Refactor the implementation to use the new method `phaseList.zipMerge`.
This is commit is changing the behaviour in the case when
the first new phase does not exist in the current list.
Before the change, all new phases were added just before the "routes"
phase.
After this change, new phases are added to the head of the list,
until an existing phase is encountered, at which point the regular
merge algorithm kicks in.
Example:
app.defineMiddlewarePhases(['first', 'routes', 'subapps']);
Before the change: code throws an error - 'routes' already exists.
After the change: phases are merged with the following result:
'first', 'initial', ..., 'routes', 'subapps', ...
Implement method for registering (new) middleware phases.
- If all names are new, then the phases are added just before
the "routes" phase.
- Otherwise the provided list of names is merged with the existing
phases in such way that the order of phases is preserved.
Example
// built-in phases:
// initial, session, auth, parse, routes, files, final
app.defineMiddlewarePhases('custom');
// new list of phases
// initial, session, auth, parse,
// custom,
// routes, files, final
app.defineMiddlewarePhases([
'initial', 'postinit', 'preauth', 'routes', 'subapps'
]);
// new list of phases
// initial,
// postinit, preauth,
// session, auth, parse, custom,
// routes,
// subapps,
// files, final
Implement a function registering a middleware using a factory function
and a JSON config.
Example:
app.middlewareFromConfig(compression, {
enabled: true,
phase: 'initial',
config: {
threshold: 128
}
});
Modify the app and router implementation, so that the middleware is
executed in order defined by phases.
Predefined phases:
'initial', 'session', 'auth', 'parse', 'routes', 'files', 'final'
Methods defined via `app.use`, `app.route` and friends are executed
as the first thing in 'routes' phase.
API usage:
app.middleware('initial', compression());
app.middleware('initial:before', serveFavicon());
app.middleware('files:after', loopback.urlNotFound());
app.middleware('final:after', errorHandler());
Middleware flavours:
// regular handler
function handler(req, res, next) {
// do stuff
next();
}
// error handler
function errorHandler(err, req, res, next) {
// handle error and/or call next
next(err);
}