Im new to breeze js, I understand that breeze has it's own query language related to OData
But I am trying to get breeze js working with a custom query language, as an example FIQL is
one of the form to make queries to backend, can we get breeze run with this type of query language.
Overview of FIQL :-
http://jaxenter.com/tutorial-smarter-search-with-fiql-and-apache-cxf-46876.html
(this is not a technical answer, at the very most it's an advice)
As mentionned from their website documentation :
Today, out of the box, the Breeze product ships with adapters for the
ASP.NET Web API and for OData. It also ships with .NET components that
interface with the Entity Framework and that generate Breeze metadata
from an Entity Framework model; that EF model could be developed code
first or database first. The Breeze client is in no way limited to
these technologies; they are merely the first backend components
available; we’d be thrilled to help you adapt Breeze to your preferred
server stack.
First question is whether
1) you want breeze to actually create FICL queries on the client and send them to a FICL service. This involves translating a client side breeze EntityQuery into FICL url syntax. If so you would need to create a new a 'uriBuilder' adapter.
2) you want to translate a breeze query already sent to your service into FIQL syntax on the server so that you can further refine the query and then send it on to your FICL service. If so you would need to create a breeze DataService endpoint.
Both of these are certainly possible.
If you are looking at the 1st option, take a look at the 'b000_uriBuilder.xxx' files in the breeze GitHub repo under the 'src' directory. There should be two 'uriBuilder.xxx' files, one which translates an EntityQuery into OData syntax and another that translates the EntityQuery into a new 'json' query syntax. There is also additional information on this 2nd syntax here:
http://www.getbreezenow.com/documentation/query-using-json
Both of these 'uriBuilder's make use an internal 'visitor' framework that we have not yet documented but should be reasonably understandable by looking at the source.
If you are looking at the 2nd option, I would recommend looking at the link mentioned above and then taking a look at the 'breeze.node.js' repo and the 'breeze-sequelize' subdir within it. In this repo we take a serialized server side breeze EntityQuery and translate it into a 'Node' Sequelize query that we can apply to a variety of backends.
Another option is to contact our professional services arm, at breeze#ideablade.com and ask them to assist in building the adapters for you or to ask for more detailed technical help.
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.
Is it possible for Breeze to access a third party API that does not have a "BreezeController" nor supports OData?
"BreezeController" is simply a .NET attribute that helps .NET WebApi provide support for query filtering and ordering via OData "syntax" and well as json serialization support for entity graphs and type identity. Type identity is important so that breeze can track the entities within its entityManager and merge the results of queries and update relation properties. OData itself is never required.
If you don't want the ability for the client to add filtering and ordering instructions to the server, you can write your own attribute that simply provides the json serialization support. The json serialization consists simply of configuring the json.net formatter that web api is already using.
The source for the BreezeControllerAttribute may be found in the Breeze.WebApi project and is really pretty short. Just create your own 'FooControllerAttribute' by copying the 'BreezeControllerAttribute' and remove the IFilterProvider code.
On the other hand, the query and filtering support won't hurt anything and this logic isn't even applied unless you use the EntityQuery 'where' 'orderBy' 'select' or 'expand' methods, so unless you want to explicitly remove this ability there is no need to not use the 'breezeControllerAttribute'
I'm very new with breezejs and having a few questions.
I think that breezejs has very nice features so I can replace my own datacontext. However, I don't want breezejs to interact directly with the dbcontext layer. In fact, in my application, the Service layer only exposes ViewModels - not even the real Business models - to the Controllers . So i'm not so sure whether I can use Breeze or not, since in few Breeze's examples, I only saw Breeze interact directly with DBContext.
Thanks.
=========================================
Thanks Ward for the answer,
About the features that I like from Breeze is that it will help to reduce a lot of time to build my own client-side view models. And to build a SPA, maintaining client-side view models is really painful for me, especially my application have desktop app client and other hand-held device's apps as well. Also, to handle the mapping from a JSon object to Knockout - which means with each view models, I will need a mapper as well.
Currently, my architecture is like this:
Server-side:
Repository layer <=> Service layer <=> Controllers (with the Web API that exposes to Client-side)
Controllers only can get the data (in format of a View Model) by sending request through Service.
So, my question is whether it is possible to make use of Breeze to query and also its integration with knockout.
Breeze never works directly with your DbContext; it works with the service model that you expose through endpoints on your service (e.g., Web API controller methods). But you certainly get the most value from Breeze when the client can query and save entities that are structurally the same as entities on the server.
You can retrieve ViewModels with Breeze - you can call almost any HTTP service method with Breeze. It's not clear to me how Breeze would help you manage those ViewModels on the client once you had retrieved them.
What features of Breeze seem "very nice" to you? Your answer to that question will help you determine if Breeze can be helpful with your preferred architectural style.
Querying data through Breeze without API controllers using DBContext directly should be no problem, saving might be harder but still manageable. I think the most complicated part is to get metadata to the client.
According to this SO answer, samples for exposing metadata from other sources that DBContext directly should be out in a week or so.
Meanwhile, check BreezeJS spa-template sample as there is repository pattern involved on the server side which makes it similar to your data access setup.
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.