[1.x] Implement Support for Translatable Validation Attribute Errors

[DavideIadeluca]

Fixes #0000

Changes proposed in this pull request:

• Implement support for translating attributes of backend validation errors.
• Add English translations for new attributes

Reviewers should focus on:

Screenshot

QA

1. Install a language pack such as flarum-lang/german or flarum-lang/dutch
2. Switch the Forum UI to another language (not english)
3. Try to submit a new discussions with no title or content. You should now see the translated version of title or content

Necessity

• Has the problem that is being solved here been clearly explained?
• If applicable, have various options for solving this problem been considered?
• For core PRs, does this need to be in core, or could it be in an extension?
• Are we willing to maintain this for years / potentially forever?

Confirmed

• Frontend changes: tested on a local Flarum installation.
• Backend changes: tests are green (run composer test).
• Core developer confirmed locally this works as intended.
• Tests have been added, or are not appropriate here.

Required changes:

• Related documentation PR: (Remove if irrelevant)
• Related core extension PRs: (Remove if irrelevant)

[SychO9]

It should be possible to edit AbstractValidator and manipulate the messages to dynamically check for the existence of a validation attribute translation. Mainly, the result of getMessages.

[SychO9]

The only concern is potential conflicts in attribute names between extensions. So might be better to put extension validation under the extension namespace.

[imorland]

As @SychO9 suggests, we run the possibility of conflicts here if extensions register the same attribute names, but want a different translation.

Let's scope everything under the extension name(s) please

[DavideIadeluca]

@imorland I moved the validation translations to the extension namespaces

It should be possible to edit AbstractValidator and manipulate the messages to dynamically check for the existence of a validation attribute translation. Mainly, the result of getMessages.

@SychO9 Can you make an example of what you were thinking? Now that some validation strings are in the extension namespaces, I feel like it would get messy if the AbstractValidator has to support both the structure of core and extensions but maybe I'm missing something here

[SychO9]

here is a proof of concept of how you can obtain the extension ID related to the validator:

// this would be nice in a trait, used by the abstract validator in this case
protected function getClassExtensionId(): ?string
{
    $extensions = resolve(ExtensionManager::class);

    return $extensions->getExtensions()
                ->mapWithKeys(function (\Flarum\Extension\Extension $extension) {
                    return [$extension->getId() => $extension->getNamespace()];
                })
                ->where(function ($namespace) use ($class) {
                    return $namespace && str_starts_with(static::class, $namespace);
                })
                ->keys()
                ->first();
}

you would have to add this to Extension.php

    public function getNamespace(): ?string
    {
        return Collection::make($this->composerJsonAttribute('autoload.psr-4'))
            ->filter(function ($source) {
                return $source === 'src/';
            })
            ->keys()
            ->first();
    }

once you have that, you could theoretically use it in the getMessages method to automatically point to $extId.validation.attributes.$attribute or validation.attributes.$attribute if core (extId null)

also imo it's not necessary to replace . with _ for attribute locale key.

[imorland]

I'll tentatively add this to the 1.8.9 milestone, if you have the chance to complete it before the due date, then I'm happy to include it in that release @DavideIadeluca

[DavideIadeluca]

@imorland I've now refactored the implementation per Samis suggestion. Three cases that are knowingly missing here is for example the validation logic in SaveTagsToDatabase. The SaveTagsToDatabase class creates it's own validator, which then doesn't use the new logic.

framework/extensions/tags/src/Listener/SaveTagsToDatabase.php

Lines 131 to 145 in 8eb56b1

	protected function validateTagCount($type, $count)
	{
	$min = $this->settings->get('flarum-tags.min_'.$type.'_tags');
	$max = $this->settings->get('flarum-tags.max_'.$type.'_tags');
	$key = 'tag_count_'.$type;
	$validator = $this->validator->make(
	[$key => $count],
	[$key => ['numeric', $min === $max ? "size:$min" : "between:$min,$max"]]
	);
	if ($validator->fails()) {
	throw new ValidationException([], ['tags' => $validator->getMessageBag()->first($key)]);
	}
	}

There are two other examples where a new validator is created instead of the AbstractValidator extended:

• SettingsValidator
• RegisterUserHandler

Should refactoring of the non-standard validation logic be done in this PR or separately (or not at all)?

Also, would it make sense to add tests for this?