VirtualLib::getDisplayName() - Code Metrics - Inspection of "Support for virtual libraries" - seblucas/cops - Measure and Improve Code Quality continuously with Scrutinizer

Completed

Pull Request — master (#233)

unknown

created 2016-01-17 11:48 UTC

VirtualLib::getDisplayName() A

↳ Parent: VirtualLib

Complexity

Conditions	4
Paths	8

Size

Total Lines	10
Code Lines	9

Duplication

Lines	0
Ratio	0 %

Metric	Value
dl	0
loc	10
rs	9.2
cc	4
eloc	9
nc	8
nop	2

<?php
/**
 * COPS (Calibre OPDS PHP Server) class file
 *
 * @license    GPL 2 (http://www.gnu.org/licenses/gpl.html)
 * @author     Klaus Broelemann <[email protected]>
 */

require_once('base.php');

/**
 * Read and filter virtual libraries
 */
class VirtualLib {
	const SQL_VL_KEY = "virtual_libraries";  // Key for the virtual library entries.
	
	private $db_id = null;   // Database Index for the virtual lib
	private $vl_id = null;   // Library Index
	private $filter = null;  // structured representation of the current filter 
	
	private static $currentVL = null;  // Singleton: current virtual lib
	
	/**
	 * The constructor parses the calibre search string and creates a array-based representation out of it.
	 * 
	 * @param int $database The database id of the new object.
	 * @param int $virtualLib The virtual library id of the new object.
	 */
	private function __construct($database, $virtualLib) {
		$this->db_id  = $database;
		$this->vl_id  = $virtualLib;
		
		// Get the current search string
		$vlList = self::getVLList($database);
		$vlList = array_values($vlList);
		$searchStr = $vlList[$virtualLib];
		
		$this->filter = self::includeBookFilter(
						Filter::parseFilter($searchStr)
					);
	}
	
	/**
	 * Includes the booke filter (see $config['cops_books_filter'])
	 * @param Filter $filter
	 * @return string
	 */
	private static function includeBookFilter($filter) {
		$bookFilter = getURLParam ("tag", NULL);
		if (empty ($bookFilter)) return $filter;
		
		$negated = false;
		if (preg_match ("/^!(.*)$/", $bookFilter, $matches)) {
			$negated = true;
			$bookFilter = $matches[1];
		}
		$bookFilter = new ComparingFilter("tags", $bookFilter, "=");
		if ($negated)
			$bookFilter->negate();
		
		$result = new CombinationFilter(array($filter, $bookFilter));
		return $result->simplify();
	}
	
	/**
	 * Returns a SQL query that finds the IDs of all books accepted by the filter.
	 *
	 * The sql statement return only one column with the name 'id'.
	 * This statement can be included into other sql statements in order to apply the filter, e.g. by using inner joins
	 * like "select books.* from books inner join ({0}) as filter on books.id = filter.id"
	 * @see Filter
	 * 
	 * @return string an sql query
	 */
	public function getFilterQuery() {
		return $this->filter->toSQLQuery();
	}
	
	/**
	 * Get the name of the virtual library.
	 * 
	 * @return string Name of the virtual library.
	 */
	public function getName() {
		$names = self::getVLNameList($this->db_id);
		return $names[$this->vl_id];
	}
	
	/**
	 * Get the current VirtualLib object. 
	 *  
	 * @param int $database The current database id.
	 * @param int $virtualLib The current virtual library id.
	 * @return VirtualLib The corresponding VirtualLib object.
	 */
	public static function getVL($database = null, $virtualLib = null) {
		if (is_null($database))
			$database = getURLParam(DB, 0);
		if ( is_null(self::$currentVL) || self::$currentVL->db_id != $database || (self::$currentVL->vl_id != $virtualLib && !is_null($virtualLib))) {
			if (is_null($virtualLib))
				$virtualLib = GetUrlParam (VL, 0);
			self::$currentVL = new VirtualLib($database, $virtualLib);
		}
		return self::$currentVL;
	}
	
	/**
	 * Checks if the support for virtual libraries is enabled in the settings.
	 * 
	 * @return boolean true, if virtual libraries are enabled.
	 */
	public static function isVLEnabled() {
		global $config;
		return ($config['enable_virtual_libraries'] == 1);
	}
	
	/**
	 * Gets a list of all virtual libraries in a database.
	 * If virtual libraries are disabled, only an empty entry is returned.
	 * 
	 * @param int $database id of the database
	 * @return array An array of virtual libraries with the names as keys and the filter strings as values.  
	 */
	public static function getVLList($database = NULL) {
		// Standard return if virtual libraries are not enabled
		if (!self::isVLEnabled())
			return array("" => "");
		// Load list from Database
		$vLibs = json_decode(Base::getCalibreSetting(self::SQL_VL_KEY, $database), true);
		// Add "All Books" at the beginning
		if (is_null($vLibs))
			return array(localize ("allbooks.title") => "");
		else
			return array_merge(array(localize ("allbooks.title") => ""), $vLibs);
	}
	
	/**
	 * Gets a list of all virtual libraries in a database.
	 *
	 * @param int $database id of the database
	 * @return array An array of virtual libraries with the names as keys and the filter strings as values.
	 */
	public static function getVLNameList($database = NULL) {
		return array_keys(self::getVLList($database));
	}
	
	/**
	 * Combines the database and virtual lib names into a merged name.
	 * 
	 * The resulting name has the form "{$dbName} - {$vlName}". If one of these parameters is empty, the dash will also be removed.
	 * If the support for virtual libraries is not enabled, this function simply returns the database name.
	 * 
	 * @param string $dbName The database name. If NULL, the name of the current db is taken.
	 * @param string $vlName The name of the virtual library. If NULL, the name of the current vl is taken.
	 */
	public static function getDisplayName($dbName = NULL, $vlName = NULL) {
		if (is_null($dbName))
			$dbName = Base::getDbName();
		if (is_null($vlName))
			$vlName = self::getVL()->getName();
		if (self::isVLEnabled())
			return trim(str_format('{0} - {1}', $dbName, $vlName), ' -');
		else
			return $dbName;
	}
}

/**
 * Abstract classe to store filters internally. It's derived classes represent the different filter types.
 *
 */
abstract class Filter {
	// Special settings for known attributes
	private static $KNOWN_ATTRIBUTES = array(
		"authors"    => array(),
		"series"     => array("link_join_on" => "series"),
		"publishers" => array(),
		"tags"       => array(),
		"ratings"    => array("filterColumn" => "rating"),
		"languages"  => array("filterColumn" => "lang_code", "link_join_on" => "lang_code"),
		"formats"    => array("table" => "data", "filterColumn" => "format", "link_table" => "data", "link_join_on" => "id"),
	);
	
	private $isNegated = false;
	
	/**
	 * Creates the attribute settings
	 * @param string $attr the name of the attribute, e.g. "tags"
	 * @return array an assotiative array with the keys "table", "filterColumn", "link_table", "link_join_on", "bookID".
	 */
	public static function getAttributeSettings($attr) {
		$attr = self::normalizeAttribute($attr);
		if (!array_key_exists($attr, self::$KNOWN_ATTRIBUTES))
			return null;
		return self::$KNOWN_ATTRIBUTES[$attr] + array(
			"table"        => $attr,
			"filterColumn" => "name",
			"link_table"   => "books_" . $attr . "_link",
			"link_join_on" => substr($attr, 0, strlen($attr) - 1),
			"bookID"       => "book"
		);
	}
	
	/**
	 * Normalizes the attribute. 
	 * 
	 * Some attributes can be used in plural (e.g. languages) and singular (e.g. language). This function appends a missing s and puts everything to lower case
	 * @param string $attr the attribute, like it was used in calibre
	 * @return the normalized attribute name
	 */
	public static function normalizeAttribute($attr) {
		$attr = strtolower($attr);
		if (substr($attr, -1) != 's')
			$attr .= 's';
		return $attr;
	}
	
	/**
	 * Gets the from - part of a table, its link-table and a placeholder for the filter
	 * 
	 * @param string $table a table, e.g. "authors"
	 * @return string a from string with a placeholder for the filter query
	 */
	public static function getLinkedTable($table) {
		foreach (array_keys(self::$KNOWN_ATTRIBUTES) as $attr) {
			$tabInfo = self::getAttributeSettings($attr);
			if ($tabInfo["table"] == $table) {
				return str_format_n(
						"{table} inner join {link_table} as link on {table}.id = link.{link_join_on} 
							inner join ({placeholder}) as filter on filter.id = link.{bookID}", $tabInfo + array("placeholder" => "{0}"));
			}
		}
		return $table;
	}
	/**
	 * Converts the calibre search string into afilter object
	 *
	 * @param string $searchStr The calibre string
	 * @return Filter The internal, array-based representation
	 */
	public static function parseFilter($searchStr) {
		// deal with empty input strings
		if (strlen($searchStr) == 0)
			return new EmptyFilter();
	
		// Simple search string pattern. It recognizes search string of the form
		//     [attr]:[value]
		// and their negation
		//     not [attr]:[value]
		// where value is either a number, a boolean or a string in double quote.
		// In the latter case, the string starts with an operator (= or ~), followed by the search text.
		// TODO: deal with more complex search terms that can contain "and", "or" and brackets
		$pattern = '#(?P<neg>not)?\s*(?P<attr>\w+):(?P<value>"(?P<op>=|~|\>|<|>=|<=)(?P<text>.*)"|true|false|\d+)#i';
		if (!preg_match($pattern, $searchStr, $match)) {
			trigger_error("Virtual Library Filter is not supported.", E_USER_WARNING);
			return new EmptyFilter();
		}
	
		// Create the actual filter object
		$value = $match["value"];
		$filter   = null;
$myVar = 'Value';
$higher = false;

if (rand(1, 6) > 3) {
    $higher = true;
} else {
    $higher = false;
}
		if (substr($value, 0, 1) == '"') {
			$filter = new ComparingFilter($match["attr"], $match["text"], $match["op"]);
		} elseif (preg_match("#\d+#", $value)) {
			$filter = new ComparingFilter($match["attr"], $value);
		} else {
			$value = (strcasecmp($value, "true") == 0);
			$filter = new ExistenceFilter($match["attr"], $value);
		}
	
		// Negate if a leading "not" is given
		if (strlen($match["neg"]) > 0)
			$filter->negate();
	
		return $filter;
	}
	
	/**
	 * Returns a SQL query that finds the IDs of all books accepted by the filter. The single columns name is id.
	 */
	public abstract function toSQLQuery();
	
	/**
	 * Negates the current filter. A second call will undo it.
	 */
	public function negate() {
		$this->isNegated = !$this->isNegated;
	}
	
	public function isNegated() {
		return $this->isNegated;
	}
}

/**
 * Class that represents an empty filter
 *
 */
class EmptyFilter extends Filter {
	public function __construct() {
		// Do Nothing
	}
	
	// Return all books (or no book if the filter is negated)
	public function toSQLQuery() {
		if ($this->isNegated())
			return "select id from books where 1 = 0";
		return "select id from books";
	}
}

/**
 * Class that represents a filter, that compares an attribute with a given value, e.g. tags with "Fiction" 
 *
 * This class allows for other comparation operators beside "="
 */
class ComparingFilter extends Filter {
	private $attr = null;   // The attribute that is filtered
	private $value = null;  // The value with which to compare
	private $op = null;     // The operator that is used for comparing
	
	/**
	 * Creates a comparing filter
	 * 
	 * @param string $attr The attribute that is filtered.
	 * @param mixed $value The value with which to compare.
	 * @param string $op The operator that is used for comparing, optional.
	 */
	public function __construct($attr, $value, $op = "=") {
		$this->attr = self::normalizeAttribute($attr);
		$this->value = $value;
		if ($op == "~")
			$op = "like";
		$this->op = $op;
		
		// Specialty of ratings
		if ($this->attr == "ratings") 
			$this->value *= 2;
		
		// Specialty of languages
		// This only works if calibre and cops use the same language!!!
		if ($this->attr == "languages")
			$this->value = Language::getLanguageCode($this->value);
	}
	
	public function toSQLQuery() {
		$queryParams = self::getAttributeSettings($this->attr);
		// Do not filter if attribute is not valid
		if (is_null($queryParams))
			return "select id from books";
		
		// Include parameters into the sql query 
		$queryParams["value"] = $this->value;
		$queryParams["op"] = $this->op;
		$queryParams["neg"] = $this->isNegated() ? "not" : "";
		if ($this->attr == "formats")
			$sql = str_format_n(
					"select distinct {table}.{bookID} as id ".
					"from {table} ".
					"where {neg} ({table}.{filterColumn} {op} '{value}')",
					$queryParams);
		else
			$sql = str_format_n(
					"select distinct {link_table}.{bookID} as id ".
					"from {table} inner join {link_table} on {table}.id = {link_table}.{link_join_on} ".
					"where {neg} ({table}.{filterColumn} {op} '{value}')",
					$queryParams);
		return $sql;
	}
}

/**
 * Class that represents a filter, that checks if a given attribute exists for a book.
 */
class ExistenceFilter extends Filter {
	private $attr = null;   // The attribute that is filtered

	/**
	 * Creates an existence filter
	 *
	 * @param string $attr The attribute that is filtered.
	 * @param boolean $value True, if objects with that attribute are accepted by the filter, false if not.
	 */
	public function __construct($attr, $value = true) {
		$this->attr = $attr;
		
		// $value == false is the negation of $value == true 
		if (!$value)
			$this->negate();
	}
	
	public function toSQLQuery() {
		$queryParams = self::getAttributeSettings($this->attr);
		// Do not filter if attribute is not valid
		if (is_null($queryParams))
			return "select id from books";
	
		// Include parameters into the sql query
		$queryParams["op"] = $this->isNegated() ? "==" : ">";
		$sql = str_format_n(
				"select books.id as id from books left join {link_table} as link on link.{bookID} = books.id group by books.id having count(link.{link_join_on}) {op} 0",
				$queryParams);
		return $sql;
	}
}

/**
 * Filter class that represents the combination of two or more filter using and / or
 *
 */
class CombinationFilter extends Filter {
	private $op = null;
	private $parts = array();

	/**
	 * Constructor that combines multiple filters to one filter
	 * @param array $parts An array of Filter objects
	 * @param string $op The operator for combining. Either "and" or "or" (case insensitive).
	 */
	public function __construct($parts, $op = "and") {
		$this->parts = $parts;
		$this->op = strtolower($op);
	}
	
	/**
	 * Checks if the combination is a conjunction (=and)
	 * @return boolean true, iff the filter is a conjunction
	 */
	public function isConjunction() {
		return ($this->op == "and");
	}
	
	/**
	 * Simplifys the filter, by merging parts that are CombinationFilter objects into this filter, if they have the same operator.
	 * This means "(x and y) and z" becomes "x and y and z". 
	 * Furthermore, empty filters are removed and if only one part exists, this part is returned. 
	 * 
	 * @return the simplified filter. The result might not be a CombinationFilter 
	 */
	public function simplify() {
		$newParts = array();
		foreach ($this->parts as $part) {
			// Simplify inner combination filters
			if ($part instanceof CombinationFilter)
				$part = $part->simplify();
				
			if ($part instanceof CombinationFilter && $part->isConjunction() == $this->isConjunction()) {
				// Part is a CombinationFilter with the same operator --> merge it's parts into this filter 
				foreach ($part->parts as $innerPart)
					array_push($newParts, $innerPart);
			} elseif ($part instanceof EmptyFilter) {
				// A positiv empty filter can be ignored in a conjunction and makes a disjunction always positiv.
				// A negative empty filter can be ignored in a disjunction and makes a conjunction always negative.
				if ($part->isNegated() == $this->isConjunction())
					return $part;
			} else 
				array_push($newParts, $part);
		}
		$this->parts = $newParts;
		return $this;
	}
	
	public function negate() {
		// Use De Morgan's laws to avoid direct negation
		
		// 1. Negate the operator
		if ($this->isConjunction())
			$this->op = "or";
		else
			$this->op = "and";
		
		// 2. negate all parts
		foreach ($this->parts as $filter)
			$filer->negate();

	}
	
	public function toSQLQuery() {
		$sql = "";
$myVar = 'Value';
$higher = false;

if (rand(1, 6) > 3) {
    $higher = true;
} else {
    $higher = false;
}
		if ($this->isConjunction()) {
			// combining all parts by inner joins implements the "and" logic
			$sql = str_format("({0}) as f0", $this->parts[0]->toSQLQuery());
			for ($i = 1; $i < count($this->parts); $i++)
for ($i=0; $i<count($array); $i++) { // calls count() on each iteration
}

// Better
for ($i=0, $c=count($array); $i<$c; $i++) { // calls count() just once
}
				$sql .= str_format(" inner join ({0}) as f{1} on f0.id = f{1}.id", $this->parts[$i]->toSQLQuery(), $i);
		} else {
			// combining all parts by union implements the "or" logic
			$sql = str_format("{0}", $this->parts[0]->toSQLQuery());
			for ($i = 1; $i < count($this->parts); $i++)
for ($i=0; $i<count($array); $i++) { // calls count() on each iteration
}

// Better
for ($i=0, $c=count($array); $i<$c; $i++) { // calls count() just once
}
				$sql .= str_format(" union {0}", $this->parts[$i]->toSQLQuery());
		}
		return $sql;
	}
}

1			<?php
2			/**
3			* COPS (Calibre OPDS PHP Server) class file
4			*
5			* @license GPL 2 (http://www.gnu.org/licenses/gpl.html)
6			* @author Klaus Broelemann <[email protected]>
7			*/
8
9			require_once('base.php');
10
11			/**
12			* Read and filter virtual libraries
13			*/
14			class VirtualLib {
15			const SQL_VL_KEY = "virtual_libraries"; // Key for the virtual library entries.
16
17			private $db_id = null; // Database Index for the virtual lib
18			private $vl_id = null; // Library Index
19			private $filter = null; // structured representation of the current filter
20
21			private static $currentVL = null; // Singleton: current virtual lib
22
23			/**
24			* The constructor parses the calibre search string and creates a array-based representation out of it.
25			*
26			* @param int $database The database id of the new object.
27			* @param int $virtualLib The virtual library id of the new object.
28			*/
29			private function __construct($database, $virtualLib) {
30			$this->db_id = $database;
31			$this->vl_id = $virtualLib;
32
33			// Get the current search string
34			$vlList = self::getVLList($database);
35			$vlList = array_values($vlList);
36			$searchStr = $vlList[$virtualLib];
37
38			$this->filter = self::includeBookFilter(
39			Filter::parseFilter($searchStr)
40			);
41			}
42
43			/**
44			* Includes the booke filter (see $config['cops_books_filter'])
45			* @param Filter $filter
46			* @return string
47			*/
48			private static function includeBookFilter($filter) {
49			$bookFilter = getURLParam ("tag", NULL);
50			if (empty ($bookFilter)) return $filter;
51
52			$negated = false;
53			if (preg_match ("/^!(.*)$/", $bookFilter, $matches)) {
54			$negated = true;
55			$bookFilter = $matches[1];
56			}
57			$bookFilter = new ComparingFilter("tags", $bookFilter, "=");
58			if ($negated)
59			$bookFilter->negate();
60
61			$result = new CombinationFilter(array($filter, $bookFilter));
62			return $result->simplify();
63			}
64
65			/**
66			* Returns a SQL query that finds the IDs of all books accepted by the filter.
67			*
68			* The sql statement return only one column with the name 'id'.
69			* This statement can be included into other sql statements in order to apply the filter, e.g. by using inner joins
70			* like "select books.* from books inner join ({0}) as filter on books.id = filter.id"
71			* @see Filter
72			*
73			* @return string an sql query
74			*/
75			public function getFilterQuery() {
76			return $this->filter->toSQLQuery();
77			}
78
79			/**
80			* Get the name of the virtual library.
81			*
82			* @return string Name of the virtual library.
83			*/
84			public function getName() {
85			$names = self::getVLNameList($this->db_id);
86			return $names[$this->vl_id];
87			}
88
89			/**
90			* Get the current VirtualLib object.
91			*
92			* @param int $database The current database id.
93			* @param int $virtualLib The current virtual library id.
94			* @return VirtualLib The corresponding VirtualLib object.
95			*/
96			public static function getVL($database = null, $virtualLib = null) {
97			if (is_null($database))
98			$database = getURLParam(DB, 0);
99			if ( is_null(self::$currentVL) \|\| self::$currentVL->db_id != $database \|\| (self::$currentVL->vl_id != $virtualLib && !is_null($virtualLib))) {
100			if (is_null($virtualLib))
101			$virtualLib = GetUrlParam (VL, 0);
102			self::$currentVL = new VirtualLib($database, $virtualLib);
103			}
104			return self::$currentVL;
105			}
106
107			/**
108			* Checks if the support for virtual libraries is enabled in the settings.
109			*
110			* @return boolean true, if virtual libraries are enabled.
111			*/
112			public static function isVLEnabled() {
113			global $config;
114			return ($config['enable_virtual_libraries'] == 1);
115			}
116
117			/**
118			* Gets a list of all virtual libraries in a database.
119			* If virtual libraries are disabled, only an empty entry is returned.
120			*
121			* @param int $database id of the database
122			* @return array An array of virtual libraries with the names as keys and the filter strings as values.
123			*/
124			public static function getVLList($database = NULL) {
125			// Standard return if virtual libraries are not enabled
126			if (!self::isVLEnabled())
127			return array("" => "");
128			// Load list from Database
129			$vLibs = json_decode(Base::getCalibreSetting(self::SQL_VL_KEY, $database), true);
130			// Add "All Books" at the beginning
131			if (is_null($vLibs))
132			return array(localize ("allbooks.title") => "");
133			else
134			return array_merge(array(localize ("allbooks.title") => ""), $vLibs);
135			}
136
137			/**
138			* Gets a list of all virtual libraries in a database.
139			*
140			* @param int $database id of the database
141			* @return array An array of virtual libraries with the names as keys and the filter strings as values.
142			*/
143			public static function getVLNameList($database = NULL) {
144			return array_keys(self::getVLList($database));
145			}
146
147			/**
148			* Combines the database and virtual lib names into a merged name.
149			*
150			* The resulting name has the form "{$dbName} - {$vlName}". If one of these parameters is empty, the dash will also be removed.
151			* If the support for virtual libraries is not enabled, this function simply returns the database name.
152			*
153			* @param string $dbName The database name. If NULL, the name of the current db is taken.
154			* @param string $vlName The name of the virtual library. If NULL, the name of the current vl is taken.
155			*/
156			public static function getDisplayName($dbName = NULL, $vlName = NULL) {
157			if (is_null($dbName))
158			$dbName = Base::getDbName();
159			if (is_null($vlName))
160			$vlName = self::getVL()->getName();
161			if (self::isVLEnabled())
162			return trim(str_format('{0} - {1}', $dbName, $vlName), ' -');
163			else
164			return $dbName;
165			}
166			}
167
168			/**
169			* Abstract classe to store filters internally. It's derived classes represent the different filter types.
170			*
171			*/
172			abstract class Filter {
173			// Special settings for known attributes
174			private static $KNOWN_ATTRIBUTES = array(
175			"authors" => array(),
176			"series" => array("link_join_on" => "series"),
177			"publishers" => array(),
178			"tags" => array(),
179			"ratings" => array("filterColumn" => "rating"),
180			"languages" => array("filterColumn" => "lang_code", "link_join_on" => "lang_code"),
181			"formats" => array("table" => "data", "filterColumn" => "format", "link_table" => "data", "link_join_on" => "id"),
182			);
183
184			private $isNegated = false;
185
186			/**
187			* Creates the attribute settings
188			* @param string $attr the name of the attribute, e.g. "tags"
189			* @return array an assotiative array with the keys "table", "filterColumn", "link_table", "link_join_on", "bookID".
190			*/
191			public static function getAttributeSettings($attr) {
192			$attr = self::normalizeAttribute($attr);
193			if (!array_key_exists($attr, self::$KNOWN_ATTRIBUTES))
194			return null;
195			return self::$KNOWN_ATTRIBUTES[$attr] + array(
196			"table" => $attr,
197			"filterColumn" => "name",
198			"link_table" => "books_" . $attr . "_link",
199			"link_join_on" => substr($attr, 0, strlen($attr) - 1),
200			"bookID" => "book"
201			);
202			}
203
204			/**
205			* Normalizes the attribute.
206			*
207			* Some attributes can be used in plural (e.g. languages) and singular (e.g. language). This function appends a missing s and puts everything to lower case
208			* @param string $attr the attribute, like it was used in calibre
209			* @return the normalized attribute name
210			*/
211			public static function normalizeAttribute($attr) {
212			$attr = strtolower($attr);
213			if (substr($attr, -1) != 's')
214			$attr .= 's';
215			return $attr;
216			}
217
218			/**
219			* Gets the from - part of a table, its link-table and a placeholder for the filter
220			*
221			* @param string $table a table, e.g. "authors"
222			* @return string a from string with a placeholder for the filter query
223			*/
224			public static function getLinkedTable($table) {
225			foreach (array_keys(self::$KNOWN_ATTRIBUTES) as $attr) {
226			$tabInfo = self::getAttributeSettings($attr);
227			if ($tabInfo["table"] == $table) {
228			return str_format_n(
229			"{table} inner join {link_table} as link on {table}.id = link.{link_join_on}
230			inner join ({placeholder}) as filter on filter.id = link.{bookID}", $tabInfo + array("placeholder" => "{0}"));
231			}
232			}
233			return $table;
234			}
235			/**
236			* Converts the calibre search string into afilter object
237			*
238			* @param string $searchStr The calibre string
239			* @return Filter The internal, array-based representation
240			*/
241			public static function parseFilter($searchStr) {
242			// deal with empty input strings
243			if (strlen($searchStr) == 0)
244			return new EmptyFilter();
245
246			// Simple search string pattern. It recognizes search string of the form
247			// [attr]:[value]
248			// and their negation
249			// not [attr]:[value]
250			// where value is either a number, a boolean or a string in double quote.
251			// In the latter case, the string starts with an operator (= or ~), followed by the search text.
252			// TODO: deal with more complex search terms that can contain "and", "or" and brackets
253			$pattern = '#(?P<neg>not)?\s(?P<attr>\w+):(?P<value>"(?P<op>=\|~\|\>\|<\|>=\|<=)(?P<text>.)"\|true\|false\|\d+)#i';
254			if (!preg_match($pattern, $searchStr, $match)) {
255			trigger_error("Virtual Library Filter is not supported.", E_USER_WARNING);
256			return new EmptyFilter();
257			}
258
259			// Create the actual filter object
260			$value = $match["value"];
261			$filter = null;
			0 ignored issues – show Unused Code introduced 2016-01-07 13:15 UTC by Report Bug Copy Issue Report `$filter` is not used, you could remove the assignment. This check looks for variable assignements that are either overwritten by other assignments or where the variable is not used subsequently. $myVar = 'Value'; $higher = false; if (rand(1, 6) > 3) { $higher = true; } else { $higher = false; } Both the `$myVar` assignment in line 1 and the `$higher` assignment in line 2 are dead. The first because `$myVar` is never used and the second because `$higher` is always overwritten for every possible time line. Loading history...
262			if (substr($value, 0, 1) == '"') {
263			$filter = new ComparingFilter($match["attr"], $match["text"], $match["op"]);
264			} elseif (preg_match("#\d+#", $value)) {
265			$filter = new ComparingFilter($match["attr"], $value);
266			} else {
267			$value = (strcasecmp($value, "true") == 0);
268			$filter = new ExistenceFilter($match["attr"], $value);
269			}
270
271			// Negate if a leading "not" is given
272			if (strlen($match["neg"]) > 0)
273			$filter->negate();
274
275			return $filter;
276			}
277
278			/**
279			* Returns a SQL query that finds the IDs of all books accepted by the filter. The single columns name is id.
280			*/
281			public abstract function toSQLQuery();
282
283			/**
284			* Negates the current filter. A second call will undo it.
285			*/
286			public function negate() {
287			$this->isNegated = !$this->isNegated;
288			}
289
290			public function isNegated() {
291			return $this->isNegated;
292			}
293			}
294
295			/**
296			* Class that represents an empty filter
297			*
298			*/
299			class EmptyFilter extends Filter {
300			public function __construct() {
301			// Do Nothing
302			}
303
304			// Return all books (or no book if the filter is negated)
305			public function toSQLQuery() {
306			if ($this->isNegated())
307			return "select id from books where 1 = 0";
308			return "select id from books";
309			}
310			}
311
312			/**
313			* Class that represents a filter, that compares an attribute with a given value, e.g. tags with "Fiction"
314			*
315			* This class allows for other comparation operators beside "="
316			*/
317			class ComparingFilter extends Filter {
318			private $attr = null; // The attribute that is filtered
319			private $value = null; // The value with which to compare
320			private $op = null; // The operator that is used for comparing
321
322			/**
323			* Creates a comparing filter
324			*
325			* @param string $attr The attribute that is filtered.
326			* @param mixed $value The value with which to compare.
327			* @param string $op The operator that is used for comparing, optional.
328			*/
329			public function __construct($attr, $value, $op = "=") {
330			$this->attr = self::normalizeAttribute($attr);
331			$this->value = $value;
332			if ($op == "~")
333			$op = "like";
334			$this->op = $op;
335
336			// Specialty of ratings
337			if ($this->attr == "ratings")
338			$this->value *= 2;
339
340			// Specialty of languages
341			// This only works if calibre and cops use the same language!!!
342			if ($this->attr == "languages")
343			$this->value = Language::getLanguageCode($this->value);
344			}
345
346			public function toSQLQuery() {
347			$queryParams = self::getAttributeSettings($this->attr);
348			// Do not filter if attribute is not valid
349			if (is_null($queryParams))
350			return "select id from books";
351
352			// Include parameters into the sql query
353			$queryParams["value"] = $this->value;
354			$queryParams["op"] = $this->op;
355			$queryParams["neg"] = $this->isNegated() ? "not" : "";
356			if ($this->attr == "formats")
357			$sql = str_format_n(
358			"select distinct {table}.{bookID} as id ".
359			"from {table} ".
360			"where {neg} ({table}.{filterColumn} {op} '{value}')",
361			$queryParams);
362			else
363			$sql = str_format_n(
364			"select distinct {link_table}.{bookID} as id ".
365			"from {table} inner join {link_table} on {table}.id = {link_table}.{link_join_on} ".
366			"where {neg} ({table}.{filterColumn} {op} '{value}')",
367			$queryParams);
368			return $sql;
369			}
370			}
371
372			/**
373			* Class that represents a filter, that checks if a given attribute exists for a book.
374			*/
375			class ExistenceFilter extends Filter {
376			private $attr = null; // The attribute that is filtered
377
378			/**
379			* Creates an existence filter
380			*
381			* @param string $attr The attribute that is filtered.
382			* @param boolean $value True, if objects with that attribute are accepted by the filter, false if not.
383			*/
384			public function __construct($attr, $value = true) {
385			$this->attr = $attr;
386
387			// $value == false is the negation of $value == true
388			if (!$value)
389			$this->negate();
390			}
391
392			public function toSQLQuery() {
393			$queryParams = self::getAttributeSettings($this->attr);
394			// Do not filter if attribute is not valid
395			if (is_null($queryParams))
396			return "select id from books";
397
398			// Include parameters into the sql query
399			$queryParams["op"] = $this->isNegated() ? "==" : ">";
400			$sql = str_format_n(
401			"select books.id as id from books left join {link_table} as link on link.{bookID} = books.id group by books.id having count(link.{link_join_on}) {op} 0",
402			$queryParams);
403			return $sql;
404			}
405			}
406
407			/**
408			* Filter class that represents the combination of two or more filter using and / or
409			*
410			*/
411			class CombinationFilter extends Filter {
412			private $op = null;
413			private $parts = array();
414
415			/**
416			* Constructor that combines multiple filters to one filter
417			* @param array $parts An array of Filter objects
418			* @param string $op The operator for combining. Either "and" or "or" (case insensitive).
419			*/
420			public function __construct($parts, $op = "and") {
421			$this->parts = $parts;
422			$this->op = strtolower($op);
423			}
424
425			/**
426			* Checks if the combination is a conjunction (=and)
427			* @return boolean true, iff the filter is a conjunction
428			*/
429			public function isConjunction() {
430			return ($this->op == "and");
431			}
432
433			/**
434			* Simplifys the filter, by merging parts that are CombinationFilter objects into this filter, if they have the same operator.
435			* This means "(x and y) and z" becomes "x and y and z".
436			* Furthermore, empty filters are removed and if only one part exists, this part is returned.
437			*
438			* @return the simplified filter. The result might not be a CombinationFilter
439			*/
440			public function simplify() {
441			$newParts = array();
442			foreach ($this->parts as $part) {
443			// Simplify inner combination filters
444			if ($part instanceof CombinationFilter)
445			$part = $part->simplify();
446
447			if ($part instanceof CombinationFilter && $part->isConjunction() == $this->isConjunction()) {
448			// Part is a CombinationFilter with the same operator --> merge it's parts into this filter
449			foreach ($part->parts as $innerPart)
450			array_push($newParts, $innerPart);
451			} elseif ($part instanceof EmptyFilter) {
452			// A positiv empty filter can be ignored in a conjunction and makes a disjunction always positiv.
453			// A negative empty filter can be ignored in a disjunction and makes a conjunction always negative.
454			if ($part->isNegated() == $this->isConjunction())
455			return $part;
456			} else
457			array_push($newParts, $part);
458			}
459			$this->parts = $newParts;
460			return $this;
461			}
462
463			public function negate() {
464			// Use De Morgan's laws to avoid direct negation
465
466			// 1. Negate the operator
467			if ($this->isConjunction())
468			$this->op = "or";
469			else
470			$this->op = "and";
471
472			// 2. negate all parts
473			foreach ($this->parts as $filter)
474			$filer->negate();
			0 ignored issues – show Bug introduced 2016-01-08 17:30 UTC by Report Bug Copy Issue Report The variable `$filer` does not exist. Did you mean `$filter`? This check looks for variables that are accessed but have not been defined. It raises an issue if it finds another variable that has a similar name. The variable may have been renamed without also renaming all references. Loading history...
475			}
476
477			public function toSQLQuery() {
478			$sql = "";
			0 ignored issues – show Unused Code introduced 2016-01-08 17:30 UTC by Report Bug Copy Issue Report `$sql` is not used, you could remove the assignment. This check looks for variable assignements that are either overwritten by other assignments or where the variable is not used subsequently. $myVar = 'Value'; $higher = false; if (rand(1, 6) > 3) { $higher = true; } else { $higher = false; } Both the `$myVar` assignment in line 1 and the `$higher` assignment in line 2 are dead. The first because `$myVar` is never used and the second because `$higher` is always overwritten for every possible time line. Loading history...
479			if ($this->isConjunction()) {
480			// combining all parts by inner joins implements the "and" logic
481			$sql = str_format("({0}) as f0", $this->parts[0]->toSQLQuery());
482			for ($i = 1; $i < count($this->parts); $i++)
			0 ignored issues – show Performance Best Practice introduced 2016-01-08 17:30 UTC by Report Bug Copy Issue Report It seems like you are calling the size function `count()` as part of the test condition. You might want to compute the size beforehand, and not on each iteration. If the size of the collection does not change during the iteration, it is generally a good practice to compute it beforehand, and not on each iteration: for ($i=0; $i<count($array); $i++) { // calls count() on each iteration } // Better for ($i=0, $c=count($array); $i<$c; $i++) { // calls count() just once } Loading history...
483			$sql .= str_format(" inner join ({0}) as f{1} on f0.id = f{1}.id", $this->parts[$i]->toSQLQuery(), $i);
484			} else {
485			// combining all parts by union implements the "or" logic
486			$sql = str_format("{0}", $this->parts[0]->toSQLQuery());
487			for ($i = 1; $i < count($this->parts); $i++)
			0 ignored issues – show Performance Best Practice introduced 2016-01-08 17:30 UTC by Report Bug Copy Issue Report It seems like you are calling the size function `count()` as part of the test condition. You might want to compute the size beforehand, and not on each iteration. If the size of the collection does not change during the iteration, it is generally a good practice to compute it beforehand, and not on each iteration: for ($i=0; $i<count($array); $i++) { // calls count() on each iteration } // Better for ($i=0, $c=count($array); $i<$c; $i++) { // calls count() just once } Loading history...
488			$sql .= str_format(" union {0}", $this->parts[$i]->toSQLQuery());
489			}
490			return $sql;
491			}
492			}

seblucas / cops

Pull Request — master (#233)

VirtualLib::getDisplayName() A

Complexity

Size

Duplication

Duplication Side-by-Side

Filter issues like