Foxx service context
The service context provides access to methods and attributes that are specificto a given service. In a Foxx service the context is generally available as themodule.context
variable. Within a router’s request handler the request andresponse objects’ context
attribute also provide access to the context of theservice the route was mounted in (which may be different from the one the routehandler was defined in).
Examples
// in service /my-foxx-1
const createRouter = require('@arangodb/foxx/router');
const router = createRouter();
// See the chapter on dependencies for more info on
// how exports and dependencies work across services
module.exports = {routes: router};
router.get(function (req, res) {
module.context.mount === '/my-foxx-1';
req.context.mount === '/my-foxx-2';
res.write('Hello from my-foxx-1');
});
// in service /my-foxx-2
const createRouter = require('@arangodb/foxx/router');
const router2 = createRouter();
module.context.use(router2);
router2.post(function (req, res) {
module.context.mount === '/my-foxx-2';
req.context.mount === '/my-foxx-2';
res.write('Hello from my-foxx-2');
});
const router1 = module.context.dependencies.myFoxx1.routes;
module.context.use(router1);
The service context specifies the following properties:
- argv:
any
Any arguments passed in if the current file was executed as ascript or queued job.
- basePath:
string
The file system path of the service, i.e. the folder in which the servicewas installed to by ArangoDB.
- baseUrl:
string
The base URL of the service, relative to the ArangoDB server,e.g. /_db/_system/my-foxx
.
- collectionPrefix:
string
The prefix that will be used by collection and collectionName to derivethe names of service-specific collections. This is derived from theservice’s mount point, e.g. /my-foxx
becomes my_foxx
.
- configuration:
Object
Configuration options for the service.
- dependencies:
Object
Configured dependencies for the service.
- isDevelopment:
boolean
Indicates whether the service is running in development mode.
- isProduction:
boolean
The inverse of isDevelopment.
- manifest:
Object
The parsed manifest file of the service.
- mount:
string
The mount point of the service, e.g. /my-foxx
.
apiDocumentation
module.context.apiDocumentation([options]): Function
DEPRECATED
Creates a request handler that serves the API documentation.
Note: This method has been deprecated in ArangoDB 3.1 and replaced withthe more straightforward createDocumentationRouter
method providing thesame functionality.
Arguments
See createDocumentationRouter
below.
Examples
// Serve the API docs for the current service
router.get('/docs/*', module.context.apiDocumentation());
// Note that the path must end with a wildcard
// and the route must use HTTP GET.
createDocumentationRouter
module.context.createDocumentationRouter([options]): Router
Creates a router that serves the API documentation.
Note: The router can be mounted like any other child router(see examples below).
Arguments
- options:
Object
(optional)
An object with any of the following properties:
- mount:
string
(Default:module.context.mount
)
The mount path of the service to serve the documentation of.
- indexFile:
string
(Default:"index.html"
)
File name of the HTML file serving the API documentation.
- swaggerRoot:
string
(optional)
Full path of the folder containing the Swagger assets and the indexFile.Defaults to the Swagger assets used by the web interface.
- before:
Function
(optional)
A function that will be executed before a request is handled.
If the function returns false
the request will not be processed any further.
If the function returns an object, its attributes will be used to overridethe options for the current request.
Any other return value will be ignored.
If options is a function it will be used as the before option.
If options is a string it will be used as the swaggerRoot option.
Returns a Foxx router.
Examples
// Serve the API docs for the current service
router.use('/docs', module.context.createDocumentationRouter());
// -- or --
// Serve the API docs for the service the router is mounted in
router.use('/docs', module.context.createDocumentationRouter(function (req) {
return {mount: req.context.mount};
}));
// -- or --
// Serve the API docs only for users authenticated with ArangoDB
router.use('/docs', module.context.createDocumentationRouter(function (req, res) {
if (req.suffix === 'swagger.json' && !req.arangoUser) {
res.throw(401, 'Not authenticated');
}
}));
collection
module.context.collection(name): ArangoCollection | null
Passes the given name to collectionName, then looks up the collection withthe prefixed name.
Arguments
- name:
string
Unprefixed name of the service-specific collection.
Returns a collection or null
if no collection with the prefixed name exists.
collectionName
module.context.collectionName(name): string
Prefixes the given name with the collectionPrefix for this service.
Arguments
- name:
string
Unprefixed name of the service-specific collection.
Returns the prefixed name.
Examples
module.context.mount === '/my-foxx'
module.context.collectionName('doodads') === 'my_foxx_doodads'
file
module.context.file(name, [encoding]): Buffer | string
Passes the given name to fileName, then loads the file with the resulting name.
Arguments
- name:
string
Name of the file to load, relative to the current service.
- encoding:
string
(optional)
Encoding of the file, e.g. utf-8
. If omitted the file will be loaded as araw buffer instead of a string.
Returns the file’s contents.
fileName
module.context.fileName(name): string
Resolves the given file name relative to the current service.
Arguments
- name:
string
Name of the file, relative to the current service.
Returns the absolute file path.
use
module.context.use([path], router): Endpoint
Mounts a given router on the service to expose the router’s routes on theservice’s mount point.
Arguments
- path:
string
(Default:"/"
)
Path to mount the router at, relative to the service’s mount point.
- router:
Router | Middleware
A router or middleware to mount.
Returns an Endpoint for the given router or middleware.
Note: Mounting services at run time (e.g. within request handlers orqueued jobs) is not supported.