Collaboration diagram for ilDclExpressionParser:

Public Member Functions
	__construct ($expression, ilDclBaseRecordModel $record, ilDclBaseFieldModel $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,
		ilDclBaseRecordModel	$record,
		ilDclBaseFieldModel	$field
	)

Parameters

string	$expression
ilDclBaseRecordModel	$record
ilDclBaseFieldModel	$field

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

    {
        $this->expression = $expression;
        $this->record = $record;
        $this->field = $field;
    }

References $expression, $field, and $record.

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 428 of file class.ilDclExpressionParser.php.

    {
        switch ($operator) {
            case '+':
                $result = $left + $right;
                break;
            case '-':
                $result = $left - $right;
                break;
            case '*':
                $result = $left * $right;
                break;
            case '/':
                $result = ($right == 0) ? 0 : $left / $right;
                break;
            case '^':
                $result = pow($left, $right);
                break;
            default:
                throw new ilException("Unrecognized operator '$operator'");
        }
 
        return $result;
    }

References $result.

Referenced by parseMath().

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◆ calculateFunction()

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

protected

Calculate a function with its arguments.

Parameters

	$function	Function name to calculate
array	$args	Arguments of function

Returns: float|int|number

Exceptions

ilException

Definition at line 401 of file class.ilDclExpressionParser.php.

    {
        switch ($function) {
            case 'AVERAGE':
                $count = count($args);
 
                return ($count) ? array_sum($args) / $count : 0;
            case 'SUM':
                return array_sum($args);
            case 'MIN':
                return min($args);
            case 'MAX':
                return max($args);
            default:
                throw new ilException("Unrecognized function '$function'");
        }
    }

References $function.

Referenced by calculateFunctions().

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◆ calculateFunctions()

ilDclExpressionParser::calculateFunctions ( $token )

protected

Execute any math functions inside a token.

Parameters

string $token

Returns: string

Definition at line 193 of file class.ilDclExpressionParser.php.

    {
        if (isset(self::$cache_math_function_tokens[$this->field->getId()][$token])) {
            $result = self::$cache_math_function_tokens[$this->field->getId()][$token];
            if ($result === false) {
                return $token;
            }
        } else {
            $pattern = '#';
            foreach (self::getFunctions() as $function) {
                $pattern .= "($function)\\(([^)]*)\\)|";
            }
            if (!preg_match_all(rtrim($pattern, '|') . '#', $token, $result)) {
                // No functions found inside token, just return token again
                self::$cache_math_function_tokens[$this->field->getId()][$token] = false;
 
                return $token;
            }
        }
        // Function found inside token, calculate!
        foreach ($result[0] as $k => $to_replace) {
            $function_args = $this->getFunctionArgs($k, $result);
            $function = $function_args['function'];
            $args = $this->substituteFieldValues($function_args['args']);
            $token = str_replace($to_replace, $this->calculateFunction($function, $args), $token);
        }
 
        return $token;
    }

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

Referenced by parse().

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◆ formatScientific()

ilDclExpressionParser::formatScientific ( $value )

protected

Parameters

$value

Returns: string

Definition at line 127 of file class.ilDclExpressionParser.php.

    {
        if (abs($value) >= self::SCIENTIFIC_NOTATION_UPPER) {
            return sprintf("%e", $value);
        }
        if (abs($value) <= self::SCIENTIFIC_NOTATION_LOWER && $value != 0) {
            return sprintf("%e", $value);
        }
        if (is_float($value)) {
            return $value;
        }
 
        return $value;
    }

References sprintf.

Referenced by parse().

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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 232 of file class.ilDclExpressionParser.php.

    {
        $return = array(
            'function' => '',
            'args' => array(),
        );
        for ($i = 1; $i < count($data); $i++) {
            $_data = $data[$i];
            if ($_data[$index]) {
                $function = $_data[$index];
                $args = explode(';', $data[$i + 1][$index]);
                $return['function'] = $function;
                $return['args'] = $args;
                break;
            }
        }
 
        return $return;
    }

References $data, $function, $i, and $index.

Referenced by calculateFunctions().

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◆ getFunctions()

static ilDclExpressionParser::getFunctions ( )

static

Returns: array

Definition at line 155 of file class.ilDclExpressionParser.php.

    {
        return self::$functions;
    }

References $functions.

Referenced by ilDclFormulaFieldRepresentation\buildFieldCreationInput(), and isMathToken().

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◆ getOperators()

static ilDclExpressionParser::getOperators ( )

static

Returns: array

Definition at line 146 of file class.ilDclExpressionParser.php.

    {
        return self::$operators;
    }

References $operators.

Referenced by ilDclFormulaFieldRepresentation\buildFieldCreationInput(), and ilDclTokenizer\getMathTokens().

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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 168 of file class.ilDclExpressionParser.php.

    {
        if (isset(self::$cache_math_tokens[$this->field->getId()][$token])) {
            return self::$cache_math_tokens[$this->field->getId()][$token];
        } else {
            if (strpos($token, '"') === 0) {
                return false;
            }
            $operators = array_keys(self::getOperators());
            $functions = self::getFunctions();
            $result = (bool) preg_match('#(\\' . implode("|\\", $operators) . '|' . implode('|', $functions) . ')#', $token);
            self::$cache_math_tokens[$this->field->getId()][$token] = $result;
 
            return $result;
        }
    }

References $functions, $operators, $result, and getFunctions().

Referenced by parse().

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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 84 of file class.ilDclExpressionParser.php.

    {
        if (isset(self::$cache_tokens[$this->field->getId()])) {
            $tokens = self::$cache_tokens[$this->field->getId()];
        } else {
            $tokens = ilDclTokenizer::getTokens($this->expression);
            self::$cache_tokens[$this->field->getId()] = $tokens;
        }
        //                      ilUtil::sendInfo( "<pre>" . print_r($tokens, 1) . "</pre>");
        $parsed = '';
        foreach ($tokens as $token) {
            if (empty($token)) {
                continue;
            }
            if ($this->isMathToken($token)) {
                $token = $this->calculateFunctions($token);
                $math_tokens = ilDclTokenizer::getMathTokens($token);
                $value = $this->parseMath($this->substituteFieldValues($math_tokens));
 
                $value = $this->formatScientific($value);
 
                $parsed .= $value;
            } else {
                // Token is a string, either a field placeholder [[Field name]] or a string starting with "
                if (strpos($token, '"') === 0) {
                    $parsed .= strip_tags(trim($token, '"'));
                } elseif (strpos($token, '[[') === 0) {
                    $parsed .= trim(strip_tags($this->substituteFieldValue($token)));
                } else {
                    throw new ilException("Unrecognized string token: '$token'");
                }
            }
        }
 
        return $parsed;
    }

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

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◆ parseMath()

ilDclExpressionParser::parseMath ( array $tokens )

protected

Parse a math expression.

Parameters

array $tokens

Returns: null

Exceptions

Exception

Definition at line 320 of file class.ilDclExpressionParser.php.

    {
        $operators = self::$operators;
        $precedence = 0;
        $stack = new ilDclStack();
        $precedences = new ilDclStack();
        $in_bracket = false;
        foreach ($tokens as $token) {
            if (empty($token) or is_null($token)) {
                $token = 0;
            }
            if (is_numeric($token) or $token === '(') {
                $stack->push($token);
                if ($token === '(') {
                    $in_bracket = true;
                }
            } elseif (in_array($token, array_keys($operators))) {
                $new_precedence = $operators[$token]['precedence'];
                if ($new_precedence > $precedence || $in_bracket) {
                    // Precedence of operator is higher, push operator on stack
                    $stack->push($token);
                    $precedences->push($new_precedence);
                    $precedence = $new_precedence;
                } else {
                    // Precedence is equal or lower, calculate result on stack
                    while ($new_precedence <= $precedence && $stack->count() > 1) {
                        $right = (float) $stack->pop();
                        $operator = $stack->pop();
                        $left = (float) $stack->pop();
                        $result = $this->calculate($operator, $left, $right);
                        $stack->push($result);
                        $precedence = $precedences->pop();
                    }
                    $stack->push($token);
                    $precedence = $new_precedence;
                    $precedences->push($new_precedence);
                }
            } elseif ($token === ')') {
                // Need to calculate stack back to opening bracket
                $_tokens = array();
                $elem = $stack->pop();
                while ($elem !== '(' && !$stack->isEmpty()) {
                    $_tokens[] = $elem;
                    $elem = $stack->pop();
                }
                // Get result within brackets recursive and push to stack
                $stack->push($this->parseMath(array_reverse($_tokens)));
                $in_bracket = false;
            } else {
                throw new ilException("Unrecognized token '$token'");
            }
            // $stack->debug();
        }
        // If one element is left on stack, we are done. Otherwise calculate
        if ($stack->count() == 1) {
            $result = $stack->pop();
 
            return (ctype_digit((string) $result)) ? $result : number_format($result, self::N_DECIMALS, '.', "'");
        } else {
            while ($stack->count() >= 2) {
                $right = $stack->pop();
                $operator = $stack->pop();
                $left = $stack->count() ? $stack->pop() : 0;
                $stack->push($this->calculate($operator, $left, $right));
            }
            $result = $stack->pop();
 
            return $result;
        }
    }

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

Referenced by parse(), and parseMath().

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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 260 of file class.ilDclExpressionParser.php.

    {
        $replaced = array();
        foreach ($tokens as $token) {
            if (strpos($token, '[[') === 0) {
                $replaced[] = $this->substituteFieldValue($token);
            } else {
                $replaced[] = $token;
            }
        }
 
        return $replaced;
    }

Referenced by calculateFunctions(), and parse().

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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().

◆ $functions

ilDclExpressionParser::$functions

staticprotected

Initial value:

= array(
        'SUM',
        'AVERAGE',
        'MIN',
        'MAX',
    )

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

Referenced by getFunctions(), and 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 getOperators(), 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:

Modules/DataCollection/classes/Fields/Formula/class.ilDclExpressionParser.php

Public Member Functions

Static Public Member Functions

Data Fields

Protected Member Functions

Protected Attributes

Static Protected Attributes

Detailed Description

Constructor & Destructor Documentation

◆ __construct()

Member Function Documentation

◆ calculate()

◆ calculateFunction()

◆ calculateFunctions()

◆ formatScientific()

◆ getFunctionArgs()

◆ getFunctions()

◆ getOperators()

◆ isMathToken()

◆ parse()

◆ parseMath()

◆ substituteFieldValues()

Field Documentation

◆ $cache_fields

◆ $cache_math_function_tokens

◆ $cache_math_tokens

◆ $cache_tokens

◆ $expression

◆ $field

◆ $functions

◆ $operators

◆ $record

◆ N_DECIMALS

◆ SCIENTIFIC_NOTATION_LOWER

◆ SCIENTIFIC_NOTATION_UPPER