I had a look at the following issue: <https://github.com/gradle/kotlin-dsl/issues/1287> Where it s...

# gradle

[Allan Wang]

I had a look at the following issue:

https://github.com/gradle/kotlin-dsl/issues/1287

Where it seems that only main build scripts have type safe accessors (https://docs.gradle.org/current/userguide/kotlin_dsl.html#type-safe-accessors)

In that case, is there a desired approach to multi module projects, where I want to reuse some scripts for each module? Typically I’d have another gradle file they can include, but that won’t work with kotlin dsl

[gildor]

Yes, use precompiled script plugins

[gildor]

you will get type safe accessors

[gildor]

you can use also common plugin, but precompiled script plugins require less boilerplate and provide the same DSL as build.gradle.kts

[gildor]

official doc
https://docs.gradle.org/current/userguide/kotlin_dsl.html#kotdsl:precompiled_plugins

[Matej Drobnič]

I'm currently writing extensions myself

[Matej Drobnič]

for example

// Hack to allow android block below. See <https://github.com/gradle/kotlin-dsl/issues/1287>
@Suppress("UnstableApiUsage")
fun Project.android(
    configure: com.android.build.gradle.BaseExtension.() -> Unit
): Unit =
    (this as ExtensionAware).extensions.configure("android", configure)

[Matej Drobnič]

@gildor What would be solution to build scripts that have conflicting namespaces?

[Matej Drobnič]

For example, I have modules com.android.library and com.android.application in my app

[Matej Drobnič]

both of these expose different type for android extension. However both extensions extend from the com.android.build.gradle.BaseExtension, so I can manually add extension like with code snippet above

[gildor]

Only by checking type inside of your Project.android function

[gildor]

Also I’m not sure that your approach is correct, why do you write function to configure existing extension

[gildor]

it shouldn’t work like this

[gildor]

Hack to allow android block below

It’s not needed

[gildor]

Static accessors generated automatically if you use plugins block

[gildor]

did you read official guide?

[gildor]

https://docs.gradle.org/current/userguide/kotlin_dsl.html#type-safe-accessors

[Matej Drobnič]

I think I explained my use case poorly

[Matej Drobnič]

let me rephrase

[Matej Drobnič]

It is multi-module project

[Matej Drobnič]

that has both application and library modules

[Matej Drobnič]

Then in main build.gradle.kts I have a line like this:

subprojects {
	android {
        // Perform some  configuration that is common to both android library and applicaton projects
     }
}

[Matej Drobnič]

so basically I want to apply android block in single file to both library and application modules

[Matej Drobnič]

If i I add

plugins {
    id("com.android.application")
}

to this common file, then it will break libraries

if I add

plugins {
    id("com.android.library")
}

then it will break application modules

[Matej Drobnič]

because both of those modules import their own type for android extension, so I would get ClassCastExceptions

[gildor]

What you want to achieve? Create a custom plugin with common configuration?

[Matej Drobnič]

I want to be able to update configuration of both library and application modules at once

[gildor]

I got it, how you want to apply this configuration?

[Matej Drobnič]

what do you mean

[gildor]

Do you use some function in buildSrc, custom plugin, just a config in root build.grafle?

[Matej Drobnič]

just a config in root build.grafle

[gildor]

Than it's the only way

[gildor]

Originally in this thread I talk about precompiled script plugins, which is different approach

[Matej Drobnič]

would I be able to do this from precompiled plugins?

[Matej Drobnič]

or any other way 😄

[gildor]

In case of precompiled plugin I would create 2 plugins: application-convention and library-convention and applied them instead of com.android.*

[gildor]

And extract shared config of them to an extension function for BaseExtension

[gildor]

And call it from android extension static accessor of each plugin

[Matej Drobnič]

I see

[Matej Drobnič]

so basically this would be `application-convention.gradle.kts`:

plugins {
    id("com.android.application")
}

subprojects {
	android {
        performCommonConfiguration()
     }
}

[gildor]

Again, nothing wrong in your approach, it's just not so declarative

[gildor]

No, without subprojects

[Matej Drobnič]

oh, so I would need to manually apply it to every project?

[gildor]

You can apply it in submodules block of your root project

[gildor]

But than how would you skip application module?

[gildor]

But I believe that each module should declare main plugin manually, apply the same is never work, you always have application, library, often dynamic-feature etc

[gildor]

We also have many pure java modules

[gildor]

Again, it's just my opinion which I believe based on currently Kotlin DSL and Gradle recommendations

[gildor]

Of course, if every module in your project has the same type it's fine to use submodules and apply common config, it also works for some other configs, like repositories or resolution strategies

[Matej Drobnič]

thanks for your info

[gildor]

Also, want to be clear, that if I would create *-convention plugins, I would apply them instead of com.android.*, not together

[Matej Drobnič]

ah I see

[Matej Drobnič]

yeah that would make sense

[gildor]

One more thing, approach with configuring extension is fine for most medium-sized project if you have only app and library modules, not sure tho that you need any helpers with all this casting, you can just add it to root build,gradle

// Configure exten
subprojects { // or even allprojects, depends on your project structure
// Apply this config only when any of android plugins is applied
plugins.withType<com.android.build.gradle.BasePlugin<*>> {
     // configure extension by common type for all android plugins
    configure<com.android.build.gradle.BaseExtension> { 
        // this has type BaseExtension, so you can configure common properties
        compileSdkVersion(28)
    }
}
}

[gildor]

but there is no approach better because you don’t have static accessors in root build.gradle, so you have to use dynamic API