Rails plugins with Frontends

OpenProject Community edition has some plugins that contain a frontend, e.g., Costs or My Project Page.

For developing these plugins, they need to be linked so either the Legacy or Angular frontend can see and process them.

Installing a Plugin

To install a plugin, you clone it locally and place it into your Gemfile.plugins like so:

group :opf_plugins do
  gem 'openproject-costs', path: '../plugins/openproject-costs'
end

After that you first need to bundle the application with bundle install.

The plugin is now known in the OpenProject application, but their frontends are not linked. For development, before you run any webpack or CLI commands, execute this rake task:

./bin/rake openproject:plugins:register_frontend

This will ensure those plugins with a frontend are symlinked to frontend/src/app/modules/plugins/linked/ for plugins with an exported Angular module under frontend/module/main.ts.

Example: OpenProject Costs plugin

The Costs plugin has both legacy components that are still used by Rails templates as well as an entry module file to register to the Angular frontend.

Let's take a look at the file structure of the costs folder frontend/:

module
├── main.ts
└── wp-display
    ├── costs-by-type-display-field.module.ts
    └── currency-display-field.module.ts

The Angular frontend entry point is frontend/module/main.ts and should export a PluginModule ngModule that looks like the following:

export function initializeCostsPlugin() {
        window.OpenProject.getPluginContext()
            .then((pluginContext:OpenProjectPluginContext) => {
    		// Register a field type to the core EditField functionality
            pluginContext.services.editField.extendFieldType('select', ['Budget']);
	
            // Register a hook callback for a specific core hook
            pluginContext.hooks.workPackageSingleContextMenu(function(params:any) {
                return {
                    key: 'log_costs',
                    icon: 'icon-projects',
                    indexBy: function(actions:any) {
                        var index = _.findIndex(actions, {key: 'log_time'});
                        return index !== -1 ? index + 1 : actions.length;
                    },
                    resource: 'workPackage',
                    link: 'logCosts'
                };
            });
        });
}


@NgModule({
    providers: [
    ],
})
export class PluginModule { // The name PluginModule is important!
  constructor() {
    initializeCostsPlugin();
  }
}

The rake task will generate a Module under frontend/src/app/modules/plugins/linked-plugin-module.ts that will import all these plugin modules. This happens by filling an ERB template by the rake task and is performed in lib/open_project/plugins/frontend_linking/*