[REQ] Add isDeprecated field to schema object.

[yuji38kwmt]

Is your feature request related to a problem? Please describe.

I created the following yaml file that tag field of Pet Object is deprecated.
I executed generate command with -DdebugModels option and I printed JSON model.
But json model does not include isDeprecated field.
So I can not use isDrecated variable in model.mustache file.

petstore.yaml

openapi: "3.0.0"
info:
  version: 1.0.0
  title: Swagger Petstore
  license:
    name: MIT
servers:
  - url: http://petstore.swagger.io/v1
paths:
  /pets/{petId}:
    get:
      summary: Info for a specific pet
      operationId: showPetById
      tags:
        - pets
      parameters:
        - name: petId
          in: path
          required: true
          description: The id of the pet to retrieve
          schema:
            type: string
      responses:
        '200':
          description: Expected response to a valid request
          content:
            application/json:
              schema:
                $ref: "#/components/schemas/Pet"
components:
  schemas:
    Pet:
      type: object
      required:
        - id
        - name
      properties:
        id:
          type: integer
          format: int64
        name:
          type: string
        tag:
          type: string
          deprecated: true
          

Executed command

$  java -Dmodels   -DmodelTests=false -DmodelDocs=false -DdebugModels \
 -jar openapi-generator-cli-4.0.3.jar  generate \
  -g python -i petstore.yaml 

JSON model with -DdebugModels option

 {
      "openApiType" : "string",
      "baseName" : "tag",
      "getter" : "getTag",
      "setter" : "setTag",
      "dataType" : "str",
      "datatypeWithEnum" : "str",
      "name" : "tag",
      "defaultValueWithParam" : " = data.tag;",
      "baseType" : "str",
      "example" : "null",
      "jsonSchema" : "{\n  \"type\" : \"string\",\n  \"deprecated\" : true\n}",
      "exclusiveMinimum" : false,
      "exclusiveMaximum" : false,
      "hasMore" : false,
      "required" : false,
      "secondaryParam" : false,
      "hasMoreNonReadOnly" : false,
      "isPrimitiveType" : true,
      "isModel" : false,
      "isContainer" : false,
      "isString" : true,
      "isNumeric" : false,
      "isInteger" : false,
      "isLong" : false,
      "isNumber" : false,
      "isFloat" : false,
      "isDouble" : false,
      "isByteArray" : false,
      "isBinary" : false,
      "isFile" : false,
      "isBoolean" : false,
      "isDate" : false,
      "isDateTime" : false,
      "isUuid" : false,
      "isUri" : false,
      "isEmail" : false,
      "isFreeFormObject" : false,
      "isListContainer" : false,
      "isMapContainer" : false,
      "isEnum" : false,
      "isReadOnly" : false,
      "isWriteOnly" : false,
      "isNullable" : false,
      "isSelfReference" : false,
      "vendorExtensions" : { },
      "hasValidation" : false,
      "isInherited" : false,
      "nameInCamelCase" : "Tag",
      "nameInSnakeCase" : "TAG",
      "isXmlAttribute" : false,
      "isXmlWrapped" : false,
      "iexclusiveMaximum" : false,
      "datatype" : "str"
    } 

Describe the solution you'd like

Add isDeprecated field to schema object.

Additional context

isDeprecated variable is available in api.mustache file.

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[jimschubert]

https://github.com/OAI/OpenAPI-Specification/blob/master/versions/3.0.2.md#fixed-fields-20

We'll probably want to evaluate the other deprecated fields as well (operations, paths).

[ackintosh]

I'm addressing to this issue for the kotlin-spring generator with my colleague @yutaka0m. 😃

[cljk]

Same is the case for all java generators I´ve tested - and I think that are all available.

Marking operations as deprecated is working - but marking model classes or fields as deprecated is not in the generated source code.
I would really like to have this - since this would improve backward compatible API changes.

[kpaaro]

Same is the case for all java generators I´ve tested - and I think that are all available.

Marking operations as deprecated is working - but marking model classes or fields as deprecated is not in the generated source code. I would really like to have this - since this would improve backward compatible API changes.

+1