How to use a dependency of a module within a Play app - module

Question

I am writing a Play Framework module in order to share some common logic among multiple Play apps. One of the things I would like my module to do is provide some frequently-used functionality by way of 3rd-party modules, for example the excellent Markdown module.
First of all, is it possible to do this? I want all the apps that include my module to be able to use the .markdown().raw() String extension without needing to explicitly declare the Markdown module as a dependency. The Play Framework Cookbook chapter 5 seems to imply that it is possible, unless I am reading it wrong.
Secondly, if it is possible, how does it work? I have created the following vanilla example case, but I'm still getting errors.
I created a new, empty application "myapp", and a new, empty module "mymod", both in the same parent directory. I then modified mymod/conf/dependencies.yml to:
self: mymod -> mymod 0.1
require:
- play
- play -> markdown [1.5,)
I ran play deps on mymod and it successfully downloaded and installed the Markdown module. Running play build-module also worked fine with no errors.
Then, I modified myapp/conf/dependencies.yml to:
# Application dependencies
require:
- play
- mymod -> mymod 0.1
repositories:
- Local Modules:
type: local
artifact: ${application.path}/../[module]
contains:
- mymod
I ran play deps on myapp and it successfully found mymod, and generated the myapp/modules/mymod file, containing the absolute path to mymod.
I ran myapp using play run and was able to see the welcome page on http://localhost:9000/. So far so good.
Next, I modified myapp/app/views/Application/index.html to:
#{extends 'main.html' /}
#{set title:'Home' /}
${"This is _MarkDown_, by [John Gruber](http://daringfireball.net/projects/markdown/).".markdown().raw()}
I restarted myapp, and now I get the following error.
09:03:23,425 ERROR ~
#6a6eppo46
Internal Server Error (500) for request GET /
Template execution error (In /app/views/Application/index.html around line 4)
Execution error occured in template /app/views/Application/index.html. Exception raised was MissingMethodException : No signature of method: java.lang.String.markdown() is applicable for argument types: () values: [].
play.exceptions.TemplateExecutionException: No signature of method: java.lang.String.markdown() is applicable for argument types: () values: []
at play.templates.BaseTemplate.throwException(BaseTemplate.java:86)
at play.templates.GroovyTemplate.internalRender(GroovyTemplate.java:257)
at play.templates.Template.render(Template.java:26)
at play.templates.GroovyTemplate.render(GroovyTemplate.java:187)
at play.mvc.results.RenderTemplate.<init>(RenderTemplate.java:24)
at play.mvc.Controller.renderTemplate(Controller.java:660)
at play.mvc.Controller.renderTemplate(Controller.java:640)
at play.mvc.Controller.render(Controller.java:695)
at controllers.Application.index(Application.java:13)
at play.mvc.ActionInvoker.invokeWithContinuation(ActionInvoker.java:548)
at play.mvc.ActionInvoker.invoke(ActionInvoker.java:502)
at play.mvc.ActionInvoker.invokeControllerMethod(ActionInvoker.java:478)
at play.mvc.ActionInvoker.invokeControllerMethod(ActionInvoker.java:473)
at play.mvc.ActionInvoker.invoke(ActionInvoker.java:161)
at Invocation.HTTP Request(Play!)
Caused by: groovy.lang.MissingMethodException: No signature of method: java.lang.String.markdown() is applicable for argument types: () values: []
at /app/views/Application/index.html.(line:4)
at play.templates.GroovyTemplate.internalRender(GroovyTemplate.java:232)
... 13 more
And just to confirm I'm not crazy, I tried adding the play -> markdown [1.5,) line to myapp/conf/dependencies.yml and restarted the app, and confirmed that it works.
I feel like I'm missing something obvious. Many thanks in advance to anyone who can help! :)

Answer 1

Yes I had the same problem, it seems that transitive dependencies through custom home made modules does not work