Consider the following method in a Web Api controller:
[Queryable(AllowedQueryOptions= AllowedQueryOptions.All)]
public override IQueryable<Mandate> Get()
{
return new List<Mandate>() { new Mandate() {
Id = 1,
PolicyNumber = "350000000",
OpenPositions = new List<OpenPosition>(){
new OpenPosition(){ Id = 1, Amount =2300 },
new OpenPosition(){ Id = 2, Amount =2100 }
}},
new Mandate() {
Id = 2,
PolicyNumber = "240000000" ,
OpenPositions = new List<OpenPosition>(){
new OpenPosition(){ Id = 3, Amount =2500 },
new OpenPosition(){ Id = 2, Amount =2100 }
}
} }.AsQueryable<Mandate>();
}
Here the list is built manually and if I browse to the following url:
http://localhost:52446/odata/Mandates?$filter=Id eq 1 it returns the correct item from the list.
Now obviously the list is more likely to be a database structure. Data would be retrieved using some ORM and returned to the Web API service.
I don't use Entity Framework (and I can't because of legacy systems).
How would I use Web API in this case? How would I translate the url parameters so that the filters are applied by the layer responsible of the data access?
Got it. You pointed me into the right direction with your LINQ provider. I found out I can do it easily with the ORM we are using (OpenAccess). More info here :http://docs.telerik.com/data-access/developers-guide/using-web-services/asp.net-web-api/developer-guide-wcfservices-web-api-expose-oacontext
Related
I have looked at other similar questions (such as this one Is there a way to force ASP.NET Web API to return plain text?) on SO but they all seem to address WebAPI 1 or 2, not the latest version you use with MVC6.
I need to return plain text on one of my Web API controllers. Only one - the others should keep returning JSON. This controller is used for dev purposes to output a list of records in a database, which will be imported into a traffic load generator. This tool takes CSV as input so I'm trying to output that (users will only have to save the content of the page).
[HttpGet]
public HttpResponseMessage AllProductsCsv()
{
IList<Product> products = productService.GetAllProducts();
var sb = new StringBuilder();
sb.Append("Id,PartNumber");
foreach(var product in products)
{
sb.AppendFormat("{0},{1}", product.Id, product.PartNumber);
}
HttpResponseMessage result = new HttpResponseMessage(HttpStatusCode.OK);
result.Content = new StringContent(sb.ToString(), System.Text.Encoding.UTF8, "text/plain");
return result;
}
Based on various searches this seems like the simplest way to proceed since I'll need this only for this one action. However when I request this, I get the following output:
{
"Version": {
"Major": 1,
"Minor": 1,
"Build": -1,
"Revision": -1,
"MajorRevision": -1,
"MinorRevision": -1
},
"Content": {
"Headers": [
{
"Key": "Content-Type",
"Value": [
"text/plain; charset=utf-8"
]
}
]
},
"StatusCode": 200,
"ReasonPhrase": "OK",
"Headers": [],
"RequestMessage": null,
"IsSuccessStatusCode": true
}
So it seems that MVC still tries to output JSON, and I have no idea why they'd output these values. When I debug the code step by step I can see that the content of the StringBuilder is okay and what I want to output.
Is there any easy way to just output a string with MVC6?
Have a go with this:
var httpResponseMessage = new HttpResponseMessage();
httpResponseMessage.Content = new StringContent(stringBuilder.ToString());
httpResponseMessage.Content.Headers.ContentType = new MediaTypeHeaderValue("text/plain");
return httpResponseMessage;
The solution was to return a FileContentResult. This seems to bypass the built-in formatters:
[HttpGet]
public FileContentResult AllProductsCsv()
{
IList<Product> products = productService.GetAllProducts();
var sb = new StringBuilder();
sb.Append("Id,PartNumber\n");
foreach(var product in products)
{
sb.AppendFormat("{0},{1}\n", product.Id, product.PartNumber);
}
return File(Encoding.UTF8.GetBytes(sb.ToString()), "text/csv");
}
I need to get the following code to work
public IQueryable<BankingDTO> Get(ODataQueryOptions<TillSummaryDTO> options)
{
return((IQueryable<BankingDTO>)options.ApplyTo(this._bankingService.GetBanking()));
}
I would like to query on TillSummaryDTO because it has the field "TillOpID" on it. However I would like to return BankingDTO as this is the end result which contains the group by and sum. When I run the query I receive the error "Cannot apply ODataQueryOptions of 'Bepoz.Presentation.ViewModels.TillSummaryDTO' to IQueryable of 'Bepoz.Presentation.ViewModels.BankingDTO" what is the best practice for this?
The bankingservice.GetBanking method looks like this
var query = from t in _tillSummaryRepository.Table
join w in _workStationRepository.Table on t.TillOpID equals w.WorkstationID
join s in _storeRepository.Table on w.StoreID equals s.StoreID
join v in _venueRepository.Table on s.VenueID equals v.VenueID
select new TillSummaryDTO
{
TillOpID = t.TillOpID,
Cash = t.Cash,
Workstation = new WorkstationDTO()
{
WorkstationID = w.WorkstationID,
Name = w.Name,
Store = new StoreDTO()
{
StoreID = s.StoreID,
StoreGroup = s.StoreGroup,
Name = s.Name,
Venue = new VenueDTO()
{
VenueID = v.VenueID,
VenueGroup = v.VenueGroup,
Name = v.Name,
}
}
}
};
return query.GroupBy(x => x.Workstation.Name)
.Select(x => new BankingDTO()
{
TotalCash = x.Sum(y => y.Cash),
WorkstationName = x.Key
});
The scenario you want to achieve is that you have an entity set of TillSummaryDTO that you want to query, and you would like the return type to be a collection of BankingDTO. The query for the BankingDTO is carried out by applying the query options in the URL onto TillSummaryDTO . But the fact that the BankingDTO and TillSummaryDTO are different kind of types makes it impossible achieve that in a simple Get action method, right?
This scenario can be better resolved by the function feature of the OData protocol that the function takes the TillSummaryDTO collection as input parameter, has some internal complicated logic to query for the right BankingDTO, and returns the BankingDTO instead of TillSummaryDTO.
For the concept of function in OData protocol, you can refer to this link for V4 and section "10.4.2. Functions" of this page for V3.
For implementation, this sample can be referred to for Web API OData V4 and this tutorial can be referred to for Web API OData V3.
I have this bit of code that does not work because Entity Framework doesn't recognize the CreateItemDC method. CreateItemDC is a modular private method that creates a data contract for the given Item entity. I use CreateItemDC all throughout my service whenever I need to return an Item data contract, but I can't use it here. I can realize the sequence of ProjectItems into an array or enumerable because I would have to do this to all ProjectItem entities in my database as the query criteria is specified on the client and I don't have access to it here. Do I have any better options here? It seems that RIA Services is not worth the trouble. I'm really wishing I had used plain WCF with this project.
[Query]
public IQueryable<ProjectItemDC> GetProjectItems()
{
return from projectItem in ObjectContext.ProjectItems
select new ProjectItemDC
{
ID = projectItem.ID,
LibraryItem = CreateItemDC(projectItem.LibraryItem),
LibraryItemID = projectItem.LibraryItemID,
ProjectID = projectItem.ProjectID,
Quantity = projectItem.Quantity,
Width = projectItem.Width,
Height = projectItem.Height,
Depth = projectItem.Depth,
SheetMaterialID = projectItem.SheetMaterialID,
BandingMaterialID = projectItem.BandingMaterialID,
MaterialVolume = projectItem.MaterialVolume,
MaterialWeight = projectItem.MaterialWeight
};
}
P.S. I do love LINQ and E.F. though. :)
Well, if you want to go with plain WCF, you can, no problem, just change the code to
[Query(IsComposable=false)]
public IEnumerable<ProjectItemDC> GetProjectItems(string myParm1, string myParm2)
{
return from projectItem in ObjectContext.ProjectItems
select new ProjectItemDC
{
ID = projectItem.ID,
LibraryItem = CreateItemDC(projectItem.LibraryItem),
LibraryItemID = projectItem.LibraryItemID,
ProjectID = projectItem.ProjectID,
Quantity = projectItem.Quantity,
Width = projectItem.Width,
Height = projectItem.Height,
Depth = projectItem.Depth,
SheetMaterialID = projectItem.SheetMaterialID,
BandingMaterialID = projectItem.BandingMaterialID,
MaterialVolume = projectItem.MaterialVolume,
MaterialWeight = projectItem.MaterialWeight
}.ToArray();
}
write your own filtering/sorting logic and you're done.
Yes, you've lost WCF Ria Services dynamic query capabilities, but this is pretty much what you get with plain old WCF, isnt'it ?
If you instead need WCF Ria dynamic sorting/filtering/grouping you must take some additional steps, involving the visit of the Expression that WCF Ria Services create for you.
HTH
You can call ToArray() against ObjectContext.ProjectItems to force EF to load all the items, however, your query will no longer be composable on the client.
[Query]
public IQueryable<ProjectItemDC> GetProjectItems()
{
return from projectItem in ObjectContext.ProjectItems.ToArray()
select new ProjectItemDC
{
ID = projectItem.ID,
LibraryItem = CreateItemDC(projectItem.LibraryItem),
LibraryItemID = projectItem.LibraryItemID,
ProjectID = projectItem.ProjectID,
Quantity = projectItem.Quantity,
Width = projectItem.Width,
Height = projectItem.Height,
Depth = projectItem.Depth,
SheetMaterialID = projectItem.SheetMaterialID,
BandingMaterialID = projectItem.BandingMaterialID,
MaterialVolume = projectItem.MaterialVolume,
MaterialWeight = projectItem.MaterialWeight
};
}
Edit:
As mentioned in your comment, it gets all of the data out of the database at once which is not ideal. In order to create the LibraryItem with your private method, you cannot compose the query on the client. Instead, you should filter within the query method and then create the array.
[Query]
public IQueryable<ProjectItemDC> GetProjectItems(int id, string filter, object blah)
{
var projectItems = ObjectContext.ProjectItems.Where(...).ToArray();
return projectItems.Select(projectItem => new ProjectItemDC{...};
}
Currently I'm developing an OAuth2 authorization server using DotNetOpenAuth CTP version. My authorization server is in asp.net MVC3, and it's based on the sample provided by the library. Everything works fine until the app reaches the point where the user authorizes the consumer client.
There's an action inside my OAuth controller which takes care of the authorization process, and is very similar to the equivalent action in the sample:
[Authorize, HttpPost, ValidateAntiForgeryToken]
public ActionResult AuthorizeResponse(bool isApproved)
{
var pendingRequest = this.authorizationServer.ReadAuthorizationRequest();
if (pendingRequest == null)
{
throw new HttpException((int)HttpStatusCode.BadRequest, "Missing authorization request.");
}
IDirectedProtocolMessage response;
if (isApproved)
{
var client = MvcApplication.DataContext.Clients.First(c => c.ClientIdentifier == pendingRequest.ClientIdentifier);
client.ClientAuthorizations.Add(
new ClientAuthorization
{
Scope = OAuthUtilities.JoinScopes(pendingRequest.Scope),
User = MvcApplication.LoggedInUser,
CreatedOn = DateTime.UtcNow,
});
MvcApplication.DataContext.SaveChanges();
response = this.authorizationServer.PrepareApproveAuthorizationRequest(pendingRequest, User.Identity.Name);
}
else
{
response = this.authorizationServer.PrepareRejectAuthorizationRequest(pendingRequest);
}
return this.authorizationServer.Channel.PrepareResponse(response).AsActionResult();
}
Everytime the program reaches this line:
this.authorizationServer.Channel.PrepareResponse(response).AsActionResult();
The system throws an exception which I have researched with no success. The exception is the following:
Only parameterless constructors and initializers are supported in LINQ to Entities.
The stack trace: http://pastebin.com/TibCax2t
The only thing I've done differently from the sample is that I used entity framework's code first approach, an I think the sample was done using a designer which autogenerated the entities.
Thank you in advance.
If you started from the example, the problem Andrew is talking about stays in DatabaseKeyNonceStore.cs. The exception is raised by one on these two methods:
public CryptoKey GetKey(string bucket, string handle) {
// It is critical that this lookup be case-sensitive, which can only be configured at the database.
var matches = from key in MvcApplication.DataContext.SymmetricCryptoKeys
where key.Bucket == bucket && key.Handle == handle
select new CryptoKey(key.Secret, key.ExpiresUtc.AsUtc());
return matches.FirstOrDefault();
}
public IEnumerable<KeyValuePair<string, CryptoKey>> GetKeys(string bucket) {
return from key in MvcApplication.DataContext.SymmetricCryptoKeys
where key.Bucket == bucket
orderby key.ExpiresUtc descending
select new KeyValuePair<string, CryptoKey>(key.Handle, new CryptoKey(key.Secret, key.ExpiresUtc.AsUtc()));
}
I've resolved moving initializations outside of the query:
public CryptoKey GetKey(string bucket, string handle) {
// It is critical that this lookup be case-sensitive, which can only be configured at the database.
var matches = from key in db.SymmetricCryptoKeys
where key.Bucket == bucket && key.Handle == handle
select key;
var match = matches.FirstOrDefault();
CryptoKey ck = new CryptoKey(match.Secret, match.ExpiresUtc.AsUtc());
return ck;
}
public IEnumerable<KeyValuePair<string, CryptoKey>> GetKeys(string bucket) {
var matches = from key in db.SymmetricCryptoKeys
where key.Bucket == bucket
orderby key.ExpiresUtc descending
select key;
List<KeyValuePair<string, CryptoKey>> en = new List<KeyValuePair<string, CryptoKey>>();
foreach (var key in matches)
en.Add(new KeyValuePair<string, CryptoKey>(key.Handle, new CryptoKey(key.Secret, key.ExpiresUtc.AsUtc())));
return en.AsEnumerable<KeyValuePair<string,CryptoKey>>();
}
I'm not sure that this is the best way, but it works!
It looks like your ICryptoKeyStore implementation may be attempting to store CryptoKey directly, but it's not a class that is compatible with the Entity framework (due to not have a public default constructor). Instead, define your own entity class for storing the data in CryptoKey and your ICryptoKeyStore is responsible to transition between the two data types for persistence and retrieval.
I'm trying to project parts of a Display and its list of locations from a WCF Data service into a custom type. Is this doable in WCF Data Services in a Silverlight client? There is some help here, but it doesn't show getting a list back as well as simple strings.
Currently I'm getting "NotSupportedException: Constructing or initializing instances of the type UserQuery+Info with the expression d.Base.Title is not supported.".
It would be a bonus if you could tell me how to do Expand on Locations in this syntax (I know about Displays.Expand("Locations")) or if I need it.
LINQPad snippet
var displays = from d in Displays.Where(d => d.Id == 3136)
select new Info
{
Name = d.Base.Title,
};
displays.Dump();
}
public class Info
{
private string name;
public string Name
{
get
{
return this.name;
}
set
{
this.name = value;
}
}
public IEnumerable<Location> locations;
public IEnumerable<Location> Locations
{
get{ return this.locations;}
set{ this.locations = value;}
}
The problem is that you are effectively asking your WCF server to construct some type it has no knowledge about. Since it is unable to do so, you have to it yourself on your computer:
Displays
.Where(d => d.Id == 3136)
.AsEnumerable()
.Select(d => new Info { Name = d.Base.Title })
This will run the Where() on the server, but the Select() on your computer.
As already noted by svick you can't ask the server for types it doesn't understand (at least not using OData that is). But you can still only ask for properties you want and nothing more.
Since I don't have your service available the below sample uses the demo service on odata.org:
DemoService ctx = new DemoService(new Uri("http://services.odata.org/OData/OData.svc/"));
var q =
ctx.Products
.Where(p => p.ID == 1)
.Select(p =>
new Product
{
Category = new Category
{
Name = p.Category.Name
}
});
var r =
q.AsEnumerable()
.Select(p =>
new
{
CategoryName = p.Category.Name
});
The first query "q" will run compoletely on server (except for creation of the client side objects) and it will only get the Name of the category (and metadata about all the entities in question). It will translate to URL like /Products(1)?$expand=Category&$select=Category/Name.
The second query starts with the AsEnumerable, which effectively executes the first query and then it just performs a simple transform into an anonymous type. This is done completely on the client (no server interaction).