[cpprest] Empty vendorExtension causes build error.

[p-groarke]

Description

In api-source.mustache at line 384:

vendorExtensions.x-codegen-response.items.datatype

may be empty. Causes build error :

      no member named 'FromJson' in 'io::swagger::client::model::ModelBase'
            result = ModelBase::FromJson(json);

as that function doesn't exist.

API used to trigger error : https://esi.tech.ccp.is/latest/swagger.json

Swagger-codegen version

master

Swagger declaration file content or url

https://esi.tech.ccp.is/latest/swagger.json

Command line used for generation

java -jar swagger-codegen-cli.jar generate -i https://esi.tech.ccp.is/latest/swagger.json -l cpprest -o src

Steps to reproduce

Requires PR (to fix other build errors) : #7571

Related issues/PRs

Suggest a fix/enhancement

No suggestions yet.

[p-groarke]

This is the endpoint. My intuition points me to a float/double problem.

"/characters/{character_id}/cspa/": {
    "post": {
        "description": "Takes a source character ID in the url and a set of target character ID's in the body, returns a CSPA charge cost\n\n---\nAlternate route: `/dev/characters/{character_id}/cspa/`\n\nAlternate route: `/v4/characters/{character_id}/cspa/`\n",
        "summary": "Calculate a CSPA charge cost",
        "tags": [
            "Character"
        ],
        "parameters": [
            {
                "$ref": "#/parameters/character_id"
            },
            {
                "name": "characters",
                "in": "body",
                "description": "The target characters to calculate the charge for",
                "required": true,
                "schema": {
                    "type": "array",
                    "minItems": 1,
                    "uniqueItems": true,
                    "maxItems": 100,
                    "items": {
                        "type": "integer",
                        "format": "int32",
                        "title": "post_characters_character_id_cspa_character",
                        "description": "character integer"
                    },
                    "title": "post_characters_character_id_cspa_characters",
                    "description": "characters array"
                }
            },
            {
                "$ref": "#/parameters/datasource"
            },
            {
                "$ref": "#/parameters/token"
            },
            {
                "$ref": "#/parameters/user_agent"
            },
            {
                "$ref": "#/parameters/X-User-Agent"
            }
        ],
        "responses": {
            "201": {
                "description": "Aggregate cost of sending a mail from the source character to the target characters, in ISK",
                "examples": {
                    "application/json": 2950.0
                },
                "schema": {
                    "type": "number",
                    "format": "float",
                    "title": "post_characters_character_id_cspa_created",
                    "description": "201 created number"
                }
            },
            "403": {
                "description": "Forbidden",
                "schema": {
                    "$ref": "#/definitions/forbidden"
                },
                "examples": {
                    "application/json": {
                        "error": "Forbidden message"
                    }
                }
            },
            "500": {
                "description": "Internal server error",
                "schema": {
                    "$ref": "#/definitions/internal_server_error"
                },
                "examples": {
                    "application/json": {
                        "error": "Internal server error message"
                    }
                }
            }
        },
        "security": [
            {
                "evesso": [
                    "esi-characters.read_contacts.v1"
                ]
            }
        ],
        "operationId": "post_characters_character_id_cspa",
        "x-alternate-versions": [
            "dev",
            "v4"
        ]
    }
},

[p-groarke]

Ok I've debugged this and have an answer, working on fix.

{{vendorExtensions.x-codegen-response.items.datatype}} assumes the primitive is contained in an item. The api I'm using returns the value itself. Changing to {{vendorExtensions.x-codegen-response.datatype}} fixes the issue.

[larsyxa]

Usually generated code looks like this. Static FromJson does not exist. But specialized version do!!

double result(0.0);
if (responseHttpContentType == utility::conversions::to_string_t("application/json"))
{
web::json::value json = web::json::value::parse(response);
result = ModelBase::FromJson(json);
}

Change (in this case) result = ModelBase::FromJson(json) -> ModelBase::doubleFromJson(json);

Voila!