ng-swagger-gen
v2.3.1
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A Swagger 2.0 codegen for Angular
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ng-swagger-gen: A Swagger 2.0 code generator for Angular
This project is a NPM module that generates model interfaces and web service clients from a Swagger 2.0 specification. The generated classes follow the principles of Angular.
NOTICE: This project isn't actively maintained anymore.
Since 2019 our development focus has shifted to ng-openapi-gen,
and the Cyclos project, which maintains both projects has long ago moved to OpenAPI 3.
As such, the maintainance of ng-swagger-gen
is basically done by the community, via pull requests.
However, as ng-swagger-gen
has no automated tests, accepting PR's for new features is also challenging,
because the original maintainers have no practical way to test if anything else is broken.
As such, only important bug fixes will be accepted.
Angular / RxJS version compatibility:
- Starting with version
2.0.0
, Angular 7+ is required. - Starting with version
1.0.0
, Angular 6+ is required. - Version
0.11.x
supports Angular 4.3+ (with rxjs 5.5) and Angular 5.
OpenAPI 3
If you are interested in generating a client for services described using OpenAPI 3, take a look on ng-openapi-gen.
Major version upgrade notices
- Angular 6
bundles RxJS 6, which
changed the API, mostly imports.
As such, starting with
ng-swagger-gen
version1.0.0
, both peer dependencies for@angular/core
andrxjs
have been upgraded. If you plan to stay in Angular 5, change theng-swagger-gen
version inpackage.json
to~0.11.0
; - Up to the version
0.8.x
of this generator the deprecatedHttp
Angular module was used to generating requests. Starting with version 0.9,HttpClient
is used instead - hence the requirement for Angular 4.3+. Also, taking the opportunity to break backwards compatibility, some additional changes were also performed, such as returningObservable
s instead ofPromise
s. For more details, please see the wiki page Upgrading from previous versions to 0.9.
Design principles
- It must be easy to use;
- It should provide access to the original response, so, for example, headers can be read. But also it should provide easy access to the result;
- It should generate code which follows the concepts of an Angular 4+ application, such as Modules, Injectables, etc;
- All the server communication is implemented using
HttpClient
; - The generated model should handle correctly inheritance and enumerations.
Starting from version
0.10
all modules are generated as TypeScript interfaces rather than classes, avoiding additional overhead on generated JavaScript; - An Angular Module (
@NgModule
) is generated, which exports all services; - One service is generated per Swagger tag;
- It should be possible to choose a subset of tags from which to generate services;
- It should generate only the models actually used by the generated services;
- The configuration of the root URL for the API is set globally in an
@Injectable
class calledApiConfiguration
, but can also be set on each service, for increased flexibility.
Here are a few notes:
- Starting with version 0.11.0, the Swagger definition can be either a JSON or YAML file (thanks to @jfyne);
- Starting with version 0.11.0, file downloads / uploads are supported using the native Blob type;
- Each operation is assumed to have a single tag. If none is declared, a default
of
Api
(configurable) is assumed. If multiple tags are declared, the first one is used; - Each tag generates a service class;
- Operations that don't declare an id have an id generated. However, it is recommended that all operations define an id;
- Two methods are generated for each service operation: one returning
Observable<HttpResponse<T>>
(the method is suffixed withResponse
) and another one returningObservable<T>
; - This generator may not cover all corner cases of the Swagger 2.0 specification;
- OpenAPI 3.0 is not supported, but may be added in the future;
- Probably many more.
Requirements
The generator itself has very few requirements, basically json-schema-ref-parser, argparse and mustache.
However, starting with the version 1.0.0, the generated code requires
both Angular 6.0+ and RxJS 6.0+. These versions are expressed as
peerDependencies
, so make sure you don't have unmet peer dependencies.
If you are stuck on previous versions of Angular / RxJS, you can use
ng-swagger-gen
version as ~0.11.0
, which supports Angular 4.3, and RxJS 5.5.
How to use it
In your project, run:
cd <your_angular_app_dir>
npm install ng-swagger-gen --save-dev
node_modules/.bin/ng-swagger-gen -i <path_to_swagger_json> [-o output_dir]
Where:
path_to_swagger_json
is either a relative path to the Swagger JSON file or an URL.output_dir
is the directory where the generated code will be outputted. It is recommended that this directory is ignored on GIT (or whatever source control software you are using), for example, by adding its name to.gitignore
. The default output directory if nothing is specified issrc/app/api
.
Please, run the ng-swagger-gen
with the --help
argument to view all
available command line arguments.
Generated folder structure
The folder src/app/api
(or your custom folder) will contain the following
structure:
project_root
+- src
+- app
+- api
+- models
| +- model1.ts
| +- model1.example.json
| +- ...
| +- modeln.ts
| +- modeln.example.json
+- services
| +- tag1.service.ts
| +- ...
| +- tagn.service.ts
+- api.module.ts
+- api-configuration.ts
+- base-service.ts
+- models.ts
+- services.ts
The files are:
- api/models/modeln.ts: One file per model file is generated here. Enumerations are also correctly generated;
- api/models/modeln.ts: One file per example is generated for each model that has
example
section. - api/models.ts: An index script which exports all model interfaces. It is
used to make it easier for application classes to import models, so they can
use
import { Model1, Model2 } from 'api/models'
instead ofimport { Model1 } from 'api/models/model1'
andimport { Model2 } from 'api/models/model2'
; - api/services/tagn.service.ts: One file per Swagger tag is generated here;
- api/services.ts: An index script which exports all service classes, similar to the analog file for models;
- api/api-configuration.ts: An
@Injectable
class that holds global configuration. Currently the only global configuration option isrootUrl
, which defaults to the URL in the source Swagger definition, and can be overridden in your application before doing the first API call; - api/base-service.ts: Base class which all generated services extend. It
provides the ability to override the root URL used by a particular service.
If the service root URL is
null
, which is the default, the service will use the global root URL defined inApiConfiguration
; - api/api.module.ts: A module that declares an
NgModule
that provides all services, plus theApiConfiguration
instance. Your root application module should import this module to ensure all services are available via dependency injection on your application.
Using a configuration file
On regular usage it is recommended to use a configuration file instead of
passing command-line arguments to ng-swagger-gen
. The default configuration
file name is ng-swagger-gen.json
, and should be placed on the root folder
of your NodeJS project. Besides allowing to omit the command-line arguments,
using a the configuration file allows a greater degree of control over the
generation.
An accompanying JSON schema is also available, so the configuration file can be
validated, and IDEs can autocomplete the file. If you have installed and
saved the ng-swagger-gen
module in your node project, you can use a local copy
of the JSON schema on ./node_modules/ng-swagger-gen/ng-swagger-gen-schema.json
.
It is also possible to use the online version at
https://github.com/cyclosproject/ng-swagger-gen/blob/master/ng-swagger-gen-schema.json
.
It is also possible to specify the configuration file to use. This is useful
when multiple APIs are generated. To specify a configuration file, use the
argument --config
or its short form, -c
, like this:
ng-swagger-gen --config custom-config.json
When working with multiple APIs, it is advised to set a different prefix for
each one. This impacts the generated global files, such as ApiModule
and
ApiConfiguration
. The default prefix is Api
, leading to those names.
But, if the specified prefix
in the configuration file is, for example,
Customers
, the generated files will be CustomersModule
and CustomersConfiguration
. The prefix support has been added in version 1.3.
Generating the configuration file
To generate a configuration file, run the following in the root folder of your project;
ng-swagger-gen --gen-config [-i path_to_swagger_json] [-o output_dir]
This will generate the ng-swagger-gen.json
file in the current directory
with the property defaults, plus the input Swagger JSON path (or URL) and
the output directory that were specified together. Both are optional, and the
file is generated anyway.
Configuration file reference
The supported properties in the JSON file are:
swagger
: The location of the swagger descriptor in JSON format. May be either a local file or URL.output
: Where generated files will be written to. Defaults tosrc/app/api
.prefix
: A prefix to the generated global classes, such asConfiguration
andModule
. Defaults to 'Api', so the default generated files areApiConfiguration
andApiModule
.includeTags
: When specified, filters the generated services, including only those corresponding to this list of tags.excludeTags
: When specified, filters the generated services, excluding any service corresponding to this list of tags.ignoreUnusedModels
: Indicates whether or not to ignore model files that are not referenced by any operation. Defaults to true.minParamsForContainer
: Indicates the minimum number of parameters to wrap operation parameters in a container class. Defaults to 2.sortParams
: How to sort operation parameters. Required always come first. For backwards compatibility, the default value isdesc
, butnone
is recommended for new projects.defaultTag
: The assumed tag for operations that don't define any. Defaults toApi
.removeStaleFiles
: Indicates whether or not to remove any files in the output folder that were not generated by ng-swagger-gen. Defaults to true.modelIndex
: Indicates whether or not to generate the file which exports all models. Defaults to true.serviceIndex
: Indicates whether or not to generate the file which exports all services. Defaults to true.apiModule
: Indicates whether or not to generate the Angular module which provides all services and theApiConfiguration
. Defaults to true.enumModule
: Indicates whether or not to export an additional TypeScript module (not to be confused with Angular's @NgModule) for each enum model, exporting values as constants and providing the values() method. Setting to false will reduce the size of the generated code. Defaults to true.templates
: Path to override the Mustache templates used to generate files.generateExamples
: When set to true, for models that provide an example section, will generate a corresponding<model>.example.ts
file, exporting a function calledget<Model>Example()
, which will return the data present in the example section.camelCase
: Generates service methods in camelCase instead of PascalCase.customFileSuffix
: Set custom suffixes for generated files.timeout
: Set the amount of time (in milliseconds) to wait for a response from the server when downloading files. Default to 20 seconds.skipProxySetup
: Skip the proxy setup when unable to generate from localhost.
Configuration file example
The following is an example of a configuration file which will choose a few
tags to generate, and chose not to generate the ApiModule
class:
{
"$schema": "./node_modules/ng-swagger-gen/ng-swagger-gen-schema.json",
"swagger": "my-swagger.json",
"includeTags": [
"Blogs",
"Comments",
"Users"
],
"apiModule": false
}
This will generate only the services for the chosen tags, and also skip the generation of any interfaces for models which are not used by any of the generated services.
Setting up a node script
Regardless If your Angular project was generated or is managed by Angular CLI, or you have started your project with some other seed (for example, using webpack directly), you can setup a script to make sure the generated API classes are consistent with the swagger descriptor.
To do so, create the ng-swagger-gen.json
configuration file and add the
following scripts
to your package.json
:
{
"scripts": {
"start": "ng-swagger-gen && ng serve",
"build": "ng-swagger-gen && ng build -prod"
}
}
This way whenever you run npm start
or npm run build
, the API classes
will be generated before actually serving / building your application.
Also, if you use several configuration files, you can specify multiple times
the call to ng-swagger-gen
, like:
{
"scripts": {
"start": "ng-swagger-gen -c api1.json && ng-swagger-gen -c api2.json && ng serve",
"build": "ng-swagger-gen -c api1.json && ng-swagger-gen -c api2.json && ng build -prod"
}
}
Specifying the root URL / web service endpoint
The easiest way to specify a custom root URL (web service endpoint URL) is to
use forRoot
method of ApiModule
and set the rootUrl
property from there.
@NgModule({
declarations: [
AppComponent
],
imports: [
ApiModule.forRoot({rootUrl: 'https://some-root-url.com'}),
],
bootstrap: [
AppComponent
]
})
export class AppModule { }
Alternatively, you can inject the ApiConfiguration
instance in some service
or component, such as the AppComponent
and set the rootUrl
property there.
Passing request headers / customizing the request
To pass request headers, such as authorization or API keys, as well as having a
centralized error handling, a standard
HttpInterceptor should
be used. It is basically an @Injectable
that is called before each request,
and can customize both requests and responses.
Here is an example:
@Injectable()
export class ApiInterceptor implements HttpInterceptor {
intercept(req: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
// Apply the headers
req = req.clone({
setHeaders: {
'ApiToken': '234567890'
}
});
// Also handle errors globally
return next.handle(req).pipe(
tap(x => x, err => {
// Handle this err
console.error(`Error performing request, status code = ${err.status}`);
})
);
}
}
Then, both the HttpInterceptor
implementation and the injection token
HTTP_INTERCEPTORS
pointing to it must be provided in your application module,
like this:
import { NgModule, Provider, forwardRef } from '@angular/core';
import { HTTP_INTERCEPTORS } from '@angular/common/http';
import { ApiInterceptor } from './api.interceptor';
export const API_INTERCEPTOR_PROVIDER: Provider = {
provide: HTTP_INTERCEPTORS,
useExisting: forwardRef(() => ApiInterceptor),
multi: true
};
@NgModule({
providers: [
ApiInterceptor,
API_INTERCEPTOR_PROVIDER
]
})
export class AppModule {}
Finer control over specific requests can also be achieved, such as:
- Set the immediate next request to use a BASIC authentication for login, and the subsequent ones to use a session key in another request header;
- Set the next request to not use the default error handling, and handle errors directly in the calling code.
To do so, just create another shared @Injectable()
, for example, called
ApiRequestConfiguration
, which has state for such special cases. Then inject
it on both the HttpInterceptor
and in the client code that makes requests.
Here is an example for such class for controlling the authentication:
import { Injectable } from '@angular/core';
import { HttpRequest } from '@angular/common/http';
/**
* Configuration for the performed HTTP requests
*/
@Injectable()
export class ApiRequestConfiguration {
private nextAuthHeader: string;
private nextAuthValue: string;
/** Set to basic authentication */
basic(user: string, password: string): void {
this.nextAuthHeader = 'Authorization';
this.nextAuthValue = 'Basic ' + btoa(user + ':' + password);
}
/** Set to session key */
nextAsSession(sessionKey: string): void {
this.nextAuthHeader = 'Session';
this.nextAuthValue = sessionKey;
}
/** Clear any authentication headers (to be called after logout) */
clear(): void {
this.nextAuthHeader = null;
this.nextAuthValue = null;
}
/** Apply the current authorization headers to the given request */
apply(req: HttpRequest<any>): HttpRequest<any> {
const headers = {};
if (this.nextAuthHeader) {
headers[this.nextAuthHeader] = this.nextAuthValue;
}
// Apply the headers to the request
return req.clone({
setHeaders: headers
});
}
}
Then change the ApiInterceptor
class to call the apply
method.
And, of course, add ApiRequestConfiguration
to your module providers
and
inject it on your components or services.
Swagger extensions
The swagger specification doesn't allow referencing an enumeration to be used
as an operation parameter. Hence, ng-swagger-gen
supports the vendor
extension x-type
in operations, whose value could either be a model name
representing an enumeration or Array<EnumName>
or List<EnumName>
(both are
equivalents) to use an array of models.
Who uses this project
This project was developed by the Cyclos development team, and, in fact, the Cyclos REST API is the primary test case for generated classes. However, since Cyclos 4.12, the project has changed the API descriptor to OpenAPI 3. As such, a new generator was developed: ng-openapi-gen.
That doesn't mean that the generator works only for the Cyclos API. For instance, the following commands will generate an API client for Swagger's PetStore example, assuming Angular CLI is installed:
ng new petstore
cd petstore
npm install --save-dev ng-swagger-gen
node_modules/.bin/ng-swagger-gen -i http://petstore.swagger.io/v2/swagger.json