What is AngularJS? Introduction to AngularJS_AngularJS
May 16, 2016 pm 04:28 PM
What is AngularJS?
AngularJS is a structural framework designed for dynamic WEB applications. It allows you to use HTML as a template language, and by extending the syntax of HTML, you can build your application components more clearly and concisely. Its innovation is that it uses data binding and dependency injection to save you from writing a lot of code. These are all implemented through browser-side Javascript, which also makes it perfectly integrated with any server-side technology.
AngularJS is designed to overcome the shortcomings of HTML in building applications. HTML is a good declarative language designed for static text display, but it is weak when it comes to building WEB applications. So I did some work (tricks if you will) to get the browser to do what I wanted. formatDate
Usually, we use the following technologies to solve the shortcomings of static web page technology in building dynamic applications:
1. Class library - A class library is a collection of functions that can help you write WEB applications. It's your code that takes control, and it's you who decides when to use the library. Class libraries include: jQuery, etc.
2. Framework - A framework is a special, already implemented WEB application. You only need to fill it with specific business logic. The framework here plays a leading role, calling your code according to specific application logic. Frameworks include: knockout, sproutcore, etc.
AngularJS uses a different approach, trying to make up for the shortcomings of HTML itself in building applications. AngularJS enables browsers to recognize the new syntax by using structures we call directives. For example:
1. Use double curly braces {{}} syntax for data binding;
2. Use DOM control structures to iterate or hide DOM fragments;
3. Support forms and form validation;
4. Ability to associate logical codes to relevant DOM elements;
5. Ability to group HTML into reusable components.
End-to-end solution
AngularJS attempts to be an end-to-end solution for WEB applications. This means that it is not just a small part of your WEB application, but a complete end-to-end solution. This will make AngularJS very "opinionated" (original text is opinionated, meaning there are not many other ways) when building a CRUD (add Create, query Retrieve, update Update, delete Delete) application. However, even though it is "stubborn", it still ensures that its "stubbornness" is only at the starting point when you build the application, and you still have the flexibility to change. Some of the outstanding features of AngularJS are as follows:
1. Everything that may be used to build a CRUD application includes: data binding, basic template identifiers, form validation, routing, deep linking, component reuse, and dependency injection.
2. Testing includes: unit testing, end-to-end testing, simulation and automated testing framework.
3. Seed application with directory layout and test scripts as a starting point.
The cuteness of AngularJS
AngularJS simplifies application development by presenting developers with a higher level of abstraction. As with other abstraction techniques, some flexibility is lost. In other words, not all applications are suitable for AngularJS. AngularJS is primarily concerned with building CRUD applications. Fortunately, at least 90% of WEB applications are CRUD applications. But to understand what is suitable for building with AngularJS, you need to understand what is not suitable for building with AngularJS.
For example, games, graphical interface editors, applications with frequent and complex DOM operations are very different from CRUD applications, and they are not suitable to be built with AngularJS. In situations like this it might be better to use some lighter, simpler technology like jQuery.
A simple AngularJS example
The following is a typical CRUD application containing a form. The form value is first validated and then used to calculate the total value, which is formatted into a local style. Here are some common concepts among developers that you need to understand first:
1. Associate the data model (data-model) to the view (UI);
2. Write, read, and verify user input;
3. Calculate new values ??according to the model;
4. Localize the output format.
index.html:
???
???????
???????
???
???
???????
??????????? Invoice:
???????????
???????????
???????????
| Quantity | Cost |
???????????
??????????? Total: {{qty * cost | currency}}
???????
???
script.js:
function InvoiceCntl($scope) {
??? $scope.qty = 1;
??? $scope.cost = 19.95;
}
end-to-end test:
it('should show of angular binding', function() {
??? expect(binding('qty * cost')).toEqual('$19.95');
??? input('qty').enter('2');
??? input('cost').enter('5.00');
??? expect(binding('qty * cost')).toEqual('$10.00');
});
function InvoiceCntl($scope){$scope.qty = 1;$scope.cost = 19.95;}
運(yùn)行效果：
Invoice:
Quantity? Cost
Total: {{qty * cost | currency}}
試一下上面這個例子，然后我們一起來看下這個例子的工作原理。 在``標(biāo)簽里, 我們用一個`ng-app`標(biāo)識符標(biāo)明這是一個AngularJS應(yīng)用。這個`ng-app`標(biāo)識符會使AngularJS**自動初始化**(auto initialize)你的應(yīng)用。 我們用``標(biāo)簽來加載AngularJS腳本：
Hot AI Tools
Undress AI Tool
Undress images for free
Undresser.AI Undress
AI-powered app for creating realistic nude photos
AI Clothes Remover
Online AI tool for removing clothes from photos.
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
Java vs. JavaScript: Clearing Up the Confusion
Jun 20, 2025 am 12:27 AM
Java and JavaScript are different programming languages, each suitable for different application scenarios. Java is used for large enterprise and mobile application development, while JavaScript is mainly used for web page development.
Javascript Comments: short explanation
Jun 19, 2025 am 12:40 AM
JavaScriptcommentsareessentialformaintaining,reading,andguidingcodeexecution.1)Single-linecommentsareusedforquickexplanations.2)Multi-linecommentsexplaincomplexlogicorprovidedetaileddocumentation.3)Inlinecommentsclarifyspecificpartsofcode.Bestpractic
How to work with dates and times in js?
Jul 01, 2025 am 01:27 AM
The following points should be noted when processing dates and time in JavaScript: 1. There are many ways to create Date objects. It is recommended to use ISO format strings to ensure compatibility; 2. Get and set time information can be obtained and set methods, and note that the month starts from 0; 3. Manually formatting dates requires strings, and third-party libraries can also be used; 4. It is recommended to use libraries that support time zones, such as Luxon. Mastering these key points can effectively avoid common mistakes.
JavaScript vs. Java: A Comprehensive Comparison for Developers
Jun 20, 2025 am 12:21 AM
JavaScriptispreferredforwebdevelopment,whileJavaisbetterforlarge-scalebackendsystemsandAndroidapps.1)JavaScriptexcelsincreatinginteractivewebexperienceswithitsdynamicnatureandDOMmanipulation.2)Javaoffersstrongtypingandobject-orientedfeatures,idealfor
Why should you place tags at the bottom of the ?
Jul 02, 2025 am 01:22 AM
PlacingtagsatthebottomofablogpostorwebpageservespracticalpurposesforSEO,userexperience,anddesign.1.IthelpswithSEObyallowingsearchenginestoaccesskeyword-relevanttagswithoutclutteringthemaincontent.2.Itimprovesuserexperiencebykeepingthefocusonthearticl
JavaScript: Exploring Data Types for Efficient Coding
Jun 20, 2025 am 12:46 AM
JavaScripthassevenfundamentaldatatypes:number,string,boolean,undefined,null,object,andsymbol.1)Numbersuseadouble-precisionformat,usefulforwidevaluerangesbutbecautiouswithfloating-pointarithmetic.2)Stringsareimmutable,useefficientconcatenationmethodsf
What is event bubbling and capturing in the DOM?
Jul 02, 2025 am 01:19 AM
Event capture and bubble are two stages of event propagation in DOM. Capture is from the top layer to the target element, and bubble is from the target element to the top layer. 1. Event capture is implemented by setting the useCapture parameter of addEventListener to true; 2. Event bubble is the default behavior, useCapture is set to false or omitted; 3. Event propagation can be used to prevent event propagation; 4. Event bubbling supports event delegation to improve dynamic content processing efficiency; 5. Capture can be used to intercept events in advance, such as logging or error processing. Understanding these two phases helps to accurately control the timing and how JavaScript responds to user operations.
What's the Difference Between Java and JavaScript?
Jun 17, 2025 am 09:17 AM
Java and JavaScript are different programming languages. 1.Java is a statically typed and compiled language, suitable for enterprise applications and large systems. 2. JavaScript is a dynamic type and interpreted language, mainly used for web interaction and front-end development.
