I am using Web API and EnableQuery to return Queryable list of Users. There is some sensitive data, which I want to omit, thus I am using both JsonIgnore and ShouldSerialize{DataMember} pattern to remove email addresses, orders, etc.
Now all works fine if I return a single object or a query without parameters.
Once I start using $expand or $select, all those properties get included.
Any ideas why this is happening?
P.S., I have noticed when $expand is used, values get wrapped around SelectAllAndExpand<T> object.
Related
I would like to override the Query Async Method with some Custom code, so I can access an external api, get some data and then use this data to query the db tables to get the results, this should support all the default sync and paging features provided by the base method. I'm using the latest 5.0 DataSync library. Old versions returned a IQueryable so this was easy to do, but now it returns an action result. Is there any solution? Could not find any docs.
e.g. I get a set of guids from api. I query the db tables with these guids and get all the matching rows and return back to client.
I know how to override the method, call external api's, get data and query the db tables, but this provides me with a custom data format not the one that the query async gives by default with paging support.
The way to accomplish this is to create a new repository, swapping out the various CRUD elements with your own implementation. You can use the EntityTableRepository as an example. You will note that the "list" operation just returns an IQueryable, so you can do what you need to do and then return the updated IQueryable.
I have an oData model with a couple of one-to-many relationship, say person->addresses and person->driving-licences. I would like to be able to sort the result set based on properties in the address entity and driving licence entity. As there could be more than one address, I would initially select a single item from the addresses set, based on a property called IsPrimary. As there could be more that one driving licence, I would select the 'UK' driving licence. Is this possible?
I was hoping I could do something like:
/people?$expand=addresses($filter=isPrimary eq true),drivinglicences($filter=country eq 'UK')&$orderby=addresses/postcode,drivinglicences/active
Unfortunately I get the following error:
"The query specified in the URI is not valid. The parent value for a property access of a property 'isPrimary' is not a single value. Property access can only be applied to a single value."
Does anyone know if what I'm trying to do is supported by the spec? Or whether it is an issue with my query? Or whether it is an issue with the .NET library.
I'm using:
Microsoft.AspNet.OData - 7.2.3
Many Thanks.
What you see here is by design, or rather not supported by the specification, the error message even highlights the only type of expressions supported:
The query specified in the URI is not valid. The parent value for a property access of a property 'isPrimary' is not a single value. Property access can only be applied to a single value.
So the simplest solution is to modify the API either to include a Function bound to the people collection that applies the $filter or $order directly, or a Function that returns the data in a new shape, one that only has perhaps a singleton PrimaryAddress property. How you include driving license in this result is up to you, it could even be a parameter to the function, perhaps your people controller has a queryable function with this signature:
[EnableQuery]
public IHttpActionResult WithLicences(string countryCode)
However that is out of the scope of OPs question about specific syntax support
Although it seems like an important feature, we must remember that $select (Projection) and $filter are evaluated at different points in time, OData queries follow a similar execution sequence to SQL however the filter criteria and $orderby are evaluated separately, and the projection of the resultset is the last evaluation to be applied.
Due to $filter and $orderby being applied independently, neither concept is even aware of the other and as such neither can reference or assume to be applied before the other.
You can prove this by specifying a field in the $orderby and/or $filter that is not included in the $select, you can even reference singleton navigation fields that are not included in an $expand and the query will evaluate correctly.
The OData spec is similar to a law document, in that to properly understand and apply it we need to understand the original intent of the authors. We can get an initial understanding from the early listing of Addressing Entities
Addressing Entities describes functions that can be bound to collections or entities that return either a single entity or a collection of entities
By allowing special provision of custom functions to be applied the authors are encouraging API designers to provide natural extensions to their resource endpoints that can facilitate the execution of pre-determined queries that may be otherwise complex or problematic to express in pure OData query syntax.
In other words, we are encouraged to customise our APIs to make them easier for the end process to consume, and to guide the consuming developer to make the best use of the API, they shouldn't have to discover everything from first principals.
To achieve OPs type of query in pure SQL would still require either a nested lookup, CTE or self join... advanced syntax. In OData v4, the specification does not provide a syntax for targeting specific items within a collection for path expressions (of which $orderby derives from)
5.1.1.15 Path Expressions
Properties and navigation properties of the entity type of the set of resources that are addressed by the request URL can be used as operands or function parameters, as shown in the preceding examples.
Properties of complex properties can be used via the same syntax as in resource paths, i.e. by specifying the name of a complex property, followed by a forward slash (/) and the name of a property of the complex property, and so on,
Properties and navigation properties of entities related with a target cardinality 0..1 or 1 can be used by specifying the navigation property, followed by a forward slash (/) and the name of a property of the related entity, and so on.
If a complex property is null, or no entity is related (in case of target cardinality 0..1), its value, and the values of its components, are treated as null.
RE: I couldn't find anything explicit in the spec. :)
That is the very thing about the OData specification,the specification does not list what is not supported, only what should be supported. So by omission, if you cannot find a reference to how to do something, then that something is not required to be supported.
Introduction http://docs.oasis-open.org/odata/odata/v4.01/odata-v4.01-part2-url-conventions.html#sec_Introduction ... This specification defines a set of recommended (but not required) rules for constructing URLs to identify the data and metadata exposed by an OData service as well as a set of reserved URL query string operators, which if accepted by an OData service, MUST be implemented as required by this document.
This has been on ongoing discussion held in may threads, recently https://stackoverflow.com/a/55324393/1690217
Many people complain that this is surely a fundamental feature of a data access platform, however it is important to respect the original intent of the OData platform and keep our APIs simple by providing customised endpoints to suit our business domain.
I'm currently building a ASP.NET OData service which uses code first with EF5. When I do the query of a entity, it is returned as JSON along with empty values for the related entities.
I want the related entities attributes not to be included in the returned JSON for the entity query unless 'Include' is explicitly mentioned.
Is there a way to achieve this?
You have to enable lazy loading by setting the related members as virtual
I am trying to pass an array of custom objects from my asp.net code behind to a webservice method. The webservice is ASMX and I can't change that for now. I can verify up to the point of the code behind calling the webservice, that the custom object is in the array and has the proper values. When I put a break point in the webservice, I notice that the array is null.
I have checked my Service Reference and the collection type is System.array.
I read that I might need to mark my custom class with [DataContract] and the properties as [Datamember] for this to work, but these don't even show up in the intellisense.
I tried all kinds of things and I couldn't get this to work. I tried casting the custom objects as objects and passing them that way. I also tried to cast the whole array as type object and that didn't work. I tried collections; no go. I read a lot on this and couldn't find anyone who could actually do this. So I gave up on doing this with ASMX and tried it with a WCF service. That did work nicely. I created a custom object. I created a strongly typed collection of this class and populated the collection. I then passed this collection to the WCF service and the method was able to see all the objects properly. So if anybody is stuck in the situation I was, try a regular WCF service.
I have an existing web application that uses EF and POCO objects. I want to improve the client experience by exposing some of my objects through WCF(JSON). I have this working fine but where I am unsure is how to handle derived objects(not sure if that is the correct term) or IEnumerable anonymous objects if you will.
Let's say I have 3 tables structured like so:
Templates
ID
Template
Groups
ID
Group
Instances
ID
TemplateID
GroupID
This is obviously a one-to-many type relationship. I have my navigation properties setup correctly and getting strongly typed object properties works great. However, how do I send serialized anonymous type object(s) over the wire. Like an object that sends all instances that are equal to groupid=1 and include the names of the template and the object.
Am I missing something or do I have to create another class object for WCF that would look like this:
WCF Object
InstanceID
TemplateID
TemplateName
GroupID
GroupName
I guess I could alter my tables to account for this but that seems wrong too. I know that IEnumerable objects can't be serialized and I know that throw away objects are probably not the way to go either. I want to do this the right way but I am not sure how to go about it.
Your suggestions are appreciated.
Regards
Based on what you're doing, I'd suggest looking at OData with WCF Data Services. You state that you want to be able to send all instances where the groupid=1 - OData is great at this type of filtering.
If you're want to stick with your current approach and not use OData, then my first question is why are you sending back anonymous types at all? You can do what you are seeking (all instances with a groupid=1) without sending back an anonymous type. In your select clause you just create new instances of your concrete objects rather than newing up anonymous types. If your query is really just filtering and not executing any meaningful projection with the selct to anonymous type, then I don't see any reason to send back your anonymous type at all.