
  26   /**
  27    * Used for categorizing functions in the UI
  28    *
  29    * @var string
  30    */
  31   protected static $category;
  32
  33   const CATEGORY_AGGREGATE = 'aggregate',
  34     CATEGORY_COMPARISON = 'comparison',
  35     CATEGORY_DATE = 'date',
  36     CATEGORY_MATH = 'math',
  37     CATEGORY_STRING = 'string';
  38
  39   /**
  40    * Parse the argument string into an array of function arguments
  41    */
  42   protected function initialize() {
  43     $arg = trim(substr($this->expr, strpos($this->expr, '(') + 1, -1));
  44     foreach ($this->getParams() as $idx => $param) {
  45       $prefix = NULL;
  46       if ($param['name']) {
  47         $prefix = $this->captureKeyword([$param['name']], $arg);
  48         // Supply api_default
  49         if (!$prefix && isset($param['api_default'])) {
  50           $this->args[$idx] = [
  51             'prefix' => [$param['name']],
  52             'expr' => array_map([parent::class, 'convert'], $param['api_default']['expr']),
  53             'suffix' => [],
  54           ];
  55           continue;
  56         }
  57         if (!$prefix && !$param['optional']) {
  58           throw new \API_Exception("Missing {$param['name']} for SQL function " . static::getName());
  59         }
  60       }
  61       elseif ($param['flag_before']) {
  62         $prefix = $this->captureKeyword(array_keys($param['flag_before']), $arg);
  63       }
  64       $this->args[$idx] = [
  65         'prefix' => (array) $prefix,
  66         'expr' => [],
  67         'suffix' => [],
  68       ];
  69       if ($param['max_expr'] && (!$param['name'] || $param['name'] === $prefix)) {
  70         $exprs = $this->captureExpressions($arg, $param['must_be']);
  71         if (count($exprs) < $param['min_expr'] || count($exprs) > $param['max_expr']) {
  72           throw new \API_Exception('Incorrect number of arguments for SQL function ' . static::getName());
  73         }
  74         $this->args[$idx]['expr'] = $exprs;
  75
  76         $this->args[$idx]['suffix'] = (array) $this->captureKeyword(array_keys($param['flag_after']), $arg);
  77       }
  78     }
  79   }
  80
  81   /**
  82    * Change $dataType according to output of function
  83    *
  84    * @see \Civi\Api4\Utils\FormattingUtil::formatOutputValues
  85    * @param string $value
  86    * @param string $dataType
  87    * @return string
  88    */
  89   public function formatOutputValue($value, &$dataType) {
  90     if (static::$dataType) {
  91       $dataType = static::$dataType;
  92     }
  93     return $value;
  94   }
  95
  96   /**
  97    * Shift a keyword off the beginning of the argument string and return it.
  98    *
  99    * @param array $keywords
 100    *   Whitelist of keywords
 101    * @param string $arg
 102    * @return mixed|null
 103    */
 104   private function captureKeyword($keywords, &$arg) {
 105     foreach ($keywords as $key) {
 106       if (strpos($arg, $key . ' ') === 0) {
 107         $arg = ltrim(substr($arg, strlen($key)));
 108         return $key;
 109       }
 110     }
 111     return NULL;
 112   }
 113
 114   /**
 115    * Shifts 0 or more expressions off the argument string and returns them
 116    *
 117    * @param string $arg
 118    * @param array $mustBe
 119    * @return array
 120    * @throws \API_Exception
 121    */
 122   private function captureExpressions(&$arg, $mustBe) {
 123     $captured = [];
 124     $arg = ltrim($arg);
 125     while ($arg) {
 126       $item = $this->captureExpression($arg);
 127       $arg = ltrim(substr($arg, strlen($item)));
 128       $expr = SqlExpression::convert($item, FALSE, $mustBe);
 129       $this->fields = array_merge($this->fields, $expr->getFields());
 130       $captured[] = $expr;
 131       // Keep going if we have a comma indicating another expression follows
 132       if (substr($arg, 0, 1) === ',') {
 133         $arg = ltrim(substr($arg, 1));
 134       }
 135       else {
 136         break;
 137       }
 138     }
 139     return $captured;
 140   }
 141
 142   /**
 143    * Scans the beginning of a string for an expression; stops when it hits delimiter
 144    *
 145    * @param $arg
 146    * @return string
 147    */
 148   private function captureExpression($arg) {
 149     $isEscaped = $quote = NULL;
 150     $item = '';
 151     $quotes = ['"', "'"];
 152     $brackets = [
 153       ')' => '(',
 154     ];
 155     $enclosures = array_fill_keys($brackets, 0);
 156     foreach (str_split($arg) as $char) {
 157       if (!$isEscaped && in_array($char, $quotes, TRUE)) {
 158         // Open quotes - we'll ignore everything inside
 159         if (!$quote) {
 160           $quote = $char;
 161         }
 162         // Close quotes
 163         elseif ($char === $quote) {
 164           $quote = NULL;
 165         }
 166       }
 167       if (!$quote) {
 168         // Delineates end of expression
 169         if (($char == ',' || $char == ' ') && !array_filter($enclosures)) {
 170           return $item;
 171         }
 172         // Open brackets - we'll ignore delineators inside
 173         if (isset($enclosures[$char])) {
 174           $enclosures[$char]++;
 175         }
 176         // Close brackets
 177         if (isset($brackets[$char]) && $enclosures[$brackets[$char]]) {
 178           $enclosures[$brackets[$char]]--;
 179         }
 180       }
 181       $item .= $char;
 182       // We are escaping the next char if this is a backslash not preceded by an odd number of backslashes
 183       $isEscaped = $char === '\\' && ((strlen($item) - strlen(rtrim($item, '\\'))) % 2);
 184     }
 185     return $item;
 186   }
 187
 188   /**
 189    * Render the expression for insertion into the sql query
 190    *
 191    * @param array $fieldList
 192    * @return string
 193    */
 194   public function render(array $fieldList): string {
 195     $output = '';
 196     foreach ($this->args as $arg) {
 197       $rendered = $this->renderArg($arg, $fieldList);
 198       if (strlen($rendered)) {
 199         $output .= (strlen($output) ? ' ' : '') . $rendered;
 200       }
 201     }
 202     return $this->getName() . '(' . $output . ')';
 203   }
 204
 205   /**
 206    * @param array $arg
 207    * @param array $fieldList
 208    * @return string
 209    */
 210   private function renderArg($arg, $fieldList): string {
 211     $rendered = implode(' ', $arg['prefix']);
 212     foreach ($arg['expr'] ?? [] as $idx => $expr) {
 213       if (strlen($rendered) || $idx) {
 214         $rendered .= $idx ? ', ' : ' ';
 215       }
 216       $rendered .= $expr->render($fieldList);
 217     }
 218     if ($arg['suffix']) {
 219       $rendered .= (strlen($rendered) ? ' ' : '') . implode(' ', $arg['suffix']);
 220     }
 221     return $rendered;
 222   }
 223
 224   /**
 225    * @inheritDoc
 226    */
 227   public function getAlias(): string {
 228     return $this->alias ?? $this->getName() . ':' . implode('_', $this->fields);
 229   }
 230
 231   /**
 232    * Get the name of this sql function.
 233    * @return string
 234    */
 235   public static function getName(): string {
 236     $className = static::class;
 237     return substr($className, strrpos($className, 'SqlFunction') + 11);
 238   }
 239
 240   /**
 241    * Get the param metadata for this sql function.
 242    * @return array
 243    */
 244   final public static function getParams(): array {
 245     $params = [];
 246     foreach (static::params() as $param) {
 247       // Merge in defaults to ensure each param has these properties
 248       $params[] = $param + [
 249         'name' => NULL,
 250         'min_expr' => 1,
 251         'max_expr' => 1,
 252         'flag_before' => [],
 253         'flag_after' => [],
 254         'optional' => FALSE,
 255         'must_be' => ['SqlField', 'SqlFunction', 'SqlString', 'SqlNumber', 'SqlNull'],
 256         'api_default' => NULL,
 257       ];
 258     }
 259     return $params;
 260   }
 261
 262   abstract protected static function params(): array;
 263
 264   /**
 265    * Get the arguments passed to this sql function instance.
 266    * @return array[]
 267    */
 268   public function getArgs(): array {
 269     return $this->args;
 270   }
 271
 272   /**
 273    * @return string
 274    */
 275   public static function getCategory(): string {
 276     return static::$category;
 277   }
 278
 279   /**
 280    * @return string
 281    */
 282   abstract public static function getTitle(): string;
 283
 284   /**
 285    * @return string
 286    */
 287   abstract public static function getDescription(): string;
 288
 289 }