ILIAS  release_5-1 Revision 5.0.0-5477-g43f3e3fab5f
Public Member Functions | Static Public Member Functions | Data Fields | Protected Member Functions | Protected Attributes | Static Protected Attributes
ilDclExpressionParser Class Reference

Class ilDclExpressionParser. More...

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Public Member Functions

 __construct ($expression, ilDataCollectionRecord $record, ilDataCollectionField $field)
 
 parse ()
 Parse expression and return result. More...
 

Static Public Member Functions

static getOperators ()
 
static getFunctions ()
 

Data Fields

const N_DECIMALS = 1
 
const SCIENTIFIC_NOTATION_UPPER = 1000000000000
 
const SCIENTIFIC_NOTATION_LOWER = 0.000000001
 

Protected Member Functions

 formatScientific ($value)
 
 isMathToken ($token)
 Check if a given token is a math expression. More...
 
 calculateFunctions ($token)
 Execute any math functions inside a token. More...
 
 getFunctionArgs ($index, array $data)
 Helper method to return the function and its arguments from a preg_replace_all $result array. More...
 
 substituteFieldValues (array $tokens)
 Given an array of tokens, replace each token that is a placeholder (e.g. More...
 
 parseMath (array $tokens)
 Parse a math expression. More...
 
 calculateFunction ($function, array $args=array())
 Calculate a function with its arguments. More...
 
 calculate ($operator, $left, $right)
 

Protected Attributes

 $record
 
 $field
 
 $expression
 

Static Protected Attributes

static $operators
 
static $cache_tokens = array()
 
static $cache_fields = array()
 
static $cache_math_tokens = array()
 
static $cache_math_function_tokens = array()
 
static $functions
 

Detailed Description

Class ilDclExpressionParser.

Author
Stefan Wanzenried sw@st.nosp@m.uder.nosp@m.-raim.nosp@m.ann..nosp@m.ch
Fabian Schmid fs@st.nosp@m.uder.nosp@m.-raim.nosp@m.ann..nosp@m.ch

Definition at line 9 of file class.ilDclExpressionParser.php.

Constructor & Destructor Documentation

◆ __construct()

ilDclExpressionParser::__construct (   $expression,
ilDataCollectionRecord  $record,
ilDataCollectionField  $field 
)
Parameters
string$expression
ilDataCollectionRecord$record
ilDataCollectionField$field

Definition at line 68 of file class.ilDclExpressionParser.php.

References $expression, $field, and $record.

68  {
69  $this->expression = $expression;
70  $this->record = $record;
71  $this->field = $field;
72  }

Member Function Documentation

◆ calculate()

ilDclExpressionParser::calculate (   $operator,
  $left,
  $right 
)
protected
Parameters
string$operator
float$left
float$right
Returns
float|number
Exceptions
ilException

Definition at line 416 of file class.ilDclExpressionParser.php.

References $result.

Referenced by parseMath().

416  {
417  switch ($operator) {
418  case '+':
419  $result = $left + $right;
420  break;
421  case '-':
422  $result = $left - $right;
423  break;
424  case '*':
425  $result = $left * $right;
426  break;
427  case '/':
428  $result = ($right == 0) ? 0 : $left / $right;
429  break;
430  case '^':
431  $result = pow($left, $right);
432  break;
433  default:
434  throw new ilException("Unrecognized operator '$operator'");
435  }
436 
437  return $result;
438  }
ilException
Base class for ILIAS Exception handling.
Definition: class.ilException.php:34
$result
$result
Definition: CleanUpTest.php:407
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◆ calculateFunction()

ilDclExpressionParser::calculateFunction (   $function,
array  $args = array() 
)
protected

Calculate a function with its arguments.

Parameters
$functionFunction name to calculate
array$argsArguments of function
Returns
float|int|number
Exceptions
ilException

Definition at line 390 of file class.ilDclExpressionParser.php.

Referenced by calculateFunctions().

390  {
391  switch ($function) {
392  case 'AVERAGE':
393  $count = count($args);
394 
395  return ($count) ? array_sum($args) / $count : 0;
396  case 'SUM':
397  return array_sum($args);
398  case 'MIN':
399  return min($args);
400  case 'MAX':
401  return max($args);
402  default:
403  throw new ilException("Unrecognized function '$function'");
404  }
405  }
ilException
Base class for ILIAS Exception handling.
Definition: class.ilException.php:34
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◆ calculateFunctions()

ilDclExpressionParser::calculateFunctions (   $token)
protected

Execute any math functions inside a token.

Parameters
string$token
Returns
string

Definition at line 187 of file class.ilDclExpressionParser.php.

References $result, calculateFunction(), getFunctionArgs(), and substituteFieldValues().

Referenced by parse().

187  {
188  if (isset(self::$cache_math_function_tokens[$this->field->getId()][$token])) {
189  $result = self::$cache_math_function_tokens[$this->field->getId()][$token];
190  if ($result === false) {
191  return $token;
192  }
193  } else {
194  $pattern = '#';
195  foreach (self::getFunctions() as $function) {
196  $pattern .= "($function)\\(([^)]*)\\)|";
197  }
198  if (!preg_match_all(rtrim($pattern, '|') . '#', $token, $result)) {
199  // No functions found inside token, just return token again
200  self::$cache_math_function_tokens[$this->field->getId()][$token] = false;
201 
202  return $token;
203  }
204  }
205  // Function found inside token, calculate!
206  foreach ($result[0] as $k => $to_replace) {
207  $function_args = $this->getFunctionArgs($k, $result);
208  $function = $function_args['function'];
209  $args = $this->substituteFieldValues($function_args['args']);
210  $token = str_replace($to_replace, $this->calculateFunction($function, $args), $token);
211  }
212 
213  return $token;
214  }
$result
$result
Definition: CleanUpTest.php:407
ilDclExpressionParser\substituteFieldValues
substituteFieldValues(array $tokens)
Given an array of tokens, replace each token that is a placeholder (e.g.
Definition: class.ilDclExpressionParser.php:252
ilDclExpressionParser\getFunctionArgs
getFunctionArgs($index, array $data)
Helper method to return the function and its arguments from a preg_replace_all $result array...
Definition: class.ilDclExpressionParser.php:225
ilDclExpressionParser\calculateFunction
calculateFunction($function, array $args=array())
Calculate a function with its arguments.
Definition: class.ilDclExpressionParser.php:390
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◆ formatScientific()

ilDclExpressionParser::formatScientific (   $value)
protected
Parameters
$value
Returns
string

Definition at line 125 of file class.ilDclExpressionParser.php.

Referenced by parse().

125  {
126  if (abs($value) >= self::SCIENTIFIC_NOTATION_UPPER) {
127  return sprintf("%e", $value);
128  }
129  if (abs($value) <= self::SCIENTIFIC_NOTATION_LOWER && $value != 0 ) {
130  return sprintf("%e", $value);
131  }
132  if (is_float($value)) {
133  return $value;
134  }
135 
136  return $value;
137  }
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◆ getFunctionArgs()

ilDclExpressionParser::getFunctionArgs (   $index,
array  $data 
)
protected

Helper method to return the function and its arguments from a preg_replace_all $result array.

Parameters
$index
array$data
Returns
array

Definition at line 225 of file class.ilDclExpressionParser.php.

Referenced by calculateFunctions().

225  {
226  $return = array(
227  'function' => '',
228  'args' => array(),
229  );
230  for ($i = 1; $i < count($data); $i ++) {
231  $_data = $data[$i];
232  if ($_data[$index]) {
233  $function = $_data[$index];
234  $args = explode(';', $data[$i + 1][$index]);
235  $return['function'] = $function;
236  $return['args'] = $args;
237  break;
238  }
239  }
240 
241  return $return;
242  }
$data
$data
Definition: example_011.php:126
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◆ getFunctions()

static ilDclExpressionParser::getFunctions ( )
static
Returns
array

Definition at line 151 of file class.ilDclExpressionParser.php.

Referenced by ilDataCollectionFieldEditGUI\initForm().

151  {
152  return self::$functions;
153  }
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◆ getOperators()

static ilDclExpressionParser::getOperators ( )
static
Returns
array

Definition at line 143 of file class.ilDclExpressionParser.php.

Referenced by ilDclTokenizer\getMathTokens(), and ilDataCollectionFieldEditGUI\initForm().

143  {
144  return self::$operators;
145  }
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◆ isMathToken()

ilDclExpressionParser::isMathToken (   $token)
protected

Check if a given token is a math expression.

Parameters
string$token
Returns
bool

Definition at line 163 of file class.ilDclExpressionParser.php.

References $functions, $operators, and $result.

Referenced by parse().

163  {
164  if (isset(self::$cache_math_tokens[$this->field->getId()][$token])) {
165  return self::$cache_math_tokens[$this->field->getId()][$token];
166  } else {
167  if (strpos($token, '"') === 0) {
168  return false;
169  }
170  $operators = array_keys(self::getOperators());
171  $functions = self::getFunctions();
172  $result = (bool)preg_match('#(\\' . implode("|\\", $operators) . '|' . implode('|', $functions) . ')#', $token);
173  self::$cache_math_tokens[$this->field->getId()][$token] = $result;
174 
175  return $result;
176  }
177  }
$result
$result
Definition: CleanUpTest.php:407
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◆ parse()

ilDclExpressionParser::parse ( )

Parse expression and return result.

This method loops the tokens and checks if Token is of type string or math. Concatenates results to produce resulting string of parsed expression.

Exceptions
ilException
Returns
string

Definition at line 83 of file class.ilDclExpressionParser.php.

References calculateFunctions(), formatScientific(), ilDclTokenizer\getMathTokens(), ilDclTokenizer\getTokens(), isMathToken(), parseMath(), and substituteFieldValues().

83  {
84  if (isset(self::$cache_tokens[$this->field->getId()])) {
85  $tokens = self::$cache_tokens[$this->field->getId()];
86  } else {
87  $tokens = ilDclTokenizer::getTokens($this->expression);
88  self::$cache_tokens[$this->field->getId()] = $tokens;
89  }
90  // ilUtil::sendInfo( "<pre>" . print_r($tokens, 1) . "</pre>");
91  $parsed = '';
92  foreach ($tokens as $token) {
93  if (empty($token)) {
94  continue;
95  }
96  if ($this->isMathToken($token)) {
97  $token = $this->calculateFunctions($token);
98  $math_tokens = ilDclTokenizer::getMathTokens($token);
99  $value = $this->parseMath($this->substituteFieldValues($math_tokens));
100 
101  $value = $this->formatScientific($value);
102 
103  $parsed .= $value;
104  } else {
105  // Token is a string, either a field placeholder [[Field name]] or a string starting with "
106  if (strpos($token, '"') === 0) {
107  $parsed .= strip_tags(trim($token, '"'));
108  } elseif (strpos($token, '[[') === 0) {
109  $parsed .= trim(strip_tags($this->substituteFieldValue($token)));
110  } else {
111  throw new ilException("Unrecognized string token: '$token'");
112  }
113  }
114  }
115 
116  return $parsed;
117  }
ilException
Base class for ILIAS Exception handling.
Definition: class.ilException.php:34
ilDclExpressionParser\substituteFieldValues
substituteFieldValues(array $tokens)
Given an array of tokens, replace each token that is a placeholder (e.g.
Definition: class.ilDclExpressionParser.php:252
ilDclExpressionParser\parseMath
parseMath(array $tokens)
Parse a math expression.
Definition: class.ilDclExpressionParser.php:309
ilDclExpressionParser\isMathToken
isMathToken($token)
Check if a given token is a math expression.
Definition: class.ilDclExpressionParser.php:163
ilDclExpressionParser\calculateFunctions
calculateFunctions($token)
Execute any math functions inside a token.
Definition: class.ilDclExpressionParser.php:187
ilDclTokenizer\getTokens
static getTokens($expression)
Split expression by & (ignore escaped &-symbols with backslash)
Definition: class.ilDclTokenizer.php:18
ilDclTokenizer\getMathTokens
static getMathTokens($math_expression)
Generate tokens for a math expression.
Definition: class.ilDclTokenizer.php:44
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◆ parseMath()

ilDclExpressionParser::parseMath ( array  $tokens)
protected

Parse a math expression.

Parameters
array$tokens
Returns
null
Exceptions
Exception

Definition at line 309 of file class.ilDclExpressionParser.php.

References $operators, $result, and calculate().

Referenced by parse().

309  {
310  $operators = self::$operators;
311  $precedence = 0;
312  $stack = new ilDclStack();
313  $precedences = new ilDclStack();
314  $in_bracket = false;
315  foreach ($tokens as $token) {
316  if (empty($token) OR is_null($token)) {
317  $token = 0;
318  }
319  if (is_numeric($token) OR $token === '(') {
320  $stack->push($token);
321  if ($token === '(') {
322  $in_bracket = true;
323  }
324  } elseif (in_array($token, array_keys($operators))) {
325  $new_precedence = $operators[$token]['precedence'];
326  if ($new_precedence > $precedence || $in_bracket) {
327  // Precedence of operator is higher, push operator on stack
328  $stack->push($token);
329  $precedences->push($new_precedence);
330  $precedence = $new_precedence;
331  } else {
332  // Precedence is equal or lower, calculate result on stack
333  while ($new_precedence <= $precedence && $stack->count() > 1) {
334  $right = (float)$stack->pop();
335  $operator = $stack->pop();
336  $left = (float)$stack->pop();
337  $result = $this->calculate($operator, $left, $right);
338  $stack->push($result);
339  $precedence = $precedences->pop();
340  }
341  $stack->push($token);
342  $precedence = $new_precedence;
343  $precedences->push($new_precedence);
344  }
345  } elseif ($token === ')') {
346  // Need to calculate stack back to opening bracket
347  $_tokens = array();
348  $elem = $stack->pop();
349  while ($elem !== '(' && !$stack->isEmpty()) {
350  $_tokens[] = $elem;
351  $elem = $stack->pop();
352  }
353  // Get result within brackets recursive and push to stack
354  $stack->push($this->parseMath(array_reverse($_tokens)));
355  $in_bracket = false;
356  } else {
357  throw new ilException("Unrecognized token '$token'");
358  }
359  // $stack->debug();
360  }
361  // If one element is left on stack, we are done. Otherwise calculate
362  if ($stack->count() == 1) {
363  $result = $stack->pop();
364 
365  return (ctype_digit((string)$result)) ? $result : number_format($result, self::N_DECIMALS, '.', "'");
366  } else {
367 
368  while ($stack->count() >= 2) {
369  $right = $stack->pop();
370  $operator = $stack->pop();
371  $left = $stack->count() ? $stack->pop() : 0;
372  $stack->push($this->calculate($operator, $left, $right));
373  }
374  $result = $stack->pop();
375 
376  return $result;
377  }
378  }
ilException
Base class for ILIAS Exception handling.
Definition: class.ilException.php:34
$result
$result
Definition: CleanUpTest.php:407
ilDclExpressionParser\calculate
calculate($operator, $left, $right)
Definition: class.ilDclExpressionParser.php:416
ilDclStack
Class ilDclStack.
Definition: class.ilDclStack.php:9
ilDclExpressionParser\parseMath
parseMath(array $tokens)
Parse a math expression.
Definition: class.ilDclExpressionParser.php:309
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◆ substituteFieldValues()

ilDclExpressionParser::substituteFieldValues ( array  $tokens)
protected

Given an array of tokens, replace each token that is a placeholder (e.g.

[[Field name]]) with it's value

Parameters
array$tokens
Returns
array

Definition at line 252 of file class.ilDclExpressionParser.php.

References $field, $lng, and ilDataCollectionCache\getTableCache().

Referenced by calculateFunctions(), and parse().

252  {
253  $replaced = array();
254  foreach ($tokens as $token) {
255  if (strpos($token, '[[') === 0) {
256  $replaced[] = $this->substituteFieldValue($token);
257  } else {
258  $replaced[] = $token;
259  }
260  }
261 
262  return $replaced;
263  }
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Field Documentation

◆ $cache_fields

ilDclExpressionParser::$cache_fields = array()
staticprotected

Definition at line 43 of file class.ilDclExpressionParser.php.

◆ $cache_math_function_tokens

ilDclExpressionParser::$cache_math_function_tokens = array()
staticprotected

Definition at line 51 of file class.ilDclExpressionParser.php.

◆ $cache_math_tokens

ilDclExpressionParser::$cache_math_tokens = array()
staticprotected

Definition at line 47 of file class.ilDclExpressionParser.php.

◆ $cache_tokens

ilDclExpressionParser::$cache_tokens = array()
staticprotected

Definition at line 39 of file class.ilDclExpressionParser.php.

◆ $expression

ilDclExpressionParser::$expression
protected

Definition at line 25 of file class.ilDclExpressionParser.php.

Referenced by __construct().

◆ $field

ilDclExpressionParser::$field
protected

Definition at line 21 of file class.ilDclExpressionParser.php.

Referenced by __construct(), and substituteFieldValues().

◆ $functions

ilDclExpressionParser::$functions
staticprotected
Initial value:
= array(
'SUM',
'AVERAGE',
'MIN',
'MAX',
)

Definition at line 55 of file class.ilDclExpressionParser.php.

Referenced by isMathToken().

◆ $operators

ilDclExpressionParser::$operators
staticprotected
Initial value:
= array(
'+' => array( 'precedence' => 1 ),
'-' => array( 'precedence' => 1 ),
'*' => array( 'precedence' => 2 ),
'/' => array( 'precedence' => 2 ),
'^' => array( 'precedence' => 3 ),
)

Definition at line 29 of file class.ilDclExpressionParser.php.

Referenced by isMathToken(), and parseMath().

◆ $record

ilDclExpressionParser::$record
protected

Definition at line 17 of file class.ilDclExpressionParser.php.

Referenced by __construct().

◆ N_DECIMALS

const ilDclExpressionParser::N_DECIMALS = 1

Definition at line 11 of file class.ilDclExpressionParser.php.

◆ SCIENTIFIC_NOTATION_LOWER

const ilDclExpressionParser::SCIENTIFIC_NOTATION_LOWER = 0.000000001

Definition at line 13 of file class.ilDclExpressionParser.php.

◆ SCIENTIFIC_NOTATION_UPPER

const ilDclExpressionParser::SCIENTIFIC_NOTATION_UPPER = 1000000000000

Definition at line 12 of file class.ilDclExpressionParser.php.

The documentation for this class was generated from the following file: