XML example cannot be generated; root element name is undefined

[fdcds]

Q&A (please complete the following information)

• OS: Linux
• Browser: Firefox
• Version: 74
• Method of installation: docker.io/swaggerapi/swagger-editor:v3.8.0@sha256:8a4fd361c61415ddfc30390d345ddaf4eccaabde240f610020fe4cbef8e2fd31
• Swagger-Editor version: 3.8.0
• Swagger/OpenAPI version: OpenAPI 3.0.1

Content & configuration

I took the Swagger Editor example (Swagger 2.0), saved it, converted it to OpenAPI 3.0, and loaded it into the editor again.

Example Swagger/OpenAPI definition:

openapi: 3.0.1
info:
  title: Swagger Petstore
  description: >-
    This is a sample server Petstore server.  You can find out more about    
    Swagger at [http://swagger.io](http://swagger.io) or on [irc.freenode.net,
    #swagger](http://swagger.io/irc/).      For this sample, you can use the api
    key `special-key` to test the authorization     filters.
  termsOfService: 'http://swagger.io/terms/'
  contact:
    email: [email protected]
  license:
    name: Apache 2.0
    url: 'http://www.apache.org/licenses/LICENSE-2.0.html'
  version: 1.0.0
externalDocs:
  description: Find out more about Swagger
  url: 'http://swagger.io'
servers:
  - url: 'https://petstore.swagger.io/v2'
  - url: 'http://petstore.swagger.io/v2'
tags:
  - name: pet
    description: Everything about your Pets
    externalDocs:
      description: Find out more
      url: 'http://swagger.io'
  - name: store
    description: Access to Petstore orders
  - name: user
    description: Operations about user
    externalDocs:
      description: Find out more about our store
      url: 'http://swagger.io'
paths:
  /pet:
    put:
      tags:
        - pet
      summary: Update an existing pet
      operationId: updatePet
      requestBody:
        description: Pet object that needs to be added to the store
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/Pet'
          application/xml:
            schema:
              $ref: '#/components/schemas/Pet'
        required: true
      responses:
        '400':
          description: Invalid ID supplied
        '404':
          description: Pet not found
        '405':
          description: Validation exception
      security:
        - petstore_auth:
            - 'write:pets'
            - 'read:pets'
      x-codegen-request-body-name: body
    post:
      tags:
        - pet
      summary: Add a new pet to the store
      operationId: addPet
      requestBody:
        description: Pet object that needs to be added to the store
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/Pet'
          application/xml:
            schema:
              $ref: '#/components/schemas/Pet'
        required: true
      responses:
        '405':
          description: Invalid input
          content: {}
      security:
        - petstore_auth:
            - 'write:pets'
            - 'read:pets'
      x-codegen-request-body-name: body
  /pet/findByStatus:
    get:
      tags:
        - pet
      summary: Finds Pets by status
      description: Multiple status values can be provided with comma separated strings
      operationId: findPetsByStatus
      parameters:
        - name: status
          in: query
          description: Status values that need to be considered for filter
          required: true
          style: form
          explode: true
          schema:
            type: array
            items:
              type: string
              default: available
              enum:
                - available
                - pending
                - sold
      responses:
        '200':
          description: successful operation
          content:
            application/xml:
              schema:
                type: array
                items:
                  $ref: '#/components/schemas/Pet'
            application/json:
              schema:
                type: array
                items:
                  $ref: '#/components/schemas/Pet'
        '400':
          description: Invalid status value
          content: {}
      security:
        - petstore_auth:
            - 'write:pets'
            - 'read:pets'
  /pet/findByTags:
    get:
      tags:
        - pet
      summary: Finds Pets by tags
      description: >-
        Muliple tags can be provided with comma separated strings. Use        
        tag1, tag2, tag3 for testing.
      operationId: findPetsByTags
      parameters:
        - name: tags
          in: query
          description: Tags to filter by
          required: true
          style: form
          explode: true
          schema:
            type: array
            items:
              type: string
      responses:
        '200':
          description: successful operation
          content:
            application/xml:
              schema:
                type: array
                items:
                  $ref: '#/components/schemas/Pet'
            application/json:
              schema:
                type: array
                items:
                  $ref: '#/components/schemas/Pet'
        '400':
          description: Invalid tag value
          content: {}
      deprecated: true
      security:
        - petstore_auth:
            - 'write:pets'
            - 'read:pets'
  '/pet/{petId}':
    get:
      tags:
        - pet
      summary: Find pet by ID
      description: Returns a single pet
      operationId: getPetById
      parameters:
        - name: petId
          in: path
          description: ID of pet to return
          required: true
          schema:
            type: integer
            format: int64
      responses:
        '200':
          description: successful operation
          content:
            application/xml:
              schema:
                $ref: '#/components/schemas/Pet'
            application/json:
              schema:
                $ref: '#/components/schemas/Pet'
        '400':
          description: Invalid ID supplied
          content: {}
        '404':
          description: Pet not found
          content: {}
      security:
        - api_key: []
    post:
      tags:
        - pet
      summary: Updates a pet in the store with form data
      operationId: updatePetWithForm
      parameters:
        - name: petId
          in: path
          description: ID of pet that needs to be updated
          required: true
          schema:
            type: integer
            format: int64
      requestBody:
        content:
          application/x-www-form-urlencoded:
            schema:
              properties:
                name:
                  type: string
                  description: Updated name of the pet
                status:
                  type: string
                  description: Updated status of the pet
      responses:
        '405':
          description: Invalid input
          content: {}
      security:
        - petstore_auth:
            - 'write:pets'
            - 'read:pets'
    delete:
      tags:
        - pet
      summary: Deletes a pet
      operationId: deletePet
      parameters:
        - name: api_key
          in: header
          schema:
            type: string
        - name: petId
          in: path
          description: Pet id to delete
          required: true
          schema:
            type: integer
            format: int64
      responses:
        '400':
          description: Invalid ID supplied
          content: {}
        '404':
          description: Pet not found
          content: {}
      security:
        - petstore_auth:
            - 'write:pets'
            - 'read:pets'
  '/pet/{petId}/uploadImage':
    post:
      tags:
        - pet
      summary: uploads an image
      operationId: uploadFile
      parameters:
        - name: petId
          in: path
          description: ID of pet to update
          required: true
          schema:
            type: integer
            format: int64
      requestBody:
        content:
          multipart/form-data:
            schema:
              properties:
                additionalMetadata:
                  type: string
                  description: Additional data to pass to server
                file:
                  type: string
                  description: file to upload
                  format: binary
      responses:
        '200':
          description: successful operation
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ApiResponse'
      security:
        - petstore_auth:
            - 'write:pets'
            - 'read:pets'
  /store/inventory:
    get:
      tags:
        - store
      summary: Returns pet inventories by status
      description: Returns a map of status codes to quantities
      operationId: getInventory
      responses:
        '200':
          description: successful operation
          content:
            application/json:
              schema:
                type: object
                additionalProperties:
                  type: integer
                  format: int32
      security:
        - api_key: []
  /store/order:
    post:
      tags:
        - store
      summary: Place an order for a pet
      operationId: placeOrder
      requestBody:
        description: order placed for purchasing the pet
        content:
          '*/*':
            schema:
              $ref: '#/components/schemas/Order'
        required: true
      responses:
        '200':
          description: successful operation
          content:
            application/xml:
              schema:
                $ref: '#/components/schemas/Order'
            application/json:
              schema:
                $ref: '#/components/schemas/Order'
        '400':
          description: Invalid Order
          content: {}
      x-codegen-request-body-name: body
  '/store/order/{orderId}':
    get:
      tags:
        - store
      summary: Find purchase order by ID
      description: >-
        For valid response try integer IDs with value >= 1 and <= 10.        
        Other values will generated exceptions
      operationId: getOrderById
      parameters:
        - name: orderId
          in: path
          description: ID of pet that needs to be fetched
          required: true
          schema:
            maximum: 10
            minimum: 1
            type: integer
            format: int64
      responses:
        '200':
          description: successful operation
          content:
            application/xml:
              schema:
                $ref: '#/components/schemas/Order'
            application/json:
              schema:
                $ref: '#/components/schemas/Order'
        '400':
          description: Invalid ID supplied
          content: {}
        '404':
          description: Order not found
          content: {}
    delete:
      tags:
        - store
      summary: Delete purchase order by ID
      description: >-
        For valid response try integer IDs with positive integer value.        
        Negative or non-integer values will generate API errors
      operationId: deleteOrder
      parameters:
        - name: orderId
          in: path
          description: ID of the order that needs to be deleted
          required: true
          schema:
            minimum: 1
            type: integer
            format: int64
      responses:
        '400':
          description: Invalid ID supplied
          content: {}
        '404':
          description: Order not found
          content: {}
  /user:
    post:
      tags:
        - user
      summary: Create user
      description: This can only be done by the logged in user.
      operationId: createUser
      requestBody:
        description: Created user object
        content:
          '*/*':
            schema:
              $ref: '#/components/schemas/User'
        required: true
      responses:
        default:
          description: successful operation
          content: {}
      x-codegen-request-body-name: body
  /user/createWithArray:
    post:
      tags:
        - user
      summary: Creates list of users with given input array
      operationId: createUsersWithArrayInput
      requestBody:
        description: List of user object
        content:
          '*/*':
            schema:
              type: array
              items:
                $ref: '#/components/schemas/User'
        required: true
      responses:
        default:
          description: successful operation
          content: {}
      x-codegen-request-body-name: body
  /user/createWithList:
    post:
      tags:
        - user
      summary: Creates list of users with given input array
      operationId: createUsersWithListInput
      requestBody:
        description: List of user object
        content:
          '*/*':
            schema:
              type: array
              items:
                $ref: '#/components/schemas/User'
        required: true
      responses:
        default:
          description: successful operation
          content: {}
      x-codegen-request-body-name: body
  /user/login:
    get:
      tags:
        - user
      summary: Logs user into the system
      operationId: loginUser
      parameters:
        - name: username
          in: query
          description: The user name for login
          required: true
          schema:
            type: string
        - name: password
          in: query
          description: The password for login in clear text
          required: true
          schema:
            type: string
      responses:
        '200':
          description: successful operation
          headers:
            X-Rate-Limit:
              description: calls per hour allowed by the user
              schema:
                type: integer
                format: int32
            X-Expires-After:
              description: date in UTC when token expires
              schema:
                type: string
                format: date-time
          content:
            application/xml:
              schema:
                type: string
            application/json:
              schema:
                type: string
        '400':
          description: Invalid username/password supplied
          content: {}
  /user/logout:
    get:
      tags:
        - user
      summary: Logs out current logged in user session
      operationId: logoutUser
      responses:
        default:
          description: successful operation
          content: {}
  '/user/{username}':
    get:
      tags:
        - user
      summary: Get user by user name
      operationId: getUserByName
      parameters:
        - name: username
          in: path
          description: 'The name that needs to be fetched. Use user1 for testing. '
          required: true
          schema:
            type: string
      responses:
        '200':
          description: successful operation
          content:
            application/xml:
              schema:
                $ref: '#/components/schemas/User'
            application/json:
              schema:
                $ref: '#/components/schemas/User'
        '400':
          description: Invalid username supplied
          content: {}
        '404':
          description: User not found
          content: {}
    put:
      tags:
        - user
      summary: Updated user
      description: This can only be done by the logged in user.
      operationId: updateUser
      parameters:
        - name: username
          in: path
          description: name that need to be updated
          required: true
          schema:
            type: string
      requestBody:
        description: Updated user object
        content:
          '*/*':
            schema:
              $ref: '#/components/schemas/User'
        required: true
      responses:
        '400':
          description: Invalid user supplied
          content: {}
        '404':
          description: User not found
          content: {}
      x-codegen-request-body-name: body
    delete:
      tags:
        - user
      summary: Delete user
      description: This can only be done by the logged in user.
      operationId: deleteUser
      parameters:
        - name: username
          in: path
          description: The name that needs to be deleted
          required: true
          schema:
            type: string
      responses:
        '400':
          description: Invalid username supplied
          content: {}
        '404':
          description: User not found
          content: {}
components:
  schemas:
    Order:
      type: object
      properties:
        id:
          type: integer
          format: int64
        petId:
          type: integer
          format: int64
        quantity:
          type: integer
          format: int32
        shipDate:
          type: string
          format: date-time
        status:
          type: string
          description: Order Status
          enum:
            - placed
            - approved
            - delivered
        complete:
          type: boolean
          default: false
      xml:
        name: Order
    Category:
      type: object
      properties:
        id:
          type: integer
          format: int64
        name:
          type: string
      xml:
        name: Category
    User:
      type: object
      properties:
        id:
          type: integer
          format: int64
        username:
          type: string
        firstName:
          type: string
        lastName:
          type: string
        email:
          type: string
        password:
          type: string
        phone:
          type: string
        userStatus:
          type: integer
          description: User Status
          format: int32
      xml:
        name: User
    Tag:
      type: object
      properties:
        id:
          type: integer
          format: int64
        name:
          type: string
      xml:
        name: Tag
    Pet:
      required:
        - name
        - photoUrls
      type: object
      properties:
        id:
          type: integer
          format: int64
        category:
          $ref: '#/components/schemas/Category'
        name:
          type: string
          example: doggie
        photoUrls:
          type: array
          xml:
            name: photoUrl
            wrapped: true
          items:
            type: string
        tags:
          type: array
          xml:
            name: tag
            wrapped: true
          items:
            $ref: '#/components/schemas/Tag'
        status:
          type: string
          description: pet status in the store
          enum:
            - available
            - pending
            - sold
      xml:
        name: Pet
    ApiResponse:
      type: object
      properties:
        code:
          type: integer
          format: int32
        type:
          type: string
        message:
          type: string
  securitySchemes:
    petstore_auth:
      type: oauth2
      flows:
        implicit:
          authorizationUrl: 'http://petstore.swagger.io/oauth/dialog'
          scopes:
            'write:pets': modify pets in your account
            'read:pets': read your pets
    api_key:
      type: apiKey
      name: api_key
      in: header

Swagger-Editor configuration options: defaults for the Application Container from docker.io/swaggerapi/swagger-editor:v3.8.0@sha256:8a4fd361c61415ddfc30390d345ddaf4eccaabde240f610020fe4cbef8e2fd31, I did not change any settings.

Describe the bug you're encountering

Looking at the example for /pet/findByTags, Swagger Editor displays for Media Type application/xml:

<?xml version="1.0" encoding="UTF-8"?>
<!-- XML example cannot be generated; root element name is undefined -->

Changing the declaration to:

      responses:
        '200':
          description: successful operation
          content:
            application/xml:
              schema:
                type: array
                xml:
                  name: XZY # <<<
                items:
                  $ref: '#/components/schemas/Pet'

Will make the example render as:

<?xml version="1.0" encoding="UTF-8"?>
<Pet>
	<id>0</id>
	<Category>
		<id>0</id>
		<name>string</name>
	</Category>
	<name>doggie</name>
	<photoUrl>
		<photoUrl>string</photoUrl>
	</photoUrl>
	<tag>
		<Tag>
			<id>0</id>
			<name>string</name>
		</Tag>
	</tag>
	<status>available</status>
</Pet>

Note that there is no XYZ tag anywhere and no root tag either.

To reproduce...

Steps to reproduce the behavior:

1. Go to localhost:1234, where 1234 is the port you started Swagger Editor on
2. Click File > Convert and save as JSON
3. POST the file's contents to docker.io/swaggerapi/swagger-converter:v1.0.2@sha256:90a122587733a0b802e6c9a7cda33c35115c38694912cce4678c66dff312d6b1
4. Save the response to a JSON file
5. Back in Swagger Editor click File > Import file
6. On the right hand side scroll down to GET /pet/findByTags
7. Scroll down to Responses, 200
8. Change the media type to application/xml
9. See the error message in the example box
10. On the left hand side scroll down to /pet/findByTags
11. Scroll down to responses: '200'
12. Change content: application/xml: schema, add xml: name: XYZ
13. On the right hand side observe how the example is being rendered without root tag

Expected behavior

When adding xml: name: XYZ, I would expect a root tag "XYZ" to be rendered around the example data. Alternatively the editor should not complain and just render the example.

[hkosova]

Hi @fdcds, thanks for the detailed report. This issue is already tracked in swagger-api/swagger-ui#4650, so I'll close this one as a duplicate. Please follow the linked issue for updates.

[julienchabanon]

Any updates on this issue? Thanks

[JeroenHeemskerk]

Found it, you also need to include wrapped: true next to the name, so the full example should read:

        '200':
          description: successful operation
          content:
            application/xml:
              schema:
                type: array
                xml:
                  name: XZY      # <<<
                  wrapped: true  # <<<
                items:
                  $ref: '#/components/schemas/Pet'

[Aravinda93]

@JeroenHeemskerk Thanks for this but where to add wrapped:true if I am using the Java OpenAPI? I am getting same issue when I use the XML type:

@Path("/api")
public class RestControllerResponse {

    @Path("/generate")
    @POST
    @Consumes({MediaType.APPLICATION_JSON, MediaType.APPLICATION_XML})
    @Produces({MediaType.APPLICATION_JSON, MediaType.APPLICATION_XML})
    public String generator(final Map<String, Object> input) throws Exception {
        return "Hello From Generator Method";
    }
}