mistpark 2.0 infrasturcture lands

library/HTMLPurifier/VarParser.php

@@ -0,0 +1,154 @@
+<?php
+
+/**
+ * Parses string representations into their corresponding native PHP
+ * variable type. The base implementation does a simple type-check.
+ */
+class HTMLPurifier_VarParser
+{
+
+    const STRING    = 1;
+    const ISTRING   = 2;
+    const TEXT      = 3;
+    const ITEXT     = 4;
+    const INT       = 5;
+    const FLOAT     = 6;
+    const BOOL      = 7;
+    const LOOKUP    = 8;
+    const ALIST     = 9;
+    const HASH      = 10;
+    const MIXED     = 11;
+
+    /**
+     * Lookup table of allowed types. Mainly for backwards compatibility, but
+     * also convenient for transforming string type names to the integer constants.
+     */
+    static public $types = array(
+        'string'    => self::STRING,
+        'istring'   => self::ISTRING,
+        'text'      => self::TEXT,
+        'itext'     => self::ITEXT,
+        'int'       => self::INT,
+        'float'     => self::FLOAT,
+        'bool'      => self::BOOL,
+        'lookup'    => self::LOOKUP,
+        'list'      => self::ALIST,
+        'hash'      => self::HASH,
+        'mixed'     => self::MIXED
+    );
+
+    /**
+     * Lookup table of types that are string, and can have aliases or
+     * allowed value lists.
+     */
+    static public $stringTypes = array(
+        self::STRING    => true,
+        self::ISTRING   => true,
+        self::TEXT      => true,
+        self::ITEXT     => true,
+    );
+
+    /**
+     * Validate a variable according to type. Throws
+     * HTMLPurifier_VarParserException if invalid.
+     * It may return NULL as a valid type if $allow_null is true.
+     *
+     * @param $var Variable to validate
+     * @param $type Type of variable, see HTMLPurifier_VarParser->types
+     * @param $allow_null Whether or not to permit null as a value
+     * @return Validated and type-coerced variable
+     */
+    final public function parse($var, $type, $allow_null = false) {
+        if (is_string($type)) {
+            if (!isset(HTMLPurifier_VarParser::$types[$type])) {
+                throw new HTMLPurifier_VarParserException("Invalid type '$type'");
+            } else {
+                $type = HTMLPurifier_VarParser::$types[$type];
+            }
+        }
+        $var = $this->parseImplementation($var, $type, $allow_null);
+        if ($allow_null && $var === null) return null;
+        // These are basic checks, to make sure nothing horribly wrong
+        // happened in our implementations.
+        switch ($type) {
+            case (self::STRING):
+            case (self::ISTRING):
+            case (self::TEXT):
+            case (self::ITEXT):
+                if (!is_string($var)) break;
+                if ($type == self::ISTRING || $type == self::ITEXT) $var = strtolower($var);
+                return $var;
+            case (self::INT):
+                if (!is_int($var)) break;
+                return $var;
+            case (self::FLOAT):
+                if (!is_float($var)) break;
+                return $var;
+            case (self::BOOL):
+                if (!is_bool($var)) break;
+                return $var;
+            case (self::LOOKUP):
+            case (self::ALIST):
+            case (self::HASH):
+                if (!is_array($var)) break;
+                if ($type === self::LOOKUP) {
+                    foreach ($var as $k) if ($k !== true) $this->error('Lookup table contains value other than true');
+                } elseif ($type === self::ALIST) {
+                    $keys = array_keys($var);
+                    if (array_keys($keys) !== $keys) $this->error('Indices for list are not uniform');
+                }
+                return $var;
+            case (self::MIXED):
+                return $var;
+            default:
+                $this->errorInconsistent(get_class($this), $type);
+        }
+        $this->errorGeneric($var, $type);
+    }
+
+    /**
+     * Actually implements the parsing. Base implementation is to not
+     * do anything to $var. Subclasses should overload this!
+     */
+    protected function parseImplementation($var, $type, $allow_null) {
+        return $var;
+    }
+
+    /**
+     * Throws an exception.
+     */
+    protected function error($msg) {
+        throw new HTMLPurifier_VarParserException($msg);
+    }
+
+    /**
+     * Throws an inconsistency exception.
+     * @note This should not ever be called. It would be called if we
+     *       extend the allowed values of HTMLPurifier_VarParser without
+     *       updating subclasses.
+     */
+    protected function errorInconsistent($class, $type) {
+        throw new HTMLPurifier_Exception("Inconsistency in $class: ".HTMLPurifier_VarParser::getTypeName($type)." not implemented");
+    }
+
+    /**
+     * Generic error for if a type didn't work.
+     */
+    protected function errorGeneric($var, $type) {
+        $vtype = gettype($var);
+        $this->error("Expected type ".HTMLPurifier_VarParser::getTypeName($type).", got $vtype");
+    }
+
+    static public function getTypeName($type) {
+        static $lookup;
+        if (!$lookup) {
+            // Lazy load the alternative lookup table
+            $lookup = array_flip(HTMLPurifier_VarParser::$types);
+        }
+        if (!isset($lookup[$type])) return 'unknown';
+        return $lookup[$type];
+    }
+
+}
+
+// vim: et sw=4 sts=4