Replacing a String on page render?

MrPowerGamerBR

I'm trying to make a simple extension to Flarum, however I'm stuck.

I need to replace the string when the user looks at the post (or comment, whatever).

Here is a example:
1. User posts "[simple_example]"
2. The extensions replaces the "[simple_example]" with "[other_example]" when a user (or any other people) sees the post.
3. If the user edits the post, instead of showing "[other_example]", it will show "[simple_example]" (and, if he saves the post, the "[simple_example]" will be replaced with "[other_example]" again, like the emoji extension, but it is a bit different because I will need to use a bit of PHP code to check some variables)

I would use PostWillBeSaved, however, if I edit the post again, the "edited" text will stay.

I also tried to use ScopePostVisibility and using a foreach on the posts (and doing this: $p->content = preg_replace("\a\i", "x", $text);), however that didn't work.

(Also, I'm registering the events correctly, because if I add a "echo" in the code... Flarum will show a error because of the invalid JSON message)

matpompili

MrPowerGamerBR take a look at how emoji extension (or markdown) works. It only changes the displayed text, not the text itself.
Since it runs in php, you can totally run your check there!

MrPowerGamerBR

matpompili yeah, the first thing I done was see the emoji source, however I need to get the post contents to use a RegEx matcher to get some informations from the "tag".

So I decided to see the Markdown source...

    public function subscribe(Dispatcher $events)
    {
        $events->listen(ConfigureFormatter::class, [$this, 'addMarkdownFormatter']);
    }

    public function addMarkdownFormatter(ConfigureFormatter $event)
    {
        $event->configurator->Litedown;
    }

Now I'm stuck.

EDIT: wow, I found where the Litedown parser is.

MrPowerGamerBR

I'm officially stuck.

Does anyone has a simple example on how to get the post contents to replace it when the post is loaded? I tried searching every example, I tried editing the BBCode/Markdown/Emoji formatter so I could understand what was happening, I tried viewing every TextFormatter Plugin example... but it confused me, because a lot of the formatters are inside the /vendor/ folder instead of just being inside the extension file... and the extension just registers the formatter.

Also, another thing I noticed, why the remappers has a ".js" and a ".php" file? Maybe I'm missing something obvious, but the two files most of the time has the same remapper, but, of course, one is written in ".js" and another in ".php".

JoshyPHP

Check out the flarum/mentions formatter, that's probably the closest to what you're trying to do.

If you can describe specifically what you're trying to do I can point you to the relevant bits. Otherwise, you can look into those pages:

MrPowerGamerBR

JoshyPHP ...oh, now that is something useful!

I will at the flarum/mentions and the TextFormatter documentation, thanks!

MrPowerGamerBR

JoshyPHP Okay, I tried messing around with the mentions extension, so I created a bootstrap.php which registers a "FormatConfigMentions" (src/Listener/FormatConfigMentions.php), the FormatConfigMentions is nearly "empty".

<?php 
namespace Flarum\ConfigMentions\Listener;

use Flarum\Core\Post\CommentPost;
use Flarum\Event\ConfigureFormatter;
use Flarum\Event\ConfigureFormatterRenderer;
use Flarum\Forum\UrlGenerator;
use Illuminate\Contracts\Events\Dispatcher;

class FormatConfigMentions
{
    /**
     * @var UrlGenerator
     */
    protected $url;

    /**
     * @param UrlGenerator $url
     */
    public function __construct(UrlGenerator $url)
    {
        $this->url = $url;
    }

    /**
     * @param Dispatcher $events
     */
    public function subscribe(Dispatcher $events)
    {

    }

    /**
     * @param ConfigureFormatter $event
     */
    public function configure(ConfigureFormatter $event)
    {
        $configurator = $event->configurator;

    }

    /**
     * @param ConfigureFormatterRenderer $event
     */
    public function render(ConfigureFormatterRenderer $event)
    {

    }

    /**
     * @param $tag
     * @return bool
     */
    public static function addId($tag)
    {
        return true;
    }
}

bootstrap.php

<?php
/*
 * This file is part of Flarum.
 *
 * (c) Toby Zerner <toby.zerner@gmail.com>
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */
use Flarum\ConfigMentions\Listener;
use Illuminate\Contracts\Events\Dispatcher;
use Illuminate\Contracts\View\Factory;

error_reporting(-1);
ini_set('display_errors', 'On');

return function (Dispatcher $events) {
    $events->subscribe(Listener\FormatConfigMentions::class);
};

However, when loading the extension, this error appear:

Fatal error: Uncaught exception 'ReflectionException' with message 'Class Flarum\ConfigMentions\Listener\FormatConfigMentions does not exist' in /var/www/mrpowergamerbr/forum/vendor/illuminate/container/Container.php:741 Stack trace: #0 /var/www/mrpowergamerbr/forum/vendor/illuminate/container/Container.php(741): ReflectionClass->__construct('Flarum\\ConfigMe...') #1 /var/www/mrpowergamerbr/forum/vendor/illuminate/container/Container.php(631): Illuminate\Container\Container->build('Flarum\\ConfigMe...', Array) #2 /var/www/mrpowergamerbr/forum/vendor/flarum/core/src/Foundation/Application.php(484): Illuminate\Container\Container->make('Flarum\\ConfigMe...', Array) #3 /var/www/mrpowergamerbr/forum/vendor/illuminate/events/Dispatcher.php(149): Flarum\Foundation\Application->make('Flarum\\ConfigMe...') #4 /var/www/mrpowergamerbr/forum/vendor/illuminate/events/Dispatcher.php(135): Illuminate\Events\Dispatcher->resolveSubscriber('Flarum\\ConfigMe...') #5 /var/www/mrpowergamerbr/forum/extensions/power-escaper/bootstrap.php(18): in /var/www/mrpowergamerbr/forum/vendor/illuminate/container/Container.php on line 741

What I want to do is this:

A user writes [text:text2]
PHP verifies if the file at the folder "example/text/text2/config.yml" (those text and text2 are from the tag) exists, if yes, the tag is replaced with the text inside the config.yml, if not, the text is replaced with "The file wasn't found".

The only thing I can't understand is how I can get the Formatter to work, after viewing the s9e TextFormatter docs (also, great job on creating TextFormatter! 🙂 ), it seems that it is possible to do what I want, after reading the Twitter Username > URL example.

luceos

First off don't use the Flarum vendor in the namespace.

The reason your Class is not found is because your package is unknown to Composer. You can use the following repository path tutorial to solve this. It also explains about the vendor name.

MrPowerGamerBR

luceos Yeah, I was using the Flarum vendor name because everything I was trying didn't work.

I will try configure the workbench later (It seems that just adding

    "autoload": {
        "psr-4": {
            "MrPowerGamerBR\\ConfigMentions\\": "src/"
        }
    },

in the composer.json doesn't work.)

luceos

MrPowerGamerBR If your code is publicly available (eg on github) we could more easily debug mistakes.

MrPowerGamerBR

luceos Here is it on GitHub: https://github.com/MrPowerGamerBR/FlarumWhateverTest (Ignore the "FormatConfigMentions.php" on the directory root, I made that before I knew the files should be used on the /src/ directory)

EDIT: The bootstrap.php "subscribe" is commented because, if I didn't do that, I couldn't get to the admin panel, of course I was uncommenting when I was testing it.

JoshyPHP I'm not 100% expert in PHP, but I know how to make MySQL queries via PHP, so that is something? right? :/

Anyway, actually the text1 and the text2 are a bit "hard-coded", the text1 and the text2 will be used on a SQL Query (using PDO + bind, because of SQL Injection), if the query returns more than 1 row, then the file will be get.

EDIT: ooooooh, I get it, when a package is installed via composer, it is added to the main Flarum composer.json file.

EDIT 2: Now I could activate it without showing a error! Now progress is being made!

EDIT 3: It seems it is not doing anything at all... I tried using this code to test:

    public function configure(ConfigureFormatter $event)
    {
        $configurator = $event->configurator;
        
        $configurator->Preg->replace('/_(.*?)_/', '<em>$1</em>');
        $configurator->Preg->replace('/%(.*?)%/', '<s>$1</s>');
    }

However when writing %hi%, nothing happens.

The event is registered on the subscribe function:

    public function subscribe(Dispatcher $events)
    {
        $events->listen(ConfigureFormatter::class, [$this, 'configure']);
        $events->listen(ConfigureFormatterRenderer::class, [$this, 'render']);
    }

I also tried the code @JoshyPHP shared, however it didn't work (No errors, just... nothing changed)

The event is registered, because if I add a echo in the subscribe function, it shows the text on the top of the page.

This is the bootstrap.php:

use MrPowerGamerBR\ConfigMarker\Listener;
use Illuminate\Contracts\Events\Dispatcher;

error_reporting(-1);
ini_set('display_errors', 'On');

return function (Dispatcher $events) {
    $events->subscribe(Listener\FormatConfig::class);
};

This is the FormatConfig file:

namespace MrPowerGamerBR\ConfigMarker\Listener;

use Flarum\Core\Post\CommentPost;
use Flarum\Event\ConfigureFormatter;
use Flarum\Event\ConfigureFormatterRenderer;
use Illuminate\Contracts\Events\Dispatcher;

class FormatConfig
{
    /**
     * @param Dispatcher $events
     */
    public function subscribe(Dispatcher $events)
    {
        $events->listen(ConfigureFormatter::class, [$this, 'configure']);
        $events->listen(ConfigureFormatterRenderer::class, [$this, 'render']);
    }
    /**
     * @param ConfigureFormatter $event
     */
    public function configure(ConfigureFormatter $event)
    {
        $configurator = $event->configurator;
        
        $configurator->Preg->replace('/_(.*?)_/', '<em>$1</em>');
        $configurator->Preg->replace('/%(.*?)/', '<s>$1</s>');
    }
    /**
     * @param ConfigureFormatterRenderer $event
     */
    public function render(ConfigureFormatterRenderer $event)
    {

    }
}

JoshyPHP

It should look like that: (haven't actually tested it)

public function configure(ConfigureFormatter $event)
{
    $configurator = $event->configurator;

    $tagName = 'MYTAG';
    $tag = $configurator->tags->add($tagName);
    $tag->attributes->add('text')->filterChain->append('#identifier');
    $tag->attributes->add('text2')->filterChain->append('#identifier');
    $tag->attributes->add('config')->required = false;
    $tag->template =
        '<xsl:choose>
            <xsl:when test="@config"><xsl:value-of select="@config"/></xsl:when>
            <xsl:otherwise>The file wasn\'t found</xsl:otherwise>
        </xsl:choose>';

    $tag->filterChain->append([static::class, 'addConfig']);
    $configurator->Preg->match('/\\[(?<text>\\w+):(?<text2>\\w+)\\]/', $tagName);
}

public static function addConfig($tag)
{
    $path = '/path/to/' . $tag->getAttribute('text') . '/' . $tag->getAttribute('text2') . '/config.yml';
    if (file_exists($path))
    {
        $tag->setAttribute('config', file_get_contents($path));
    }

    return true;
}

I assume you know PHP well enough to complete it. If you don't then I strongly recommend against creating markup that reads files from your server and publishes their content. In this example, text and text2 are filtered as identifiers so they'll only contain letters and numbers but a single misstep could allow an attacker to read arbitrary files from your disk.

The content of the file will be rendered as plain text. There is no recursion of any kind.