1. Django + Vue.JS
JavaScript de 3ª generación para
modernizar Django
@javierabadia
PyConES 2017 Cáceres

2. SPAs - Single Page Applications
initial request
HTML
GET url
HTML
POST form
HTML
initial request
HTML
GET url (AJAX)
JSON
POST url (AJAX)
JSON
page
reload
Ciclo de Vida Tradicional
de una Página Web
Ciclo de Vida
de una App SPA
page
reload

3. GET url (AJAX)
JSON
POST url (AJAX)
JSON
El problema fundamental en el ‘front’

4. Frameworks de JS
1ª generación
2ª generación
3ª generación

5. Un poco de Vue.js

6. ¡ Se dice /vjuː/ !
¿ Sabes que estoy
aprendiendo vue ?

7. Lo simple es fácil
var app = new Vue({
el: '#app',
data: {
msg: ’Hi there!',
frameworks: ['React',
'Vue.js',
'Angular.io'],
},
methods: {
isCool(framework) {
return framework === 'Vue.js';
},
},
});
<div id="app">
{{msg}}
<ul>
<li v-for="framework in frameworks">
{{framework}}
<span v-if="isCool(framework)">
, so cool!
</span>
</li>
</ul>
</div>
HTML JavaScript
Declarative Rendering
Condicionales y Bucles

8. Eventos
var app = new Vue({
...
methods: {
isCool(framework) {
return this.cool.indexOf(framework) !== -1;
},
toggleCool(framework) {
if( this.isCool(framework) )
this.cool.splice(this.cool.indexOf(framework),1);
else
this.cool.push(framework);
}
},
});
<ul>
<li
v-for="framework in frameworks"
@click="toggleCool(framework)">
{{framework}}
<span v-if="isCool(framework)">
, so cool!
</span>
</li>
</ul>
HTML JavaScript

9. Enlazando (binding) atributos
<ul>
<li class="framework-item"
:class="{cool: isCool(framework)}"
v-for="framework in frameworks"
@click="toggleCool(framework)">
{{framework}}<span v-if="isCool(framework)">, so cool!</span>
</li>
</ul>

10. Vue.js

11. Componentes
vue instances

12. Single-File components
// MyComponent.vue
<template>
<div></div>
</template>
<script>
export default {
data() {
return {};
},
};
</script>
<style lang="less">
</style>
js
css
webpack
(o browserify)

13. Single-File components
// MyComponent.vue
<template>
<div></div>
</template>
<script>
export default {
data() {
return {};
},
};
</script>
<style lang="less">
</style>
js
css
webpack
(o browserify)

14. Arquitectura de una SPA de Vue.js
$ vue init webpack-simple frontend
$ cd frontend
$ yarn
$ yarn run dev
localhost:8080

15. DEMO
1

16. Ejemplo: Catálogo de GIFs para IoT
http://localhost:8000/ http://localhost:8000/detail/323

17. La estructura clásica de Django
Vistas
Templates
Modelos
ORM
Autenticación
Middleware
Formularios
Administración
HTML

18. DEMO
2

19. Django
:8000
Webpack
:8080

20. La experiencia ‘óptima’ de desarrollo
• Trabajar de forma unificada
(mismo IDE)
• Desarrollo en el backend
• debugging
• breakpoints, etc
• Desarrollo en el frontend
• con agilidad
• usando Hot Module
Replacement (HMR)

21. El puente entre Django y Webpack
$ cd frontend
$ npm install --save-dev webpack-bundle-tracker
# (en un virtualenv, por supuesto)
$ pip install django-webpack-loader

22. Todo junto
var path = require('path')
var webpack = require('webpack')
var BundleTracker = require('webpack-bundle-tracker');
module.exports = {
…
plugins: [
new BundleTracker({filename: './webpack-stats.json'})
]
}
// frontend/webpack.conf.js
{% extends 'base.html' %}
{% load render_bundle from webpack_loader %}
{% block content %}
<div id="app"></div>
{% render_bundle 'main' %}
{% endblock %}
{# backend/templates/index.html #}
{
"status": "done",
"publicPath": "http://localhost:8080/dist/",
"chunks": {
"main": [
{
"name": "build.js",
"publicPath": "http://localhost:8080/dist/build.js",
"path": "/Users/jami/…/gif_catalog/frontend/dist/build.js"
}
]
}
}
// frontend/webpack-stats.json
…
WEBPACK_LOADER = {
'DEFAULT': {
'BUNDLE_DIR_NAME': 'dist/',
'STATS_FILE': os.path.join(BASE_DIR,
'frontend/webpack-stats.json'),
}
}
# settings.py

23. def index(request):
return render(request, 'index.html', {})
# backend/views.py
{% extends 'base.html' %}
{% load render_bundle from webpack_loader %}
{% block content %}
<div id="app"></div>
{% render_bundle 'main' %}
{% endblock %}
{# backend/templates/index.html #}
Django
:8000
Webpack
:8080
urlpatterns = [
url(r'^', views.index),
]
# backend/urls.py
App.vue
main.js
*.vue
localhost:8000/
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
…
</head>
<body>
<div id="app"></div>
<script type="text/javascript"
src="http://localhost:8080/dist/build.js">
</script>
</body
</html>
HMRbuild.js

25. DEMO
3

26. Webpack: detalles de configuración
var path = require('path')
var webpack = require('webpack')
var BundleTracker = require('webpack-bundle-tracker');
module.exports = {
entry: './src/main.js',
output: {
path: path.resolve(__dirname, './dist'),
publicPath: 'http://localhost:8080/dist/',
filename: 'build.js'
},
module: {
...
},
devServer: {
historyApiFallback: true,
noInfo: true,
headers: {
'Access-Control-Allow-Origin': '*'
}
},
plugins: [
new BundleTracker({filename: './webpack-stats.json'})
]
}
url absoluta
incluyendo puerto
activar CORS para que el cliente
HMR pueda hacer peticiones al
devServer de webpack
// webpack.config.js

27. Django
:8000
localhost:8000/
HTML
localhost:8000/api/*
JSON
Webpack
:8080
HMR

28. Implementar una API ¿REST?
urlpatterns = [
url(r'^api/pics', api.pics),
url(r'^', views.index),
]
# backend/urls.py
def pics(request):
count = GifPicture.objects.all().count()
all_ids = range(count)
random.shuffle(all_ids)
picked_ids = all_ids[:18]
gif_pictures = GifPicture.objects
.filter(id__in=picked_ids)
.order_by('-upload_date')
result = {
'pics': gif_pictures,
}
return JsonResponse(result)
# backend/api.py
import axios from 'axios';
export default {
getRandomPics() {
return axios.get('/api/pics')
.then(response => {
return response.data.pics;
});
},
}
// gifPicsApi.js
Django
:8000
…
<script>
import gifPicsApi from '../services/gifPicsApi.js';
export default {
…
mounted() {
gifPicsApi.getRandomPics().then(pics => {
this.pics = pics;
});
},
};
</script>
// GifHome.vue

29. DEMO
4

30. Autenticación
Una posible implementación: 2PA
http://localhost:8000/login http://localhost:8000/*
create session
redirect
set cookie
vue-routing

31. Django + auth + sessions
<script>
export default {
name: 'app',
data() {
return {
msg: 'Welcome to Your Vue.js App!',
user: {},
}
},
created() {
this.user = window.user;
},
}
</script>
// App.vue
@login_required
def index(request):
context = {
'user': request.user,
}
return render(request, 'index.html', context)
# backend/views.py
{% extends 'base.html' %}
{% load render_bundle from webpack_loader %}
{% block content %}
<div id="app"></div>
<script>
var user = {
username: "{{ user.username }}",
email: "{{ user.email }}",
};
</script>
{% render_bundle 'main' %}
{% endblock %}
# backend/templates/index.html

32. DEMO
5

33. Routing

34. DEMO
6

35. Rutas
urlpatterns = [
url(r'^api/suggestions/$', api.suggestions),
url(r'^api/search/$', api.search),
url(r'^api/pics/(?P<id>[0-9]+)$', api.pic_details),
url(r'^api/pics/$', api.pics),
url(r'^', views.index),
]
# backend/urls.py
Vue.use(Router);
const router = new Router({
mode: 'history',
routes: [
{
path: '/',
name: 'home',
component: GifHome
},{
path: '/detail/:id',
name: 'detail',
component: GifDetail,
props:true
},{
path: '*',
component: Error404
}, // Not found
],
});
# router.js
urlpatterns = [
url(r'^admin/', admin.site.urls),
url('^', include('django.contrib.auth.urls')),
url(r'^', include('backend.urls'))
]
# urls.py
/login
/logout

36. ¿Es Django el mejor backend?
código
isomórfico
server-side
rendering
async I/O

37. Comentarios Finales
• APIs
• REST?
• ‘a pelo’
• django-tastypie
• django-rest-framework
• GraphQL
• graphene (django)
• apollo (vue)
• (no lo he probado)
• Server Side Rendering
• nope
• seeding
• sip
• SEO
• pre-render
• inyectar contenido en Django

38. Conclusión

39. Referencias
• Doc de Vue: https://vuejs.org/v2/guide/single-file-components.html
• Doc de Webpack: https://webpack.js.org/
• SurviveJS: https://survivejs.com/webpack/
• webpack-bundle-tracker: https://github.com/ezhome/webpack-bundle-tracker
• django-webpack-loader: https://github.com/ezhome/django-webpack-loader
• hello-vue + Django project: https://github.com/rokups/hello-vue-django
• modernize Django frontend: http://owaislone.org/blog/modern-frontends-with-django/
• Django + REACT with HMR: http://owaislone.org/blog/webpack-plus-reactjs-and-django/
• Django-angular: http://django-angular.readthedocs.io/en/latest/index.html

40. Gracias!
@javierabadia