How to provide example for XML parameter in swagger

Question

I am using Swashbuckle 5.6.0 and Swashbuckle.Examples.3.5.1 to document a WebApi2 project. I have an action which consumes an XML body and returns a text response. I want the documentation to include an example of the XML input - e.g. <SampleXml><!-- example XML --></SampleXml>.

My swagger output is below, except that for the purposes of this question I have added the content-type application/json to the comsumes property. In reality, I only want to allow application/xml and text/xml.

When I view this with Swagger, I see:

• When parameter content type application/xml is selected, I get a generated XML example with my model name, i.e. <XmlModel></XmlModel>.

• When parameter content type application/json is selected, I get my desired example input <SampleXml><!-- example XML --></SampleXml>.

How can I get the example input while parameter content type application/xml is selected?

{
  "swagger": "2.0",
  "info": {
    "version": "v1",
    "title": "Sample"
  },
  "host": "localhost:63434",
  "schemes": [
    "http"
  ],
  "paths": {
    "/sampleXml/": {
      "post": {
        "tags": [
          "xmlSample"
        ],
        "summary": "XML sample.",
        "description": "Post XML sample",
        "operationId": "Xml_Post",
        "consumes": [
          "application/xml",
          "application/json",
          "text/xml",
        ],
        "produces": [
          "text/plain"
        ],
        "parameters": [
          {
            "name": "xmlContent",
            "in": "body",
            "description": "The content of the XML document.",
            "required": true,
            "schema": {
              "$ref": "#/definitions/XmlModel"
            }
          }
        ],
        "responses": {
          "200": {
            "description": "OK",
            "schema": {
              "type": "string"
            }
          },
        }
      }
    }
  },
  "definitions": {
    "XmlModel": {
      "type": "object",
      "properties": {},
      "example": "<SampleXml><!-- example XML --></SampleXml>"
    }
  }
}

Answer 1

To change the root XML tag from <XmlModel> to <SampleXml>, add xml.name to your schema definition:

  "definitions": {
    "XmlModel": {
      "type": "object",
      "xml": {
         "name": "SampleXml"
      }
    }
  }

This will produce the following sample XML in Swagger UI:

<?xml version="1.0" encoding="UTF-8"?>
<SampleXml>
</SampleXml>

And if you add property definitions:

  "definitions": {
    "XmlModel": {
      "type": "object",
      "xml": {
         "name": "SampleXml"
      },
      "properties": {
        "id": {
          "type": "integer",
          "example": 7,
          "xml": {
            "attribute": true
          }
        },
        "foo": {
          "type": "string",
          "example": "bar"
        }
      }
    }
  }

your XML example will include the corresponding elements:

<?xml version="1.0" encoding="UTF-8"?>
<SampleXml id="7">
    <foo>bar</foo>
</SampleXml>

However, if you want the literal string <SampleXml><!-- example XML --></SampleXml> containing a <!-- comment -->, it's not possible AFAIK.

Update: Swagger UI supports using literal XML strings only in response examples:

"responses": {
  "200": {
    "description": "OK",
    "schema": {
      "type": "string"
    },
    "examples": {
      "application/xml": "<SampleXml><!-- example XML --></SampleXml>"
    }
  }
}

but not in request body examples.