The $format query option, if present in a request, MUST take precedence over the value(s) specified in the Accept request header.
The value of the $format system query option is a valid internet media type, optionally including parameters.
In addition, format-specific abbreviations may be used, e.g. json for application/json, see [OData-JSON], but format parameters MUST NOT be appended to the format abbreviations.
is equivalent to a request with an Accept header using the same media type; it requests the set of Order entities represented using the JSON media type including full metadata, as defined in [OData-JSON].
is equivalent to a request with the Accept header set to application/json; it requests the set of Order entities represented using the JSON media type with minimal metadata, as defined in [OData-JSON].
In metadata document requests, the values application/xml and application/json, along with their subtypes and parameterized variants, as well as the format-specific abbreviations xml and json, are reserved for this specification.
Hello Zack,
a feature that is not implemented too.
http://docs.oasis-open.org/odata/odata/v4.01/odata-v4.01-part1-protocol.html#_Toc31358963 11.2.11 System Query Option $format The $format system query option specifies the media type of the response.
The $format query option, if present in a request, MUST take precedence over the value(s) specified in the Accept request header.
The value of the $format system query option is a valid internet media type, optionally including parameters.
In addition, format-specific abbreviations may be used, e.g. json for application/json, see [OData-JSON], but format parameters MUST NOT be appended to the format abbreviations.
Regards, Richard
Example 74: the request
GET http://host/service/Orders?$format=application/json;metadata=full
is equivalent to a request with an Accept header using the same media type; it requests the set of Order entities represented using the JSON media type including full metadata, as defined in [OData-JSON].
Example 75: the request
GET http://host/service/Orders?$format=json
is equivalent to a request with the Accept header set to application/json; it requests the set of Order entities represented using the JSON media type with minimal metadata, as defined in [OData-JSON].
In metadata document requests, the values application/xml and application/json, along with their subtypes and parameterized variants, as well as the format-specific abbreviations xml and json, are reserved for this specification.