peerlibrary/flow-router

Name: flow-router

Owner: PeerLibrary

Description: Carefully Designed Client Side Router for Meteor

Created: 2015-11-08 07:43:36.0

Updated: 2016-02-28 19:52:59.0

Pushed: 2016-08-03 00:00:07.0

Homepage: https://atmospherejs.com/peerlibrary/flow-router

Size: 476

Language: JavaScript

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README

FlowRouter Build Status Stories in Ready

Carefully Designed Client Side Router for Meteor.

FlowRouter is a very simple router for Meteor. It does routing for client-side apps and does not handle rendering itself.

It exposes a great API for changing the URL and reactively getting data from the URL. However, inside the router, it's not reactive. Most importantly, FlowRouter is designed with performance in mind and it focuses on what it does best: routing.

We've released 2.0 and follow this migration guide if you are already using FlowRouter.

This is a fork of Flow Router which adds ignoring links feature to it. Pull request was not accepted.

TOC
Meteor Routing Guide

Meteor Routing Guide is a completed guide into routing and related topics in Meteor. It talks about how to use FlowRouter properly and use it with Blaze and React. It also shows how to manage subscriptions and implement auth logic in the view layer.

Meteor Routing Guide

Getting Started

Add FlowRouter to your app:

or add peerlibrary:flow-router

Let's write our first route (add this file to lib/router.js):

Router.route('/blog/:postId', {
action: function(params, queryParams) {
    console.log("Yeah! We are on the post:", params.postId);
}

Then visit /blog/my-post-id from the browser or invoke the following command from the browser console:

Router.go('/blog/my-post-id');

Then you can see some messages printed in the console.

Routes Definition

FlowRouter routes are very simple and based on the syntax of path-to-regexp which is used in both Express and iron:router.

Here's the syntax for a simple route:

Router.route('/blog/:postId', {
// do some action for this route
action: function(params, queryParams) {
    console.log("Params:", params);
    console.log("Query Params:", queryParams);
},

name: "<name for the route>" // optional

So, this route will be activated when you visit a url like below:

Router.go('/blog/my-post?comments=on&color=dark');

After you've visit the route, this will be printed in the console:

ms: {postId: "my-post"}
y Params: {comments: "on", color: "dark"}

For a single interaction, the router only runs once. That means, after you've visit a route, first it will call triggers, then subscriptions and finally action. After that happens, none of those methods will be called again for that route visit.

You can define routes anywhere in the client directory. But, we recommend to add them in the lib directory. Then fast-render can detect subscriptions and send them for you (we'll talk about this is a moment).

Group Routes

You can group routes for better route organization. Here's an example:

adminRoutes = FlowRouter.group({
efix: '/admin',
me: 'admin',
iggersEnter: [function(context, redirect) {
console.log('running group triggers');



andling /admin route
nRoutes.route('/', {
tion: function() {
BlazeLayout.render('componentLayout', {content: 'admin'});

iggersEnter: [function(context, redirect) {
console.log('running /admin trigger');



andling /admin/posts
nRoutes.route('/posts', {
tion: function() {
BlazeLayout.render('componentLayout', {content: 'posts'});


All of the options for the FlowRouter.group() are optional.

You can even have nested group routes as shown below:

adminRoutes = FlowRouter.group({
prefix: "/admin",
name: "admin"


superAdminRoutes = adminRoutes.group({
prefix: "/super",
name: "superadmin"


andling /admin/super/post
rAdminRoutes.route('/post', {
action: function() {

}

You can determine which group the current route is in using:

Router.current().route.group.name

This can be useful for determining if the current route is in a specific group (e.g. admin, public, loggedIn) without needing to use prefixes if you don't want to. If it's a nested group, you can get the parent group's name with:

Router.current().route.group.parent.name

As with all current route properties, these are not reactive, but can be combined with FlowRouter.watchPathChange() to get group names reactively.

Rendering and Layout Management

FlowRouter does not handle rendering or layout management. For that, you can use:

Then you can invoke the layout manager inside the action method in the router.

Router.route('/blog/:postId', {
action: function(params) {
    BlazeLayout.render("mainLayout", {area: "blog"});
}

Triggers

Triggers are the way FlowRouter allows you to perform tasks before you enter into a route and after you exit from a route.

Defining triggers for a route

Here's how you can define triggers for a route:

Router.route('/home', {
 calls just before the action
iggersEnter: [trackRouteEntry],
tion: function() {
// do something you like

 calls when when we decide to move to another route
 but calls before the next route started
iggersExit: [trackRouteClose]


tion trackRouteEntry(context) {
 context is the output of `FlowRouter.current()`
xpanel.track("visit-to-home", context.queryParams);


tion trackRouteClose(context) {
xpanel.track("move-from-home", context.queryParams);

Defining triggers for a group route

This is how you can define triggers on a group definition.

adminRoutes = FlowRouter.group({
efix: '/admin',
iggersEnter: [trackRouteEntry],
iggersExit: [trackRouteEntry]

You can add triggers to individual routes in the group too.

Defining Triggers Globally

You can also define triggers globally. Here's how to do it:

Router.triggers.enter([cb1, cb2]);
Router.triggers.exit([cb1, cb2]);

iltering
Router.triggers.enter([trackRouteEntry], {only: ["home"]});
Router.triggers.exit([trackRouteExit], {except: ["home"]});

As you can see from the last two examples, you can filter routes using the only or except keywords. But, you can't use both only and except at once.

If you'd like to learn more about triggers and design decisions, visit here.

Redirecting With Triggers

You can redirect to a different route using triggers. You can do it from both enter and exit triggers. See how to do it:

Router.route('/', {
iggersEnter: [function(context, redirect) {
redirect('/some-other-path');
,
tion: function(_params) {
throw new Error("this should not get called");


Every trigger callback comes with a second argument: a function you can use to redirect to a different route. Redirect also has few properties to make sure it's not blocking the router.

Check this PR to learn more about our redirect API.

Stopping the Callback With Triggers

In some cases, you may need to stop the route callback from firing using triggers. You can do this in before triggers, using the third argument: the stop function. For example, you can check the prefix and if it fails, show the notFound layout and stop before the action fires.

localeGroup = FlowRouter.group({
efix: '/:locale?',
iggersEnter: [localeCheck]


leGroup.route('/login', {
tion: function (params, queryParams) {
BlazeLayout.render('componentLayout', {content: 'login'});



tion localeCheck(context, redirect, stop) {
r locale = context.params.locale;

 (locale !== undefined && locale !== 'fr') {
BlazeLayout.render('notFound');
stop();


Note: When using the stop function, you should always pass the second redirect argument, even if you won't use it.

Not Found Routes

You can configure Not Found routes like this:

Router.notFound = {
// Subscriptions registered here don't have Fast Render support.
subscriptions: function() {

},
action: function() {

}

Ignoring Links

If you want that some links are not handled by FlowRouter but that a normal HTTP request is made to the server (for example, to link to a static file/asset), you can register path to be ignored:

Router.ignore('/storage');

This will ignore all same-origin links which start with /storage. You can also pass an regexp instead.

Additionally, links are ignored by FlowRouter if:

API

FlowRouter has a rich API to help you to navigate the router and reactively get information from the router.

FlowRouter.getParam(paramName);

Reactive function which you can use to get a parameter from the URL.

oute def: /apps/:appId
rl: /apps/this-is-my-app

appId = FlowRouter.getParam("appId");
ole.log(appId); // prints "this-is-my-app"
FlowRouter.getQueryParam(queryStringKey);

Reactive function which you can use to get a value from the queryString.

oute def: /apps/:appId
rl: /apps/this-is-my-app?show=yes&color=red

color = FlowRouter.getQueryParam("color");
ole.log(color); // prints "red"
FlowRouter.path(pathDef, params, queryParams)

Generate a path from a path definition. Both params and queryParams are optional.

Special characters in params and queryParams will be URL encoded.

pathDef = "/blog/:cat/:id";
params = {cat: "met eor", id: "abc"};
queryParams = {show: "y+e=s", color: "black"};

path = FlowRouter.path(pathDef, params, queryParams);
ole.log(path); // prints "/blog/met%20eor/abc?show=y%2Be%3Ds&color=black"

If there are no params or queryParams, this will simply return the pathDef as it is.

Using Route name instead of the pathDef

You can also use the route's name instead of the pathDef. Then, FlowRouter will pick the pathDef from the given route. See the following example:

Router.route("/blog/:cat/:id", {
name: "blogPostRoute",
action: function(params) {
    //...
}


params = {cat: "meteor", id: "abc"};
queryParams = {show: "yes", color: "black"};

path = FlowRouter.path("blogPostRoute", params, queryParams);
ole.log(path); // prints "/blog/meteor/abc?show=yes&color=black"
FlowRouter.go(pathDef, params, queryParams);

This will get the path via FlowRouter.path based on the arguments and re-route to that path.

You can call FlowRouter.go like this as well:

Router.go("/blog");
FlowRouter.url(pathDef, params, queryParams)

Just like FlowRouter.path, but gives the absolute url. (Uses Meteor.absoluteUrl behind the scenes.)

FlowRouter.setParams(newParams)

This will change the current params with the newParams and re-route to the new path.

oute def: /apps/:appId
rl: /apps/this-is-my-app?show=yes&color=red

Router.setParams({appId: "new-id"});
hen the user will be redirected to the following path
    /apps/new-id?show=yes&color=red
FlowRouter.setQueryParams(newQueryParams)

Just like FlowRouter.setParams, but for queryString params.

To remove a query param set it to null like below:

Router.setQueryParams({paramToRemove: null});
FlowRouter.getRouteName()

To get the name of the route reactively.

ker.autorun(function() {
r routeName = FlowRouter.getRouteName();
nsole.log("Current route name is: ", routeName);

FlowRouter.current()

Get the current state of the router. This API is not reactive. If you need to watch the changes in the path simply use FlowRouter.watchPathChange().

This gives an object like this:

oute def: /apps/:appId
rl: /apps/this-is-my-app?show=yes&color=red

current = FlowRouter.current();
ole.log(current);

rints following object

   path: "/apps/this-is-my-app?show=yes&color=red",
   params: {appId: "this-is-my-app"},
   queryParams: {show: "yes", color: "red"}
   route: {pathDef: "/apps/:appId", name: "name-of-the-route"}

FlowRouter.watchPathChange()

Reactively watch the changes in the path. If you need to simply get the params or queryParams use dedicated APIs like FlowRouter.getQueryParam().

ker.autorun(function() {
owRouter.watchPathChange();
r currentContext = FlowRouter.current();
 do anything with the current context
 or anything you wish

FlowRouter.withReplaceState(fn)

Normally, all the route changes made via APIs like FlowRouter.go and FlowRouter.setParams() add a URL item to the browser history. For example, run the following code:

Router.setParams({id: "the-id-1"});
Router.setParams({id: "the-id-2"});
Router.setParams({id: "the-id-3"});

Now you can hit the back button of your browser two times. This is normal behavior since users may click the back button and expect to see the previous state of the app.

But sometimes, this is not something you want. You don't need to pollute the browser history. Then, you can use the following syntax.

Router.withReplaceState(function() {
owRouter.setParams({id: "the-id-1"});
owRouter.setParams({id: "the-id-2"});
owRouter.setParams({id: "the-id-3"});

Now, there is no item in the browser history. Just like FlowRouter.setParams, you can use any FlowRouter API inside FlowRouter.withReplaceState.

We named this function as withReplaceState because, replaceState is the underline API used for this functionality. Read more about replace state & the history API.

FlowRouter.reload()

FlowRouter routes are idempotent. That means, even if you call FlowRouter.go() to the same URL multiple times, it only activates in the first run. This is also true for directly clicking on paths.

So, if you really need to reload the route, this is the API you want.

FlowRouter.wait() and FlowRouter.initialize()

By default, FlowRouter initializes the routing process in a Meteor.startup() callback. This works for most of the apps. But, some apps have custom initializations and FlowRouter needs to initialize after that.

So, that's where FlowRouter.wait() comes to save you. You need to call it directly inside your JavaScript file. After that, whenever your app is ready call FlowRouter.initialize().

eg:-

ile: app.js
Router.wait();
EverYourAppIsReady(function() {
owRouter.initialize();

For more information visit issue #180.

FlowRouter.onRouteRegister(cb)

This API is specially designed for add-on developers. They can listen for any registered route and add custom functionality to FlowRouter. This works on both server and client alike.

Router.onRouteRegister(function(route) {
 do anything with the route object
nsole.log(route);

Let's say a user defined a route like this:

Router.route('/blog/:post', {
me: 'postList',
iggersEnter: [function() {}],
bscriptions: function() {},
tion: function() {},
iggersExit: [function() {}],
stomField: 'customName'

Then the route object will be something like this:


thDef: '/blog/:post',
me: 'postList',
tions: {customField: 'customName'}

So, it's not the internal route object we are using.

Subscription Management

For Subscription Management, we highly suggest you to follow Template/Component level subscriptions. Visit this guide for that.

FlowRouter also has it's own subscription registration mechanism. We will remove this in version 3.0. We don't remove or deprecate it in version 2.x because this is the easiest way to implement FastRender support for your app. In 3.0 we've better support for FastRender with Server Side Rendering.

FlowRouter only deals with registration of subscriptions. It does not wait until subscription becomes ready. This is how to register a subscription.

Router.route('/blog/:postId', {
subscriptions: function(params, queryParams) {
    this.register('myPost', Meteor.subscribe('blogPost', params.postId));
}

We can also register global subscriptions like this:

Router.subscriptions = function() {
is.register('myCourses', Meteor.subscribe('courses'));

All these global subscriptions run on every route. So, pay special attention to names when registering subscriptions.

After you've registered your subscriptions, you can reactively check for the status of those subscriptions like this:

ker.autorun(function() {
console.log("Is myPost ready?:", FlowRouter.subsReady("myPost"));
console.log("Are all subscriptions ready?:", FlowRouter.subsReady());

So, you can use FlowRouter.subsReady inside template helpers to show the loading status and act accordingly.

FlowRouter.subsReady() with a callback

Sometimes, we need to use FlowRouter.subsReady() in places where an autorun is not available. One such example is inside an event handler. For such places, we can use the callback API of FlowRouter.subsReady().

late.myTemplate.events({
click #id": function(){
  FlowRouter.subsReady("myPost", function() {
     // do something
  });


Arunoda has discussed more about Subscription Management in FlowRouter in this blog post about FlowRouter and Subscription Management.

He's showing how to build an app like this:

FlowRouter's Subscription Management

Fast Render

FlowRouter has built in support for Fast Render.

You can exclude Fast Render support by wrapping the subscription registration in an isClient block:

Router.route('/blog/:postId', {
subscriptions: function(params, queryParams) {
    // using Fast Render
    this.register('myPost', Meteor.subscribe('blogPost', params.postId));

    // not using Fast Render
    if(Meteor.isClient) {
        this.register('data', Meteor.subscribe('bootstrap-data');
    }
}

Subscription Caching

You can also use Subs Manager for caching subscriptions on the client. We haven't done anything special to make it work. It should work as it works with other routers.

IE9 Support

FlowRouter has IE9 support. But it does not ship the HTML5 history polyfill out of the box. That's because most apps do not require it.

If you need to support IE9, add the HTML5 history polyfill with the following package.

or add tomwasd:history-polyfill
Hashbang URLs

To enable hashbang urls like mydomain.com/#!/mypath simple set the hashbang option to true in the initialize function:

ile: app.js
Router.wait();
EverYourAppIsReady(function() {
owRouter.initialize({hashbang: true});

Prefixed paths

In cases you wish to run multiple web application on the same domain name, you?ll probably want to serve your particular meteor application under a sub-path (eg example.com/myapp). In this case simply include the path prefix in the meteor ROOT_URL environment variable and FlowRouter will handle it transparently without any additional configuration.

Add-ons

Router is a base package for an app. Other projects like useraccounts should have support for FlowRouter. Otherwise, it's hard to use FlowRouter in a real project. Now a lot of packages have started to support FlowRouter.

So, you can use your your favorite package with FlowRouter as well. If not, there is an easy process to convert them to FlowRouter.

Add-on API

We have also released a new API to support add-on developers. With that add-on packages can get a notification, when the user created a route in their app.

If you've more ideas for the add-on API, let us know.

Difference with Iron Router

FlowRouter and Iron Router are two different routers. Iron Router tries to be a full featured solution. It tries to do everything including routing, subscriptions, rendering and layout management.

FlowRouter is a minimalistic solution focused on routing with UI performance in mind. It exposes APIs for related functionality.

Let's learn more about the differences:

Rendering

FlowRouter doesn't handle rendering. By decoupling rendering from the router it's possible to use any rendering framework, such as Blaze Layout to render with Blaze's Dynamic Templates. Rendering calls are made in the the route's action. We have a layout manager for React as well.

Subscriptions

With FlowRouter, we highly suggest using template/component layer subscriptions. But, if you need to do routing in the router layer, FlowRouter has subscription registration mechanism. Even with that, FlowRouter never waits for the subscriptions and view layer to do it.

Reactive Content

In Iron Router you can use reactive content inside the router, but any hook or method can re-run in an unpredictable manner. FlowRouter limits reactive data sources to a single run; when it is first called.

We think that's the way to go. Router is just a user action. We can work with reactive content in the rendering layer.

router.current() is evil

Router.current() is evil. Why? Let's look at following example. Imagine we have a route like this in our app:

s/:appId/:section

Now let's say, we need to get appId from the URL. Then we will do, something like this in Iron Router.

lates['foo'].helpers({
"someData": function() {
    var appId = Router.current().params.appId;
    return doSomething(appId);
}

Let's say we changed :section in the route. Then the above helper also gets rerun. If we add a query param to the URL, it gets rerun. That's because Router.current() looks for changes in the route(or URL). But in any of above cases, appId didn't get changed.

Because of this, a lot parts of our app get re-run and re-rendered. This creates unpredictable rendering behavior in our app.

FlowRouter fixes this issue by providing the Router.getParam() API. See how to use it:

lates['foo'].helpers({
"someData": function() {
    var appId = FlowRouter.getParam('appId');
    return doSomething(appId);
}

No data context

FlowRouter does not have a data context. Data context has the same problem as reactive .current(). We believe, it'll possible to get data directly in the template (component) layer.

Built in Fast Render Support

FlowRouter has built in Fast Render support. Just add Fast Render to your app and it'll work. Nothing to change in the router.

For more information check docs.

Server Side Routing

FlowRouter is a client side router and it does not support server side routing at all. But subscriptions run on the server to enable Fast Render support.

Reason behind that

Meteor is not a traditional framework where you can send HTML directly from the server. Meteor needs to send a special set of HTML to the client initially. So, you can't directly send something to the client yourself.

Also, in the server we need look for different things compared with the client. For example:

So, it's better to use a dedicated server-side router like meteorhacks:picker. It supports connect and express middlewares and has a very easy to use route syntax.

Server Side Rendering

FlowRouter 3.0 will have server side rendering support. We've already started the initial version and check our ssr branch for that.

It's currently very usable and Kadira already using it for https://kadira.io

Better Initial Loading Support

In Meteor, we have to wait until all the JS and other resources send before rendering anything. This is an issue. In 3.0, with the support from Server Side Rendering we are going to fix it.

Migrating into 2.0

Migrating into version 2.0 is easy and you don't need to change any application code since you are already using 2.0 features and the APIs. In 2.0, we've changed names and removed some deprecated APIs.

Here are the steps to migrate your app into 2.0.

Use the New FlowRouter Package Change FlowLayout into BlazeLayout Stop using deprecated Apis

This work is supported by the National Institutes of Health's National Center for Advancing Translational Sciences, Grant Number U24TR002306. This work is solely the responsibility of the creators and does not necessarily represent the official views of the National Institutes of Health.