node.js - KoaJS middleware and database access -

if had show index users model:

app.use(route.get('/user', list));  function *list() {   var res = yield users.find({});   this.body = res; }; 

is possible put database access part own middleware , call next?

how pass resulting list of users down next middleware? , somehow pass next through route?

so first middleware db access needed, , second middleware presentation?

essentially attach information request context or this keyword within middleware.

i created screencast on writing middleware might helpful:

http://knowthen.com/episode-4-writing-middleware-in-koajs/

here example of how pass information downstream middleware.

let koa   = require('koa'),     users = require('./users'),     app   = koa();  function *firstmiddleware (next) {   this.session = {     user: yield users.find({});   }   yield next; }  function *secondmiddleware (next) {   // this.session.user available here   yield next; }  app.use(firstmiddleware); app.use(secondmiddleware);  app.use(function *(){   // this.session.user available here   this.body = this.session.user; });  app.listen(3000);