Django and Reactjs: complex templates - javascript

I've been looking for this question for a while and still not quite clear. What approaches you use to build templates for Django application using Reacjs? How do you show different menus for authorized and not authorized users? Is it possible to keep html layout in .html file and just render Reactjs components in required places? How to communicate between those components?
Here's for example:
I have a page like this, with menu, and list of items:
<body>
<div>
{% if not user.authenticated %}
Login
{% else %}
Logout
Add item
{% endif %}
</div>
<ul>
<li>One</li>
<li>Two</li>
</ul>
</body>
If user is not authorized i show a button "Login" in it, otherwise there are two buttons: "Logout" and "Add item". When i click "Add item" button i need to open modal window with form. On form submit i want to append item to <ul> list. This is just example, page can contain a lot of html markup. The questions above.
Please ask in comments if my question is not clear.

I think you are a bit confused, if you are using react ( or any other js framework for single page app) you shouldn't use the django template to render some part ( even though you can ). The logic to show or not the login should be in the react template, not in the django template. For example:
Django template
<head>
<script>
var userInfo = {
authenticated : {% user.authenticated %}
// add anyother user info
}
</script>
<head>
<body>
<div id="app"/>
</body>
JS application:
var React = require("react");
var Component = require("./components/Login");
function render(element, id) {
React.render(<Login/>, document.getElementById(id));
}
render(Component, "app");
Login:
var React = require("react");
var Login = React.createClass({
renderLogin: function () {
var loginButton;
if (userInfo.authenticated) {
loginButton = <LogoutButton />;
} else {
loginButton = <LoginButton />;
}
return loginButton;
}
render: function() {
return (
<div className="Login">
{renderLogin}
</div>
</div>
);
}
});
module.exports = Login;
I wound't just access the global variable from any react component, rather I would access it from the root componenent and then propagate it down to the children components by means of props or context.

Related

How to add view count in vue?

I am building a post website in vue.
I want to implement the functionality so that people can see how many views ('vues') the post got.
Every time someone clicks on a post, the view count should increase by 1.
I use firebase as my backend.
This is my simplified code based on my question:
<template>
<h1>{{ title }}</h1>
<p>This page has {{ views }}</p>
</template>
<script>
export default {
setup() {
const title = "Blog 1"
let views = 0
return { title, views }
}
};
</script>

(Nuxt) Vue component doesn't show up until page refresh

I'm storing nav items in my Vuex store and iterating over them for conditional output, in the form of a Vue/Bulma component, as follows:
<b-navbar-item
v-for='(obj, token) in $store.state.nav'
v-if='privatePage'
class=nav-link
tag=NuxtLink
:to=token
:key=token
>
{{obj.text}}
</b-navbar-item>
As shown, it should be output only if the component's privatePage data item resolves to true, which it does:
export default {
data: ctx => ({
privatePage: ctx.$store.state.privateRoutes.includes(ctx.$route.name)
})
}
The problem I have is when I run the dev server (with ssr: false) the component doesn't show up initially when I navigate to the page via a NuxtLink tag. If I navigate to the page manually, or refresh it, the component shows.
I've seen this before in Nuxt and am not sure what causes it. Does anyone know?
recommendation :
use mapState and other vuex mapping helper to have more readable code :).
dont use v-for and v-if at the same element
use "nuxt-link" for your tag
use / for to (if your addresses dont have trailing slash)
<template v-if='privatePage'>
<b-navbar-item
v-for='(obj, token) in nav'
class=nav-link
tag="nuxt-link"
:to="token" Or "`/${token}`"
:key="token"
>
{{obj.text}}
</b-navbar-item>
</template>
and in your script :
<script>
import {mapState} from 'vuex'
export default{
data(){
return {
privatePage: false
}
},
computed:{
...mapState(['privateRoutes','nav'])
},
mounted(){
// it's better to use name as a query or params to the $route
this.privatePage = this.privateRoutes.includes(this.$route.name)
}
}
</script>
and finally if it couldn't have help you , I suggest to inspect your page via dev tools and see what is the rendered component in html. it should be an <a> tag with href property. In addition, I think you can add the link address (that work with refresh and not by nuxt link) to your question, because maybe the created href is not true in navbar-item.
NOTE: token is index of nav array . so your url with be for example yourSite.com/1.so it's what you want?
This question has been answered here: https://stackoverflow.com/a/72500720/12747502
In addition, the solution to my problem was a commented part of my HTML that was outside the wrapper div.
Example:
<template>
<!-- <div>THIS CREATES THE PROBLEM</div> -->
<div id='wrapper'> main content here </div>
</template>
Correct way:
<template>
<div id='wrapper'>
<!-- <div>THIS CREATES THE PROBLEM</div> -->
main content here
</div>
</template>

Parse and Render external HTML in React component

I'm writing a React-based application where one of the components receives its HTML content as a string field in props. This content is returned by an API call.
I need to:
Render this content as a standard HTML (i.e. with the styles applied)
Parse the content to see if the sections within the content have "accept-comments" tag and show a "Comment" button beside the section
For example, if I receive the HTML below, I should show the "Comment" button beside section with id "s101".
<html>
<head/>
<body>
<div id="content">
<section id="s101" accept-comments="true">Some text that needs comments</section>
<section id="s102">Some text that doesn't need comments</section>
</div>
</body>
</html>
Questions:
What would be the most efficient way to parse and render the HTML as the content can get a bit large, close to 1MB at times?
How can I ensure that React does not re-render this component as it will not be updated? I'd assume always return "false" from shouldComponentUpdate().
Things I've tried:
Render the HTML with "dangerouslySetInnerHTML" or "react-html-parser". With this option, cannot parse the "accept-comments" sections.
Use DOMParser().parseFromString to parse the content. How do I render its output in a React component as HTML? Will this be efficient with 1MB+ content?
This answer comes from Chris G's code in the comments. I used the code with different sizes of documents and it works well. Thanks Chris G!
Posting the code here in case the link link in the comments breaks.
The solution uses DOMParser to parse the HTML content provided by the API call and scans it to find the content that should include the "Comment" button. Here are the relevant parts.
import React from "react";
import { render } from "react-dom";
const HTML =
"<div><section but='yes'>Section 1</section><section>Section 2</section></div>";
class DOMTest extends React.Component {
constructor(props) {
super(props);
const doc = new DOMParser().parseFromString(HTML, "application/xml");
const htmlSections = doc.childNodes[0].childNodes;
this.sections = Object.keys(htmlSections).map((key, i) => {
let el = htmlSections[key];
let contents = [<p>{el.innerHTML}</p>];
if (el.hasAttribute("but")) contents.push(<button>Comment</button>);
return <div key={i}>{contents}</div>;
});
}
render() {
return <div>{this.sections}</div>;
}
}
const App = () => (
<div>
<DOMTest />
</div>
);
render(<App />, document.getElementById("root"));

How to enhance a server side generated page with Aurelia.io?

I'm writing an app with some parts as SPA and some pages generated on server side for SEO. I've chosen Aurelia.io framework and I use enhance method to enable custom elements on my pages. But I can't find the best way to use aurelia specific template directives and interpolation on my server side page. Let's start with an exemple.
All of my pages contains a dynamic header. This header will be a custom element named my-cool-header. This header will load authentified user and display its name, or, if no user is currently authentified, a link to the signin will be displayed. The body of the page will be generated on server side and cached. So, we'll have something like that :
<html>
<body>
<my-cool-header>
<img src="logo.png">
<div
show.bind="user">${user.name}</div>
<div
show.bind="!user">Sign-in</div>
</my-cool-header>
<div>Cachabled content</div>
</body>
</html>
Then, my header will by defined by :
import {UserService} from './user';
import {inject} from 'aurelia-framework';
#inject(UserService)
export class MyCoolHeader {
constructor(userService) {
this.userService = userService;
}
async attached() {
this.user = await this.userService.get();
}
}
With the following template :
<template>
<content></content>
</template>
And this bootstrap script :
export function configure(aurelia) {
aurelia.use
.standardConfiguration()
.developmentLogging()
.globalResources('my-cool-header');
aurelia.start().then(a => a.enhance(document.body));
}
In this configuration, the custom element is well loaded and instanciated. But, I can't access the viewModel of the node inside the <content> node. So, all the interpolation (${user.name}) and attributes (show.bind) are ignored. If I include a custom-element in my content template, it will be loaded only if it is declared as global in the bootstrap : the` tag is ignored.
I've found a workaround to be able to change the viewModel after reading the doc by setting a custom viewModel to enhance method and then, injecting it to my custom element class. Something like :
import {MainData} from './main-data';
export function configure(aurelia) {
const mainData = aurelia.container.get(MainData);
aurelia.use
.standardConfiguration()
.developmentLogging()
.globalResources('my-cool-header');
aurelia.start().then(a => a.enhance(mainData, document.body));
}
Custom element:
import {UserService} from './user';
import {inject} from 'aurelia-framework';
import {MainData} from './main-data';
#inject(UserService, MainData)
export class MyCustomElement {
constructor(userService, mainData) {
this.userService = userService;
this.mainData = mainData;
}
async attached() {
this.mainData.user = await this.userService.get();
}
}
And finally, if I change my template like that, it will work :
<html>
<body>
<my-cool-header
user.bind="user">
<img src="logo.png">
<div
show.bind="user">${user.name}</div>
<div
show.bind="!user">Sign-in</div>
</my-cool-header>
<div>Cachabled content</div>
</body>
</html>
I can't believe it is the right way to do because it's ugly and it does not resolve the problem of <require> tag. So my question is : What is the best way to do ?
Thanks to your clues, I found the solution!
Custom element need to construct its own template:
import {processContent, noView} from 'aurelia-framework';
#processContent(function(viewCompiler, viewResources, element, instruction) {
instruction.viewFactory = viewCompiler.compile(`<template>${element.innerHTML}</template>`, viewResources, instruction);
element.innerHTML = '';
return false;
})
#noView
export class MyCustomElement {
attached() {
this.world = 'World!';
this.display = true;
}
}
Then, in my view from server, we can interpolate and require custom elements!
<body>
<my-custom-element>
<require="./other-custom-element"></require>
<p
if.bind="display">Hello ${world}</p>
<other-custom-element></other-custom-element>
</my-custom-element>
</body>
I've wrote a decorator to help creating this kind of enhanced custom elements : https://github.com/hadrienl/aurelia-enhanced-template
Plus de détails en français sur mon blog : https://blog.hadrien.eu/2016/02/04/amelioration-progressive-avec-aurelia-io/
EDIT: <require> is not really working with this solution. I have to dig again :(
Change your MyCoolHeader's template from:
<template>
<content></content>
</template>
to:
<template>
<img src="logo.png">
<div show.bind="user">${user.name}</div>
<div show.bind="!user">Sign-in</div>
</template>
then change your server-generated page to something like this:
<html>
<body>
<my-cool-header></my-cool-header>
<div>Cachabled content</div>
</body>
</html>
Hope that helps. If this doesn't solve the problem or is not an acceptable solution, let me know.
Edit
After reading your reply and thinking about this a bit more I'm leaning towards removing the <my-cool-header> element. It's not providing any behavior, it only acts as a data loader, it's template is provided by the server-side rendering process and it's expected to be rendered outside of the aurelia templating system, there's no real need to re-render it. Here's what this approach would look like, let me know if it seems like a better fit:
<html>
<body>
<div class="my-cool-header">
<img src="logo.png">
<div show.bind="user">${user.name}</div>
<div show.bind="!user">Sign-in</div>
</div>
<div>Cachabled content</div>
</body>
</html>
import {MainData} from './main-data';
import {UserService} from './user';
export function configure(aurelia) {
const mainData = aurelia.container.get(MainData);
const userService = aurelia.container.get(UserService);
aurelia.use
.standardConfiguration()
.developmentLogging();
Promise.all([
this.userService.get(),
aurelia.start()
]).then(([user, a]) => {
mainData.user = user;
a.enhance(mainData, document.body);
});
}
To supplement Jeremy's answer, if you did change the template to:
<template>
<img src="logo.png">
<div show.bind="user">${user.name}</div>
<div show.bind="!user">Sign-in</div>
</template>
This content would be present when Aurelia processed the element and in the absence of a content selector, anything inside the custom element tags will be replaced by the template
If you then put your non-javascript content inside the custom element tags:
<my-cool-header>
<div>This stuff will be visible when JS is turned off</div>
</my-cool-header>
In the example above, in the absence of JS the div should still be there as Aurelia won't remove it from the DOM.
(This is of course assuming your server side tech doesn't mangle/fix the unknown HTML tags in the DOM for some reason when serving pages - which it probably won't since it would break Aurelia anyway)
EDIT:
The alternative you may be looking for is the #processContent decorator.
This allows you to pass a callback function that runs before Aurelia inspects the element.
At this point you could just lift the content between the custom element tags and add it as a child of the template element. The content should then be in scope of your viewmodel.
This way you can have the same markup in between the custom element tags with no javascript, and inside your template in the correct scope when Aurelia is running
import {processContent, TargetInstruction, inject} from 'aurelia-framework';
#inject(Element, TargetInstruction)
#processContent(function(viewCompiler, viewResources, element, instruction) {
// Do stuff
instruction.templateContent = element;
return true;
})
class MyViewModel {
constructor(element, targetInstruction) {
var behavior = targetInstruction.behaviorInstructions[0];
var userTemplate = behavior.templateContent;
element.addChild(userTemplate);
}
}
Disclaimer: the above code hasn't been tested and I pulled it from my grid which is several releases old - you may need to tweak

How to switch between login page and app with Aurelia

I'm using the Aurelia skeleton for my project. Everything seemed so intuitive, however I'm stuck with a problem which I suspect is fairly easy (if you know how).
The problem is that the app.html / app.js is initially showing a nav bar and loading some default styles.
Now I need a login page, which does not load anything but its own styles, no navbar no nothing - just its own login form.
So I tried something like this:
app.js
<template>
<div if.bind="auth.isNotAuthenticated()">
<require from="components/login/index" ></require>
<login router.bind="router"></login>
</div>
<div if.bind="auth.isAuthenticated()">
<require from="nav-bar.html" ></require>
<require from="../styles/styles.css"></require>
<div class="container" id="banner">
<div class="row">
<img src="images/logo.png" />
</div>
</div>
<nav-bar router.bind="router"></nav-bar>
<div class="page-host">
<router-view></router-view>
</div>
</div>
</template>
Obviously that doesn't work (unless you refresh the page/f5), since the app.js / app.html is the root route which is always present and never changes. But I hope the logic within the markup helps illustrate what I'm looking to solve?
I guess my if only I knew how to reload the parent route (app.js) when I navigate from the login route, on login success, to another route. And again when I logout, the parent route (app.js) should be refreshed as well once again. Then all my problems would be solved.
What am I missing here? :-)
I think aurelia's setRoot(module) function will help with this.
Here's the standard main.js file that "bootstraps" the aurelia app:
main.js
export function configure(aurelia) {
aurelia.use
.standardConfiguration()
.developmentLogging();
aurelia.start()
.then(a => a.setRoot()); // this is the equivalent of setRoot('app')
}
When setRoot is called with no arguments Aurelia looks for an app.js + app.html viewmodel and view.
We can adjust the logic to check whether the user is logged in and if not, show the login screen:
main.js
export function configure(aurelia) {
aurelia.use
.standardConfiguration()
.developmentLogging();
aurelia.start()
.then(a => {
if (userIsLoggedIn()) {
a.setRoot('app');
} else {
a.setRoot('login');
}
});
}
Then in your login view model you can call setRoot('app') after the user has successfully logged in:
login.js
import {Aurelia, inject} from 'aurelia-framework';
import {AuthService} from './my-auth-service';
#inject(Aurelia, AuthService)
export class Login {
userName = '';
password = '';
constructor(aurelia, authService) {
this.aurelia = aurelia;
this.authService = authService;
}
submit() {
// attempt to login and if successful, launch the app view model.
this.authService.login(userName, password)
.then(() => this.aurelia.setRoot('app'));
}
}
Note: if your app includes a "logout" feature that will send the user back to the login screen (eg setRoot('login')), be sure to reset the router and update the url accordingly. This will prevent issues when the user signs back in. More details in here and here.
For a working example of setRoot you can check also
https://foursails.github.io/sentry
https://github.com/foursails/sentry

Categories

Resources