Hook OData's $metadata response and convert it from XML to JSON

Question

The answer of Get OData $metadata in JSON format states that OData cannot return the metadata as JSON by default.

But is it possible then to capture or hook its response for the $metadata URL, and then convert it on the fly to JSON before sending it to the client?

I imagine pseudocode like this:

[HttpGet] [ODataRoute("$metadata")] public string GetMetadataAsJson() {     string xml = GetOdataMetadataAsXML();     string json = ConvertToJson(xml);     return json; } 

I don't know how to implement it correctly, though, in particular I'm not sure how to get the standard OData response as a string, and how to hook the $metadata URL.

Answer 1

Newtonsoft supports the Json part checkout https://www.newtonsoft.com/json/help/html/ConvertXmlToJson.htm

So the actual solution for the Json Part would be quite simple, as soon as you have your XML

[HttpGet] [ODataRoute("$metadata")] public string GetMetadataAsJson() {     string xml = GetOdataMetadataAsXML();     XmlDocument doc = new XmlDocument();     doc.LoadXml(xml);     string json = JsonConvert.SerializeXmlNode(doc);     return json; } 

Also you should probably first check if e.g. a format query is set for example with this code

[HttpGet] [ODataRoute("$metadata")] public string GetMetadataAsJson([FromQuery(Name="Format")]string format) {     string metaResult = GetOdataMetadataAsXML();     if(format.Equals("json",StringComparison.OrdinalIgnoreCase))     {         XmlDocument metaDoc = new XmlDocument();         doc.LoadXml(metaResult);         metaResult = JsonConvert.SerializeXmlNode(doc);     }     return metaResult; }