I have a grails app. Why do some properties work in one but not the other? When do I put properties in one and when do I put them in the other one?
From Grails doc here
The first,
BuildConfig.groovy, is for settings that are used when running Grails
commands, such as compile, doc, etc. The second file, Config.groovy,
is for settings that are used when your application is running. This
means that Config.groovy is packaged with your application, but
BuildConfig.groovy is not.
Related
I want to migrate an application from grails 2.4.4 to grails 3.3.9.
As the structure of the conf directory in grails 2.x is completely different from 3.x, there is no config.groovy in 3.x anymore. In config.groovy of 2.x I used to define lists of constants for my select boxes like:
metals=['au','ag','pl']
and I accessed them via
static List getMetals() {
grails.util.Holders.config.metals
}
in my groovy code.
What is the corresponding way in 3.x?
I would start by checking out the upgrade guides:
http://docs.grails.org/latest/guide/upgrading.html
http://docs.grails.org/3.2.0/guide/upgrading.html#upgrading2x
config.groovy, by default becomes application.yml, but you can convert that to application.groovy, and there is a script in the external config plugin that will help with that:
http://plugins.grails.org/plugin/grails/external-config
In general it is conserdered back practice to use the holders, it would be better to use either an injected bean/service
GrailsApplication grailsApplication
grailsApplication.config.etc
Or wire in a bean using resources. The only reason to use holders is in another object that is outside of grails, that for some reason, you can't wire up as a bean. In that cases there is now a Holders class, that you can get the config from. Here's some other ways to get at the config from an OCI blog:
http://grailsblog.objectcomputing.com/posts/2016/08/31/retrieving-config-values.html
I have some values from a plugin's Config.groovy that I wanted incorporated as part of the main Application. However, it seems that they're excluded, according to the docs.
How can I define values in a plugin and have those values propagated to the main app?
You have a few options:
define a configuration file that is not excluded in src/groovy. eg. MyPluginConfig.groovy and merge it in in the doWithSpring and onConfigChange closures in your plugin's definition class. This method is outlined in this blog post.
use your plugin's _Install.groovy script to manually write your configuration into the host application's Config.groovy. This method is evident in the S2Quickstart script from the Spring Security Core plugin.
Use the Plugin Config plugin. This plugin handles these situations very nicely.
I have already create a Grails application. For some reasons I need to create another console application for someone to modify database data.
Is it possible to package Grails application as a JAR library, so that the console application can reuse those domain classes?
Or, I add/create some classes in Grails application and package it as a JAR and run as console application?
If no better answer, probably I will use the batch-launcher plugin to do that.
You can put the domain classes in a JAR and tell Grails that these are your domain classes by adding a Hibernate XML file (in grails-app/conf/hibernate) that refers to the classes in this JAR. You can use this JAR in any other Java/Groovy application, but obviously they'll only have the persistence methods (dynamic finders, save(), etc.) when used in a Grails app.
I used Grails recently, and added Grails plugin for JQuery, but I don't think it did anything more than just copy some jQuery files over.
So far, I have seen info only on 'how to install and use' plugins...but I can't find anything that describes the concept of a plugin.
Can somebody please tell me, what is a Grails Plugin? And what does it mean to 'Install' a plugin?
A Grails plugin is (or should be) a self-contained bundle of functionality that can be installed into a Grails application. When a Grails plugin is installed, it can do any of the following:
define additional Spring beans
modify the generated web.xml
add new methods to the application's artefacts (controllers, domain classes, services, etc.)
provide new tag libraries
make additional resources and classes available to the application
provide new Grails commands
For example, when you install the JQuery plugin
the JQuery JavaScript files are added to the application
a new Grails tag <jq:jquery> is added to the application
a new Grails command grails install-plugin jquery is added to the application
When you install a Grails plugin, that plugin's functionality is made available to the installing application. However, the plugin itself is not actually copied into the application, only the plugin name and version is added to the application's application.properties file. The plugin itself is downloaded to $HOME/.grails and the application loads it from there.
The structure of a Grails plugin project is identical to that of a Grails application, with the exception of a configuration file (known as a plugin descriptor) that is included in a plugin's root directory.
Well, a Grails plugin is some piece of software that extends the frameworks funcionalities in some manner. Generally, installing a plugin in Grails means copying it to your Grails folder, so projects can refer to it and Grails will know where to find it.
Grails plugins have this folder structure:
grails-app
controllers
domain
taglib
service
etc
lib
src
java
groovy
web-app
js
css
So anything it has there will also be available to the application that uses it. For example, the Searchable plugin has a service class which you can use to perform advanced searchs in your own domain classes .
The jQuery plugin you mentioned has the jQuery .js file, and a tag to include that file.
For information on creating plugins, see http://grails.org/doc/latest/guide/12.%20Plug-ins.html
A plugin is just a set of functionality around a desired purpose. So the Spring Security plugin provides a way to lock down your app, assign roles to users, restrict access, whatever. The Searchable plugin allows you to integrate advanced searching into your app. There are lots of plugins
The point is to provide useful functionality so that you don't have to implement hard things yourself. Someone did something useful, and they wanted to contribute back to the community, so they organized their functionality and made it available.
A plugin is code and configuration, like any functionality you would implement yourself.
There is some documentation here: http://grails.org/doc/latest/ref/Plug-ins/Usage.html
I'm writing a Grails app which I'd like 3rd parties to augment at runtime. Ideally they would be able to add a JAR/WAR to the webapp directory which contains new domain, controller and service classes, new views, and other content.
Is there a simple way to do this within grails? Would it be simplest to create a startup script which copies the new classes etc. into the relevant directories and then updates grails.xml and web.xml?
You will be able to do this in version 2 of grails in which plugins will be also OSGI plugins http://jira.codehaus.org/browse/GRAILS/fixforversion/15421
It seems that the Grails plugins will actually fit quite well for this: http://www.grails.org/Understanding+Plugins
A plugin can do just about anything... One thing a plugin cannot do though is modify the web-app/WEB-INF/web.xml or web-app/WEB-INF/applicationContext.xml files. A plugin can participate in web.xml generation, but not modify the file or provide a replacement. A plugin can NEVER change the applicationContext.xml file, but can provide runtime bean definitions