mistpark 2.0 infrasturcture lands

1 files changed, 206 insertions, 0 deletions

diff --git a/library/HTMLPurifier/ConfigSchema/Validator.php b/library/HTMLPurifier/ConfigSchema/Validator.php
new file mode 100644
index 000000000..f374f6a02
--- /dev/null
+++ b/library/HTMLPurifier/ConfigSchema/Validator.php
@@ -0,0 +1,206 @@
+<?php
+
+/**
+ * Performs validations on HTMLPurifier_ConfigSchema_Interchange
+ *
+ * @note If you see '// handled by InterchangeBuilder', that means a
+ *       design decision in that class would prevent this validation from
+ *       ever being necessary. We have them anyway, however, for
+ *       redundancy.
+ */
+class HTMLPurifier_ConfigSchema_Validator
+{
+
+    /**
+     * Easy to access global objects.
+     */
+    protected $interchange, $aliases;
+
+    /**
+     * Context-stack to provide easy to read error messages.
+     */
+    protected $context = array();
+
+    /**
+     * HTMLPurifier_VarParser to test default's type.
+     */
+    protected $parser;
+
+    public function __construct() {
+        $this->parser = new HTMLPurifier_VarParser();
+    }
+
+    /**
+     * Validates a fully-formed interchange object. Throws an
+     * HTMLPurifier_ConfigSchema_Exception if there's a problem.
+     */
+    public function validate($interchange) {
+        $this->interchange = $interchange;
+        $this->aliases = array();
+        // PHP is a bit lax with integer <=> string conversions in
+        // arrays, so we don't use the identical !== comparison
+        foreach ($interchange->directives as $i => $directive) {
+            $id = $directive->id->toString();
+            if ($i != $id) $this->error(false, "Integrity violation: key '$i' does not match internal id '$id'");
+            $this->validateDirective($directive);
+        }
+        return true;
+    }
+
+    /**
+     * Validates a HTMLPurifier_ConfigSchema_Interchange_Id object.
+     */
+    public function validateId($id) {
+        $id_string = $id->toString();
+        $this->context[] = "id '$id_string'";
+        if (!$id instanceof HTMLPurifier_ConfigSchema_Interchange_Id) {
+            // handled by InterchangeBuilder
+            $this->error(false, 'is not an instance of HTMLPurifier_ConfigSchema_Interchange_Id');
+        }
+        // keys are now unconstrained (we might want to narrow down to A-Za-z0-9.)
+        // we probably should check that it has at least one namespace
+        $this->with($id, 'key')
+            ->assertNotEmpty()
+            ->assertIsString(); // implicit assertIsString handled by InterchangeBuilder
+        array_pop($this->context);
+    }
+
+    /**
+     * Validates a HTMLPurifier_ConfigSchema_Interchange_Directive object.
+     */
+    public function validateDirective($d) {
+        $id = $d->id->toString();
+        $this->context[] = "directive '$id'";
+        $this->validateId($d->id);
+
+        $this->with($d, 'description')
+            ->assertNotEmpty();
+
+        // BEGIN - handled by InterchangeBuilder
+        $this->with($d, 'type')
+            ->assertNotEmpty();
+        $this->with($d, 'typeAllowsNull')
+            ->assertIsBool();
+        try {
+            // This also tests validity of $d->type
+            $this->parser->parse($d->default, $d->type, $d->typeAllowsNull);
+        } catch (HTMLPurifier_VarParserException $e) {
+            $this->error('default', 'had error: ' . $e->getMessage());
+        }
+        // END - handled by InterchangeBuilder
+
+        if (!is_null($d->allowed) || !empty($d->valueAliases)) {
+            // allowed and valueAliases require that we be dealing with
+            // strings, so check for that early.
+            $d_int = HTMLPurifier_VarParser::$types[$d->type];
+            if (!isset(HTMLPurifier_VarParser::$stringTypes[$d_int])) {
+                $this->error('type', 'must be a string type when used with allowed or value aliases');
+            }
+        }
+
+        $this->validateDirectiveAllowed($d);
+        $this->validateDirectiveValueAliases($d);
+        $this->validateDirectiveAliases($d);
+
+        array_pop($this->context);
+    }
+
+    /**
+     * Extra validation if $allowed member variable of
+     * HTMLPurifier_ConfigSchema_Interchange_Directive is defined.
+     */
+    public function validateDirectiveAllowed($d) {
+        if (is_null($d->allowed)) return;
+        $this->with($d, 'allowed')
+            ->assertNotEmpty()
+            ->assertIsLookup(); // handled by InterchangeBuilder
+        if (is_string($d->default) && !isset($d->allowed[$d->default])) {
+            $this->error('default', 'must be an allowed value');
+        }
+        $this->context[] = 'allowed';
+        foreach ($d->allowed as $val => $x) {
+            if (!is_string($val)) $this->error("value $val", 'must be a string');
+        }
+        array_pop($this->context);
+    }
+
+    /**
+     * Extra validation if $valueAliases member variable of
+     * HTMLPurifier_ConfigSchema_Interchange_Directive is defined.
+     */
+    public function validateDirectiveValueAliases($d) {
+        if (is_null($d->valueAliases)) return;
+        $this->with($d, 'valueAliases')
+            ->assertIsArray(); // handled by InterchangeBuilder
+        $this->context[] = 'valueAliases';
+        foreach ($d->valueAliases as $alias => $real) {
+            if (!is_string($alias)) $this->error("alias $alias", 'must be a string');
+            if (!is_string($real))  $this->error("alias target $real from alias '$alias'",  'must be a string');
+            if ($alias === $real) {
+                $this->error("alias '$alias'", "must not be an alias to itself");
+            }
+        }
+        if (!is_null($d->allowed)) {
+            foreach ($d->valueAliases as $alias => $real) {
+                if (isset($d->allowed[$alias])) {
+                    $this->error("alias '$alias'", 'must not be an allowed value');
+                } elseif (!isset($d->allowed[$real])) {
+                    $this->error("alias '$alias'", 'must be an alias to an allowed value');
+                }
+            }
+        }
+        array_pop($this->context);
+    }
+
+    /**
+     * Extra validation if $aliases member variable of
+     * HTMLPurifier_ConfigSchema_Interchange_Directive is defined.
+     */
+    public function validateDirectiveAliases($d) {
+        $this->with($d, 'aliases')
+            ->assertIsArray(); // handled by InterchangeBuilder
+        $this->context[] = 'aliases';
+        foreach ($d->aliases as $alias) {
+            $this->validateId($alias);
+            $s = $alias->toString();
+            if (isset($this->interchange->directives[$s])) {
+                $this->error("alias '$s'", 'collides with another directive');
+            }
+            if (isset($this->aliases[$s])) {
+                $other_directive = $this->aliases[$s];
+                $this->error("alias '$s'", "collides with alias for directive '$other_directive'");
+            }
+            $this->aliases[$s] = $d->id->toString();
+        }
+        array_pop($this->context);
+    }
+
+    // protected helper functions
+
+    /**
+     * Convenience function for generating HTMLPurifier_ConfigSchema_ValidatorAtom
+     * for validating simple member variables of objects.
+     */
+    protected function with($obj, $member) {
+        return new HTMLPurifier_ConfigSchema_ValidatorAtom($this->getFormattedContext(), $obj, $member);
+    }
+
+    /**
+     * Emits an error, providing helpful context.
+     */
+    protected function error($target, $msg) {
+        if ($target !== false) $prefix = ucfirst($target) . ' in ' .  $this->getFormattedContext();
+        else $prefix = ucfirst($this->getFormattedContext());
+        throw new HTMLPurifier_ConfigSchema_Exception(trim($prefix . ' ' . $msg));
+    }
+
+    /**
+     * Returns a formatted context string.
+     */
+    protected function getFormattedContext() {
+        return implode(' in ', array_reverse($this->context));
+    }
+
+}
+
+// vim: et sw=4 sts=4