[Validator] Access container array in Expression/Context #23134

Engerim · 2017-06-11T14:45:43Z

Q	A
Branch?	3.4
Bug fix?	no
New feature?	yes
BC breaks?	no
Deprecations?	no
Tests pass?	yes/no
Fixed tickets	#12315
License	MIT
Doc PR	symfony/symfony-docs#...

This solves an old issues with arrays and the expression validator. Below is a melody script which throws an exception because "this" is null and not an array like expected.

This PR adds a dataPath property to the Expression constraint, which allows the validator to retrieve the "this" value in an other way from the context.

I'm not sure about the name "dataPath", so i'm open for a better naming.

Documentation PR will be added later, if this PR is approved.

<?php
<<<CONFIG
packages:
    - "symfony/form: ~3.3.0"
    - "symfony/validator: ~3.3.0"
    - "symfony/expression-language: ~3.3.0"
CONFIG;

use Symfony\Component\Form\Forms;
use Symfony\Component\Validator\Constraints\Expression;
use Symfony\Component\Form\Extension\Core\Type\DateType;
use Symfony\Component\Form\Extension\Validator\ValidatorExtension;
use Symfony\Component\Validator\ValidatorBuilder;


$form = Forms::createFormFactoryBuilder()->addExtension(new ValidatorExtension((new ValidatorBuilder())->getValidator()))->getFormFactory()->createBuilder()
    ->add('dateStart', DateType::class, [
        'constraints' => [
            new Expression([
                'expression' => 'this["dateStart"] <= this["dateEnd"]'
            ]),
        ],
    ])
    ->add('dateEnd', DateType::class, [
        'constraints' => [
            new Expression([
                'expression' => 'this["dateEnd"] >= this["dateStart"]'
            ]),
        ],
    ])
    ->getForm();


$form->submit(['dateEnd' => '2011-06-05', 'dataStart' => '2011-06-07']);

yceruto · 2017-06-11T15:32:09Z

src/Symfony/Component/Validator/Constraints/ExpressionValidator.php

@@ -46,6 +47,10 @@ public function validate($value, Constraint $constraint)
        $variables['value'] = $value;
        $variables['this'] = $this->context->getObject();

+        if (strlen($constraint->dataPath) > 0) {


This is correct but following the code base style I suggest null !== $constraint->dataPath to avoid function call?

should be null !== $constraint->dataPath && '' !== $constraint->dataPath

What about allowing the $dataPath option to also be a PropertyPath instance?

Hm i don't like this because than it can be a string or instanceof PropertyPath. If we keep in mind that we want to use later on scalar type hints for version 4.0, we would have a problem.

yceruto · 2017-06-11T15:35:35Z

src/Symfony/Component/Validator/Constraints/ExpressionValidator.php

@@ -46,6 +47,10 @@ public function validate($value, Constraint $constraint)
        $variables['value'] = $value;
        $variables['this'] = $this->context->getObject();

+        if (strlen($constraint->dataPath) > 0) {
+            $variables['this'] = $this->getPropertyAccessor()->getValue($this->context, $constraint->dataPath);


if $variables['this'] may be overridden I suggest move $variables['this'] = $this->context->getObject(); to else statement?

yceruto · 2017-06-11T16:04:32Z

src/Symfony/Component/Validator/Constraints/ExpressionValidator.php

@@ -46,6 +47,10 @@ public function validate($value, Constraint $constraint)
        $variables['value'] = $value;
        $variables['this'] = $this->context->getObject();

+        if (strlen($constraint->dataPath) > 0) {
+            $variables['this'] = $this->getPropertyAccessor()->getValue($this->context, $constraint->dataPath);


In the other hand, if Symfony deciders decides to make it configurable I think we could start the path from the root i.e.:

$this->getPropertyAccessor()->getValue($this->context->getRoot(), $constraint->dataPath);

else, I suggest pass the root value to this directly if it's null i.e::

if (null === $variables['this'] = $this->context->getObject()) { $variables['this'] = $this->context->getRoot(); }

thus, you don't have to worry about the "dataPath", you know the data linked to the root, therefore you just have to access them:

new Expression(array('expression' => 'value <= this["data"]["dateEnd"]'));

wdyt?

I like the idea, to pass the root value directly to this if it's null. No dataPath and so easier to use. I will wait to change it because I would like to know how the deciders think about this.

yceruto · 2017-06-11T16:10:19Z

This one could fix this #22403 ticket too ;)

nicolas-grekas · 2017-06-14T08:08:03Z

@Engerim I changed the base branch to 3.4. Can you please rebase on branch 3.4 and push again on your side?

Engerim · 2017-06-19T06:46:23Z

@nicolas-grekas sorry for the late response, i rebased and pushed again.

dmaicher · 2017-06-19T19:59:13Z

src/Symfony/Component/Validator/Tests/Constraints/ExpressionValidatorTest.php

@@ -235,4 +235,17 @@ public function testExpressionLanguageUsage()

        $this->assertTrue($used, 'Failed asserting that custom ExpressionLanguage instance is used.');
    }
+
+    public function testExpressionLanguageUsageWithCustomDataPath()


does this name make sense? Maybe just testExpressionWithCustomDataPath?

I orientated me on the naming from the test function above with name testExpressionLanguageUsage . But I can change it for better understanding

Yes I saw that. But the previous test actually tests that passing in a custom ExpressionLanguage instance works. Hence the name 😄

* add dataPath Property to extract "this" in a different way from the context

* update changelog

* change string check

* change test method name to a better name

xabbuh · 2017-09-15T09:39:19Z

src/Symfony/Component/Validator/Constraints/ExpressionValidator.php

+    private function getPropertyAccessor()
+    {
+        if (!class_exists('Symfony\Component\PropertyAccess\PropertyAccess')) {
+            throw new RuntimeException('Unable to use expressions with data path as the Symfony PropertyAccess component is not installed.');


I wonder if we should not throw this exception in the constraint to allow to detect this mistake earlier.

Of course we could throw it there. But than we need to check there if dataPath is set because only then we check if the PropertyAccess is avaibale

I think that would be fine.

nicolas-grekas · 2017-10-08T16:22:49Z

@xabbuh how should we move on here? 4.1?

xabbuh · 2017-10-08T17:48:55Z

src/Symfony/Component/Validator/CHANGELOG.md

@@ -11,6 +11,7 @@ CHANGELOG
   the `Url::CHECK_DNS_TYPE_*` constants values and will throw an exception in Symfony 4.0
 * added min/max amount of pixels check to `Image` constraint via `minPixels` and `maxPixels`
 * added a new "propertyPath" option to comparison constraints in order to get the value to compare from an array or object
+ * added a `dataPath` option to the `Expression` constraint to allow an other way to get "this" from the context


"this" should be enclosed with backticks

xabbuh · 2017-10-08T17:49:39Z

src/Symfony/Component/Validator/Constraints/ExpressionValidator.php

+
+    private function getPropertyAccessor()
+    {
+        if (!class_exists('Symfony\Component\PropertyAccess\PropertyAccess')) {


we should use the class constant instead

xabbuh · 2017-10-08T17:50:19Z

src/Symfony/Component/Validator/Constraints/ExpressionValidator.php

@@ -46,6 +47,10 @@ public function validate($value, Constraint $constraint)
        $variables['value'] = $value;
        $variables['this'] = $this->context->getObject();


to improve readability I would make this line an else branch of the if below

xabbuh · 2017-10-08T17:51:19Z

For me, if @Engerim could address my last comments very soon this could be merged into 3.4. Otherwise, I would vote for 4.1 too.

Engerim · 2017-10-09T07:41:33Z

I work on this at the moment

* moved check if property access component is installed to constraint * improve readability

* cs

Engerim · 2017-10-09T08:35:07Z

the failing test has nothing to do with the changes i made

nicolas-grekas · 2017-10-09T09:02:22Z

src/Symfony/Component/Validator/Constraints/ExpressionValidator.php

@@ -44,7 +45,12 @@ public function validate($value, Constraint $constraint)

        $variables = array();
        $variables['value'] = $value;
-        $variables['this'] = $this->context->getObject();
+
+        if (null !== $constraint->dataPath && '' !== $constraint->dataPath) {


if ($constraint->dataPath) { should be better

nicolas-grekas · 2017-10-09T09:03:12Z

src/Symfony/Component/Validator/Constraints/ExpressionValidator.php

+
+    private function getPropertyAccessor()
+    {
+        return PropertyAccess::createPropertyAccessor();


the exception in src/Symfony/Component/Validator/Constraints/Expression.php should be moved here IMHO:
since the property is public, the check in the constructor is very fragile, only here would be robust

I would rather make the property private then. Catching these mistakes when the constraint is created allows to spot issues earlier which improves DX.

I made the property private and added a magic __get like it was done in the File Constraint.

xabbuh · 2017-10-09T09:24:21Z

src/Symfony/Component/Validator/Constraints/ExpressionValidator.php

@@ -65,4 +71,9 @@ private function getExpressionLanguage()

        return $this->expressionLanguage;
    }
+
+    private function getPropertyAccessor()


IMO we don't need this method anymore and can inline the createPropertyAccessor() call instead.

* made dataPath private

* made dataPath protected so test is not failing

Engerim · 2017-10-09T11:35:58Z

I don't know why windows is failing. This is not a problem from my changes

yceruto · 2017-10-09T12:45:50Z

src/Symfony/Component/Validator/Constraints/ExpressionValidator.php

-        $variables['this'] = $this->context->getObject();
+
+        if ($constraint->dataPath) {
+            $variables['this'] = PropertyAccess::createPropertyAccessor()->getValue($this->context, $constraint->dataPath);


Still I think we can get rid of dataPath altogether and set the root context directly for this case. Even, if the root is a form instance then we could set the form data.

How would you do that if the data is not available at the time you configure the constraint (which by the way is almost always the case when not using PHP to set up your constraints)?

I'm not sure to understand your question :( but in short this is what I meant:

if (null === $variables['this'] = $this->context->getObject()) { if (($root = $this->context->getRoot()) instanceof FormInterface) { $variables['this'] = $root->getData(); } else { $variables['this'] = $root; } }

This will work with the example of the PR description and even for cases where there is data_class and the expression is setting over form fields.

But this would force the Validator component to know something about the Form component. I don't think that's a good idea. There may also be other similar issues (not related to Symfony) which we couldn't fix here.

Right, then just:

$variables['this'] = $this->context->getObject() ?: $this->context->getRoot();

?

IMHO there is no need to configure a dataPath if we have already a data root that we know, why not start from it directly?

nicolas-grekas · 2017-10-12T16:17:31Z

Moving to 4.1.

ostrolucky · 2017-12-17T19:09:01Z

I'm 👎 for this solution, because if this option is used in conjunction with form which have data binded, this value will be replaced with something different (in this case Form instance). Maybe just consider to exposecontext, or root variable in expression?

Also, this is really "fix" for #22403, rather than #12315

For more proper fix of #12315 see #25529

Also #25529 can be used with a trick to get out of this situation in user space. Something like this:

$obj = new \stdClass();

$builder->addEventListener(FormEvents::POST_SET_DATA, function(FormEvent $f) use ($obj) {
    $obj->form = $f->getForm();
});
...
new Expression([
  'expression' => 'obj.form["dateEnd"] >= obj.form["dateStart"]', 
  'variables' => ['obj' => $obj],
]);

Similar solution could be built into Form component.

…sion validator (ostrolucky) This PR was merged into the 4.1-dev branch. Discussion ---------- [Validator] Add option to pass custom values to Expression validator | Q | A | ------------- | --- | Branch? | master | Bug fix? | no | New feature? | yes | BC breaks? | no | Deprecations? | no | Tests pass? | yes | Fixed tickets | - | License | MIT | Doc PR | - I needed this in a Form. I had no way to pass things from `$options` into Expression validator. Maybe can aid in #23134 Commits ------- ba0565e [Validator] Add option to pass custom values to Expression validator

fabpot · 2018-02-07T06:43:15Z

Closing as #25529 was merged.

carsonbot added Status: Needs Review Validator Feature labels Jun 11, 2017

yceruto requested changes Jun 11, 2017

View reviewed changes

nicolas-grekas changed the base branch from master to 3.4 June 14, 2017 08:07

nicolas-grekas added this to the 3.4 milestone Jun 14, 2017

Engerim force-pushed the fix-issue-12315 branch from 524c916 to f9d6bc0 Compare June 19, 2017 06:38

dmaicher reviewed Jun 19, 2017

View reviewed changes

Alexander Miehe added 6 commits June 28, 2017 15:30

Fix symfony#12315

2aa3e7c

* add dataPath Property to extract "this" in a different way from the context

Fix symfony#12315

c6d83d5

* update changelog

* fix cs

9e0882b

* fix issue with test lowest

c964fcb

Fix symfony#12315

53016a5

* change string check

Fix symfony#12315

1907d8b

* change test method name to a better name

Engerim force-pushed the fix-issue-12315 branch from 87a1214 to 1907d8b Compare June 28, 2017 13:30

Merge branch '3.4' into fix-issue-12315

209c386

xabbuh reviewed Sep 15, 2017

View reviewed changes

xabbuh reviewed Oct 8, 2017

View reviewed changes

Alexander Miehe added 2 commits October 9, 2017 09:53

Fix symfony#12315

afd2406

* moved check if property access component is installed to constraint * improve readability

Fix symfony#12315

26f4505

* cs

nicolas-grekas reviewed Oct 9, 2017

View reviewed changes

xabbuh reviewed Oct 9, 2017

View reviewed changes

Alexander Miehe added 2 commits October 9, 2017 11:34

Fix symfony#12315

bd3abc9

* made dataPath private

Fix symfony#12315

5c849fe

* made dataPath protected so test is not failing

yceruto reviewed Oct 9, 2017

View reviewed changes

nicolas-grekas modified the milestones: 3.4, 4.1 Oct 12, 2017

ostrolucky mentioned this pull request Dec 17, 2017

[Validator] Add option to pass custom values to Expression validator #25504

Merged

fabpot closed this Feb 7, 2018

Engerim deleted the fix-issue-12315 branch February 8, 2018 08:01

		@@ -46,6 +47,10 @@ public function validate($value, Constraint $constraint)
		$variables['value'] = $value;
		$variables['this'] = $this->context->getObject();

[Validator] Access container array in Expression/Context #23134

[Validator] Access container array in Expression/Context #23134

Conversation

Engerim commented Jun 11, 2017

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Engerim Jun 19, 2017 • edited Loading

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Engerim Jun 11, 2017 • edited Loading

Choose a reason for hiding this comment

yceruto commented Jun 11, 2017

nicolas-grekas commented Jun 14, 2017

Engerim commented Jun 19, 2017

Choose a reason for hiding this comment

Engerim Jun 20, 2017 • edited Loading

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

nicolas-grekas commented Oct 8, 2017

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

xabbuh commented Oct 8, 2017

Engerim commented Oct 9, 2017

Engerim commented Oct 9, 2017

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Engerim commented Oct 9, 2017

yceruto Oct 9, 2017 • edited Loading

Choose a reason for hiding this comment

Choose a reason for hiding this comment

yceruto Oct 9, 2017 • edited Loading

Choose a reason for hiding this comment

Choose a reason for hiding this comment

yceruto Oct 9, 2017 • edited Loading

Choose a reason for hiding this comment

yceruto Oct 9, 2017 • edited Loading

Choose a reason for hiding this comment

nicolas-grekas commented Oct 12, 2017

ostrolucky commented Dec 17, 2017 • edited Loading

fabpot commented Feb 7, 2018

Engerim Jun 19, 2017 •

edited

Loading

Engerim Jun 11, 2017 •

edited

Loading

Engerim Jun 20, 2017 •

edited

Loading

yceruto Oct 9, 2017 •

edited

Loading

yceruto Oct 9, 2017 •

edited

Loading

yceruto Oct 9, 2017 •

edited

Loading

yceruto Oct 9, 2017 •

edited

Loading

ostrolucky commented Dec 17, 2017 •

edited

Loading