supports custom routing detect path: ctx.routerPath

[fengmk2]

We want to bind helloworld.example.com/users => example.com/helloworld/users

[fengmk2]

@alexmingoia Any reviews?

[alexmingoia]

I understand the use case, but I don't think it necessitates extending koa-router. The same thing can be accomplished with middleware:

var koa = require('koa');
var Router = require('koa-router');

var app = koa();
var router = new Router();

// responds to fengmk2.example.com
router.get('/:user', function *(next) {
  console.log(this.params.user);
  // => "fengmk2"
  console.log(this.path);
  // => "/fengmk2"
  console.log(this.originalPath);
  // => "/"
});

// all routes for this router have paths rewritten to include subdomains
app.use(rewriteSubdomain, router.middleware());

// rewrites ctx.path to include subdomain
function rewriteSubdomain *(next) {
  var subdomain = this.headers.host.replace('example.com', '').split('.').join('');
  if (subdomain) {
    this.originalPath = this.path;
    this.path = '/' + subdomain + (this.path === '/' ? '' : this.path);
  }
  yield next;
};

[fengmk2]

I first do this in my project, but it change the path, that confuse for the
path is not the real current request url...

[alexmingoia]

I misunderstood. You can also respond to subdomains without changing the request path:

var koa = require('koa');
var Router = require('koa-router');

var app = koa();
var router = new Router();

// responds to fengmk2.example.com/users
router.get('/users', function *(next) {
  console.log(this.subdomain); // => "fengmk2";
  console.log(this.path);  // => "/users"
  this.body = (this.subdomain + this.path);
});

app
  .use(function *subdomainMiddleware (next) {
    this.subdomain = this.header.host.replace('example.com', '').split('.').join('');
    yield next;
  })
  .use(router.middleware());

[fengmk2]

I show my codes to explain:

var VHOST_RE = /^([a-z]\w*)\.[\w\-]+\.[\w\-]+/i;
app.use(function* vhost(next) {
    var hostname = this.hostname;
    var m = VHOST_RE.exec(hostname);
    if (m) {
      var appname = m[1];
      if (ignoreNames.indexOf(appname) === -1) {
        var prefixPath = '/' + appname;
        if (this.path.indexOf(prefixPath) !== 0) {
          this.routerPath = prefixPath + this.path;
        }
      }
    }
    yield* next;
 });

app.use(require('koa-router')(app));

// vhost 
// localhost:7001/demo/ <=> demo.test.com:7001/ <=> demo.test.com:7001/demo/
app.get('/demo/', app.controllers.demo.home);
app.post('/demo/update', app.controllers.demo.update);

$ curl demo.test.com:7001/
$ curl demo.test.com:7001/demo/

# hope both requests get the same response body: `hello demo`

[fengmk2]

wow, awesome!