The question may sound funny but I think this should be possible.
What I want is to use a repository that is purely custom but is exposed just like a Repository. This service would have methods to get, save, delete and list objects where the data could be from any arbitrary source.
Looking through the code, I think it should be possible since methods are accessed using CrudMethods and RepositoryInvoker. I belief this requires an implementation of RepositoryFactoryInformation that will be discovered by Repositories. I started experimenting a bit and it looks like a full-blown spring-data-noop module.
Am I on the right track or is there an easier way to accomplish this?
I've ended up writing spring-data-custom to create fully customized spring-data repositories, allowing custom code to be used with spring-data-rest etc.
Enable custom repositories (#EnableCustomRepositories)
Annotate eligible entities (#Custom)
Create a repository (extend CustomRepository<T, ID>)
Add custom behavior:
Let repository extend a new interface with the Custom suffix
Create an implementation of the new interface with the Impl prefix
Add one or more CRUD methods named findOne, save, findAll, delete (see DefaultCrudMethods)
Add query methods annotated with #Query
Export repository using spring-data-rest
(copied from README)
As #wwadge correctly mentioned, spring-data-keyvalue is an alternative. Repositories have to implement KeyValueAdapter, e.g. MapKeyValueAdapter.
The easier way is to use spring-data-keyvalue project which does what you are trying to do.
Related
Being new to flutter and dart, I am looking for ways to structure my projects. I have found that the Repository pattern made its way to dart (I have a strong Java background), but I have found that there's not the necessary tools yet to properly implement a repository.
How I would normally approach this is to first create the simple straightforward methods. I ended up with the following dart code:
abstract class CategoryRepository {
Future<List<Category>> getCategories();
Future<Category?> getCategoryById(String id);
}
All is good. But now imagine I have a PostRepository, and I only want to return posts of a specific category? I am missing a standardized way in flutter how to add conditions to my repository select methods. I cannot believe nobody has written something for this purpose before so I am doubting whether I am on the right track here. Maybe my Java background is throwing me off.
In Java (specifically Spring JPA) I am used to specifications, predicates and criteria as documented here.
In .NET you can implement select methods of a repository pattern with the Expression class which allows you to use LINQ to add select criteria as documented here.
For Flutter or Dart, what would be the equivalent? Or am I on the wrong track?
I have found the flutter_repository package, but it is deprecated (without a reason). Looking at the documentation it indeed had Specifications which are used to add conditions. This would be exactly what I expect/need, but again it's deprecated.
This is where I cannot find the information publicly anymore and am questioning "how to properly implement repository in flutter/dart", hence the reason for posting this.
We have an Eclipse IDE application on 3.x that uses various newWizards to allow the user to create different files. Although these files differ slightly contentwise, the structure of the wizards is quite similar.
Thus, a sound object-oriented approach would be to instantiate different wizards from the same class and initialize them with different data.
Problem:
To decide what wizard needs which data we need a way to distinguish the different already instantiated wizards (e.g during the call to the init method of the wizard).
Is there any way to do so? It would e.g. help if somebody knows a way to get the wizard's id defined in the extension point from within the instantiated wizard.
If your wizard implements IExecutableExtension, it will be passed the configuration element that represents the extension for which it is created.
You can also use extension factories in that you specify a type that implements IExecutableExtensionFactory.
The interface allows you to control how the instances provided to extension-points (wizards in your case) are created.
Extension example:
<extension point="org.eclipse.ui.wizards">
<newWizard
name="..."
class="com.example.WizardFactory">
</newWizard>
Note that the extension factory may also implement IExecutableExtension to gain access to extension attributes before creating the extension's executable class.
I'm using ASP.Net MVC 4 RTM Web API. I have a controller action with a parameter that I'd like to populate via custom model binding. To achieve this, I created a class that derives from System.Web.Http.Controllers.HttpParameterBinding that sets the value of this parameter. I then created an attribute class that derives from System.Web.Http.ParameterBindingAttribute which I use to decorate the parameter on my controller action.
This is all working great, my HttpParameterBinding class is populating the action parameter correctly. The problem I have is that my custom parameter binding class has a dependency that I'd like resolved via my IoC container (Unity). Is there a way to override how Web API creates HttpParameterBinding instances so that I can build up my custom binding class dependency from Unity? I was able to do something similar for a filter attribute by creating a custom filter provider that uses Unity's BuildUp method to populate dependencies, however I'm not seeing anything similar for Web API's HttpParameterBindings.
In general: to use IoC / Unity in the Web API you need to set it up seperately.
Try downloading the nuget package Unity.WebApi and see if that helps!
Take a look at this article: Parameter Binding in WebAPI
It walks through a couple different options from Converters to Binders to BinderProviders. It sounds like you may be able to write a custom ModelBinderProvider which knows how to provide your dependency. If that isn't high enough in the chain you can look at replacing the default IActionValueBinder service. It's a DefaultActionValueBinder instance, which you can extend or simply re-implement.
I also highly recommend downloading the WebAPI source code, as it's been an incredible help for these issues as I've run into them. Here's the WebAPI source code. I recommend downloading it so you can open it in VS for easy navigation.
Feel free to check out FlitBit too (It's very modular, don't let the number of packages scare you off)! I'm working on a WebAPI package for supporting FlitBit, specifically FlitBit.IoC and FlitBit.Dto. I'll add an update if I work out my IoC issue, since it's very similar to yours.
When the context is generated i see there are some extension methods : AcceptChanges, MarkAsAdded, MarkAsDeleted, MarkAsModified.
When should i use these methods since they are available only on the service?
They are available on the client as well - make sure you've included their namespace at the beginning of your file. If not, the intellisense will not offer a suggestion for it since these are extension methods.
Usually, you reference the same project on the client side, and you should have these methods as well. You use them when appropriate of course.
I'm working on a GWT project and I find it very tedious to have to add a function to my servlet, then copy and paste the function signature into my Service interface, then copy and paste it into my ServiceAsync interface and change the return parameter to be a callback. Is there a tool or a setting where I can just add public methods to my class and they can get copied into the other interfaces? Even if its not automatic it would be nice to be able to select specific methods and have them copied automatically.
I'm using eclipse and ideally it would update my interface each time I save implementation since thats when it checks my code and complains that my changes break the interface.
If you add the method to your *Service interface, then Eclipse can auto-generate the method ("Add unimplemented methods...") in your *ServiceImpl servlet, which you can then just fill in. Also, if you've got the Google Eclipse plugin installed, it will underline the new method in your *Service interface and complain that it's not in the *ServiceAsync. It might have a CTRL + 1 option to generate it in that interface as well.
You don't really need a tool. Just factor out the many RPC methods by just one method that takes a Request/Response. all you need to do is create subclasses of Request/Response and you don't need to think about adding new methods in the 2 interfaces.
You can use Google Guice on the server side to map the incomming request to a class handling the call... or you could use a visitor approach to forward the incoming request to the code handling the request (without resorting on a big instanceof construct).
Instantiations WindowBuilder GWT Designer does exactly what you are looking for.
The RemoteService Wizard will create all three files at the same time as well as keep them in sync as you make changes.
http://www.instantiations.com/windowbuilder/gwtdesigner/index.html
FWIW - I am only a user/purchaser of this product. I am not employed or in any other way related to Instantiations.