Desenvolvendo plugins para Discourse - Parte 4 - Configurando o git

[Discourse]

Tutorial anterior: Developing Discourse Plugins - Part 3 - Add custom site settings

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Agora que seu plugin está ficando mais sofisticado, é hora de aprimorar também a forma como você o desenvolve.

Sugerimos que você use o git para controle de versão do seu plugin. Também recomendamos que utilize o github para compartilhar seu código com outras pessoas.

Criando seu repositório Git

Depois de criar sua conta no Github, visite este link para criar um novo repositório. Você pode chamá-lo como quiser, mas geralmente algo que comece com discourse- é uma boa escolha. Certifique-se de que o repositório seja público. Veja como minha tela ficou:

Criando sua pasta de trabalho local

Neste ponto, crio um diretório local no meu computador para armazenar o plugin. Geralmente coloco o meu em ~/code, mas você pode colocá-lo onde quiser no seu computador:

mkdir -p ~/code/discourse-plugin-test
cd ~/code/discourse-plugin-test

Agora, vamos seguir as instruções do github para inicializar o repositório com um README:

echo "# discourse-plugin-test" >> README.md
git init
git add README.md
git commit -m "first commit"
git remote add origin git@github.com:eviltrout/discourse-plugin-test.git
git push -u origin main

Por fim, crie um arquivo plugin.rb para o seu plugin, conforme explicado na parte 1. Para este exemplo, criei apenas um dummy:

plugin.rb

# name: discourse-plugin-test
# about: Mostra como configurar o Git
# version: 0.0.1
# authors: Robin Ward

Criando um link simbólico

Como você seguiu nosso guia de desenvolvedor, deve ter uma cópia do Discourse verificada em algum lugar do seu computador. Eu verifiquei a minha em ~/code/discourse, mas, novamente, você poderia tê-la colocado em qualquer lugar; isso ainda funcionará se você ajustar o código a seguir de acordo:

cd ~/code/discourse/plugins
ln -s ~/code/discourse-plugin-test .

O código acima criou um link simbólico entre o código do Discourse e a pasta do seu plugin. Reinicie seu servidor de desenvolvimento e você verá que seu plugin está funcionando!

A beleza dessa configuração é que você pode simplesmente fazer o commit do seu plugin no github e não se preocupar com o código base do Discourse em que ele está inserido. Suas alterações ficarão isoladas ao próprio plugin. Se precisar editar o código do Discourse, ainda poderá fazê-lo, mas o git rastreará as alterações separadamente!

Recomendo usar uma janela de editor para o código do seu plugin e outra para o próprio Discourse. É mais fácil quando você os considera como duas coisas distintas.

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Mais na série

Parte 1: Noções básicas de plugins
Parte 2: Saídas de plugins
Parte 3: Configurações do site
Parte 4: Este tópico
Parte 5: Interfaces de administração
Parte 6: Testes de aceitação
Parte 7: Publique seu plugin

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Este documento está sob controle de versão — sugira alterações no github.

[AhmadF.Cheema]

• After many frustrating attempts, found out that apparently ln -s does not work in a Windows environment, or atleast not how it should.
• ln -s essentially just copy-pasted the plugin folder into the discourse/plugins folder
• Apparently, in Windows the way to create symbolic links is to use the mklink command in command prompt (run as administrator, and this command does not natively run in Windows PowerShell either).
• Using the mklink command (with both arguments /d and /h), although the created symbolic link could be seen present in the directory, the plugin was not working with discourse (and also not showing in /admin/plugins).
• I tried this multiple times with restarting the rails server, deleting the tmp folder, but to no avail.

@eviltrout, any idea what could I be doing wrong?

[eviltrout (Robin Ward)]

I assume you are using Vagrant on windows? If you can’t get the symbolic links sent over, I think the only way you can do it is to copy the plugin into discourse/plugins manually and work from there. It should work as long as you are not making changes to the core discourse app at the same time, which confuses git.

When your plugin is ready, you’ll want to copy it to another directory to package it up for git.

[AhmadF.Cheema]

Yeah, OK this should be fine too.
Although the OCD side of me, much preferred the comparatively “cleaner” symbolic links method.

Anyway, Thanks.

[pacharanero (Marcus Baw)]

@AhmadF.Cheema I had similar problems with the symlinking using Vagrant 1.9.8 on Linux, and a completely standard Discourse Vagrant development environment as per the docs.

The problem is simple when you look into it. From the scope of inside the Vagrant VM, the destination of the symlink is not a valid path. Try executing the command ls -al in the plugins directory inside your VM (in a standard install this is at /vagrant/plugins)

vagrant@discourse:/vagrant/plugins$ ls -al
total 36
drwxr-xr-x 1 vagrant vagrant 4096 Oct 22 09:08 ./
drwxr-xr-x 1 vagrant vagrant 4096 Oct 22 09:10 ../
drwxr-xr-x 1 vagrant vagrant 4096 Sep  7 19:51 discourse-details/
drwxrwxr-x 1 vagrant vagrant 4096 Oct 21 13:56 discourse-narrative-bot/
drwxr-xr-x 1 vagrant vagrant 4096 Oct 21 13:56 discourse-nginx-performance-report/
drwxr-xr-x 1 vagrant vagrant 4096 Sep  7 19:51 discourse-plugin-outlet-locations/
drwxrwxr-x 1 vagrant vagrant 4096 Oct 21 13:56 discourse-presence/
lrwxrwxrwx 1 vagrant vagrant   55 Oct 22 09:08 my-basic-plugin -> /home/marcus/code/discourse/my-basic-plugin
drwxr-xr-x 1 vagrant vagrant 4096 Oct 21 13:56 lazyYT/
drwxr-xr-x 1 vagrant vagrant 4096 Oct 21 13:56 poll/

As you can see, the path /home/marcus/code/discourse/my-basic-plugin cannot possibly be accessible from the VM because it doesn’t exist inside the VM!

The solution is to delete the externally created symlink and set up a separate shared folder in Vagrant, by adding a line to your Vagrantfile:

config.vm.synced_folder "/home/marcus/code/my-basic-plugin",  "/my-basic-plugin"

Then restart the Vagrant VM: vagrant halt && vagrant up so that this change is picked up

Now, when you enter your VM via SSH using vagrant ssh you can create a symlink inside the VM:

cd /vagrant/plugins
ln -s /my-basic-plugin .

Now you can develop in a neatly isolated local folder, and have the neat Git workflow that @eviltrout describes, and the symlinking happens inside the VM. Note that outside the VM, the symlink will be broken - but this shouldn’t matter for our purposes.

[sam (Sam Saffron)]

If you are developing on Linux using our docker based dev is way simpler

[schungx (Stephen Chung)]

Windows symlinks are different from Unix symlinks, thus your confusion. Windows synlinks are very fussy, requiring particular versions of OS to support and sometimes applications must be written to be aware of this. In other words, the stars must line up perfectly for windows symlinks to work.

A hard link (/H) I dont think work with directories. Your /D makes a symlink on a directory, trumping your /H (which is used to create a hard link to a file, not a directory).

Confusing? Welcome to Windows.

There are four types of links in Windows:

• MKLINK (no flags) – symbolic link to file
• MKLINK /H – hard link to file
• MKLINK /D – symbolic link to directory
• MKLINK /J – junction (i.e. hard link) to directory

What you need is is a junction which is Windows-speak for hard link to a directory.

Do MKLINK /J to your plugins directory and the system will treat it as a subdirectory. In fact it won’t know otherwise. Beware, it is not common to have a Windows directory (folder in Windows-speak) to point to the same place as another directory, so you’ll get confused very easy and forget that both are the same things.

That’s why you’ll need to run the command in Administrator mode, otherwise Windows won’t let you create the directory junction.

[pacharanero (Marcus Baw)]

Thanks for the info regarding Windows symlinks @schungx - it should be of help to the OP.

The workaround I described should work fine on any platform, since the symlinks happen inside the (Ubuntu) vagrant box

M

[schungx (Stephen Chung)]

Yup, you’re right. If you can avoid it, avoid messing with Windows. Windows is very picky and may choose to die or go wrong at the most unfortunate moment…

[1c7 (Cheng Zheng)]

Work for me! 2018-4-29

1. I put discourse & my plugin in Desktop

instead of put 1c7-plugin under discourse/plugin

2. and put a “alias” into discourse/plugins folder

alias is a macOS concept,
it’s the same things as ln -s command

3. Discourse correctly load the plugin

(After reboot server with rails s)

4. Now they are separated, use git to manage code is much easier

Thanks!

[maaatt]

Não consigo fazer o symlink funcionar na configuração do Docker do macOS. Os plugins só funcionam se forem copiados diretamente para a pasta de plugins.