Issue with generate task Jte Gradle Plugin in Multi-Module Spring Boot Project

[robertellam]

Issue Description:

I am encountering an issue with the generate build task using the Jte Gradle Plugin in a multi-module Spring Boot project.

In our project structure, we have a root project called "demo" and two sub-projects named "Application" and "Core." The Application module relies on the Core module. Within the Application Module, we have a template that calls another template located in the Core Module, as demonstrated below:

@template.base(title = "App Template", content = @`<p>App Template extends base</p>`)

During development, this setup works as expected, utilising the ResourceResolver or the CompositeCodeResolver which we came across in another issue. However, issues arise during the build process, leading to the following error:

> base.jte not found (tried to load file at /Users/rob/dev/spring-boot/demo/app/src/main/resources/templates/base.jte), referenced at app.jte:2

base.jte is actually located in Users/rob/dev/spring-boot/demo/core/src/main/resources/templates/base.jte but the generate task only accepts once source directory as far as I am aware?

Question:

Is there a way to configure the Jte Gradle Plugin to function correctly within this multi-module project structure?

Additional Information:

Here is a simplified version of my build.gradle:

buildscript {

    repositories {
        mavenCentral()
        gradlePluginPortal()
    }

    dependencies {
        classpath(libs.spring.boot.gradle.plugin)
        classpath(libs.jte.gradle.plugin)
    }
}

subprojects {

    ...
    apply plugin: 'gg.jte.gradle'
    ...

    jte {
        sourceDirectory = file("${project.projectDir}/src/main/resources/templates").toPath()
        generate()
    }

    ...
}

project(':app') {

    ...

    dependencies {
        api project(':core')
    }
}

project(':core') {

    dependencies {
        api(libs.spring.boot.starter.web)
        api(libs.spring.boot.starter.validation)
        api(libs.spring.boot.starter.security)
        api(libs.spring.boot.starter.data.jpa)
        runtimeOnly(libs.postgresql)
        api(libs.liquibase)
        api(libs.jte)
        api(libs.jte.starter3)
    }
}

Question:

Is it possible for the generate task to resolve templates from multiple sources or modules? Is there anything I can change in my build.gradle to handle this? I think the issue is that the generate task is trying to resolve templates from the source directory of each module independently but it needs to look in multiple directories or modules like it does during development.

Your assistance in resolving this issue is greatly appreciated. Thank you!

[casid]

Hi @robertellam, welcome and sorry for the late reply.

Currently jte is expecting all templates to live in one root directory. This is expected by the build plugins (maven/gradle) and the IntelliJ plugin.

We had a similiar issue once, but that one could be resolved differently:
#191

[robertellam]

@casid thanks for your reply. Are there any plans for the gradle plug-in to support multiple directories? I think this might block us from using jte in a multi module spring boot project 😭. Is there anyway we can override the gradle plug-in or use some sort of gradle task to copy all the templates into one location before the generate task?

[casid]

We already have a .jteroot file, which is used by the IntelliJ plugin to find out where the jte root directory is located.

Currently, this file is always empty, but we could use it to specify further template directories. In your project, this would look like this:

.jteroot located at jetset-demo/app/src/main/resources/templates/.jteroot

@import ../../../../../../core/src/main/resources/templates

I did some prototyping this morning with the IntelliJ plugin (which always is the hardest part when it comes to new features). This looked quite promising and I got highlighting and auto-completion working without too much effort or by complicating the plugin too much. Plugin Pull Request: casid/jte-intellij#35

In jte itself, we would need to teach the DirectoryCodeResolver about imports in .jteroot. Then, Gradle and Maven plugin should work out of the box. I'm not quite sure about the ResourceCodeResolver yet, because that one won't be able to follow those paths.

@edward3h I'm not sure if this change would have an impact on the jte-models project. Any objections/concerns about this from your side?

[casid]

Another thought I just had, maybe we don't want to make the same mistake as Java did and forbid split packages by default?

[casid]

@robertellam What I'd like to add to jte is a way to define modules, so that all template of a module still need be located in one root directory, but modules can import other modules from different locations. This way your issue would be solved, but we also could have in theory public component libraries that can be imported by other jte projects. However, this will take a while until it is finished. Currently there's a prototype running, but this needs a few more iterations and more thoughts to be releaseable. I don't expect it to be ready in the near future.

For your application, you could of course copy all templates into one directory and build from there. What you'll be missing though, is IDE support for your templates, for instance you won't get auto-complete when you use a template from your shared module in your app module.

[milgner]

I wonder: could this mechanism also be used in scenarios where there are multiple class loaders? I'm currently working on an application that uses plugins to dynamically load new functionality and would like to enable plugins to bring their own templates.

Right now I'm at the point where I managed to have a separate src/main/jte directory in each plugin and have it generate and bundle class files via Gradle.

But then I got stuck with TemplateLoader not being able to find the class because it was ignoring the class loader that I passed in to createPrecompiled: because the template classes are spread among multiple plugins, I decided to leave the classDirectory argument null - at which point RuntimeTemplateLoader::createClassLoader used Thread.currentThread().getContextClassLoader() instead of the one I supplied.

There was a simple fix for that and things are working fine now - but of course I am aware that the original code must have been there for a reason, too 😅

[C0mbatwombat]

The module system would be a nice addition to the (already great) system!

[edward3h]

Sorry I missed this until now.

Using jte-models, I would not have jte templates in one module depend directly on templates in another module. Rather I would model the dependency in Java code.

The Core module would generate a Templates interface with a method like:

@JteView("base.jte")
JteModel base(Content content);

The Application module would generate a Templates interface with a method like:

@JteView("app.jte")
JteModel app();

(Both modules generating interfaces named Templates is annoying - we might want a way to prefix the name. I assume they would be in different packages.)

Java code using the templates might look like:

coreTemplates.base(appTemplates.app()).render();

[edward3h]

I don't use Spring Boot by the way.

[heerens]

Arg, did not find this issue until now and had to come up with my own solution.

I am building a modular monolith with spring boot + modules -> https://github.com/heerens/tractor-store-htmx-tailwind/tree/main/discover
There are three modules that have templates (navigation, product, discovery). Because all three modules run in one spring app at the top level I need to have some name spacing (module name).
So to run in production and dev mode had to:

• Set the source in every module

jte {
    sourceDirectory.set(file("src/main/kotlin/com/inauditech/tractorstore/product/presentation").toPath())
    generate()
} 

• Create a ModuleDirectoryCodeResolver to look for .jteroot files

https://github.com/heerens/tractor-store-htmx-tailwind/blob/main/discover/src/main/kotlin/com/inauditech/tractorstore/discover/config/JteModuleConfiguration.kt

You can ignore the ModuleViewResolver thats just me prefixing template names. Although it would be nice to get that automatically from the module name, not from the URL path.

Maybe this helps anyone but it would cool to see the #279 merged 👍