Is it possible to describe a HATEOAS REST API with OpenAPI?
When I describe the API in HAL Format I would need to define three schemas for it (one for Request Payloads, one for Collection Resource and one for Item Resource). For Example:
components:
schemas:
Link:
type: object
properties:
href:
type: string
hreflang:
type: string
title:
type: string
type:
type: string
deprecation:
type: string
profile:
type: string
name:
type: string
templated:
type: boolean
Links:
type: object
discriminator:
propertyName: _links
properties:
_links:
type: object
additionalProperties:
type: string
$ref: "#/components/schemas/Link"
CollectionModel:
type: object
discriminator:
propertyName: _embedded
properties:
_embedded:
type: object
_links:
type: object
properties:
self:
type: string
profile:
type: string
search:
type: string
CollectionModel_Foo:
type: object
allOf:
- $ref: "#/components/schemas/CollectionModel"
properties:
_embedded:
type: object
properties:
projects:
type: array
items:
$ref: "#/components/schemas/EntityModel_Foo"
EntityModel_Foo:
type: object
allOf:
- $ref: "#/components/schemas/Foo"
- $ref: "#/components/schemas/Links"
Foo:
type: object
properties:
id:
type: string
format: uuid
readOnly: true
bar:
type: string
I don't find that very useful because that complicates the specification and since when generating a client based on that schema using OpenAPI Generator the client does not pay attention to HATEOAS and simply requests the resources. So in this context it is useless.
I thought about implementing JSON:API but sadly the full JSON Schema is only supported in the current OpenAPI 3.1 draft.
All in all I can't find a proper way to integrate OpenAPI in a HATEOAS API.
Related
I am using OpenAPI+OpenAPI-generator with spring boot, and trying to use the schema oneof as follows:
This is the configuration in the requests.yaml file:
...
requestBody:
name: request
required: true
content:
application/json:
schema:
oneOf:
- $ref: 'components.yaml#/Request'
- $ref: 'components.yaml#/ComplexRequest'
...
and this is the relevant configuration in the components.yaml file:
Request:
allOf:
- $ref: '#/BaseInfo'
- type: object
properties:
should_create:
type: boolean
enum: [ false ]
reference_id:
type: string
required:
- reference_id
ComplexRequest:
allOf:
- $ref: '#/BaseInfo'
- type: object
properties:
should_create:
type: boolean
enum: [ true ]
create_data:
$ref: '#/Reference'
required:
- create_data
BaseInfo:
type: object
properties:
customer_id:
type: string
Reference:
type: object
properties:
propery_1:
type: string
propery_2:
type: string
propery_3:
type: string
For some reason, all of these components and only these are not being generated.
Can someone enlighten me on what am I doing wrong here?
If someone is facing this issue, I hope I'll save you some investigation time;
As for March 2022, it seems like oneOf (and anyOf) is just not supported by openapi-generator:
https://openapi-generator.tech/docs/roadmap/#short-term
And though not compatible for my situation, you can try the solutions suggested here:
How to use OpenAPI "oneOf" property with openapi-generator-maven-plugin when generating Spring code
I am trying to define my API using OpenAPI version 3.0. I am trying to generate a YAML file which has four maps, and each map contains a different information. How can I create a YAML file to achieve that goal? I know that my components are not right because of which I am not getting the right result.
Request body should be like this:
[
UserInformation{FirstName, LastName},
AddressInformation{Phone, Address},
ContactInformation{Email, Phone}
]
openapi: 3.0.0
info:
version: 1.0.0
title: 'INPUT-FORM-API'
paths:
/api/v1/test/healthcheck:
get:
summary: Health check for the test api services. Used Internally
operationId: Externalhealthcheck
description: healthcheck for the test services status.
responses:
'200':
description: This status is always returned when service is Ok.
content:
application/json:
schema:
$ref: '#/components/schemas/HealthcheckObject'
/api/v1/test/newformentry:
post:
summary: End Point to insert data into the new table.
operationId: NewFormEntry
description: EndPoint to insert data for new form.
requestBody:
content:
application/json:
schema:
items:
$ref: '#/components/schemas/NewFormEntry'
responses:
'200':
description: This status is always returned when service is Ok.
content:
application/json:
schema:
$ref: '#/components/schemas/HealthcheckObject'
components:
schemas:
NewFormEntry:
$ref: '#/components/schemas/UserInformation'
$ref: '#/components/schemas/AddressInformation'
$ref: '#/components/schemas/ContactInformation'
$ref: '#/components/schemas/MessageFromBene'
UserInformation:
required:
- FirstName
- LastName
properties:
FirstName:
type: string
LastName:
type: string
AddressInformation:
required:
- StreetAddress
- City
- State
- ZipCode
properties:
StreetAddress:
type: string
StreetAddress2:
type: string
City:
type: string
State:
type: string
ZipCode:
type: integer
format: int64
ContactInformation:
required:
- PhoneNumber
- Email
properties:
PhoneNumber:
type: integer
format: int64
maximum: 9
Email:
type: string
HomePhone:
type: integer
format: int64
maximum: 9
Cell:
type: integer
format: int64
maximum: 9
WorkPhone:
type: integer
format: int64
maximum: 9
MessageFromBene:
required:
- Message
properties:
PhoneNumber:
type: integer
format: int64
maximum: 9
Message:
type: string
HealthcheckObject:
required:
- Status
- ErrorMessage
properties:
Status:
type: string
ErrorMessage:
type: string
So the NewFormEntry schema must be an array containing 3 objects, where the 1st object must be UserInformation, the second object must be AddressInformation, and the 3rd object mube be ContactInformation. This is like a tuple, i.e. an ordered sequence of elements where each element has a specfic type. Tuple definitions are slightly different in different OpenAPI versions.
OpenAPI 3.1
If or when you migrate to OAS 3.1, such an array can be defined using prefixItems. This keyword specifies the schema for each element position (in other words, it specifies the order of elements in the array):
components:
schemas:
NewFormEntry:
type: array
prefixItems:
- $ref: '#/components/schemas/UserInformation' # type of the 1st element
- $ref: '#/components/schemas/AddressInformation' # type of the 2nd element
- $ref: '#/components/schemas/ContactInformation' # type of the 3rd element
minItems: 3
maxItems: 3
additionalItems: false # can be omitted if `maxItems: 3` is specified
OpenAPI 3.0
In OAS 3.0, you can define the array length (i.e. 3 items) and the possible types of array items (i.e. each item can be either A, B, or C), but there's no way to define a specific order of objects in the array. So the most you can do is this:
components:
schemas:
NewFormEntry:
type: array
items:
oneOf:
- $ref: '#/components/schemas/UserInformation'
- $ref: '#/components/schemas/AddressInformation'
- $ref: '#/components/schemas/ContactInformation'
minItems: 3
maxItems: 3
Note that this definition allows arbitrary order of objects in the array and also multiple instances of the same object (e.g. [UserInformation, UserInformation, UserInformation]). You might want to implement additional backend validations to verify the desired order of objects in this array.
I defined in swagger editor the following object(amountInCurrency):
pot:
type: object
properties:
potId:
type: string
name:
type: string
amount:
type: number
status:
type: string
lastChangeTimestamp:
type: string
amountInCurrency:
type: object
items:
$ref: '#/definitions/amountInCurrency'
and
amountInCurrency:
type: object
properties:
currency:
type: string
amount:
type: number
I got in that items currency and amount. however on swagger visualization i see amountInCurrency as an empty map. any idea why?
i would expect to see the currency and amount fields describe in it
-- edit:
if I change the AmountInCurrency type from object to array I do see the internal docs within the doc
doing this:
amountInCurrency:
type: array
items:
$ref: '#/definitions/amountInCurrency'
The amountInCurrency property definition does not look right - it mixes type: object with an array-specific keyword items.
If the amountInCurrency property is an array of amountInCurrency objects, use type: array instead:
amountInCurrency:
type: array # <-----
items:
$ref: '#/definitions/amountInCurrency'
If the amountInCurrency property is an object (an instance of the amountInCurrency object), use $ref like so:
amountInCurrency:
$ref: '#/definitions/amountInCurrency'
In my API i would like to have a simple model for my collection and a more elaborate model for my individual resource. For example:
a GET request on /libraries should return
BaseLibrary:
type: object
properties:
library_id:
type: string
description: The id of the library
display_name:
type: string
description: Name of the library
href:
type: string
description: The URI linking to this library.
whilst a request to a specific library should return all of the above including an extra parameter books:
So a GET request to libraries/{library_id} should return:
ExtendedLibrary:
type: object
properties:
library_id:
type: string
description: The id of the library
display_name:
type: string
description: Name of the library
href:
type: string
description: The URI linking to this library.
books:
type: array
description: The books in this library
items:
$ref: "#/definitions/books"
I would very much like to not have to define a "BaseLibrary" twice and would want to simple model an additional "ExtendedLibrary" which contains all the responses of a base library and the additional books property.
I tried a lot of different things, with the closest to succes being the following definitions:
definitions:
BaseLibrary:
type: object
properties:
library_id:
type: string
description: The id of the library.
display_name:
type: string
description: Name of the library
href:
type: string
description: The URI linking to this library.
ExtendedLibrary:
type: object
properties:
$ref: "#/definitions/BaseLibrary/properties"
books:
type: array
description: The available books for this library.
items:
$ref: "#/definitions/Book"
However this gives me a "Extra JSON reference properties will be ignored: books" warning and the output seems to ignore this extra property. Is there a clean way to handle my problem? Or am I just going to have to copy paste my whole BaseLibrary model into my ExtendedLibrary model?
As mentioned in the comments section, this may be a duplicate of another question, but it's worth repeating the answer in the context of this particular example. The solution is to use the allOf property in the definition of ExtendedLibrary:
definitions:
Book:
type: object
properties:
title:
type: string
author:
type: string
BaseLibrary:
type: object
properties:
library_id:
type: string
description: The id of the library
display_name:
type: string
description: Name of the library
href:
type: string
description: The URI linking to this library.
ExtendedLibrary:
type: object
allOf:
- $ref: '#/definitions/BaseLibrary'
- properties:
books:
type: array
description: The books in this library
items:
$ref: "#/definitions/Book"
In my experience, Swagger UI visualizes this correctly. When I define an operation response to be ExtendedLibrary Swagger UI shows this example:
{
"library_id": "string",
"display_name": "string",
"href": "string",
"books": [
{
"title": "string",
"author": "string"
}
]
}
Also, Swagger Codegen does the right thing. At least when generating a Java client, it creates an ExtendedLibrary class that correctly extends BaseLibrary.
I have an object that has a property that is an object whose type would be one of list of types. All my attempts have been rejected by Swagger Editor with the following error:
Data does not match any schemas from 'anyOf'
Jump to line 43
Details
Object
code: "ANY_OF_MISSING"
message: "Data does not match any schemas from 'anyOf'"
path: Array [7]
inner: Array [2]
level: 900
type: "Swagger Error"
description: "Data does not match any schemas from 'anyOf'"
lineNumber: 43
The full swagger specification file is as follows (the field in question is DataSetsInquiryRsp.dataSets.dataSet):
swagger: '2.0'
info:
title: My API
description: My Awesome API
version: 1.0.0
paths:
/dataSetsInquiry:
get:
description: Retrieve one or more data-sets.
parameters:
- name: ids
in: query
description: List of identifiers of requested data-sets.
required: true
type: array
items:
type: string
responses:
'200':
description: Requested data-sets.
schema:
$ref: '#/definitions/DataSetsInquiryRsp'
default:
description: Unexpected error
schema:
$ref: '#/definitions/Error'
definitions:
DataSetsInquiryRsp:
type: object
additionalProperties: false
properties:
sessionIdentifier:
description: Identifier of the secure session with the server.
type: number
dataSets:
type: object
additionalProperties: false
properties:
id:
type: string
dataSet:
type: array
items:
oneOf:
- $ref: '#/definitions/Customer'
- $ref: '#/definitions/Merchant'
Customer:
type: object
additionalProperties: false
properties:
firstName:
description: First name of the customer
type: string
lastName:
description: Last name of the customer
type: string
Merchant:
type: object
additionalProperties: false
properties:
code:
description: Code the Merchant.
type: string
name:
description: Name of the Merchant.
type: string
Well, the issue is simply the fact that Swagger doesn't support oneOff. In fact, Swagger supports a subset of Json-Schema and add a few things (datatype file for instance).
What is bad here is the error returned by Swagger. It doesn't help match. And this is the case of all Json-Schema validators I have worked with so far: is-my-json-valid, jsen.