Analysis of the method of dynamically binding HTML in AngularJS
The example in this article describes the method of dynamically binding HTML in AngularJS. Share it with everyone for your reference, the details are as follows:
In Web front-end development, we often encounter the need to dynamically bind some HTML strings from the back end or dynamic splicing to the page DOM display, especially in content management System (CMS: the abbreviation of Content Management System), such needs are everywhere.
Readers of angular will definitely think of ngBindHtml first. Yes, angular provides us with this instruction to dynamically bind HTML. It will bind the calculated expression result to the DOM using innerHTML. However, the problem is not that simple. In Web security, XSS (Cross-site scripting, script injection attack) is a typical computer security vulnerability in Web applications. XSS attacks refer to injecting executable client-side code into web pages and successfully executing them by the browser to achieve the purpose of the attack, forming an effective XSS attack. Once the attack is successful, it may obtain some sensitive information of the user. Changing the user experience, inducing users and other illegal behaviors, sometimes XSS attacks are combined with other attack methods, such as SQL injection attacks on servers and databases, Click hijacking, relative link hijacking, etc. to implement phishing. The harm it brings is huge, and it is also a web The number one enemy of security. For more web security issues, please refer to the wiki https://en.wikipedia.org/wiki/Cross-site_scripting%E3%80%82
In angular, the default is not to trust the added HTML content. For the added HTML content , first you must use $sce.trustAsHtml to tell angular that this is trusted HTML content. Otherwise you will get $sce:unsafe exception error.
Error: [$sce:unsafe] Attempting to use an unsafe value in a safe context.
Here is a demo that binds a simple angular link:
HTML：
<div ng-controller="DemoCtrl as demo"> <div ng-bind-html="demo.html"></div> </div>
JavaScript：
angular.module("com.ngbook.demo", [])
.controller("DemoCtrl", ["$sce", function($sce) {
var vm = this;
var html = '<p>hello <a href="https://angular.io/">angular</a></p>';
vm.html = $sce.trustAsHtml(html);
return vm;
}]);
For simple static HTML, this problem is solved. But for complex HTML, complexity here refers to HTML templates with angular expressions and instructions. For them, we not only hope to bind large DOM displays, but also hope to get angular's powerful two-way binding mechanism. ngBindHhtml will not be associated with $scope for two-way binding. If there are ngClick, ngHref, ngSHow, ngHide and other angular instructions in HTML, they will not be compiled. Clicking these buttons will not cause any reaction. The expression of binding The formula will not be updated. For example, if you try to change the last link to: ng-href="demo.link", the link will not be parsed, and the original HTML string will still be seen in the DOM.
To take effect, all instructions in angular need to go through compile. Compile contains pre-link and post-link, and is connected to specific behaviors before they can work. In most cases, compile will be automatically compiled when angular starts. But if it is a dynamically added template, you need to compile manually. Angular provides us with the $compile service to implement this function. The following is a more general compile example:
HTML:
<body ng-controller="DemoCtrl as demo">
<dy-compile html="{{demo.html}}">
</dy-compile>
<button ng-click="demo.change();">change</button>
</body>
JavaScript:
angular.module("com.ngbook.demo", [])
.directive("dyCompile", ["$compile", function($compile) {
return {
replace: true,
restrict: 'EA',
link: function(scope, elm, iAttrs) {
var DUMMY_SCOPE = {
$destroy: angular.noop
},
root = elm,
childScope,
destroyChildScope = function() {
(childScope || DUMMY_SCOPE).$destroy();
};
iAttrs.$observe("html", function(html) {
if (html) {
destroyChildScope();
childScope = scope.$new(false);
var content = $compile(html)(childScope);
root.replaceWith(content);
root = content;
}
scope.$on("$destroy", destroyChildScope);
});
}
};
}])
.controller("DemoCtrl", [function() {
var vm = this;
vm.html = '<h2>hello : <a ng-href="{{demo.link}}">angular</a></h2>';
vm.link = 'https://angular.io/';
var i = 0;
vm.change = function() {
vm.html = '<h3>change after : <a ng-href="{{demo.link}}">' + (++i) + '</a></h3>';
};
}]);
A directive called dy-compile is created here, which first listens to the html value of the bound attribute Change, when the html content exists, it will try to first create a subscope, and then use the $compile service to dynamically connect the incoming html and replace the current DOM node; the reason for creating the subscope here is to facilitate each When destroying the DOM for the first time, you can easily destroy the scope, remove the watchers function brought by HTML compile, and try to destroy the scope when the last parent scope is destroyed.
Because of the above compile compilation and connection, the ngHref instruction can take effect. Here is just an attempt to give an example of dynamic compile angular module. For specific implementation methods, please refer to your business to declare specific directives.
Hot AI Tools
Undresser.AI Undress
AI-powered app for creating realistic nude photos
AI Clothes Remover
Online AI tool for removing clothes from photos.
Undress AI Tool
Undress images for free
Clothoff.io
AI clothes remover
Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!
Hot Article
Hot Tools
Notepad++7.3.1
Easy-to-use and free code editor
SublimeText3 Chinese version
Chinese version, very easy to use
Zend Studio 13.0.1
Powerful PHP integrated development environment
Dreamweaver CS6
Visual web development tools
SublimeText3 Mac version
God-level code editing software (SublimeText3)
Hot Topics
1660
14
1416
52
1310
25
1260
29
1233
24
The latest 5 angularjs tutorials in 2022, from entry to mastery
Jun 15, 2017 pm 05:50 PM
Javascript is a very unique language. It is unique in terms of the organization of the code, the programming paradigm of the code, and the object-oriented theory. The issue of whether Javascript is an object-oriented language that has been debated for a long time has obviously been There is an answer. However, even though Javascript has been dominant for twenty years, if you want to understand popular frameworks such as jQuery, Angularjs, and even React, just watch the "Black Horse Cloud Classroom JavaScript Advanced Framework Design Video Tutorial".
Use PHP and AngularJS to build a responsive website to provide a high-quality user experience
Jun 27, 2023 pm 07:37 PM
In today's information age, websites have become an important tool for people to obtain information and communicate. A responsive website can adapt to various devices and provide users with a high-quality experience, which has become a hot spot in modern website development. This article will introduce how to use PHP and AngularJS to build a responsive website to provide a high-quality user experience. Introduction to PHP PHP is an open source server-side programming language ideal for web development. PHP has many advantages, such as easy to learn, cross-platform, rich tool library, development efficiency
Build web applications using PHP and AngularJS
May 27, 2023 pm 08:10 PM
With the continuous development of the Internet, Web applications have become an important part of enterprise information construction and a necessary means of modernization work. In order to make web applications easy to develop, maintain and expand, developers need to choose a technical framework and programming language that suits their development needs. PHP and AngularJS are two very popular web development technologies. They are server-side and client-side solutions respectively. Their combined use can greatly improve the development efficiency and user experience of web applications. Advantages of PHPPHP
Build a single-page web application using Flask and AngularJS
Jun 17, 2023 am 08:49 AM
With the rapid development of Web technology, Single Page Web Application (SinglePage Application, SPA) has become an increasingly popular Web application model. Compared with traditional multi-page web applications, the biggest advantage of SPA is that the user experience is smoother, and the computing pressure on the server is also greatly reduced. In this article, we will introduce how to build a simple SPA using Flask and AngularJS. Flask is a lightweight Py
How to use AngularJS in PHP programming?
Jun 12, 2023 am 09:40 AM
With the popularity of web applications, the front-end framework AngularJS has become increasingly popular. AngularJS is a JavaScript framework developed by Google that helps you build web applications with dynamic web application capabilities. On the other hand, for backend programming, PHP is a very popular programming language. If you are using PHP for server-side programming, then using PHP with AngularJS will bring more dynamic effects to your website.
Introduction to the basics of AngularJS
Apr 21, 2018 am 10:37 AM
The content of this article is about the basic introduction to AngularJS. It has certain reference value. Now I share it with you. Friends in need can refer to it.
Use PHP and AngularJS to develop an online file management platform to facilitate file management
Jun 27, 2023 pm 01:34 PM
With the popularity of the Internet, more and more people are using the network to transfer and share files. However, due to various reasons, using traditional methods such as FTP for file management cannot meet the needs of modern users. Therefore, establishing an easy-to-use, efficient, and secure online file management platform has become a trend. The online file management platform introduced in this article is based on PHP and AngularJS. It can easily perform file upload, download, edit, delete and other operations, and provides a series of powerful functions, such as file sharing, search,
How to use PHP and AngularJS for front-end development
May 11, 2023 pm 05:18 PM
With the popularity and development of the Internet, front-end development has become more and more important. As front-end developers, we need to understand and master various development tools and technologies. Among them, PHP and AngularJS are two very useful and popular tools. In this article, we will explain how to use these two tools for front-end development. 1. Introduction to PHP PHP is a popular open source server-side scripting language. It is suitable for web development and can run on web servers and various operating systems. The advantages of PHP are simplicity, speed and convenience
