Isomorphic JS with Mithril

Andrea Coiutti (@andreacoiutti)

XE One Day - Mestre, 18/11/17

Andrea Coiutti

ISOMORPHIC JS?

REAL CASE STUDY

browser

server sending
HTML pages

API

Conventional app

page?

data?

browser

server sending
HTML pages

API

Conventional app

HTML

JSON

browser

server sending
HTML pages

API

Conventional app

crawlers

page?

data?

browser

server sending
HTML pages

API

Conventional app

crawlers

JSON

HTML

Conventional app

well known and tested technologies

SEO friendly

Conventional app

slow render time

different programming languages / teams?

old school DOM manipulation

jQuery.

browser

server sending
HTML pages

API

SPA

HTML

page?

browser

server sending
HTML pages

API

SPA

JSON

data?

browser

server sending
HTML pages

API

SPA

crawlers

???

HTML

page?

SPA

quick response time

better user experience

hits the server only on first render

modern JS frameworks

SPA

(very) slow initial load

not SEO friendly

browser

server sending
HTML pages

API

Isomorphic app

JSON

data?

page?

HTML

browser

server sending
HTML pages

API

Isomorphic app

JSON

data?

browser

server sending
HTML pages

API

Isomorphic app

crawlers

JSON

data?

HTML

page?

routing

state persistence

view rendering

i18n

resources

time/currency format

BROWSER

SERVER

user events
handling

localStorage,
cookies

logging

static
assets

API

auth

http://isomorphic-mithril.mvlabs.it

live demo + docs

Advantages:
1. Performance

faster render of the first view
even faster on following views

better user experience

Advantages:
2. Maintainability

code shared by server and client
no duplicate logic

less code, less bugs

Advantages:
3. SEO availability

server side rendering
good for search engine crawlers

full SEO support

Mithril what?

mithril.js.org

A modern client-side Javascript framework
for building Single Page Applications

Virtual DOM based

Mithril

Download size

Vue + Vue-Router + Vuex + fetch (40kb)

React + React-Router + Redux + fetch (64kb)

Angular (135kb)

Mithril (8kb)

API methods

Performance

Vue (9.8ms)

React (12.1ms)

Angular (11.5ms)

Mithril (6.4ms)

first render time (less is better)

Try Mithril!

easy to learn
fun to work with
great documentation
nice community

Common

challenges

RENDERING

Risk of cloaking

Client-side rendering

m()

Mithril's hyperscript function

m('div', { class: 'foo' }, 'hello')

returns a virtual DOM node (or vnode)

JS object representing the DOM element to be created

<div class="foo">hello</div>

selector (required)

attributes object

children array

express any HTML structure using Javascript syntax

Server-side rendering

https://github.com/MithrilJS/mithril-node-render

// use a mock DOM so we can run mithril on the server
require('mithril/test-utils/browserMock')(global);

const m = require('mithril');
const render = require('mithril-node-render');

const view = m('div', { class: 'foo' }, 'hello');

render(view).then((html) => {
    // html = '<div class="foo">hello</div>'
})

render Mithril views on server side on Node.js

mithril-node-render

ROUTING

Shared routes

unique set of routes

map URI patterns to route handlers

Express and Mithril use same route definition

http://localhost/

http://localhost/:page

http://localhost/:category/:post

http://localhost/:other

Shared routes

http://localhost/#!/hello

http://localhost/hello

change it to pathname strategy

m.route.prefix('');

Mithril's router uses hashbang strategy as default

Shared routes

// Mithril base components
const Home = require('./pages/Home.js');
const Login = require('./pages/Login.js');
const NotFound = require('./pages/NotFound.js');
const Section = require('./pages/Section.js');
// ...

// Plain routes (without language prefix)
const plainRoutes = {
    '/': Home,
    '/login': Login,
    '/sections/:key': Section,
    // ...
    '/:other': NotFound
};

module.exports = plainRoutes;

app/routes.js

Components

encapsulate logic into units later usable as an elements

base for making large, scalable applications

Components in Mithril

POJOs

{ }

Plain Old JavaScript Objects

Components in Mithril

// define a component
const MyComponent = {
    view: vnode => m('div', vnode.attrs, ['Hello ', vnode.children])
};

// consume it
m(MyComponent, { style: 'color: red;' }, 'world');

<div style="color: red;">Hello world</div>

const ComponentWithHooks = {
    oninit: (vnode) => {
        console.log('initialized');
    },
    oncreate: (vnode) => {
        console.log('DOM created');
    },
    onupdate: (vnode) => {
        console.log('DOM updated');
    },
    onbeforeremove: (vnode) => {
        console.log('exit animation can start');
        return new Promise(function(resolve) {
            // call after animation completes
            resolve();
        })
    },
    onremove: (vnode) => {
        console.log('removing DOM element');
    },
    onbeforeupdate: (vnode, old) => {
        return true;
    },
    view: (vnode) => {
        return 'hello';
    }
}

Lifecycle
methods

const ComponentWithHooks = {
    oninit: (vnode) => {
        console.log('initialized');
    },
    oncreate: (vnode) => {
        console.log('DOM created');
    },
    onupdate: (vnode) => {
        console.log('DOM updated');
    },
    onbeforeremove: (vnode) => {
        console.log('exit animation can start');
        return new Promise(function(resolve) {
            // call after animation completes
            resolve();
        })
    },
    onremove: (vnode) => {
        console.log('removing DOM element');
    },
    onbeforeupdate: (vnode, old) => {
        return true;
    },
    view: (vnode) => {
        return 'hello';
    }
}

Lifecycle
methods

const ComponentWithHooks = {
    oninit: (vnode) => {
        console.log('initialized');
    },
    oncreate: (vnode) => {
        console.log('DOM created');
    },
    onupdate: (vnode) => {
        console.log('DOM updated');
    },
    onbeforeremove: (vnode) => {
        console.log('exit animation can start');
        return new Promise(function(resolve) {
            // call after animation completes
            resolve();
        })
    },
    onremove: (vnode) => {
        console.log('removing DOM element');
    },
    onbeforeupdate: (vnode, old) => {
        return true;
    },
    view: (vnode) => {
        return 'hello';
    }
}

Lifecycle
methods

const ComponentWithHooks = {
    oninit: (vnode) => {
        console.log('initialized');
    },
    oncreate: (vnode) => {
        console.log('DOM created');
    },
    onupdate: (vnode) => {
        console.log('DOM updated');
    },
    onbeforeremove: (vnode) => {
        console.log('exit animation can start');
        return new Promise(function(resolve) {
            // call after animation completes
            resolve();
        })
    },
    onremove: (vnode) => {
        console.log('removing DOM element');
    },
    onbeforeupdate: (vnode, old) => {
        return true;
    },
    view: (vnode) => {
        return 'hello';
    }
}

Lifecycle
methods

const MainComponent = {
    oninit: (vnode) => {
        vnode.state.content = null;
        getSomething() // async request, returns a Promise
            .then((content) => {
                vnode.state.content = content;
            });
    },

    view: vnode => m(Layout, [
        m(Header),
        m('main', vnode.state.content || m(Loading),
        m(Footer)
    ])
};

Data flow

app/pages/MainComponent.js

Data flow

m(Header)

m(Footer)

m(Layout)

m('main')

m(Loading)

const MainComponent = {
    oninit: (vnode) => {
        vnode.state.content = null;
        getSomething() // async request, returns a Promise
            .then((content) => {
                vnode.state.content = content;
            });
    },

    view: vnode => m(Layout, [
        m(Header),
        m('main', vnode.state.content || m(Loading),
        m(Footer)
    ])
};

Data flow

app/pages/MainComponent.js

const MainComponent = {
    oninit: (vnode) => {
        vnode.state.content = null;
        getSomething() // async request, returns a Promise
            .then((content) => {
                vnode.state.content = content;
            });
    },

    view: vnode => m(Layout, [
        m(Header),
        m('main', vnode.state.content || m(Loading),
        m(Footer)
    ])
};

Data flow

app/pages/MainComponent.js

Data flow

m(Header)

m(Footer)

m(Layout)

m('main')

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const MainComponent = {
    oninit: (vnode) => new Promise((resolve) => {
        vnode.state.content = null;
        getSomething() // async request, returns a Promise
            .then((content) => {
                vnode.state.content = content;
                resolve();
            });
    }),

    view: vnode => m(Layout, [
        m(Header),
        m('main', vnode.state.content || m(Loading),
        m(Footer)
    ])
};

Async components

app/pages/MainComponent.js

const MainComponent = {
    oninit: (vnode) => {
        vnode.state.content = null;
        getSomething() // async request, returns a Promise
            .then((content) => {
                vnode.state.content = content;
            });
    },

    view: vnode => m(Layout, [
        m(Header),
        m('main', vnode.state.content || m(Loading),
        m(Footer)
    ])
};

Requests

makes XHR (aka AJAX) requests, returns a Promise

m.request()

m.request({
    method: 'PUT',
    url: '/api/v1/users/:id',
    data: {id: 1, name: 'test'}
})
.then((result) => {
    console.log(result);
});

Requests

make m.request() work server side

global.window.XMLHttpRequest = require('w3c-xmlhttprequest').XMLHttpRequest;

server.js

SHARED STATE

State manager

const state = {
    sections: {
        home: {
            title: 'Isomorphic JS with Mithril',
            slug: 'index',
            content: 'Isomorphic JavaScript webapps have been around...'
        },
        intro: {
            // ...
        },
        // ...
    },
    lang: 'en'
};

Shared state

m('script', `window.__preloadedState = ${JSON.stringify(state)}`)

app/components/Layout.js

<script>window.__preloadedState = {"sections":{...},"lang":"en"}</script>

const sharedState = window.__preloadedState || {};

app/index.js

AUTH

API

CLIENT

[POST] credentials

[HTTP 200 OK] signed JSON token

credentials
validation

[GET] resource

[HTTP 200 OK] data

token
validation

store token

Token based auth

JWT (JSON Web Tokens)

browser

server sending
HTML pages

API

Isomorphic app

cookies, localStorage

single request

MULTILANGUAGE

Multilanguage

requires changes almost everywhere in the code

resources

server init

routes

client init

views

i18n

https://github.com/StephanHoyer/translate.js

Micro library for translations
support for placeholders and multiple plural forms
plays well with VDOM-libraries such as Mithril

translate.js

const translate = require('translate.js');

const messages = {
    like: 'I like this.',
    likeThing: 'I like {thing}!',
    likeTwoThings: 'I like {0} and {1}!',
    simpleCounter: 'The count is {n}.',
    hits: {
        0: 'No Hits',
        1: '{n} Hit',
        n: '{n} Hits', // default
    }
};

const t = translate(messages);


// Simple
t('like') => 'I like this.'
t('Prosa Key') => 'This is prosa!'

// Placeholders - named
t('likeThing', {thing: 'the Sun'}) => 'I like the Sun!'
//placeholders - array
t('likeTwoThings', ['Alice', 'Bob']) => 'I like Alice and Bob!'

// Numerical subkeys (count)
t('simpleCounter', 25) => 'The count is 25'
t('hits', 0) => 'No Hits'
t('hits', 99) => '99 Hits'

Integrations

easy integration of third party libraries
on the client side

const Prism = process.browser ? require('prismjs') : null;

const MainComponent = {
    oninit: (vnode) => /*...*/,

    view: vnode => m(Layout, [
        m(Header),
        vnode.state.content ? m('section', {
            oncreate: () => Prism.highlightAll()
        }, vnode.state.content) : m(Loading),
        m(Footer)
    ])
};

app/pages/MainComponent.js

THANK YOU!

docs and demo:
http://isomorphic-mithril.mvlabs.it

Isomorphic JS with Mithril

Andrea Coiutti

ISOMORPHIC JS?

REAL CASE STUDY

Conventional app

Conventional app

Conventional app

Conventional app

Conventional app

Conventional app

jQuery.

SPA

SPA

SPA

SPA

SPA

Isomorphic app

Isomorphic app

Isomorphic app

Advantages: 1. Performance

Advantages: 2. Maintainability

Advantages: 3. SEO availability

Mithril what?

Mithril

Download size

API methods

Performance

Try Mithril!

Common

challenges

RENDERING

Risk of cloaking

Client-side rendering

Server-side rendering

ROUTING

Shared routes

Shared routes

Shared routes

Components

Components in Mithril

Components in Mithril

Lifecycle methods

Lifecycle methods

Lifecycle methods

Lifecycle methods

Data flow

Data flow

Data flow

Data flow

Data flow

Async components

Requests

Requests

SHARED STATE

State manager

Shared state

AUTH

Token based auth

Isomorphic app

MULTILANGUAGE

Multilanguage

i18n

Integrations

THANK YOU!

Advantages:
1. Performance

Advantages:
2. Maintainability

Advantages:
3. SEO availability

Lifecycle
methods

Lifecycle
methods

Lifecycle
methods

Lifecycle
methods