Meteor and Mantra - Routing redirect

Thu, 26 May 2016 10:03:22 +0000

Recently I started using Mantra to develop my Meteor apps. As with any other framework You’ll find a lot of answers to common questions in a related forum or any other resource. However I couldn’t get a good answer on how to implement routing logic properly. The Mantra specs also don’t tell much about how to approach it. So here’s my solution.

First I want to tell you about a little drawback, which is essential to understand the whole issue with routing in Mantra. The Flowrouter redirect statement can only work in the componentDidMount directive of an React component.

componentDidMount(){
  FlowRouter.go('/login');
}

As I don’t want load a component and then doing a redirect I had to make the redirect on a higher level of the Mantra architecture.

So where else could it be than in the route file? To give you a better understanding I’ll use the post module which is part of a blogging app.

client/modules/post/routes.jsx

...

  FlowRouter.route('/posts', {
    name: 'post.list',
    triggersEnter: [function(context, redirect) {
      actions.posts.access_route('post.list', redirect);
    }],
    action() {
      mount(AppLayout, {
        content: () => (<MainPage />)
      });
    }
  });

...

As you can see I’ll use a trigger action, despite the Mantra specs tell me not do so. For now it’s the only practical approach.

Import the action in the route and call the access_route function.

client/modules/post/actions/posts.js

import {cannot_access, redirect_login, redirect_verify} from '/lib/access_control';

...

access_route(routename, redirect) {
    if(redirect_login(routename)){
      redirect('/login');
    } else if(redirect_verify()){
      redirect('/email-verification');
    } else if(cannot_access(routename)){
      redirect('/');
    }
  }

...

This is done for every module. Then you get a custom routing logic for every module while still using the same function to verify f.g. a user can access a specific route.

/lib/access_control.js

// client side
export function redirect_login(routename){
  var roles = _.findWhere(Meteor.settings.public.routes, {name: routename}).roles;
  if(!_.contains(roles, "Public") && !Meteor.userId()){
    console.log("redirect login");
    return true;
  }
  return false;
};

// client side
export function redirect_verify(){
  if(Meteor.userId() && !Meteor.user().emails[0].verified){
    console.log("redirect verify");
    return true;
  }
  return false;
};

// client side
export function cannot_access(routename){
  var roles = _.findWhere(Meteor.settings.public.routes, {name: routename}).roles;
  if(_.contains(roles, "Public") || Roles.userIsInRole(Meteor.user(), roles)){
    console.log("allow route " + routename);
    return false;
  }
  console.log("deny route " + routename);
  return true;
};

Here I’ll bundle everything that is related in someway with permissions and access rights. The functions in this library are either used by the client or the server. I will use alanning roles to check role membership later on.

When assigning and checking for permissions with user, groups and rules I always use this schema:

Object <-> Access Group <-> Role <-> User

This schema is not a new invention, it’s a copy of Microsoft’s AGDLP idea.

Finally update the settings.json with access rules. Make sure to add it to the public part, otherwise the client can’t load the settings.

settings.json

...

{
  "name": "post.list",
  "roles": [
     "Admin",
     "Author",
     "Manager"
  ]
},

...

Yay! you did it. So do you like my idea? Would like to hear from you in the comment section.

Routing on Janik von Rotz

Meteor and Mantra - Routing redirect