使用Breeze获取数据库中“忽略”的数据

Question

I am building a SPA and are using BreezeJS for data management. Now I want to be able to set processed data on my model class that are not present in the database and send it up the client. The problem is that breeze also ignores these properties.

public class MyModel{
     public int Id{get; set;}
     public string Name{get; set;}
     public string ProcessedData{get; set;}
}
...
Ignore(model=> model.ProcessedData);

I realize that Breeze uses the same metadata as my datacontext, but there should be a way to override it.

The ignored properties is sent by the controller as json, it's just a matter of making breeze parse it as I need it to.

Answer 1

I haven't confirmed this but I think that if your are sure that the data is being returned from the server then you can add "unmapped" properties with the correct names to the Breeze client and it will materialize these as well. See the "unmapped" discussion here: http://www.breezejs.com/documentation/extending-entities .

Or you could try this ( I haven't actually tested this) AFTER the metadata has already been returned.

var dp = new breeze.DataProperty( {
    nameOnServer: "ProcessedData", 
    dataType: "String",
    isUnmapped: true
});

myEntityManager.metadataStore.getEntityType("MyModel").addProperty(dp);

and then try your query.

Note: only "unmapped" properties can be added to the EntityType after the EntityType has been itself added to a MetadataStore.