@@ -328,6 +328,43 @@ semantic configuration described in the cookbook.
328328 If you are defining services, they should also be prefixed with the bundle
329329 alias.
330330
331+ Custom Validation Constraints
332+ -----------------------------
333+
334+ Starting with Symfony 2.5, a new Validation API was introduced. In fact,
335+ there are 3 modes, which the user can configure in their project:
336+
337+ * 2.4: the original 2.4 and earlier validation API;
338+ * 2.5: the new 2.5 and later validation API;
339+ * 2.5-BC: the new 2.5 API with a backwards-compatible layer so that the
340+ 2.4 API still works. This is only available in PHP 5.3.9+.
341+
342+ As a bundle author, you'll want to support *both * API's, since some users
343+ may still be using the 2.4 API. Specifically, if your bundle adds a violation
344+ directly to the:class: `Symfony\C omponent\V alidator\C ontext\E xecutionContext `
345+ (e.g. like in a custom validation constraint), you'll need to check for which
346+ API is being used. The following code, would work for *all * users::
347+
348+ class ContainsAlphanumericValidator extends ConstraintValidator
349+ {
350+ public function validate($value, Constraint $constraint)
351+ {
352+ if ($this->context instanceof ExecutionContextInterface) {
353+ // the 2.5 API
354+ $this->context->buildViolation($constraint->message)
355+ ->setParameter('%string%', $value)
356+ ->addViolation();
357+ );
358+ } else {
359+ // the 2.4 API
360+ $this->context->addViolation(
361+ $constraint->message,
362+ array('%string%' => $value)
363+ );
364+ }
365+ }
366+ }
367+
331368Learn more from the Cookbook
332369----------------------------
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