What is the recommended (if there is one) future-proof way to write controllers, services and directives in ES6 (using Traceur) so that the most of same code can be used with AngularJS 2.0. I realize that AngularJS 2.0 is still on the drawing board but if I were to start a new app today what style or conventions do I follow so migrating to 2.0 will hopefully be less painful.
Declaring a class and then passing a reference to that class into the controller or service is one point i see:
var app = angular.module('myApp', []);
class MainCtrl {
....
}
class MyService {
....
}
app.controller('MainCtrl', MainCtrl);
app.service('MyService', MyService);
Should the MyService class be moved to a separate file so that potentially in the future I could just export it and have it available to be injected?
What are some other things to keep in mind as I work on a new project using AngularJS (<= 1.3.x) and ES6?
Update
After some digging around I wrote a series of blog posts talking about my findings on my blog
The angular team at ngEurope confirmed today that the $controllers, $scopes, $services and jqLite of 1.x will cease to exist in Angular 2.0. There will also be a brand new router, which they intend to backport to 1.3 in the coming months.
To prepare for migration they suggested just following the best practices/styles/conventions that have evolved in the community so far, and when 2.0 is ready (sometime next year), they'll work out the best way to migrate from there.
Also, they said that 1.3 will be fully supported for at least a year and a half after the release of 2.0.
You can define ES6 classes and add them in existing Angular 1.x applications. You will need to set up transpiling etc, but here is a general example:
class PersonService{
constructor(){
}
getPerson(){
return 'Jim Smith';
}
}
angular.module('app').value('PersonService', PersonService);
class GreetingService{
constructor(){
}
sayHello(){
return 'Hello from ES6!';
}
}
angular.module('app').service('GreetingService', GreetingService);
More details here: http://www.syntaxsuccess.com/viewarticle/552dc66f955de264e1fbbaee
Related
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Months ago, I decided to study Angular. When I was doing some advance and create some app using it, I realize that Angular 2 is in Developer preview, so it's a matter of time before it's going to be released. Because Angular 2 is not going to be compatible with Angular 1, and there are a lot of changes, the question is, is it better to continue developing with Angular 1.x or start developing Angular 2?
It's a fact that we don't always have to be using the latest version nor the newest language on the market, but in this case, the app is still small so I could change without problems.
Let me preface by saying, I'm assuming you and everyone who will be reading this is already comfortably with Angular 1 (now referred to as AngularJS, as opposed to simply Angular for the newer versions). That being said, let's get into some of the additions and key differences in Angular 2+.
They added an angular cli.
You can start a new project by running ng new [app name].
You can serve your project by running ng serve
learn more here: https://github.com/angular/angular-cli
Your angular code is written in ES6 Typescript and it compiles at runtime to Javascript in the browser.
To get a full grasp on this I recommend checking out some the resource list I have at the bottom of my answer.
Project Structure
In a basic structure, you will have a app/ts folder where you'll be doing most your work and a app/js You'll find in the app/js folder files with a .js.map extension. They "map" your ".ts" files to your browser for debugging as your browser cannot read native typescript.
Update: It's out of beta. The project structure changed a bit, in most cases and if you're using the angular cli, you'll be working in the
src/app/ folder. In a starter project, you'll have the following.
app.component.css
app.component.html
app.component.spec.ts
app.component.ts
app.module.ts
index.ts
app.component.css: CSS file you should use specific to the component.html
app.component.html: A view (variable declared in the app.component.js)
app.component.spec.ts: used for testing app.component.ts
app.component.ts: Your code that binds to app.component.html
app.module.ts: This it what kicks off your app and where you define all plugins, components, services, etc. This is the equivalent of the app.js in Angular 1
index.ts used to define or export project files
Additional information:
Pro tip: you can run ng generate [option] [name] to generate new services, components, pipes, etc.
Also the tsconfig.json file is important as it defines TS compile rules for your project.
If you're thinking I have to learn a whole new language?... Uh... kinda, TypeScript is a superset of JavaScript. Don't be intimidated; it's there to make your development easier. I felt like I had a good grasp on it after just a few hours playing with it, and had it all down after 3 days.
You bind to your HTML similarly like how you would if in an Angular 1 directive. So variable like $scope and $rootScope have been deprecated.
This one you may have been implied. Angular 2 is still a MV* but you'll be using 'components' as a way to bind code to your templates, for instance, take the following
import { Component } from '#angular/core';
#Component({
selector:'my-app',
template: '<h1> Hello World! </h1>'
})
export class AppComponent {}
Here think of the import statement as your dependency injection in a v1 controller. You use import to import your packages, where the import {Component} says you'll be making a component you'd like to bind to your HTML.
Notice the #Component decorator you have a selector and template. Here think of the selector as your $scope that you use like you use v1 directives where the name of the selector is what you use to bind to your HTML like so
<my-app> </my-app>
Where <my-app> is the name of your custom tag you'll use that will act as a placeholder for what's declared in your template. i.e.) <h1> Hello World! </h1>. Whereas this would look like the following in v1:
HTML
<h1>{{hello}}</h1>
JS
$scope.hello = "Hello World!"
Also can you add something between these tags to generate a loading message, like this:
<my-app> Loading... </my-app>
Then it will display "Loading..." as the loading message.
Note that what's declared in template is the path or the raw HTML you'll be using in your HTML in your selector tag.
A fuller implementation of Angular 1 would look more like this:
HTML
<h1 ng-controller="myCtrl">{{hello}}</h1>
In v1 this would look something like
JS
angular.module('controller', [])
.controller('myCtrl', function( $scope) {
$scope.hello = "Hello World!"
})
This is what I really like about v2. I found directive was a steep learning curve for me in v1 and even when I had them figured out I often had the CSS render not how I intended. I find this is way simpler.
V2 allows for easier scalability of your app since you can break up your app up easier than you could in v1. I like this approach as you can have all your working parts in one file as opposed to having several in angular v1.
What about converting your project from v1 to v2?
From what I've heard from the development team if you'd like to update your v1 project to v2 you'll just be going through and deleting deprecated blobs and replace your $scopes with selectors. I found this video helpful. It's with some of the Ionic team that are working side by side with the angular team as v2 has a stronger focus on mobile https://youtu.be/OZg4M_nWuIk
UPDATE: I updated by adding examples as official implementations of Angular 2 have surfaced.
UPDATE 2: This still seems to be a popular question so I just thought I'd some resource I found very helpful when I started working with angular 2.
#Helpful Resources:
For more on ES6, I recommend checking out The New Boston's ECMAScript 6 / ES6 New Features Tutorials - YouTube Playlist
To write Typescript functions and see how they compile to Javascript check out the Typescript language Playground
To see a function by function breakdown of what the Angular 1 equivalence is in Angular 2 see the Angular.io - Cookbook -A1 A2 Quick Reference
It might help you to understand the comparison of Angular 1 vs Angular 2.
The Angular 2 proved to have lots of benefits over Angular 1:
It is entirely component based.
Better change detection
Ahead of Time compilation (AOT) improves rendering speed.
TypeScript is primarily used for developing Angular 2 applications.
Angular 2 has better performance over Angular 1.
Angular 2 has a more powerful templating system than Angular 1.
Angular 2 has simpler APIs, lazy loading, easier debugging.
Angular 2 is much more testable than Angular 1.
Angular 2 provides nested components.
Angular 2 provides a way to execute more than two systems together.
And So On...
Angular 2 and Angular 1 is basically a different framework with the same name.
angular 2 is more ready for the current state of web standards and the future state of the web ( ES6\7, immutiablity, components, shadow DOM, service workers, mobile compatibilty, modules, typescript and so on and so on... )
angular 2 killed many main features in angular 1 like - controllers, $scope, directives (replaced with #component annotations), the module definition, and much more, even simple things like ng-repeat has not left the same as it was.
any way, change is good, angular 1.x had it flaws, and angular 2 is more ready for the future web requirements.
to sum things up - i do not recommend you to start an angular 1.x project now - this is probably the worst time to do so as you will have to migrate later to angular 2, i you set youre mind about angular than choose angular 2, google has already launched a project with angular 2, and by the time you finish the project angular 2 should already be in the spotlight.
if you want something stabler, you can think about react\elm and flux and redux as JS frameworks.
angular 2 is going to be awesome, that's for no doubt.
No framework is perfect. You can read about flaws in Angular 1 here and here. But that doesn't mean it is bad. The question is what problem are you solving. If you want to roll out a simple app quickly, which is lightweight, with limited data binding usage then go ahead with Angular 1. Angular 1 was built 6 years back to solve rapid prototyping which it does pretty well. Even if your use case is complex still you can use Angular 1 but then you should be aware of nuances and best practices around building a complex web app. If you are developing an app for learning purpose I would suggest to move to Angular 2 as that is where the future of Angular is.
The one stand-out feature in Angular v2 and also in ReactJs is that they both have embraced the new Web-Components architecture of development. What this means is that we can now create independent Web-Components and plug-and-play them to any website in the world that has the same technology stack of the this Web-Component. Cool! yeah very cool. :)
The other most prominent change in Angular v2 is that it's primary development language is none other than TypeScript. Although TypeScript belongs to Microsoft, and it is a superset of JavaScript of 2015 (or ECMAScript6/ES6), but it has some features that are very promising. I would recommend the readers to checkout TypeScript in a bit detail (which is fun of-course) after reading this tutorial.
Here I would say that the guys trying to interrelate Angular v1 and Angular v2 further confuse the readers, and in my humble opinion, Angular v1 and Angular v2 should be treated as two different frameworks. In Angular v2, we have Web-Components' concept of developing web applications, while in Angular v1 we have to play with Controllers, and (sadly or luckily) no controllers are present in Angular v2.
One thing to notice is angular2 is using typescript.
I did angular1 with cordova in my intern and now i am doing a angular 2. I think angular2 will be the trend as it more structured in my opinion but the cons is that there are few resources to refer when you have problem or difficulties. angular 1.x has tons of personalized directives that can be super easy to use.
Hope it helps.
Angular 2 is much better than 1, at least in what it offers: support for web components, using typescript, performance and overall simplicity of the interface, was the reason I decided to start a project using angular 2. However, from the get go, I realized there are issues in angular 2 (e.g. routing with apache) for which very little or no documentation is available, so the documentation and community of angular 2 is the biggest pitfall for angular 2, as it isn't developed enough.
I would say, if you need to raise a site quickly for a short deadline use the well known angular 1, if you're in a longer project, and can afford the time to investigate new issues (that you might be the first to encounter, which could be a bonus if you think of the contribution, you might give to the angular 2 community) than go with angular 2.
I have one situation come where i have two projects one is in AngularJS which is main project and one is in angular 8. Now, i want to import Angular8 project inside angularJS Project.
Can any one suggest me better way for this?How can i overcome from this problem?
The only possible way to start using A8 components/services etc. in an existing AngularJS project is ngUpgrade. Here is a detailed step-by-step explanation.
With ngUpgrade module you can downgrade an existing Angular component
angular.module('heroApp', [])
.directive(
'componentNameInAngularJS',
downgradeComponent({ component: ModernAngularComponent }) as angular.IDirectiveFactory
);
But you probably (I'm not sure, it depends on existing code base) should give up A8 routing and let AngularJS control the flow, until you completely replace all AngularJS components with modern Angular. You should consider such an option, cuz` AngularJS official support ends in 2021.
Our project is currently still running on AngularJS (v1.6) + TypeScript, but we want to start making the app ready to upgrade to the latest Angular, by implementing components, similar to how they are written in Angular. Currently we are not using imports or exports, but want to introduce this gradually. I.e. we would like to start using:
import * as angular from "angular";
import { MyComponentComponent } from './MyComponent.component';
export default angular
.module('myModule', [])
.component('myComponent', MyComponent);
instead of
angular
.module('myModule', [])
.component('myComponent', MyComponent);
Doing this however currently causes issues due to scope. Our app now has the global variable angular that everything gets attached to, while the import/export creates closures that inject a separate instance of angular, so the two aren't able to communicate.
Is there a way to to combine the two methods so that we can gradually upgrade the existing system?
Try to use NgUpgrade, it will upgrade your app to the latest version.
Have a look on https://angular.io/guide/upgrade
Using ngUpgrade to upgrade the angular is a very good suggestion. With the help of this, you can upgrade your existing angularjs project in a much more efficient way like converting the code side by side by running angularjs and angular code simultaneously. There are certain steps that you need to follow in order to perform migration successfully:
Installing dependencies for Angular and ngUpgrade.
Setup ngUpgrade for your project.
We are also currently in a process to migrate our angularjs project to angular. We have followed the below references for our migration. It will provide you a detailed overview of the process and hope it will help you in some way:
https://scotch.io/tutorials/get-started-with-ngupgrade-going-from-angularjs-to-angular
https://blog.angular.io/migrating-to-angular-fc9618d6fb04
https://medium.com/contentsquare-engineering-blog/angularjs-to-angular5-upgrading-a-large-application-7e6fbf70bafa
https://itnext.io/an-alternate-way-to-angular-migration-c7932cf05a1b
There are two ways (2 and 3 are similar but separate in action):
Rewriting the application (best way but difficult for huge applications)
Going to a hybrid state (e.g. upgrading without forking by having a
transitional hybrid app with both AngularJS and Angular 5). See AngularJS to Angular5 — Upgrading a large application
Migrating each module wise. See Migrating Angular 1 Applications to Latest Angular in 5 Simple Steps
I am migrating my app from Angular 1.X to Angular 2.0 and I am having thoughts about routing solution while / after migration process.
I am currently using ui-router, with resolve in order to pass data for each route.
After some reading I came across this post. As far as I understand, there is no resolve in the new router. I now have two choices:
Continue using my current ui-router with my hybrid ng1-2 app (is it possible?), and bring each route's data via router's resolve. Will it work?
Change routing and use the new Component Router. This will make the step-by-step upgrade harder, because I will have to change my current Angular 1.X data fetching to be inside each controller / directive + I won't have Angular 2's #CanActivate which will wait for data to be resolved.
Which option is better? Is there another option? What will work here?
Thanks!
I encountered the same issue at work. I tried many things, but in the end I used a service:
var data = {
'foo': 'bar'
}
export const StateData = {
data: data
};
So now at the top of my component I can import the service:
import { StateData } from '/services/StateService.ts';
Then I can set and get data from the service by simply doing:
StateData.data.foo = "something other than bar"
Now when you switch routes, you can retrieve the new updated data within the constructor() or afterViewInit() methods.
*An added bonus of using the StateService is that you can bind your data between all components by simply adding the following method (you can name it whatever):
getStateData(key) {
return StateData.data[key];
}
You can call this method from the dom itself by doing the following:
{{getStateData('foo')}} --> will print out the value "bar"
Now if you change the value of foo within the service in a different component, it will change in the dom, since getStateData() is called whenever a change occurs and the service only loads once on page load.
I believe the init and afterViewInit methods are the reason as to why they have not added resolve to the new router, or maybe they still haven't released the version with it yet.
I hope this helps you out. I do not think using Angular 1.x + Angular 2.0 would be easy, nor would it be fun lol
I recently rebuilt my personal site in angular 2.0. The code is public, so you can check it out. If you look at contactCard.ts, contact-card.html and StateService.ts you can see it in action. Here is the repo:
https://github.com/YashYash/portfolio
Closed. This question is opinion-based. It is not currently accepting answers.
Want to improve this question? Update the question so it can be answered with facts and citations by editing this post.
Closed 6 years ago.
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Months ago, I decided to study Angular. When I was doing some advance and create some app using it, I realize that Angular 2 is in Developer preview, so it's a matter of time before it's going to be released. Because Angular 2 is not going to be compatible with Angular 1, and there are a lot of changes, the question is, is it better to continue developing with Angular 1.x or start developing Angular 2?
It's a fact that we don't always have to be using the latest version nor the newest language on the market, but in this case, the app is still small so I could change without problems.
Let me preface by saying, I'm assuming you and everyone who will be reading this is already comfortably with Angular 1 (now referred to as AngularJS, as opposed to simply Angular for the newer versions). That being said, let's get into some of the additions and key differences in Angular 2+.
They added an angular cli.
You can start a new project by running ng new [app name].
You can serve your project by running ng serve
learn more here: https://github.com/angular/angular-cli
Your angular code is written in ES6 Typescript and it compiles at runtime to Javascript in the browser.
To get a full grasp on this I recommend checking out some the resource list I have at the bottom of my answer.
Project Structure
In a basic structure, you will have a app/ts folder where you'll be doing most your work and a app/js You'll find in the app/js folder files with a .js.map extension. They "map" your ".ts" files to your browser for debugging as your browser cannot read native typescript.
Update: It's out of beta. The project structure changed a bit, in most cases and if you're using the angular cli, you'll be working in the
src/app/ folder. In a starter project, you'll have the following.
app.component.css
app.component.html
app.component.spec.ts
app.component.ts
app.module.ts
index.ts
app.component.css: CSS file you should use specific to the component.html
app.component.html: A view (variable declared in the app.component.js)
app.component.spec.ts: used for testing app.component.ts
app.component.ts: Your code that binds to app.component.html
app.module.ts: This it what kicks off your app and where you define all plugins, components, services, etc. This is the equivalent of the app.js in Angular 1
index.ts used to define or export project files
Additional information:
Pro tip: you can run ng generate [option] [name] to generate new services, components, pipes, etc.
Also the tsconfig.json file is important as it defines TS compile rules for your project.
If you're thinking I have to learn a whole new language?... Uh... kinda, TypeScript is a superset of JavaScript. Don't be intimidated; it's there to make your development easier. I felt like I had a good grasp on it after just a few hours playing with it, and had it all down after 3 days.
You bind to your HTML similarly like how you would if in an Angular 1 directive. So variable like $scope and $rootScope have been deprecated.
This one you may have been implied. Angular 2 is still a MV* but you'll be using 'components' as a way to bind code to your templates, for instance, take the following
import { Component } from '#angular/core';
#Component({
selector:'my-app',
template: '<h1> Hello World! </h1>'
})
export class AppComponent {}
Here think of the import statement as your dependency injection in a v1 controller. You use import to import your packages, where the import {Component} says you'll be making a component you'd like to bind to your HTML.
Notice the #Component decorator you have a selector and template. Here think of the selector as your $scope that you use like you use v1 directives where the name of the selector is what you use to bind to your HTML like so
<my-app> </my-app>
Where <my-app> is the name of your custom tag you'll use that will act as a placeholder for what's declared in your template. i.e.) <h1> Hello World! </h1>. Whereas this would look like the following in v1:
HTML
<h1>{{hello}}</h1>
JS
$scope.hello = "Hello World!"
Also can you add something between these tags to generate a loading message, like this:
<my-app> Loading... </my-app>
Then it will display "Loading..." as the loading message.
Note that what's declared in template is the path or the raw HTML you'll be using in your HTML in your selector tag.
A fuller implementation of Angular 1 would look more like this:
HTML
<h1 ng-controller="myCtrl">{{hello}}</h1>
In v1 this would look something like
JS
angular.module('controller', [])
.controller('myCtrl', function( $scope) {
$scope.hello = "Hello World!"
})
This is what I really like about v2. I found directive was a steep learning curve for me in v1 and even when I had them figured out I often had the CSS render not how I intended. I find this is way simpler.
V2 allows for easier scalability of your app since you can break up your app up easier than you could in v1. I like this approach as you can have all your working parts in one file as opposed to having several in angular v1.
What about converting your project from v1 to v2?
From what I've heard from the development team if you'd like to update your v1 project to v2 you'll just be going through and deleting deprecated blobs and replace your $scopes with selectors. I found this video helpful. It's with some of the Ionic team that are working side by side with the angular team as v2 has a stronger focus on mobile https://youtu.be/OZg4M_nWuIk
UPDATE: I updated by adding examples as official implementations of Angular 2 have surfaced.
UPDATE 2: This still seems to be a popular question so I just thought I'd some resource I found very helpful when I started working with angular 2.
#Helpful Resources:
For more on ES6, I recommend checking out The New Boston's ECMAScript 6 / ES6 New Features Tutorials - YouTube Playlist
To write Typescript functions and see how they compile to Javascript check out the Typescript language Playground
To see a function by function breakdown of what the Angular 1 equivalence is in Angular 2 see the Angular.io - Cookbook -A1 A2 Quick Reference
It might help you to understand the comparison of Angular 1 vs Angular 2.
The Angular 2 proved to have lots of benefits over Angular 1:
It is entirely component based.
Better change detection
Ahead of Time compilation (AOT) improves rendering speed.
TypeScript is primarily used for developing Angular 2 applications.
Angular 2 has better performance over Angular 1.
Angular 2 has a more powerful templating system than Angular 1.
Angular 2 has simpler APIs, lazy loading, easier debugging.
Angular 2 is much more testable than Angular 1.
Angular 2 provides nested components.
Angular 2 provides a way to execute more than two systems together.
And So On...
Angular 2 and Angular 1 is basically a different framework with the same name.
angular 2 is more ready for the current state of web standards and the future state of the web ( ES6\7, immutiablity, components, shadow DOM, service workers, mobile compatibilty, modules, typescript and so on and so on... )
angular 2 killed many main features in angular 1 like - controllers, $scope, directives (replaced with #component annotations), the module definition, and much more, even simple things like ng-repeat has not left the same as it was.
any way, change is good, angular 1.x had it flaws, and angular 2 is more ready for the future web requirements.
to sum things up - i do not recommend you to start an angular 1.x project now - this is probably the worst time to do so as you will have to migrate later to angular 2, i you set youre mind about angular than choose angular 2, google has already launched a project with angular 2, and by the time you finish the project angular 2 should already be in the spotlight.
if you want something stabler, you can think about react\elm and flux and redux as JS frameworks.
angular 2 is going to be awesome, that's for no doubt.
No framework is perfect. You can read about flaws in Angular 1 here and here. But that doesn't mean it is bad. The question is what problem are you solving. If you want to roll out a simple app quickly, which is lightweight, with limited data binding usage then go ahead with Angular 1. Angular 1 was built 6 years back to solve rapid prototyping which it does pretty well. Even if your use case is complex still you can use Angular 1 but then you should be aware of nuances and best practices around building a complex web app. If you are developing an app for learning purpose I would suggest to move to Angular 2 as that is where the future of Angular is.
The one stand-out feature in Angular v2 and also in ReactJs is that they both have embraced the new Web-Components architecture of development. What this means is that we can now create independent Web-Components and plug-and-play them to any website in the world that has the same technology stack of the this Web-Component. Cool! yeah very cool. :)
The other most prominent change in Angular v2 is that it's primary development language is none other than TypeScript. Although TypeScript belongs to Microsoft, and it is a superset of JavaScript of 2015 (or ECMAScript6/ES6), but it has some features that are very promising. I would recommend the readers to checkout TypeScript in a bit detail (which is fun of-course) after reading this tutorial.
Here I would say that the guys trying to interrelate Angular v1 and Angular v2 further confuse the readers, and in my humble opinion, Angular v1 and Angular v2 should be treated as two different frameworks. In Angular v2, we have Web-Components' concept of developing web applications, while in Angular v1 we have to play with Controllers, and (sadly or luckily) no controllers are present in Angular v2.
One thing to notice is angular2 is using typescript.
I did angular1 with cordova in my intern and now i am doing a angular 2. I think angular2 will be the trend as it more structured in my opinion but the cons is that there are few resources to refer when you have problem or difficulties. angular 1.x has tons of personalized directives that can be super easy to use.
Hope it helps.
Angular 2 is much better than 1, at least in what it offers: support for web components, using typescript, performance and overall simplicity of the interface, was the reason I decided to start a project using angular 2. However, from the get go, I realized there are issues in angular 2 (e.g. routing with apache) for which very little or no documentation is available, so the documentation and community of angular 2 is the biggest pitfall for angular 2, as it isn't developed enough.
I would say, if you need to raise a site quickly for a short deadline use the well known angular 1, if you're in a longer project, and can afford the time to investigate new issues (that you might be the first to encounter, which could be a bonus if you think of the contribution, you might give to the angular 2 community) than go with angular 2.