Parser::combinator() - Code Metrics - arthurkushman/querypath - Measure and Improve Code Quality continuously with Scrutinizer

Parser::combinator() C
last analyzed 2022-03-28 08:12 UTC

↳ Parent: Parser

Complexity

Conditions	12
Paths	80

Size

Total Lines	56
Code Lines	34

Duplication

Lines	0
Ratio	0 %

Importance

Changes

Metric	Value
cc	12
eloc	34
nc	80
nop	0
dl	0
loc	56
rs	6.9666
c	0
b	0
f	0

How to fix Long Method Complexity

<?php
/**
 * @file
 *
 * The CSS parser
 */

namespace QueryPath\CSS;

use QueryPath\Exception;

/**
 * Parse a CSS selector.
 *
 * In CSS, a selector is used to identify which element or elements
 * in a DOM are being selected for the application of a particular style.
 * Effectively, selectors function as a query language for a structured
 * document -- almost always HTML or XML.
 *
 * This class provides an event-based parser for CSS selectors. It can be
 * used, for example, as a basis for writing a DOM query engine based on
 * CSS.
 *
 * @ingroup querypath_css
 */
class Parser
{
    protected $scanner;
    protected $buffer = '';
    protected $handler;
    private $strict = false;

    protected $DEBUG = false;

    /**
     * Construct a new CSS parser object. This will attempt to
     * parse the string as a CSS selector. As it parses, it will
     * send events to the EventHandler implementation.
     *
     * @param string $string
     * @param EventHandler $handler
     */
    public function __construct(string $string, EventHandler $handler)
    {
        $this->originalString = $string;

        $is = new InputStream($string);
        $this->scanner = new Scanner($is);
        $this->handler = $handler;
    }

    /**
     * Parse the selector.
     *
     * This begins an event-based parsing process that will
     * fire events as the selector is handled. A EventHandler
     * implementation will be responsible for handling the events.
     *
     * @throws ParseException
     * @throws Exception
     */
    public function parse(): void
    {
        $this->scanner->nextToken();

        while ($this->scanner->token !== false) {
            // Primitive recursion detection.
            $position = $this->scanner->position();

            if ($this->DEBUG) {
                echo 'PARSE ' . $this->scanner->token . PHP_EOL;
            }
            $this->selector();

            $finalPosition = $this->scanner->position();
            if ($this->scanner->token !== false && $finalPosition === $position) {
                // If we get here, then the scanner did not pop a single character
                // off of the input stream during a full run of the parser, which
                // means that the current input does not match any recognizable
                // pattern.
                throw new ParseException('CSS selector is not well formed.');
            }
        }
    }

    /**
     * A restricted parser that can only parse simple selectors.
     * The pseudoClass handler for this parser will throw an
     * exception if it encounters a pseudo-element or the
     * negation pseudo-class.
     *
     * @deprecated This is not used anywhere in QueryPath and
     *  may be removed.
     *//*
  public function parseSimpleSelector() {
    while ($this->scanner->token !== FALSE) {
      if ($this->DEBUG) print "SIMPLE SELECTOR\n";
      $this->allElements();
      $this->elementName();
      $this->elementClass();
      $this->elementID();
      $this->pseudoClass(TRUE); // Operate in restricted mode.
      $this->attribute();

      // TODO: Need to add failure conditions here.
    }
  }*/

    /**
     * Handle an entire CSS selector.
     *
     * @throws ParseException
     * @throws Exception
     */
    private function selector(): void
    {
        if ($this->DEBUG) {
            print 'SELECTOR' . $this->scanner->position() . PHP_EOL;
        }

        $this->consumeWhitespace(); // Remove leading whitespace
        $this->simpleSelectors();
        $this->combinator();
    }

    /**
     * Consume whitespace and return a count of the number of whitespace consumed.
     *
     * @throws \QueryPath\CSS\ParseException
     * @throws Exception
     */
    private function consumeWhitespace(): int
    {
        if ($this->DEBUG) {
            echo 'CONSUME WHITESPACE' . PHP_EOL;
        }

        $white = 0;
        while ($this->scanner->token === Token::WHITE) {
            $this->scanner->nextToken();
            ++$white;
        }

        return $white;
    }

    /**
     * Handle one of the five combinators: '>', '+', ' ', '~', and ','.
     * This will call the appropriate event handlers.
     *
     * @see EventHandler::directDescendant(),
     * @see EventHandler::adjacent(),
     * @see EventHandler::anyDescendant(),
     * @see EventHandler::anotherSelector().
     * @throws ParseException
     * @throws \QueryPath\Exception
     */
    private function combinator(): void
    {
        if ($this->DEBUG) {
            echo 'COMBINATOR' . PHP_EOL;
        }
        /*
         * Problem: ' ' and ' > ' are both valid combinators.
         * So we have to track whitespace consumption to see
         * if we are hitting the ' ' combinator or if the
         * selector just has whitespace padding another combinator.
         */

        // Flag to indicate that post-checks need doing
        $inCombinator = false;
        $white = $this->consumeWhitespace();
        $t = $this->scanner->token;

        if ($t === Token::RANGLE) {
            $this->handler->directDescendant();
            $this->scanner->nextToken();
            $inCombinator = true;
            //$this->simpleSelectors();
        } elseif ($t === Token::PLUS) {
            $this->handler->adjacent();
            $this->scanner->nextToken();
            $inCombinator = true;
            //$this->simpleSelectors();
        } elseif ($t === Token::COMMA) {
            $this->handler->anotherSelector();
            $this->scanner->nextToken();
            $inCombinator = true;
            //$this->scanner->selectors();
        } elseif ($t === Token::TILDE) {
            $this->handler->sibling();
            $this->scanner->nextToken();
            $inCombinator = true;
        }

        // Check that we don't get two combinators in a row.
        if ($inCombinator) {
            if ($this->DEBUG) {
                print 'COMBINATOR: ' . Token::name($t) . "\n";
            }
            $this->consumeWhitespace();
            if ($this->isCombinator($this->scanner->token)) {
                throw new ParseException('Illegal combinator: Cannot have two combinators in sequence.');
            }
        } // Check to see if we have whitespace combinator:
        elseif ($white > 0) {
            if ($this->DEBUG) {
                echo 'COMBINATOR: any descendant' . PHP_EOL;
            }
            $this->handler->anyDescendant();
        } else {
            if ($this->DEBUG) {
                echo 'COMBINATOR: no combinator found.' . PHP_EOL;
            }
        }
    }

    /**
     * Check if the token is a combinator.
     *
     * @param int $tok
     * @return bool
     */
    private function isCombinator(int $tok): bool
    {
        return in_array($tok, [Token::PLUS, Token::RANGLE, Token::COMMA, Token::TILDE], true);
    }

    /**
     * Handle a simple selector.
     *
     * @throws ParseException
     */
    private function simpleSelectors(): void
    {
        if ($this->DEBUG) {
            print 'SIMPLE SELECTOR' . PHP_EOL;
        }
        $this->allElements();
        $this->elementName();
        $this->elementClass();
        $this->elementID();
        $this->pseudoClass();
        $this->attribute();
    }

    /**
     * Handles CSS ID selectors.
     * This will call EventHandler::elementID().
     *
     * @throws \QueryPath\CSS\ParseException
     * @throws Exception
     */
    private function elementID(): void
    {
        if ($this->DEBUG) {
            echo 'ELEMENT ID' . PHP_EOL;
        }

        if ($this->scanner->token === Token::OCTO) {
            $this->scanner->nextToken();
            if ($this->scanner->token !== Token::CHAR) {
                throw new ParseException("Expected string after #");
            }
            $id = $this->scanner->getNameString();
            $this->handler->elementID($id);
        }
    }

    /**
     * Handles CSS class selectors.
     * This will call the EventHandler::elementClass() method.
     */
    private function elementClass(): void
    {
        if ($this->DEBUG) {
            print 'ELEMENT CLASS' . PHP_EOL;
        }
        if ($this->scanner->token == Token::DOT) {
            $this->scanner->nextToken();
            $this->consumeWhitespace(); // We're very fault tolerent. This should prob through error.
            $cssClass = $this->scanner->getNameString();
            $this->handler->elementClass($cssClass);
        }
    }

    /**
     * Handle a pseudo-class and pseudo-element.
     *
     * CSS 3 selectors support separate pseudo-elements, using :: instead
     * of : for separator. This is now supported, and calls the pseudoElement
     * handler, EventHandler::pseudoElement().
     *
     * This will call EventHandler::pseudoClass() when a
     * pseudo-class is parsed.
     *
     * @throws ParseException
     * @throws Exception
     */
    private function pseudoClass($restricted = false): void
    {
        if ($this->DEBUG) {
            echo 'PSEUDO-CLASS' . PHP_EOL;
        }
        if ($this->scanner->token === Token::COLON) {
            // Check for CSS 3 pseudo element:
            $isPseudoElement = false;
            if ($this->scanner->nextToken() === Token::COLON) {
                $isPseudoElement = true;
                $this->scanner->nextToken();
            }

            $name = $this->scanner->getNameString();
            if ($restricted && $name === 'not') {
                throw new ParseException("The 'not' pseudo-class is illegal in this context.");
            }

            $value = NULL;
            if ($this->scanner->token === Token::LPAREN) {
                if ($isPseudoElement) {
                    throw new ParseException('Illegal left paren. Pseudo-Element cannot have arguments.');
                }
                $value = $this->pseudoClassValue();
            }

            // FIXME: This should throw errors when pseudo element has values.
            if ($isPseudoElement) {
                if ($restricted) {
                    throw new ParseException('Pseudo-Elements are illegal in this context.');
                }
                $this->handler->pseudoElement($name);
                $this->consumeWhitespace();

                // Per the spec, pseudo-elements must be the last items in a selector, so we
                // check to make sure that we are either at the end of the stream or that a
                // new selector is starting. Only one pseudo-element is allowed per selector.
                if ($this->scanner->token !== false && $this->scanner->token !== Token::COMMA) {
                    throw new ParseException('A Pseudo-Element must be the last item in a selector.');
                }
            } else {
                $this->handler->pseudoClass($name, $value);
            }
        }
    }

    /**
     * Get the value of a pseudo-classes.
     *
     * @return string
     *  Returns the value found from a pseudo-class.
     *
     * @todo Pseudoclasses can be passed pseudo-elements and
     *  other pseudo-classes as values, which means :pseudo(::pseudo)
     *  is legal.
     */
    private function pseudoClassValue()
    {
        if ($this->scanner->token === Token::LPAREN) {
            $buf = '';

            // For now, just leave pseudoClass value vague.
            /*
            // We have to peek to see if next char is a colon because
            // pseudo-classes and pseudo-elements are legal strings here.
            print $this->scanner->peek();
            if ($this->scanner->peek() == ':') {
              print "Is pseudo\n";
              $this->scanner->nextToken();

              // Pseudo class
              if ($this->scanner->token == Token::colon) {
                $buf .= ':';
                $this->scanner->nextToken();
                // Pseudo element
                if ($this->scanner->token == Token::colon) {
                  $buf .= ':';
                  $this->scanner->nextToken();
                }
                // Ident
                $buf .= $this->scanner->getNameString();
              }
            }
            else {
              print "fetching string.\n";
              $buf .= $this->scanner->getQuotedString();
              if ($this->scanner->token != Token::rparen) {
                $this->throwError(Token::rparen, $this->scanner->token);
              }
              $this->scanner->nextToken();
            }
            return $buf;
            */
            //$buf .= $this->scanner->getQuotedString();
            $buf .= $this->scanner->getPseudoClassString();

            return $buf;
        }
    }

    /**
     * Handle element names.
     * This will call the EventHandler::elementName().
     *
     * This handles:
     * <code>
     *  name (EventHandler::element())
     *  |name (EventHandler::element())
     *  ns|name (EventHandler::elementNS())
     *  ns|* (EventHandler::elementNS())
     * </code>
     */
    private function elementName()
    {
        if ($this->DEBUG) {
            print "ELEMENT NAME\n";
        }
        if ($this->scanner->token === Token::PIPE) {
            // We have '|name', which is equiv to 'name'
            $this->scanner->nextToken();
            $this->consumeWhitespace();
            $elementName = $this->scanner->getNameString();
            $this->handler->element($elementName);
        } elseif ($this->scanner->token === Token::CHAR) {
            $elementName = $this->scanner->getNameString();
            if ($this->scanner->token == Token::PIPE) {
                // Get ns|name
                $elementNS = $elementName;
                $this->scanner->nextToken();
                $this->consumeWhitespace();
                if ($this->scanner->token === Token::STAR) {
                    // We have ns|*
                    $this->handler->anyElementInNS($elementNS);
                    $this->scanner->nextToken();
                } elseif ($this->scanner->token !== Token::CHAR) {
                    $this->throwError(Token::CHAR, $this->scanner->token);
                } else {
                    $elementName = $this->scanner->getNameString();
                    // We have ns|name
                    $this->handler->elementNS($elementName, $elementNS);
                }

            } else {
                $this->handler->element($elementName);
            }
        }
    }

    /**
     * Check for all elements designators. Due to the new CSS 3 namespace
     * support, this is slightly more complicated, now, as it handles
     * the *|name and *|* cases as well as *.
     *
     * Calls EventHandler::anyElement() or EventHandler::elementName().
     */
    private function allElements()
    {
        if ($this->scanner->token === Token::STAR) {
            $this->scanner->nextToken();
            if ($this->scanner->token === Token::PIPE) {
                $this->scanner->nextToken();
                if ($this->scanner->token === Token::STAR) {
                    // We got *|*. According to spec, this requires
                    // that the element has a namespace, so we pass it on
                    // to the handler:
                    $this->scanner->nextToken();
                    $this->handler->anyElementInNS('*');
                } else {
                    // We got *|name, which means the name MUST be in a namespce,
                    // so we pass this off to elementNameNS().
                    $name = $this->scanner->getNameString();
                    $this->handler->elementNS($name, '*');
                }
            } else {
                $this->handler->anyElement();
            }
        }
    }

    /**
     * Handler an attribute.
     * An attribute can be in one of two forms:
     * <code>[attrName]</code>
     * or
     * <code>[attrName="AttrValue"]</code>
     *
     * This may call the following event handlers: EventHandler::attribute().
     *
     * @throws \QueryPath\CSS\ParseException
     * @throws Exception
     */
    private function attribute()
    {
        if ($this->scanner->token === Token::LSQUARE) {
            $attrVal = $op = $ns = NULL;

            $this->scanner->nextToken();
            $this->consumeWhitespace();

            if ($this->scanner->token === Token::AT) {
                if ($this->strict) {
                    throw new ParseException('The @ is illegal in attributes.');
                }

                $this->scanner->nextToken();
                $this->consumeWhitespace();
            }

            if ($this->scanner->token === Token::STAR) {
                // Global namespace... requires that attr be prefixed,
                // so we pass this on to a namespace handler.
                $ns = '*';
                $this->scanner->nextToken();
            }
            if ($this->scanner->token === Token::PIPE) {
                // Skip this. It's a global namespace.
                $this->scanner->nextToken();
                $this->consumeWhitespace();
            }

            $attrName = $this->scanner->getNameString();
            $this->consumeWhitespace();

            // Check for namespace attribute: ns|attr. We have to peek() to make
            // sure that we haven't hit the |= operator, which looks the same.
            if ($this->scanner->token === Token::PIPE && $this->scanner->peek() !== '=') {
                // We have a namespaced attribute.
                $ns = $attrName;
                $this->scanner->nextToken();
                $attrName = $this->scanner->getNameString();
                $this->consumeWhitespace();
            }

            // Note: We require that operators do not have spaces
            // between characters, e.g. ~= , not ~ =.

            // Get the operator:
            switch ($this->scanner->token) {
                case Token::EQ:
                    $this->consumeWhitespace();
                    $op = EventHandler::IS_EXACTLY;
                    break;
                case Token::TILDE:
                    if ($this->scanner->nextToken() !== Token::EQ) {
                        $this->throwError(Token::EQ, $this->scanner->token);
                    }
                    $op = EventHandler::CONTAINS_WITH_SPACE;
                    break;
                case Token::PIPE:
                    if ($this->scanner->nextToken() !== Token::EQ) {
                        $this->throwError(Token::EQ, $this->scanner->token);
                    }
                    $op = EventHandler::CONTAINS_WITH_HYPHEN;
                    break;
                case Token::STAR:
                    if ($this->scanner->nextToken() !== Token::EQ) {
                        $this->throwError(Token::EQ, $this->scanner->token);
                    }
                    $op = EventHandler::CONTAINS_IN_STRING;
                    break;
                case Token::DOLLAR;
                    if ($this->scanner->nextToken() !== Token::EQ) {
                        $this->throwError(Token::EQ, $this->scanner->token);
                    }
                    $op = EventHandler::ENDS_WITH;
                    break;
                case Token::CARAT:
                    if ($this->scanner->nextToken() !== Token::EQ) {
                        $this->throwError(Token::EQ, $this->scanner->token);
                    }
                    $op = EventHandler::BEGINS_WITH;
                    break;
            }

            if (isset($op)) {
                // Consume '=' and go on.
                $this->scanner->nextToken();
                $this->consumeWhitespace();

                // So... here we have a problem. The grammer suggests that the
                // value here is String1 or String2, both of which are enclosed
                // in quotes of some sort, and both of which allow lots of special
                // characters. But the spec itself includes examples like this:
                //   [lang=fr]
                // So some bareword support is assumed. To get around this, we assume
                // that bare words follow the NAME rules, while quoted strings follow
                // the String1/String2 rules.

                if ($this->scanner->token === Token::QUOTE || $this->scanner->token === Token::SQUOTE) {
                    $attrVal = $this->scanner->getQuotedString();
                } else {
                    $attrVal = $this->scanner->getNameString();
                }

                if ($this->DEBUG) {
                    print "ATTR: $attrVal AND OP: $op\n";
                }
            }

            $this->consumeWhitespace();

            if ($this->scanner->token !== Token::RSQUARE) {
                $this->throwError(Token::RSQUARE, $this->scanner->token);
            }

            if (isset($ns)) {
                $this->handler->attributeNS($attrName, $ns, $attrVal, $op);
            } elseif (isset($attrVal)) {
                $this->handler->attribute($attrName, $attrVal, $op);
            } else {
                $this->handler->attribute($attrName);
            }
            $this->scanner->nextToken();
        }
    }

    /**
     * Utility for throwing a consistantly-formatted parse error.
     */
    private function throwError($expected, $got)
    {
        $filter = sprintf('Expected %s, got %s', Token::name($expected), Token::name($got));
        throw new ParseException($filter);
    }

    /**
     * @return Scanner
     */
    public function getScanner(): Scanner
    {
        return $this->scanner;
    }

}



1			<?php
2			/**
3			* @file
4			*
5			* The CSS parser
6			*/
7
8			namespace QueryPath\CSS;
9
10			use QueryPath\Exception;
11
12			/**
13			* Parse a CSS selector.
14			*
15			* In CSS, a selector is used to identify which element or elements
16			* in a DOM are being selected for the application of a particular style.
17			* Effectively, selectors function as a query language for a structured
18			* document -- almost always HTML or XML.
19			*
20			* This class provides an event-based parser for CSS selectors. It can be
21			* used, for example, as a basis for writing a DOM query engine based on
22			* CSS.
23			*
24			* @ingroup querypath_css
25			*/
26			class Parser
27			{
28			protected $scanner;
29			protected $buffer = '';
30			protected $handler;
31			private $strict = false;
32
33			protected $DEBUG = false;
34
35			/**
36			* Construct a new CSS parser object. This will attempt to
37			* parse the string as a CSS selector. As it parses, it will
38			* send events to the EventHandler implementation.
39			*
40			* @param string $string
41			* @param EventHandler $handler
42			*/
43			public function __construct(string $string, EventHandler $handler)
44			{
45			$this->originalString = $string;
			0 ignored issues – show Bug Best Practice introduced 2018-07-29 16:29 UTC by Report Bug Copy Issue Report The property `originalString` does not exist. Although not strictly required by PHP, it is generally a best practice to declare properties explicitly. Loading history...
46			$is = new InputStream($string);
47			$this->scanner = new Scanner($is);
48			$this->handler = $handler;
49			}
50
51			/**
52			* Parse the selector.
53			*
54			* This begins an event-based parsing process that will
55			* fire events as the selector is handled. A EventHandler
56			* implementation will be responsible for handling the events.
57			*
58			* @throws ParseException
59			* @throws Exception
60			*/
61			public function parse(): void
62			{
63			$this->scanner->nextToken();
64
65			while ($this->scanner->token !== false) {
66			// Primitive recursion detection.
67			$position = $this->scanner->position();
68
69			if ($this->DEBUG) {
70			echo 'PARSE ' . $this->scanner->token . PHP_EOL;
71			}
72			$this->selector();
73
74			$finalPosition = $this->scanner->position();
75			if ($this->scanner->token !== false && $finalPosition === $position) {
76			// If we get here, then the scanner did not pop a single character
77			// off of the input stream during a full run of the parser, which
78			// means that the current input does not match any recognizable
79			// pattern.
80			throw new ParseException('CSS selector is not well formed.');
81			}
82			}
83			}
84
85			/**
86			* A restricted parser that can only parse simple selectors.
87			* The pseudoClass handler for this parser will throw an
88			* exception if it encounters a pseudo-element or the
89			* negation pseudo-class.
90			*
91			* @deprecated This is not used anywhere in QueryPath and
92			* may be removed.
93			//
94			public function parseSimpleSelector() {
95			while ($this->scanner->token !== FALSE) {
96			if ($this->DEBUG) print "SIMPLE SELECTOR\n";
97			$this->allElements();
98			$this->elementName();
99			$this->elementClass();
100			$this->elementID();
101			$this->pseudoClass(TRUE); // Operate in restricted mode.
102			$this->attribute();
103
104			// TODO: Need to add failure conditions here.
105			}
106			}*/
107
108			/**
109			* Handle an entire CSS selector.
110			*
111			* @throws ParseException
112			* @throws Exception
113			*/
114			private function selector(): void
115			{
116			if ($this->DEBUG) {
117			print 'SELECTOR' . $this->scanner->position() . PHP_EOL;
118			}
119
120			$this->consumeWhitespace(); // Remove leading whitespace
121			$this->simpleSelectors();
122			$this->combinator();
123			}
124
125			/**
126			* Consume whitespace and return a count of the number of whitespace consumed.
127			*
128			* @throws \QueryPath\CSS\ParseException
129			* @throws Exception
130			*/
131			private function consumeWhitespace(): int
132			{
133			if ($this->DEBUG) {
134			echo 'CONSUME WHITESPACE' . PHP_EOL;
135			}
136
137			$white = 0;
138			while ($this->scanner->token === Token::WHITE) {
139			$this->scanner->nextToken();
140			++$white;
141			}
142
143			return $white;
144			}
145
146			/**
147			* Handle one of the five combinators: '>', '+', ' ', '~', and ','.
148			* This will call the appropriate event handlers.
149			*
150			* @see EventHandler::directDescendant(),
151			* @see EventHandler::adjacent(),
152			* @see EventHandler::anyDescendant(),
153			* @see EventHandler::anotherSelector().
154			* @throws ParseException
155			* @throws \QueryPath\Exception
156			*/
157			private function combinator(): void
158			{
159			if ($this->DEBUG) {
160			echo 'COMBINATOR' . PHP_EOL;
161			}
162			/*
163			* Problem: ' ' and ' > ' are both valid combinators.
164			* So we have to track whitespace consumption to see
165			* if we are hitting the ' ' combinator or if the
166			* selector just has whitespace padding another combinator.
167			*/
168
169			// Flag to indicate that post-checks need doing
170			$inCombinator = false;
171			$white = $this->consumeWhitespace();
172			$t = $this->scanner->token;
173
174			if ($t === Token::RANGLE) {
175			$this->handler->directDescendant();
176			$this->scanner->nextToken();
177			$inCombinator = true;
178			//$this->simpleSelectors();
179			} elseif ($t === Token::PLUS) {
180			$this->handler->adjacent();
181			$this->scanner->nextToken();
182			$inCombinator = true;
183			//$this->simpleSelectors();
184			} elseif ($t === Token::COMMA) {
185			$this->handler->anotherSelector();
186			$this->scanner->nextToken();
187			$inCombinator = true;
188			//$this->scanner->selectors();
189			} elseif ($t === Token::TILDE) {
190			$this->handler->sibling();
191			$this->scanner->nextToken();
192			$inCombinator = true;
193			}
194
195			// Check that we don't get two combinators in a row.
196			if ($inCombinator) {
197			if ($this->DEBUG) {
198			print 'COMBINATOR: ' . Token::name($t) . "\n";
199			}
200			$this->consumeWhitespace();
201			if ($this->isCombinator($this->scanner->token)) {
202			throw new ParseException('Illegal combinator: Cannot have two combinators in sequence.');
203			}
204			} // Check to see if we have whitespace combinator:
205			elseif ($white > 0) {
206			if ($this->DEBUG) {
207			echo 'COMBINATOR: any descendant' . PHP_EOL;
208			}
209			$this->handler->anyDescendant();
210			} else {
211			if ($this->DEBUG) {
212			echo 'COMBINATOR: no combinator found.' . PHP_EOL;
213			}
214			}
215			}
216
217			/**
218			* Check if the token is a combinator.
219			*
220			* @param int $tok
221			* @return bool
222			*/
223			private function isCombinator(int $tok): bool
224			{
225			return in_array($tok, [Token::PLUS, Token::RANGLE, Token::COMMA, Token::TILDE], true);
226			}
227
228			/**
229			* Handle a simple selector.
230			*
231			* @throws ParseException
232			*/
233			private function simpleSelectors(): void
234			{
235			if ($this->DEBUG) {
236			print 'SIMPLE SELECTOR' . PHP_EOL;
237			}
238			$this->allElements();
239			$this->elementName();
240			$this->elementClass();
241			$this->elementID();
242			$this->pseudoClass();
243			$this->attribute();
244			}
245
246			/**
247			* Handles CSS ID selectors.
248			* This will call EventHandler::elementID().
249			*
250			* @throws \QueryPath\CSS\ParseException
251			* @throws Exception
252			*/
253			private function elementID(): void
254			{
255			if ($this->DEBUG) {
256			echo 'ELEMENT ID' . PHP_EOL;
257			}
258
259			if ($this->scanner->token === Token::OCTO) {
260			$this->scanner->nextToken();
261			if ($this->scanner->token !== Token::CHAR) {
262			throw new ParseException("Expected string after #");
263			}
264			$id = $this->scanner->getNameString();
265			$this->handler->elementID($id);
266			}
267			}
268
269			/**
270			* Handles CSS class selectors.
271			* This will call the EventHandler::elementClass() method.
272			*/
273			private function elementClass(): void
274			{
275			if ($this->DEBUG) {
276			print 'ELEMENT CLASS' . PHP_EOL;
277			}
278			if ($this->scanner->token == Token::DOT) {
279			$this->scanner->nextToken();
280			$this->consumeWhitespace(); // We're very fault tolerent. This should prob through error.
281			$cssClass = $this->scanner->getNameString();
282			$this->handler->elementClass($cssClass);
283			}
284			}
285
286			/**
287			* Handle a pseudo-class and pseudo-element.
288			*
289			* CSS 3 selectors support separate pseudo-elements, using :: instead
290			* of : for separator. This is now supported, and calls the pseudoElement
291			* handler, EventHandler::pseudoElement().
292			*
293			* This will call EventHandler::pseudoClass() when a
294			* pseudo-class is parsed.
295			*
296			* @throws ParseException
297			* @throws Exception
298			*/
299			private function pseudoClass($restricted = false): void
300			{
301			if ($this->DEBUG) {
302			echo 'PSEUDO-CLASS' . PHP_EOL;
303			}
304			if ($this->scanner->token === Token::COLON) {
305			// Check for CSS 3 pseudo element:
306			$isPseudoElement = false;
307			if ($this->scanner->nextToken() === Token::COLON) {
308			$isPseudoElement = true;
309			$this->scanner->nextToken();
310			}
311
312			$name = $this->scanner->getNameString();
313			if ($restricted && $name === 'not') {
314			throw new ParseException("The 'not' pseudo-class is illegal in this context.");
315			}
316
317			$value = NULL;
318			if ($this->scanner->token === Token::LPAREN) {
319			if ($isPseudoElement) {
320			throw new ParseException('Illegal left paren. Pseudo-Element cannot have arguments.');
321			}
322			$value = $this->pseudoClassValue();
323			}
324
325			// FIXME: This should throw errors when pseudo element has values.
326			if ($isPseudoElement) {
327			if ($restricted) {
328			throw new ParseException('Pseudo-Elements are illegal in this context.');
329			}
330			$this->handler->pseudoElement($name);
331			$this->consumeWhitespace();
332
333			// Per the spec, pseudo-elements must be the last items in a selector, so we
334			// check to make sure that we are either at the end of the stream or that a
335			// new selector is starting. Only one pseudo-element is allowed per selector.
336			if ($this->scanner->token !== false && $this->scanner->token !== Token::COMMA) {
337			throw new ParseException('A Pseudo-Element must be the last item in a selector.');
338			}
339			} else {
340			$this->handler->pseudoClass($name, $value);
341			}
342			}
343			}
344
345			/**
346			* Get the value of a pseudo-classes.
347			*
348			* @return string
349			* Returns the value found from a pseudo-class.
350			*
351			* @todo Pseudoclasses can be passed pseudo-elements and
352			* other pseudo-classes as values, which means :pseudo(::pseudo)
353			* is legal.
354			*/
355			private function pseudoClassValue()
356			{
357			if ($this->scanner->token === Token::LPAREN) {
358			$buf = '';
359
360			// For now, just leave pseudoClass value vague.
361			/*
362			// We have to peek to see if next char is a colon because
363			// pseudo-classes and pseudo-elements are legal strings here.
364			print $this->scanner->peek();
365			if ($this->scanner->peek() == ':') {
366			print "Is pseudo\n";
367			$this->scanner->nextToken();
368
369			// Pseudo class
370			if ($this->scanner->token == Token::colon) {
371			$buf .= ':';
372			$this->scanner->nextToken();
373			// Pseudo element
374			if ($this->scanner->token == Token::colon) {
375			$buf .= ':';
376			$this->scanner->nextToken();
377			}
378			// Ident
379			$buf .= $this->scanner->getNameString();
380			}
381			}
382			else {
383			print "fetching string.\n";
384			$buf .= $this->scanner->getQuotedString();
385			if ($this->scanner->token != Token::rparen) {
386			$this->throwError(Token::rparen, $this->scanner->token);
387			}
388			$this->scanner->nextToken();
389			}
390			return $buf;
391			*/
392			//$buf .= $this->scanner->getQuotedString();
393			$buf .= $this->scanner->getPseudoClassString();
394
395			return $buf;
396			}
397			}
398
399			/**
400			* Handle element names.
401			* This will call the EventHandler::elementName().
402			*
403			* This handles:
404			* <code>
405			* name (EventHandler::element())
406			* \|name (EventHandler::element())
407			* ns\|name (EventHandler::elementNS())
408			* ns\|* (EventHandler::elementNS())
409			* </code>
410			*/
411			private function elementName()
412			{
413			if ($this->DEBUG) {
414			print "ELEMENT NAME\n";
415			}
416			if ($this->scanner->token === Token::PIPE) {
417			// We have '\|name', which is equiv to 'name'
418			$this->scanner->nextToken();
419			$this->consumeWhitespace();
420			$elementName = $this->scanner->getNameString();
421			$this->handler->element($elementName);
422			} elseif ($this->scanner->token === Token::CHAR) {
423			$elementName = $this->scanner->getNameString();
424			if ($this->scanner->token == Token::PIPE) {
425			// Get ns\|name
426			$elementNS = $elementName;
427			$this->scanner->nextToken();
428			$this->consumeWhitespace();
429			if ($this->scanner->token === Token::STAR) {
430			// We have ns\|*
431			$this->handler->anyElementInNS($elementNS);
432			$this->scanner->nextToken();
433			} elseif ($this->scanner->token !== Token::CHAR) {
434			$this->throwError(Token::CHAR, $this->scanner->token);
435			} else {
436			$elementName = $this->scanner->getNameString();
437			// We have ns\|name
438			$this->handler->elementNS($elementName, $elementNS);
439			}
440
441			} else {
442			$this->handler->element($elementName);
443			}
444			}
445			}
446
447			/**
448			* Check for all elements designators. Due to the new CSS 3 namespace
449			* support, this is slightly more complicated, now, as it handles
450			* the \|name and \|* cases as well as *.
451			*
452			* Calls EventHandler::anyElement() or EventHandler::elementName().
453			*/
454			private function allElements()
455			{
456			if ($this->scanner->token === Token::STAR) {
457			$this->scanner->nextToken();
458			if ($this->scanner->token === Token::PIPE) {
459			$this->scanner->nextToken();
460			if ($this->scanner->token === Token::STAR) {
461			// We got \|. According to spec, this requires
462			// that the element has a namespace, so we pass it on
463			// to the handler:
464			$this->scanner->nextToken();
465			$this->handler->anyElementInNS('*');
466			} else {
467			// We got *\|name, which means the name MUST be in a namespce,
468			// so we pass this off to elementNameNS().
469			$name = $this->scanner->getNameString();
470			$this->handler->elementNS($name, '*');
471			}
472			} else {
473			$this->handler->anyElement();
474			}
475			}
476			}
477
478			/**
479			* Handler an attribute.
480			* An attribute can be in one of two forms:
481			* <code>[attrName]</code>
482			* or
483			* <code>[attrName="AttrValue"]</code>
484			*
485			* This may call the following event handlers: EventHandler::attribute().
486			*
487			* @throws \QueryPath\CSS\ParseException
488			* @throws Exception
489			*/
490			private function attribute()
491			{
492			if ($this->scanner->token === Token::LSQUARE) {
493			$attrVal = $op = $ns = NULL;
494
495			$this->scanner->nextToken();
496			$this->consumeWhitespace();
497
498			if ($this->scanner->token === Token::AT) {
499			if ($this->strict) {
500			throw new ParseException('The @ is illegal in attributes.');
501			}
502
503			$this->scanner->nextToken();
504			$this->consumeWhitespace();
505			}
506
507			if ($this->scanner->token === Token::STAR) {
508			// Global namespace... requires that attr be prefixed,
509			// so we pass this on to a namespace handler.
510			$ns = '*';
511			$this->scanner->nextToken();
512			}
513			if ($this->scanner->token === Token::PIPE) {
514			// Skip this. It's a global namespace.
515			$this->scanner->nextToken();
516			$this->consumeWhitespace();
517			}
518
519			$attrName = $this->scanner->getNameString();
520			$this->consumeWhitespace();
521
522			// Check for namespace attribute: ns\|attr. We have to peek() to make
523			// sure that we haven't hit the \|= operator, which looks the same.
524			if ($this->scanner->token === Token::PIPE && $this->scanner->peek() !== '=') {
525			// We have a namespaced attribute.
526			$ns = $attrName;
527			$this->scanner->nextToken();
528			$attrName = $this->scanner->getNameString();
529			$this->consumeWhitespace();
530			}
531
532			// Note: We require that operators do not have spaces
533			// between characters, e.g. ~= , not ~ =.
534
535			// Get the operator:
536			switch ($this->scanner->token) {
537			case Token::EQ:
538			$this->consumeWhitespace();
539			$op = EventHandler::IS_EXACTLY;
540			break;
541			case Token::TILDE:
542			if ($this->scanner->nextToken() !== Token::EQ) {
543			$this->throwError(Token::EQ, $this->scanner->token);
544			}
545			$op = EventHandler::CONTAINS_WITH_SPACE;
546			break;
547			case Token::PIPE:
548			if ($this->scanner->nextToken() !== Token::EQ) {
549			$this->throwError(Token::EQ, $this->scanner->token);
550			}
551			$op = EventHandler::CONTAINS_WITH_HYPHEN;
552			break;
553			case Token::STAR:
554			if ($this->scanner->nextToken() !== Token::EQ) {
555			$this->throwError(Token::EQ, $this->scanner->token);
556			}
557			$op = EventHandler::CONTAINS_IN_STRING;
558			break;
559			case Token::DOLLAR;
560			if ($this->scanner->nextToken() !== Token::EQ) {
561			$this->throwError(Token::EQ, $this->scanner->token);
562			}
563			$op = EventHandler::ENDS_WITH;
564			break;
565			case Token::CARAT:
566			if ($this->scanner->nextToken() !== Token::EQ) {
567			$this->throwError(Token::EQ, $this->scanner->token);
568			}
569			$op = EventHandler::BEGINS_WITH;
570			break;
571			}
572
573			if (isset($op)) {
574			// Consume '=' and go on.
575			$this->scanner->nextToken();
576			$this->consumeWhitespace();
577
578			// So... here we have a problem. The grammer suggests that the
579			// value here is String1 or String2, both of which are enclosed
580			// in quotes of some sort, and both of which allow lots of special
581			// characters. But the spec itself includes examples like this:
582			// [lang=fr]
583			// So some bareword support is assumed. To get around this, we assume
584			// that bare words follow the NAME rules, while quoted strings follow
585			// the String1/String2 rules.
586
587			if ($this->scanner->token === Token::QUOTE \|\| $this->scanner->token === Token::SQUOTE) {
588			$attrVal = $this->scanner->getQuotedString();
589			} else {
590			$attrVal = $this->scanner->getNameString();
591			}
592
593			if ($this->DEBUG) {
594			print "ATTR: $attrVal AND OP: $op\n";
595			}
596			}
597
598			$this->consumeWhitespace();
599
600			if ($this->scanner->token !== Token::RSQUARE) {
601			$this->throwError(Token::RSQUARE, $this->scanner->token);
602			}
603
604			if (isset($ns)) {
605			$this->handler->attributeNS($attrName, $ns, $attrVal, $op);
606			} elseif (isset($attrVal)) {
607			$this->handler->attribute($attrName, $attrVal, $op);
608			} else {
609			$this->handler->attribute($attrName);
610			}
611			$this->scanner->nextToken();
612			}
613			}
614
615			/**
616			* Utility for throwing a consistantly-formatted parse error.
617			*/
618			private function throwError($expected, $got)
619			{
620			$filter = sprintf('Expected %s, got %s', Token::name($expected), Token::name($got));
621			throw new ParseException($filter);
622			}
623
624			/**
625			* @return Scanner
626			*/
627			public function getScanner(): Scanner
628			{
629			return $this->scanner;
630			}
631
632			}
633
634

arthurkushman / querypath

Parser::combinator() C last analyzed 2022-03-28 08:12 UTC

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Parser::combinator() C
last analyzed 2022-03-28 08:12 UTC