# Plugin-Development: Plugin applier plugin with evaluation dependencies

**URL:** <https://discuss.gradle.org/t/plugin-development-plugin-applier-plugin-with-evaluation-dependencies/27992>\
**Category:** Help/Discuss\
**Tags:** plugins\
**Created:** [August 2, 2018, 7:40am UTC](https://discuss.gradle.org/t/plugin-development-plugin-applier-plugin-with-evaluation-dependencies/27992 "2018-08-02T07:40:19Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![mstrangfeld](https://sea1.discourse-cdn.com/gradle/user_avatar/discuss.gradle.org/mstrangfeld/32/7105_2.png) [@mstrangfeld](https://discuss.gradle.org/u/mstrangfeld)\
**Post date:** [August 2, 2018, 7:40am UTC](https://discuss.gradle.org/t/plugin-development-plugin-applier-plugin-with-evaluation-dependencies/27992/1 "2018-08-02T07:40:19Z")

</div>

Hi, I’m currently developing some Gradle plugins and I have the following problem:  
I would like to have a _plugin applier plugin_ that determines what kind of sub-projects I have and applies the correct plugin to them.  
Something like that:

```gradle
class PluginApplierPlugin : Plugin<Project> {
    override fun apply(project: Project) {
        if (project.analyze() == ProjectType1) {
            project.applyPlugins(listOf("com.example.plugin1", "com.example.plugin2")
        } else {
            project.applyPlugins(listOf("com.example.plugin1", "com.example.plugin3")
        }
    }
    fun Project.applyPlugins(plugins: List<String>) {
        plugins.forEach {
            project.plugins.apply(it)
        }
    }
}

```

In my root-project’s `build.gradle.kts` file I want to do something like this:

```gradle
subprojects {
    apply {
        plugin("pluginApplier")
    }
}

```

This all works perfectly except for one small thing:  
Let’s say plugin1 registers an extension like this:

```gradle
class Plugin1 : Plugin<Project> {
    override fun apply(project: Project) {
        project.extensions.create("extension1", FirstExtension::class.java, project)
    }
}

```

And plugin2 registers a task and configures it with the properties of another project’s extension and therefore, it has to depend on it’s evaluation:

```gradle
class Plugin2 : Plugin<Project> {
    override fun apply(project: Project) {
        val otherProject = project.rootProject.project("otherProject")
        val extension = otherProject.extensions.getByType(FirstExtension::class.java)
        project.tasks.register("task1", MyCustomTask::class.java) {
            it.message = extension.message
        }
        project.evaluationDependsOn(otherProject)
    }
}

```

This works perfectly without specifying the extension in `./otherProject/build.gradle.kts` but when I do so:

```gradle
configure<FirstExtension> {
    message = "Hello, World!"
}

```

It throws:

```bash
FAILURE: Build failed with an exception.

* Where:
Build file '.../multiProject/otherProject/build.gradle.kts' line: 1

* What went wrong:
Extension of type 'FirstExtension' does not exist. Currently registered extension types: [ExtraPropertiesExtension]

```

What am I doing wrong here? Has anybody an idea how this could work?

---

<div class="post-metadata">

**Author:** ![mstrangfeld](https://sea1.discourse-cdn.com/gradle/user_avatar/discuss.gradle.org/mstrangfeld/32/7105_2.png) [@mstrangfeld](https://discuss.gradle.org/u/mstrangfeld)\
**Post date:** [August 2, 2018, 9:20am UTC](https://discuss.gradle.org/t/plugin-development-plugin-applier-plugin-with-evaluation-dependencies/27992/2 "2018-08-02T09:20:02Z")

</div>

So I actually found a workaround by just moving `evaluationDependsOn()` into the `configure` closure of the task:

```gradle
class Plugin2 : Plugin<Project> {
    override fun apply(project: Project) {
        val otherProject = project.rootProject.project("otherProject")
        val extension = otherProject.extensions.getByType(FirstExtension::class.java)
        project.tasks.register("task1", MyCustomTask::class.java) {
            project.evaluationDependsOn(otherProject)
            it.message = extension.message
        }
    }
}

```

But I’m not quite sure if this is the best solution…