{"action":"opened","issue":{"url":"https://api.github.com/repos/mapstruct/mapstruct/issues/584","labels_url":"https://api.github.com/repos/mapstruct/mapstruct/issues/584/labels{/name}","comments_url":"https://api.github.com/repos/mapstruct/mapstruct/issues/584/comments","events_url":"https://api.github.com/repos/mapstruct/mapstruct/issues/584/events","html_url":"https://github.com/mapstruct/mapstruct/issues/584","id":92305501,"number":584,"title":"Cannot create a method where the returned object is a String ","user":{"login":"zamrokk","id":2536368,"avatar_url":"https://avatars.githubusercontent.com/u/2536368?v=3","gravatar_id":"","url":"https://api.github.com/users/zamrokk","html_url":"https://github.com/zamrokk","followers_url":"https://api.github.com/users/zamrokk/followers","following_url":"https://api.github.com/users/zamrokk/following{/other_user}","gists_url":"https://api.github.com/users/zamrokk/gists{/gist_id}","starred_url":"https://api.github.com/users/zamrokk/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/zamrokk/subscriptions","organizations_url":"https://api.github.com/users/zamrokk/orgs","repos_url":"https://api.github.com/users/zamrokk/repos","events_url":"https://api.github.com/users/zamrokk/events{/privacy}","received_events_url":"https://api.github.com/users/zamrokk/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":0,"created_at":"2015-07-01T07:50:51Z","updated_at":"2015-07-01T07:50:51Z","closed_at":null,"body":"Hi ,\r\ni try to create a map function like this (used by more complex other mapping functions) :  \r\n\r\n@Mapping(source=\"dto.field1\")\r\nString dtoToString(Dto dto);\r\n\r\nActually, a \"target\" is required if i use the \"source\". Same issue using \"expression\", a \"target\" is needed.\r\n\r\nHow can i make it ?\r\n"}}