api.service.OrderedRoutingQueue

This service implements a class for collecting routes from different sources while maintaining their order of definition and order of processing.

Hitchy's core is using this service on bootstrap to collect routes defined by discovered plugins and the application. The service is managing slots per plugin with every slot representing a potential list of routes. In addition, dedicated slots for the routes of current application as well as blueprint routes of plugins are maintained accordingly.

A separate method is provided to eventually combine all routes in those slots into flattened lists of routes. Hitchy's core is using these lists to derive a hierarchy of routes per method and per prefix to prepare for optimized request dispatching at runtime.

Two instances of this class - e.g. named controllers and policies - are used to properly wrap controller routes inside policy routes on dispatching requests by considering routes in resulting lists of these instances in the following order:

1. routes in policies.before
2. routes in list resulting from concatenating controllers.before and controllers.after
3. routes in policies.after

Constructor

Instances of this class are constructed with the number of plugins as parameter:

const queues = new api.service.OrderedRoutingQueue( 3 );

Properties

after

Once compacted, this is a queue of routes to be considered lately on dispatching a request after early routes and routes regarding the inner slot have been processed.

before

Once compacted, this is a queue of routes to be considered early on dispatching a request prior to late routes in the after queue.

isAdjustable

This boolean property indicates if slots maintained per plugin can be extended with additional routes or not. It is true initially and becomes false after compacting the slots into queues before and after.

Methods

compact()

This method is reducing the maintained lists of routes per plugin and slot into two single lists before and after which resemble the sorting order of plugins and their slots but lists all routes previously collected per plugin and slot in a flat list of routes.

The method can't be invoked twice. Once used, all methods for fetching or replacing lists of routes throw an exception and property isAdjustable becomes false.

The method returns current instance for daisy-chaining.

getCustomSlot()

This method fetches the ordered list of routes collected for the application in stage selected by first argument.

const routes = queues.getCustomSlot( "before", [] );

The second argument is a default to return in case a list of routes hasn't been assigned before.

Once compacted, the method is throwing an exception.

getInnerSlot()

This method fetches the previously collected ordered list of blueprint routes.

const routes = queues.getInnerSlot( [] );

Provided argument is a default to return in case a list of blueprint routes hasn't been assigned before.

Once compacted, the method is throwing an exception.

getOnPlugin()

This method fetches the ordered list of routes collected for the plugin selected by its index in named stage as provided in first and second argument.

const routes = queues.getOnPlugin( 2, "before", [] );

Third argument is a default to return in case a list of routes hasn't been assigned to the addressed stage of selected plugin before.

Once compacted, the method is throwing an exception.

setCustomSlot()

This method replaces the ordered list of routes collected for the application in stage selected by first argument.

queues.setCustomSlot( "before", routes );

The method returns current instance for daisy-chaining.

Once compacted, the method is throwing an exception.

setInnerSlot()

This method replaces the previously collected ordered list of blueprint routes.

queues.setInnerSlot( routes );

The method returns current instance for daisy-chaining.

Once compacted, the method is throwing an exception.

setOnPlugin()

This method replaces the ordered list of routes collected for the plugin selected by its index in named stage as provided in first and second argument.

queues.setOnPlugin( 2, "before", routes );

The method returns current instance for daisy-chaining.

Once compacted, the method is throwing an exception.