text\/plain<\/code><\/p>\nRequest Body:<\/p>\n
$select=Id,Name,Classification,RunningTime&$filter=contains(Name,%20%27li%27)&$orderby=Name%20desc<\/pre>\nResponse Body:<\/p>\n
{\r\n \"@odata.context\": \"http:\/\/ServiceRoot\/$metadata#Movies(Id,Name,Classification,RunningTime)\",\r\n \"value\": [\r\n {\r\n \"Id\": 11,\r\n \"Name\": \"The Equalizer\",\r\n \"Classification\": \"R\",\r\n \"RunningTime\": 132\r\n },\r\n {\r\n \"Id\": 9,\r\n \"Name\": \"Dolittle\",\r\n \"Classification\": \"PG\",\r\n \"RunningTime\": 101\r\n }\r\n ]\r\n}<\/pre>\nThe OData specification prescribes that the query options specified in the request body and those specified in the request URL are processed together. Whereas a query string on a POST request is not a common thing, this feature supports that option. Here’s how the request would look like:<\/p>\n
POST: http:\/\/ServiceRoot\/Movies\/$query?$filter=contains(Name,%20%27li%27)<\/code><\/code><\/p>\nContent-Type: text\/plain<\/code><\/p>\nRequest Body:<\/p>\n
$select=Id,Name,Classification,RunningTime$orderby=Name%20desc<\/pre>\nSpecifically, note that \/$query<\/code> should be preceded by the resource path. The resource path is \/Movies<\/code> in the above example. This is the one way that the \/$query<\/code> endpoint differs from the \/$batch<\/code> endpoint.<\/p>\nFeature extensibility<\/h3>\n
We support the ability to extend this feature by providing means for the developer to plug in their own query options parser.<\/p>\n
Your first step towards accomplishing that is implementing the IODataQueryOptionsParser<\/code> interface. This interface contains two methods that you need to implement:<\/p>\n\nbool CanParse(HttpRequest)<\/code> (or bool CanParse(HttpRequestMessage<\/code>) in .NET FX)<\/li>\nTask<string> ParseAsync(Stream)<\/code><\/li>\n<\/ul>\nThe logic to analyze the request to determine if the parser is capable of processing the content goes into CanParse(HttpRequest)<\/code> method. Your logic could inspect headers, e.g. Content-Type<\/code> or any other thing in the request to evaluate whether the conditions are right for the parser to process the request content.<\/p>\nThe parsing logic goes into the ParseAsync(Stream)<\/code> method. The return value for the method is a string containing the query options part of the URL.<\/p>\nImplementing a custom query options parser<\/h3>\n
In this section, we look at how one can implement and plug in their own parser. We implement a simple parser that reads and extracts query options from a POST with text\/xml<\/code> content.<\/p>\npublic class TextXmlODataQueryOptionsParser : IODataQueryOptionsParser\r\n{\r\n private static MediaTypeHeaderValue SupportedMediaType =\r\n MediaTypeHeaderValue.Parse(\"text\/xml\");\r\n\r\n public bool CanParse(Microsoft.AspNetCore.Http.HttpRequest request)\r\n {\r\n return request.ContentType?.StartsWith(SupportedMediaType.MediaType,\r\n StringComparison.Ordinal) == true ? true : false;\r\n }\r\n\r\n public async Task<string> ParseAsync(Stream requestStream)\r\n {\r\n using (var reader = new StreamReader(\r\n requestStream,\r\n encoding: Encoding.UTF8,\r\n detectEncodingFromByteOrderMarks: false,\r\n bufferSize: 1024,\r\n leaveOpen: true))\r\n {\r\n var content = await reader.ReadToEndAsync();\r\n var document = XDocument.Parse(content);\r\n var queryOptions = document.Descendants(\"QueryOption\").Select(d =>\r\n new {\r\n Option = d.Attribute(\"Option\").Value,\r\n d.Attribute(\"Value\").Value\r\n });\r\n\r\n return string.Join(\"&\", queryOptions.Select(d => d.Option + \"=\" + d.Value));\r\n }\r\n }\r\n}<\/pre>\nLet us go ahead and plug in this parser into the dependency injection container.<\/p>\n
var queryOptionsParsers = ODataQueryOptionsParserFactory.Create();\r\nqueryOptionsParsers.Insert(0, new TextXmlODataQueryOptionsParser());\r\n\r\n\/\/ ...\r\napp.UseMvc(routeBuilder =>\r\n{\r\n \/\/ ...\r\n routeBuilder.MapODataServiceRoute(\r\n \"ROUTENAME\",\r\n \"ROUTEPREFIX\",\r\n configureAction: containerBuilder => containerBuilder\r\n .AddService(Microsoft.OData.ServiceLifetime.Singleton,\r\n typeof(IEdmModel),\r\n _ => modelBuilder.GetEdmModel()) \/\/ YOUR EDM MODEL HERE\r\n .AddService(Microsoft.OData.ServiceLifetime.Singleton,\r\n typeof(IODataPathHandler),\r\n _ => new DefaultODataPathHandler())\r\n .AddService(Microsoft.OData.ServiceLifetime.Singleton,\r\n typeof(IEnumerable<IODataRoutingConvention>),\r\n _ => ODataRoutingConventions.CreateDefault())\r\n .AddService(Microsoft.OData.ServiceLifetime.Singleton,\r\n typeof(IEnumerable<IODataQueryOptionsParser>),\r\n _ => queryOptionsParsers)\r\n );\r\n});<\/pre>\nNote:<\/strong> Inserting the new parser at index 0 elevates it above any other that could potentially handle the request.<\/p>\nThis parser can process the following request:<\/p>\n
POST: http:\/\/ServiceRoot\/Movies\/$query<\/code><\/p>\nContent-Type: text\/xml<\/code><\/p>\nRequest Body:<\/p>\n
<QueryOptions>\r\n<QueryOption Option=\"$select\" Value=\"Id,Name,Classification,RunningTime\"\/>\r\n<QueryOption Option=\"$filter\" Value=\"contains(Name,'li')\"\/>\r\n<QueryOption Option=\"$orderby\" Value=\"Name desc\"\/>\r\n<\/QueryOptions><\/pre>\n