Add Validator infrastructure

[CarlSchwan]

Originally this PR tried to fix the validation of URLs, but the scope of this
changed to instead provide a generic interface for validating user input,
configs, ... The theming API was ported to it as example and to fix the
original bug.

The API is based on Symfony Validator component but the implementation
is simplified a lot since we don't support (yet) validating class with annotation
and other more complicated (and useful) stuff.

The filter_var function is unfortunately not perfect and doesn't support
domain with unicode as well as url with underscores. Replace usage with
a regex.

See https://bugs.php.net/search.php?cmd=display&search_for=FILTER_VALIDATE_URL

Closes #27906

Signed-off-by: Carl Schwan carl@carlschwan.eu

[juliusknorr]

Mind to squash to a single commit? :)

[blizzz]

CI is unhappy tho

[CarlSchwan]

It's a bit weird that the ci report a failure for continuous-integration/drone/pr but in https://drone.nextcloud.com/nextcloud/server/7311 everything is green

[juliusknorr]

It's a bit weird that the ci report a failure for continuous-integration/drone/pr but in drone.nextcloud.com/nextcloud/server/7311 everything is green

What about https://drone.nextcloud.com/nextcloud/server/7311/9/4 😉

There were 4 failures:

1) OCA\Theming\Tests\Controller\ThemingControllerTest::testUpdateStylesheetSuccess with data set #1 ('url', 'https://nextcloud.com/aaaaaaa...aaaaaa', 'Saved')
Failed asserting that two objects are equal.
--- Expected
+++ Actual
@@ @@
 OCP\AppFramework\Http\DataResponse Object (
     'data' => Array (
         'data' => Array (
-            'message' => 'Saved'
-            'serverCssUrl' => '/nextcloudWebroot/core/css/so...s.scss'
+            'message' => 'The given web address is not a valid URL'
         )
-        'status' => 'success'
+        'status' => 'error'
     )
     'headers' => Array (...)
     'cookies' => Array ()
-    'status' => 200
+    'status' => 400
     'lastModified' => null
     'ETag' => null
     'contentSecurityPolicy' => OCP\AppFramework\Http\EmptyContentSecurityPolicy Object (...)

/drone/src/apps/theming/tests/Controller/ThemingControllerTest.php:168

2) OCA\Theming\Tests\Controller\ThemingControllerTest::testUpdateStylesheetSuccess with data set #6 ('imprintUrl', 'https://nextcloud.com/aaaaaaa...aaaaaa', 'Saved')
Failed asserting that two objects are equal.
--- Expected
+++ Actual
@@ @@
 OCP\AppFramework\Http\DataResponse Object (
     'data' => Array (
         'data' => Array (
-            'message' => 'Saved'
-            'serverCssUrl' => '/nextcloudWebroot/core/css/so...s.scss'
+            'message' => 'The given legal notice address is not a valid URL'
         )
-        'status' => 'success'
+        'status' => 'error'
     )
     'headers' => Array (...)
     'cookies' => Array ()
-    'status' => 200
+    'status' => 400
     'lastModified' => null
     'ETag' => null
     'contentSecurityPolicy' => OCP\AppFramework\Http\EmptyContentSecurityPolicy Object (...)

/drone/src/apps/theming/tests/Controller/ThemingControllerTest.php:168

3) OCA\Theming\Tests\Controller\ThemingControllerTest::testUpdateStylesheetSuccess with data set #7 ('privacyUrl', 'https://nextcloud.com/aaaaaaa...aaaaaa', 'Saved')
Failed asserting that two objects are equal.
--- Expected
+++ Actual
@@ @@
 OCP\AppFramework\Http\DataResponse Object (
     'data' => Array (
         'data' => Array (
-            'message' => 'Saved'
-            'serverCssUrl' => '/nextcloudWebroot/core/css/so...s.scss'
+            'message' => 'The given privacy policy address is not a valid URL'
         )
-        'status' => 'success'
+        'status' => 'error'
     )
     'headers' => Array (...)
     'cookies' => Array ()
-    'status' => 200
+    'status' => 400
     'lastModified' => null
     'ETag' => null
     'contentSecurityPolicy' => OCP\AppFramework\Http\EmptyContentSecurityPolicy Object (...)

/drone/src/apps/theming/tests/Controller/ThemingControllerTest.php:168

4) OCA\Theming\Tests\Controller\ThemingControllerTest::testUpdateStylesheetError with data set #1 ('url', 'http://example.com/aaaaaaaaaa...aaaaaa', 'The given web address is too long')
Failed asserting that two objects are equal.
--- Expected
+++ Actual
@@ @@
 OCP\AppFramework\Http\DataResponse Object (
     'data' => Array (
         'data' => Array (
-            'message' => 'The given web address is too long'
+            'message' => 'The given web address is not a valid URL'
         )
         'status' => 'error'
     )

/drone/src/apps/theming/tests/Controller/ThemingControllerTest.php:217

--

[CarlSchwan]

It seems idn_to_ascii is kinda evil too and just abort when the URL is too long :(

A better solution would be either to just copy the UrlValidator::validate from symfony/validator or just depends on symfony/validator and use it for all kind of validations in Nextcloud (URL, email, date ...). For reference, this is the method: https://github.com/symfony/validator/blob/14337bdf9e2e0b2e3385c9e90f13325f0c95a4f9/Constraints/UrlValidator.php#L24

[tcitworld]

It seems idn_to_ascii is kinda evil too and just abort when the URL is too long :(

That's probably because it's made to handle domains, not full URIs. You could extract the hostname with parse_url, convert it, then substr_replace it in the URL.

But using the regex from SF Validator makes sense too.

[julien-nc]

Apart from that, code looks good. Didn't try it though.

[szaimen]

What is missing here?

[szaimen]

conflicts :/