Collaboration diagram for ilAssLacConditionParser:

Public Member Functions
	__construct ()
	Construct requirements. More...

	parse ($condition)
	Parses the delivered condition and creates a composite tree Structure. More...

	getExpressions ()

Protected Member Functions
	fetchExpressions ()
	Matches all expressions in the current condition and assign these to the class attribute ConditionParser::$expressions. More...

	fetchOperators ()
	Matches all operators in the current condition and assign these to the class attribute ConditionParser::$operators. More...

	cannonicalizeCondition ()
	Cannonicalize the condition into a more general form. More...

	checkBrackets ()

	createNodeArray ()
	Creates an array representing all Nodes in a condition based on the fetched expressions and operators. More...

	surroundNegationExpression ($index)

	isNegationSurroundedByBrackets ($index)

Protected Attributes
	$condition

	$expressions

	$operators

	$index

	$spaces

Detailed Description

Definition at line 14 of file ilAssLacConditionParser.php.

Constructor & Destructor Documentation

◆ __construct()

ilAssLacConditionParser::__construct ( )

Construct requirements.

Definition at line 57 of file ilAssLacConditionParser.php.

    {
        include_once 'Modules/TestQuestionPool/classes/questions/LogicalAnswerCompare/Factory/ilAssLacExpressionManufacturer.php';
        include_once 'Modules/TestQuestionPool/classes/questions/LogicalAnswerCompare/Factory/ilAssLacOperationManufacturer.php';
        include_once "Modules/TestQuestionPool/classes/questions/LogicalAnswerCompare/ilAssLacCompositeBuilder.php";
    }

Member Function Documentation

◆ cannonicalizeCondition()

ilAssLacConditionParser::cannonicalizeCondition ( )

protected

Cannonicalize the condition into a more general form.

It replaces all expression with "n" and all orperators with "o"
so that the result of an condition after cannonicalization could be:

(n o n) o (n o n) o n

Definition at line 117 of file ilAssLacConditionParser.php.

    {
        $manufacturer = ilAssLacExpressionManufacturer::_getInstance();
        $this->condition = preg_replace($manufacturer->getPattern(), 'n', $this->condition);
        $manufacturer = ilAssLacOperationManufacturer::_getInstance();
        $this->condition = preg_replace($manufacturer->getPattern(), 'o', $this->condition);
        $this->condition = preg_replace("/no/", "n o", $this->condition);
        $this->condition = preg_replace("/on/", "o n", $this->condition);
 
        for ($i = 0; $i < strlen($this->condition); $i++) {
            if ($this->condition[$i] == "!" && !$this->isNegationSurroundedByBrackets($i)) {
                $this->surroundNegationExpression($i);
            }
        }
    }

References $i, ilAssLacExpressionManufacturer\_getInstance(), ilAssLacOperationManufacturer\_getInstance(), isNegationSurroundedByBrackets(), and surroundNegationExpression().

Referenced by parse().

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◆ checkBrackets()

ilAssLacConditionParser::checkBrackets ( )

protected

Definition at line 133 of file ilAssLacConditionParser.php.

    {
        $num_brackets_open = substr_count($this->condition, "(");
        $num_brackets_close = substr_count($this->condition, ")");
 
        if ($num_brackets_open > $num_brackets_close) {
            throw new ilAssLacMissingBracket(")");
        }
        if ($num_brackets_open < $num_brackets_close) {
            throw new ilAssLacMissingBracket("(");
        }
    }

Referenced by parse().

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◆ createNodeArray()

ilAssLacConditionParser::createNodeArray ( )

protected

Creates an array representing all Nodes in a condition based on the fetched expressions and operators.

The array has a tree representation which depth is dependent to the bracketing in the condition
The array contains of four main keys to identify the elements:

Key	Values	Description
type	"group", "expression", "operator"	The type of the node - Group is used to introduce the next tree depth
value	mixed	Contains an extracted expression or operation from a condition
nodes	array	Contains an node array

Returns: array

Definition at line 168 of file ilAssLacConditionParser.php.

    {
        $expected = array("n", "(", "!");
        $group = array();
        $negation = false;
 
        while ($this->index < strlen($this->condition)) {
            $a = $this->condition[$this->index];
            if (trim($this->condition[$this->index]) != "" && in_array($this->condition[$this->index], $expected)) {
                if ($this->condition[$this->index] == ')') {
                    return $group;
                } elseif ($this->condition[$this->index] == 'n') {
                    $group[] = array('type' => 'expression', 'value' => array_shift($this->expressions));
                    $expected = array("o", ")");
                } elseif ($this->condition[$this->index] == 'o') {
                    $group[] = array('type' => 'operator', 'value' => array_shift($this->operators));
                    $expected = array("n", "(", "!");
                } elseif ($this->condition[$this->index] == '(') {
                    $this->index++;
                    $elements = $this->createNodeArray();
                    $group[] = array('type' => "group", "negated" => $negation, 'nodes' => $elements);
                    $negation = false;
                    $expected = array("o",")");
                } elseif ($this->condition[$this->index] == "!") {
                    $negation = true;
                }
            } elseif (trim($this->condition[$this->index]) != "") {
                throw new ilAssLacConditionParserException($this->index-$this->spaces+1);
            } else {
                $this->spaces++;
            }
 
            $this->index++;
        }
        return array('type' => 'group', "negated" => $negation, 'nodes' => $group);
    }

References $index, and createNodeArray().

Referenced by createNodeArray(), and parse().

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◆ fetchExpressions()

ilAssLacConditionParser::fetchExpressions ( )

protected

Matches all expressions in the current condition and assign these to the class attribute ConditionParser::$expressions.

See also: AbstractManufacturer::match(); ExpressionManufacturer::getPattern(); Parser::$expressions

Definition at line 91 of file ilAssLacConditionParser.php.

    {
        $manufacturer = ilAssLacExpressionManufacturer::_getInstance();
        $this->expressions = $manufacturer->match($this->condition);
    }

References ilAssLacExpressionManufacturer\_getInstance().

Referenced by parse().

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◆ fetchOperators()

ilAssLacConditionParser::fetchOperators ( )

protected

Matches all operators in the current condition and assign these to the class attribute ConditionParser::$operators.

See also: AbstractManufacturer::match(); OperationManufacturer::getPattern(); Parser::$operators

Definition at line 104 of file ilAssLacConditionParser.php.

    {
        $manufacturer = ilAssLacOperationManufacturer::_getInstance();
        $this->operators = $manufacturer->match($this->condition);
    }

References ilAssLacOperationManufacturer\_getInstance().

Referenced by parse().

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◆ getExpressions()

ilAssLacConditionParser::getExpressions ( )

Returns: array

Definition at line 208 of file ilAssLacConditionParser.php.

    {
        return $this->expressions;
    }

References $expressions.

◆ isNegationSurroundedByBrackets()

ilAssLacConditionParser::isNegationSurroundedByBrackets ( $index )

protected

Parameters

int $index

Returns: boolean

Definition at line 235 of file ilAssLacConditionParser.php.

    {
        $next_bracket = strpos($this->condition, "(", $index+1);
        $next_expression = strpos($this->condition, "n", $index+1);
 
        return $next_bracket !== false & $next_bracket < $next_expression;
    }

References $index.

Referenced by cannonicalizeCondition().

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◆ parse()

ilAssLacConditionParser::parse ( $condition )

Parses the delivered condition and creates a composite tree Structure.

Parameters

$condition

See also: CompositeBuilder::create()

Returns: array

Definition at line 72 of file ilAssLacConditionParser.php.

    {
        $this->condition = $condition;
        $this->checkBrackets();
        $this->fetchExpressions();
        $this->fetchOperators();
        $this->cannonicalizeCondition();
        $nodes = $this->createNodeArray();
        $compositeBuilder = new ilAssLacCompositeBuilder();
        return $compositeBuilder->create($nodes);
    }

References $condition, cannonicalizeCondition(), checkBrackets(), createNodeArray(), fetchExpressions(), and fetchOperators().

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◆ surroundNegationExpression()

ilAssLacConditionParser::surroundNegationExpression ( $index )

protected

Parameters

int $index

Definition at line 216 of file ilAssLacConditionParser.php.

    {
        $start = strpos($this->condition, "n", $index + 1);
        $end = false;
 
        if ($start !== false) {
            $end   = strpos($this->condition, "n", $start + 1);
        }
 
        if ($start !== false && $end !== false) {
            $this->condition = substr_replace($this->condition, "(n o n)", $start, $end - $start + 1);
        }
    }