I'm looking for examples on how to implement a custom data provider for OData 4 and WebAPI (preferably for an in-memory untyped dataset).
Doese anyone know of any examples out there? My googeling turned up little of use.
I know of this example: http://msdn.microsoft.com/en-us/data/gg191846
But can't find the project-files for the example-code ... also it's from 2011 and things have changed since then...
You can refer to Web API OData Sample code at
https://aspnet.codeplex.com/SourceControl/latest
You can find the code at "Samples/WebApi/OData/v4/ODataUntypedSample" in the left panel.
There is another blog talking about "Typeless Entity Object Support in WebApi".
http://blogs.msdn.com/b/leohu/archive/2013/11/05/typeless-entity-object-support-in-webapi.aspx
Related
How can Breeze JS be used to consume a pure, simple, plain old RESTful API? Consider a web api endpoint that does not support OData and does not have Microsoft Entity Framework as the OR/M layer.
I see there's this Edmund's sample here, but I would like it to be more specific on how to manually setup BreezeJS metadata, since from what I understand about not having OData support is the fact that you lose out-of-the-box metadata resolution for the model consumed from an api endpoint. I quote from this Edmund example:
we have not yet described the Metadata Definition API properly. We ask that you rely on your intuition as you read this code ... your intuition will usually be correct. Please post questions to StackOveflow tagged with "breeze".
Is there any source of information on this topic that leaves intuition aside?
That Edmunds sample is so old, it pre-dates any of the documentation on how to write metadata.
Take a look at the Metadata by Hand topic in the BreezeJS documentation.
I am using Breeze JS and would like to implement a server with full CRUD functionality using Progress Openedge. The Breeze website talks a lot about being able to write your own server implementation but I can find no information describing the format of a save bundle that Breeze sends to the server. Does anyone know of any documentation or schema?
The documentation for this is buried in the DataServiceAdapters page. Look about halfway down, under the heading saveChanges (saveContext, saveBundle) -> promise.
There's an example of what the JSON looks like in this SO answer.
The SaveBundle is not documented for a very good reason: it has no definition in BreezeJS!
It could be any serialized object that your server requires to satisfy yoursaveChanges work flow. You can see that this is true by examining the a60_abstractDataServiceAdapter.js source in github:
proto._prepareSaveBundle = function (/*saveContext, saveBundle*/) {
...
throw new Error("Need a concrete implementation of _prepareSaveBundle");
};
Breeze does ship with an implementation b00_breeze.dataService.webApi that satisfies the expectations of the companion Breeze ASP.NET Web API helper classes such as ContextProvider. This implementation is worth studying if you decide to write your own server support code.
But it is only one of many possible implementations. An OData web server, for example, requires an entirely different package and format for "$batch" change-set saves. Only you know what's right for your "Progress Openedge" server.
All that said, we do delve into some critical aspects of the SaveBundle destined for Breeze Web API services in the documentation for "ContextProvider".
Feel free to follow-up with more specific questions after you've read that.
I'm looking for a starting point on how to extend BreezeJS (or if it's even possible!) to support sending JSON data using the Badgerfish notation to the server from BreezeJS.
I see that BreezeJS has the JsonResultsAdapter - to take a response from the server and transform it - which would work to allow Breeze to walk through a Badgerfish JSON result set and instantiate entities.
I need the other way - a JsonRequestAdapter (or something like it) - to take the JSON that Breeze has created and about to send to the server, and modify to the Badgerfish notation.
Any guidance for this problem? thanks!
Update: June 2013
I've gone with the approach of implementing a custom Breeze DataService adapter that I pass into an EntityManager instance. This approach is not for the faint of heart to be honest, and took some work to really understand what needed to happen. I took the provided Web API DataService adapter and 'adapted' it to work for a generic RESTful service.
Adam, this is a great question.
We are trying to come up with a standard mechanism analagous to the 'JsonResultsAdapter' to be used to intecept http 'puts' but really want to understand the most common use cases first. We'd love any feedback on suggestions and use cases.
Please add a 'feature request' for this to the Breeze User Voice. We take these suggestions very seriously and this is a topic that we think is important as well, but really want to get some feedback from our community on its priority.
Here is my knowing about ASP.NET SPA:
have to use Upshot to talk to the server;
have to use DbDataController to provide Web APIs;
have to use Entity Framework Code first...
so, many concerns come out:
have to provide metadata for the upshot to work, this will obviously expose the structure of your database;
can i use Entity Framework Database First instead of Code First? You may ask why. Because Code First don't provide you the ability to customize your database(index customization, stored procedure...etc.);
A problem i met: when i add a "TestUpshot.edmx" file(generated from database 'northwind') to the MySpaApp.Models folder(trying to test whether i can use the edmx classes in the MyDbDataController class, and generate proper metadata in the client side), and run the application, there is an exception:"System.ArgumentException: Could not find the conceptual model type for MySpaApp.Models.Categories."...
Need help here, thanks in advance.
Dean
I may be missing something, but there is no requirement to use any of the technologies you've listed.
An SPA is just a pattern. You can use whatever you need to achieve that. There may be benefits with choosing certain technologies, ie templates, tutorials, etc.
Doesn't really answer your question, but should lead you to experiment with what you've got.
SPA is actually a way to conceptualize your client application. SPA comes the closest to the fat client - data server concept from the current web approaches. Definitely this will be the ruling concept within a couple of years.
Your concerns can be addressed using JayData at http://jaydata.codeplex.com that provides advanced, high level data access for JavaScript against any kind of EntityFramework back-ends (db, model or code first). Check out this video that presents the whole cycle from importing your EDMX from SQL (this could eighter be model first definition as well) to inserting a new product item in the Products table from JavaScript.
I am trying to learn Asp.net Mvc so I am trying out
this Tutorial.
They talk about the Repository Pattern and how it is easy to change to another data access technology instead of just calling Linq to Sql directly.
Using LINQ to SQL within a controller class makes it difficult to switch data access technologies in the future. For example, you might decide to switch from using Microsoft LINQ to SQL to using the Microsoft Entity Framework as your data access technology. In that case, you would need to rewrite every controller that accesses the database within your application.
Note: I never really understood how an interface worked before reading this tutorial and it's still not 100% clear. I see it now as some sort of 'template' for a class.
After successfully using Linq to Sql I thought it would be nice to try out Ado.net Entity Framework since I've been reading a lot about this. They said using the Repository Pattern would make it easy to switch so I thought I would test that.
My question is: what should I do to change to Ado.net EF?
This is what I think I should do.
Add the Movie.edmx file and configure it(add my movie table).
Write a new class based on the IMovieRepository and maybe call it MovieEFRepository.
Change the parameter in the controller constructor to MovieEFRepository. This is the first thing I find strange because in the tutorial they say that not using the repository will force you to change all the controllers if you change to an other datasource. Don't I need to change every controller anyway since I am specifying the MovieRepository class?
The last adjustment I think I need to do is to change the View. Because it's using the Product class which was created by the Linq to Sql designer. I am not sure how I am going to do this. I guess I should have used some object that wasn't dependent on the dbml file?
Forgive me if I have a slightly simplistic view of Asp.net Mvc. I am webdesigner with a lot of interest for Asp.net webdevelopment.
So after a few days of reading and a lot of googling I got it to work. First I tried to find out what IoC (Inversion of Control) actually meant.
One of the first sites I found was a website with a screencast about Unity. Which is a DI/IoC framework for .Net.
Link: David Hayden screencast on Unity.
Looking at it now this is actually a very good screencast and example on how easy it is to use Unity and IoC/DI. At the time I didn't understand it completely so I went on and kept googling.
One website I kept running into was the one from Martin Fowler.
Link: Martin Fowler - IoC Container and the DI pattern
For me, a person that is a coding novice this website is a little to abstract. Also this might sound weird but the font, line-height and typography on that website was really awful which made it even harder to read.
The next website I read was about Windsor Castle since Alfredo Fernández said it was easy to use.
Link: Castle Project- Windsor Container
The documentation wasn't to bad but I had some problems converting their "getting started" basic example to my Asp.net Mvc application. Also part 2 and 3 were missing from their getting started.
After this I started looking for the different frameworks to see if i could find a really basic example. If I just looked at the first screencast again I would have fixed it a lot sooner but somehow I lost track of it.
Link: Scott Hanselman: List of .NET DI Containers(IOC): very good blog post with most of the .NET IOC solutions.
Link: Phil Haack: TTD and DI using Structure Map: Using the xml configuration file was to complicated for me and i couldn't get it to work.
Link:
Andre Loker: ASPNET-MVC-with-Windsor-programmatic-controller-registration: Didn't try this example. Looking at it now I might have been able to get it to work.
Link: MvcContrib: This adds functionality to Asp.net Mvc. It also has 3 or 4 IOC ControllerFactories build in. I couldn't get it to work I also didn't find a lot of documentation about this.
I had a lot of problems with xml configuration files and I couldn't seem to get them to work. I tried Windsor, Structure Map and Spring.net but I always got stuck with the xml files.
So I decided to go to the Asp.net Mvc site because that's where I started learning about Asp.net Mvc. I found the first screencasts and MIX09 presentations very clear and I understood most of what people were talking about. I got stuck at the second screencast by Rob Conery when building the Storefront application. Because I knew a little more about repository and IOC/DI now I thought it would a be a good idea to start watching Rob Conery's screencasts again. In one of the screencasts he talks about uploading all the samples to codeplex.
Link: Codeplex: Mvc sample apps
I went to codeplex and found out you can browse through the source files without downloading them. I tried to find out how Rob Conery handles IOC/DI with his repositories. So I was glad to see he was using Structure Map but instead of using a xml configuration file he was using a bootstrapper class that registers all the interfaces to their concrete class.
After trying this with my webapplication I finaly was able to get Structure Map to work in my application (Hooray).
He also showed me how to fix the dependency on my Product class that comes from Linq to Sql. He creates an extra object that then gets called by "select new product { }" in the Linq queries.
Wow, this answer is a little longer than I planned but I hope this helps other people like me who are very novice in coding and Asp.net Mvc.
You might have your repository decoupled because of injection, not if you followed just the examples because of
public MoviesController() : this(new **MovieRepository**())
I recomend you to read about IOC, is easy and very interesting, you can use and ioc container like castle windsor.
With that, your contoller will have only one constructor, the one with the interface, and not will need to be changed.
With your entities you can do the same that with the controllers, create an interface for each entity and use the ioc pattern too, with tha you will only have to change your configuration file for your ioc container.
If you don't do these things, your right, you will need to change all you said.
I hope that help! sorry about my english!