Suppose I want to return a list of users in JSON or CSV format depending on a query parameter.<\/p>\n
The question is:<\/b> how do I implement it with WCF (leaving aside the discussion on whether it’s a good idea)?<\/p>\n The answer:<\/b> the multi-format method must have return type <\/code><\/p>\n 1. You cannot have two methods that differ only on query parameters.<\/p>\n <\/code><\/p>\n This throws an exception at runtime saying one cannot have two methods whose URI templates differ only by query parameters.<\/p>\n 2. You cannot have a method that returns 1. If you create a 2. Don’t forget to set 3. JSON must be serialized by hand.<\/p>\n 4. Don’t forget to properly handle case of bad request parameters.<\/p>\n Code: https:\/\/github.com\/ikriv\/wcf-rest-multiformat<\/a><\/p>\n","protected":false},"excerpt":{"rendered":" Suppose I want to return a list of users in JSON or CSV format depending on a query parameter. MyService.svc\/users?format=json returns JSON MyService.svc\/users?format=csv returns CSV The question is: how do […]<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"Layout":"","footnotes":""},"categories":[15],"tags":[],"class_list":["entry","author-ikriv","post-1841","post","type-post","status-publish","format-standard","category-webdev"],"_links":{"self":[{"href":"https:\/\/ikriv.com\/blog\/index.php?rest_route=\/wp\/v2\/posts\/1841","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/ikriv.com\/blog\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/ikriv.com\/blog\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/ikriv.com\/blog\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/ikriv.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1841"}],"version-history":[{"count":0,"href":"https:\/\/ikriv.com\/blog\/index.php?rest_route=\/wp\/v2\/posts\/1841\/revisions"}],"wp:attachment":[{"href":"https:\/\/ikriv.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1841"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ikriv.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1841"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ikriv.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1841"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}MyService.svc\/users?format=json<\/code> returns JSON
\nMyService.svc\/users?format=csv<\/code> returns CSV<\/p>\nStream<\/code>. The programmer is fully responsible for formatting the response body in all cases, including setting Content-Type.<\/p>\n<\/p>\n\n [ServiceContract]\n public interface ITestService\n {\n\n [OperationContract]\n [WebInvoke(Method = \"GET\", UriTemplate = \"users?format={format}\")]\n Stream GetUsers(string format);\n }<\/pre>\nSolution attempts that did not work<\/h2>\n
<\/p>\n\n [ServiceContract]\n public interface ITestService \/\/ Does not work as expected<\/font>\n {\n\n [WebInvoke(Method = \"GET\", UriTemplate = \"users?format=json\", ResponseFormat = WebMessageFormat.Json)]\n Listobject<\/code>. I expected WCF to turn off response formatting when dynamic<\/b> response type is Stream<\/code>. This turned out to be not the case. WCF turns off response formatting only when the method’s static<\/b> return type is Stream<\/code>. See my question on StackOverflow<\/a>.<\/p>\nThings to pay attention to<\/h2>\n
MemoryStream<\/code> and write into it, make sure to reset the pointer to the beginning. If you don’t, the response body will be empty.<\/p>\nContent-Type<\/code> and (optionally) Content-Disposition<\/code>.<\/p>\n