# \[rule based model configuration \] project properties **URL:** \ **Category:** Help/Discuss\ **Created:** [May 19, 2015, 7:22pm UTC](https://discuss.gradle.org/t/rule-based-model-configuration-project-properties/9699 "2015-05-19T19:22:56Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![Francois\_Guillot](https://sea1.discourse-cdn.com/gradle/user_avatar/discuss.gradle.org/francois_guillot/32/8566_2.png) [@Francois\_Guillot](https://discuss.gradle.org/u/Francois_Guillot)\ **Post date:** [May 19, 2015, 7:22pm UTC](https://discuss.gradle.org/t/rule-based-model-configuration-project-properties/9699/1 "2015-05-19T19:22:56Z")
Hi I’d like to know if it is planned to add a construct to use project properties as rule inputs, e.g. @Mutate Void foo(rule subject, Map projectProps){ If(projectProps.contains(‘aProp’)) { //do some stuff on the subject } } ---
**Author:** ![mark\_vieira](https://sea1.discourse-cdn.com/gradle/user_avatar/discuss.gradle.org/mark_vieira/32/5396_2.png) [@mark\_vieira](https://discuss.gradle.org/u/mark_vieira)\ **Post date:** [May 20, 2015, 8:26am UTC](https://discuss.gradle.org/t/rule-based-model-configuration-project-properties/9699/2 "2015-05-20T08:26:07Z")
Not at the moment. An alternative would be to define a `@Model` and use the model DSL to assign it’s value to that of a project property then declare the model as an input to your rule. ---
**Author:** ![Francois\_Guillot](https://sea1.discourse-cdn.com/gradle/user_avatar/discuss.gradle.org/francois_guillot/32/8566_2.png) [@Francois\_Guillot](https://discuss.gradle.org/u/Francois_Guillot)\ **Post date:** [May 20, 2015, 2:07pm UTC](https://discuss.gradle.org/t/rule-based-model-configuration-project-properties/9699/3 "2015-05-20T14:07:41Z")
Hey Mark Don’t you think it would be a valid thing to add in a future release? (having project properties as rule inputs and maybe subjects) ---
**Author:** ![Francois\_Guillot](https://sea1.discourse-cdn.com/gradle/user_avatar/discuss.gradle.org/francois_guillot/32/8566_2.png) [@Francois\_Guillot](https://discuss.gradle.org/u/Francois_Guillot)\ **Post date:** [October 20, 2015, 3:11pm UTC](https://discuss.gradle.org/t/rule-based-model-configuration-project-properties/9699/4 "2015-10-20T15:11:33Z")
@mark_vieira As of today, I don’t think that anything has changed regarding this behavior. Can you confirm ? > [@mark\_vieira](#): > > An alternative would be to define a @Model and use the model DSL to assign it’s value to that of a project property then declare the model as an input to your rule. This is quite OK, but from inside a plugin, how can I do it ? ---
**Author:** ![mark\_vieira](https://sea1.discourse-cdn.com/gradle/user_avatar/discuss.gradle.org/mark_vieira/32/5396_2.png) [@mark\_vieira](https://discuss.gradle.org/u/mark_vieira)\ **Post date:** [October 20, 2015, 3:47pm UTC](https://discuss.gradle.org/t/rule-based-model-configuration-project-properties/9699/5 "2015-10-20T15:47:27Z")
> [@Francois\_Guillot](#): > > @mark_vieira As of today, I don’t think that anything has changed regarding this behavior. Can you confirm ? No, nothing new on this front although this is a known limitation. In general we want a lot more types of things to be available as rule inputs. Right now its mostly limited to other stuff that is part of the model. > [@Francois\_Guillot](#): > > This is quite OK, but from inside a plugin, how can I do it ? This cannot be done from within a rule. As stated, right now you are limited to using other model elements as rule inputs. If a user wants the convenience of specifying part of the model via a project property they’ll have to leverage the model DSL for that purpose (which has its own limitations). ``` model { myModelElement { myElementProperty = project.property('foo') } } ``` ---
**Author:** ![pledbrook](https://sea1.discourse-cdn.com/gradle/user_avatar/discuss.gradle.org/pledbrook/32/1101_2.png) [@pledbrook](https://discuss.gradle.org/u/pledbrook)\ **Post date:** [January 28, 2016, 3:43pm UTC](https://discuss.gradle.org/t/rule-based-model-configuration-project-properties/9699/6 "2016-01-28T15:43:45Z")
What about builtin properties, such as the project directory? How on earth is a RuleSource-based plugin expected to provide default values for `File` model elements if it doesn’t have access to the project directory? I know that you can add a `File` rule input with the `@Path("buildDir")` annotation, so it seems strange that other properties aren’t available. How does the Java plugin do this for the default _main_ and _test_ source sets? The conventions for those are relative to the project directory. ---
**Author:** ![lptr](https://sea1.discourse-cdn.com/gradle/user_avatar/discuss.gradle.org/lptr/32/636_2.png) [@lptr](https://discuss.gradle.org/u/lptr)\ **Post date:** [January 28, 2016, 5:47pm UTC](https://discuss.gradle.org/t/rule-based-model-configuration-project-properties/9699/7 "2016-01-28T17:47:42Z")
> What about builtin properties, such as the project directory? How on earth is a RuleSource-based plugin expected to provide default values for File model elements if it doesn’t have access to the project directory? I know that you can add a File rule input with the @Path(“buildDir”) annotation, so it seems strange that other properties aren’t available. As of now you can access the project directory by using `ProjectIdentifier` as a rule input and calling `getProjectDir()`. This is how [the core plugins access it](https://github.com/gradle/gradle/blob/4284745c48f3ea5f359dd20a1b86ca101ca00efc/subprojects/platform-base/src/main/java/org/gradle/language/base/plugins/ComponentModelBasePlugin.java#L202-L202) as well. ---
**Author:** ![pledbrook](https://sea1.discourse-cdn.com/gradle/user_avatar/discuss.gradle.org/pledbrook/32/1101_2.png) [@pledbrook](https://discuss.gradle.org/u/pledbrook)\ **Post date:** [January 29, 2016, 8:31am UTC](https://discuss.gradle.org/t/rule-based-model-configuration-project-properties/9699/8 "2016-01-29T08:31:50Z")
That’s great news, thanks. Do you know which version of Gradle that was added in? I don’t remember seeing it in the docs or release notes. ---
**Author:** ![Matthieu\_Leclercq](https://avatars.discourse-cdn.com/v4/letter/m/d2c977/32.png) [@Matthieu\_Leclercq](https://discuss.gradle.org/u/Matthieu_Leclercq)\ **Post date:** [March 24, 2016, 8:43pm UTC](https://discuss.gradle.org/t/rule-based-model-configuration-project-properties/9699/9 "2016-03-24T20:43:11Z")
I found a workaround to use project’s properties in a rule but it relies on internal APIs. As of gradle 2.12 here is what it looks like: ```gradle // in the Plugin.apply(ProjectInternal) method implementation project.getModelRegistry().configure(ModelActionRole.Defaults, new AbstractModelActionWithView( ModelReference.of("your model element name", YourType.class), new SimpleModelRuleDescriptor("a big workaround ;)"), Collections.> emptyList()) { @Override protected void execute(final MutableModelNode modelNode, final YourType view, final List> inputs) { // do what you need with the project's properties here. } }); ```