GWT - including source files outside module's package hierarchy - gwt

I have a GWT project in eclipse with the following structure for the GWT module
com.foo.gwt -> Dashboard.gwt.xml
com.foo.gwt.client
com.foo.gwt.server
I have different packages com.bar.baz1, com.bar.baz2, etc. whose contents I want to include in client side code. All the files are GWT JAVA->JS conversion compatible.
The problem is that the <source> tag in Dashboard.gwt.xml, treats the path as relative to the directory of Dashboard.gwt.xml. So I cannot reference anything outside com.foo.gwt hierarchy.
So I created a new module MyNewModule.gwt.xml in com.bar and included baz1 and baz2 sub packages using relative paths in tag. Finally I made Dashboard.gwt.xml to inherit the new module.
This works fine when I compile the Dashboard module but fails when I compile MyNewModule.
That's because some classes in MyNewModule reference classes of Dashboard module.
I tried inheriting Dashboard module in MyNewModule. This creates a circular reference, but GWT doesn't complain about it. Everything works but I am not comfortable with the circular reference. I don't need MyNewModule, all I need is a way to include code from packages outside Dashboard module's hierarchy.
I am wondering why GWT does not allow absolute source paths.
Am I missing something here?

You dont need to compile each module separately. When you compile your com.foo.gwt project, GWT compiler will look for all dependencies in your com.foo.gwt.xml file and will compile ALL .java files both your com.foo and com.bar.baz. (and other libraries) to javascript.
As you said, its correct to put MyNewModule.gwt.xml in the com.bar.baz project and "inherit" it in your DashBoard.gwt.xml file. The part you are missing is to make a .jar file with MyNewModule project and put in war/WEB-INF/lib folder (just gwt.xml file and compiled java classes).

Related

How do I reference third party library source code for client use in GWT?

The GWT documentation states that all the source code for compilation to JavaScript on the client-side must be in a subpackage of the gwt.xml file. How does this work for when one references third party libraries?
Specifically, if I have a library foo.jar and I want to use some POJOs (which are Serializable) and do not suck in any non-Serializable code, how can I use these POJOs? How do I tell GWT where the source code is for them?
Remember too that the GWT compiler needs actual Java source to compile to javascript, so it isn't enough that the classes are available and that all are serializable. For RPC to send the classes over the wire, they must be able to be used as JS when they get to the client.
That said, take a look in gwt-user, at the module javax/validation/Validation.gwt.xml. This file is put there so that other packages in javax.validation - even in other jars - can be compiled into JS for client-side validation. if you have a jar (and sources) on your classpath with code in com.thirdparty.pojos, you can create a module file in your own project in that same dir in your own source (something like com/thirdparty/pojos/ThirdParthRpc.gwt.xml, and put a <source path="" /> element in it to indicate that the entire package is legal for translation to JS. There will likely be some files that cannot be translated - use the exclude tag to deal with those.
If you have control over packaging foo into foo.jar, and you have all the sources, then it's easy.
If you have a packaged foo.jar, and happen to have the source code, then you need to expand the foo.jar, copy the source into the exploded .jar directory, generate a simple GWT module.xml file and add an tag to your project’s module.

How to create a java project as a jar for GWT

I'm wanting to use some java code as a reusable component jar in my GWT 2.4 application.
I need access to that code on the client side, so I've read that the steps involved are to
add an entry in the main projects gwt.xml file pointing to this project,
include a gwt.xml file in the jar
and put the java code under a client folder.
I assume that this has to be a gwt project itself, otherwise there would be no need to add the inherits entry or is it not possible to use a regular java project client-side?
Is there anything else I need to do for this (other than ensure the libraries in the jar fall under the JRE Emulation Reference list)?
We don't use the plugin functionality in Eclipse, but to use another project in your GWT project all you need to do is define a .gwt.xml module file in your project that you want to use in your GWT project and reference that module file with <inherits.../> in your main GWT project. You will also obviously need to add that project as a reference in the build path in Eclipse, so you don't get compilation errors. And all of that is besides the fact that your referenced project has to comply to the JRE emulation reference so it can be fully GWT compilable.

My first GWT Module

I created a module to share code across a couple of projects.
I created a GWT project: Framework. I then created a module com.framework.Framework within the project. The Framework project contains both client code, in the com.framework.client packages, and server code in the com.framework.server packages.
I try to consume this by
- Adding the project to the Java Build Path
- Adding to the module's definition
When I run the consuming project, I get NoClassDefFoundErrors for Framework classes I use in the module's server code.
What am I missing?
If I jar up the Framework project's WEB-INF\classes contents and put it into the consuming project's WEB-INF\lib folder, as well as add it to the Build Path it seems to work, but I don't see a way to keep the framework classes up to date in the consuming project(s).
Please make sure that you create gwt.xml file via menu New->Module, and in this gwt.xml file, you must declare your entry point class.

Problem using in GWT project classes from other project/source folders

My project contains 2 source folder, one is generic J2EE application another is smartCleintGWT,
I want to use some already existing DTO classes from first source folder (src)
Note that class used on client side and on server side of GWT project!
When I do that I getting error
[ERROR] Errors in 'file:/C:/..Projects/Admin/DMX/src_console/com/ho/nod/client/AdminRPC.java'
[ERROR] Line 7: No source code is available for type com.dmx.synch.server.descriptors.DMXLicense; did you forget to inherit a required module?
Source is available obviously; is there any way to import all that into GWT?
PS In the future 2 source folder will be separated into 2 projects...I hope it wont be that complicated as well.
You can find in the good docs:
Modules can specify which subpackages
contain translatable source, causing
the named package and its subpackages
to be added to the source path. Only
files found on the source path are
candidates to be translated into
JavaScript, making it possible to mix
client-side and server-side code
together in the same classpath without
conflict. When module inherit other
modules, their source paths are
combined so that each module will have
access to the translatable source it
requires.
To add another subpackage add <source path="package"/> in your host file (*.gwt.xml). From the log you posted, it seems you have to add source from the com.dmx.synch.server package.
Most RPC problems are related to Serializablity of the DTO in question, can you need to ensure that the classes have default constructor and also check if the Module definition file i.e. .gwt.xml file has source element pointing to these packages.
GWT only looks for source code in the client package by default, so if you have added new packages you must specify this in your *.gwt.xml file.
Add something like: source path='your_top_dir' in XML format.

How do I compile a module without an EntryPoint?

I have a utility module for GWT which doesn't have an UI (hence, there is no class which inherits from com.google.gwt.core.client.EntryPoint. When I try to compile this module with GWT 1.7.1, I get this error:
[ERROR] Module has no entry points defined
How do I get rid of this error? Do I really have to define a dummy entry point? How did Google ever compile their own utility modules???
Utility Jars do not need to be compiled by GWT.
If you just want to reuse this as a library in other GWT applications then you just have to jar the .class and .java files in one jar and make sure that you have a .gwt.xml that says where the client source is. If you follow the conventions (client classes in client) then you can get away with just otherwise you need to specify a tag for the client package
Then make sure that you inherit this .gwt.xml in the projects where you want to compile an entry point.
No you don't need an EntryPoint. Here is an example of one of my modules that doesn't have one:
<?xml version="1.0" encoding="UTF-8"?>
<module>
<source path="grid" />
<inherits name="com.google.gwt.user.User"/>
</module>
The short answer is you don't compile code in modules. GWT just needs them as source code. When you compile your main module (the one with the entry point) it uses the source from any other modules you have inherited in your .gwt.xml file to compile the entire project.
I'm using the gwt-maven-plugin Maven2 plugin to compile my code. I migrated the code from an old version of the maven-googlewebtoolkit2-plugin plugin. For the old plugin, I had to specify which modules were entry points like so:
<compileTargets>
<param>com.project.module.Module</param>
</compileTargets>
For the new plugin, it's
<module>com.project.module.Module</module>
Since the plugin couldn't find which modules to compile, it search for "*.gwt.xml" and compiled all of them into "UI modules" (which must have an entry point).
We've got a utilities module, which constructs & handles some common UI elements, and a bunch of javascript/json common tasks.
It looks like what we did (also migrated from the totsp plugin to the codehaus plugin somewhere along the line) was to include an entry point in the util module; it was just empty. (It includes the comment "Intentional no-op").
Then the pom just refers to the thing as a dependency.
If using eclipse GWT plugin just remove the module without an EntryPoint from the moduleslist that pops up just before compiling.