# 3.5.4.Swagger/OAI Specifications, Part 2 of 3

* 以下範例參考自<https://github.com/acloudfan/REST-API-course-swagger> (branch: definitions)
  * Swagger 2.0 Part 2包含:

    * 1.defining schema for request/response
      * JSON schema
      * examples

        ```
        definitions:
        # A general message schema in case of an error
        GeneralError:
          required:
            - message
          properties:
            message:
              type: string
        # A Not found error that is sent back in case no results are found for the 
        # requested resource
        NotFoundError:
          required:
            - message
            - hint
          properties:
            message:
              type: string
            hint:
              type: string

        Vacation:
          required:
            - name
            - description
            - type
            - numOfNights
          properties:
            # Name of the package
            name:
              type: string
            # Description of the package
            description:
              type: string

            # Type of the vacation package - shows how to use enumerations 
              type:
                type: string
                enum:
                  - resort
                  - cruise
            # All the destinations included in the vacation package  
            # Shows how to use array of complex objects
              destinations:
                type: array
                # There should be at least 1 destination in the package
                minItems: 1
                maxItems: 6
                items:
                  $ref: "#/definitions/Location"

            # Number of nights
              numOfNights:
                type: number
                minimum: 1
                maximum: 31

        # Definition for the location schema    
        # Refered from the destinations in Vacation schema
        Location:
          required:
            - city
            - country
          properties:
            city:
              type: string
            country:
              type: string
        ```
    * 2.parameters
      * request: head, body, query string

        ```
        # Parameter Definitions
        # Common parameters used in the operations
        parameters:
        IdInPath:
          name: id
          in: path
          type: string
          required: true
        ```
    * 3.security schema

    ```
    # Security Definitions
    securityDefinitions:
      KeySecurity:
        type: apiKey
          in: query
          name: api_key
    ```