How do front end devs bundle and minify files? - javascript

What's the best practice for minifying and bundling js/css in a pure front end app, and how do the tools work?
I know how this can be done with server side apps like .NET/Java/LAMP/etc. But what about pure front end projects, SPA projects or backendless projects that are built with say, ember or angular these days? Say your entire project consists of HTML/css/js, which interfaces with a RESTful service elsewhere.
What kind of process or tool do you use to minify and bundle the resources for that?
I've seen grunt plugins that exist for this, but I find the documentation to be pretty magical and it's still unclear to me how they work.
Specifically, does the tool:
1) Replace src="/js/a.js",src="/js/b.js" with src="/js/bundle-a+b.min.js"? (and likewise with css?) in the source html files?
2) have different modes for dev and release, or is the tool only run when the project is released?
Or are the resource requests entirely managed by a js tool and js/css files have to be requested via a library function? Wouldn't the lag be noticeable in this case?
Thanks.

Through the use of Build tools front end devs can have minified javascript, css, or even images and html files automatically minified as they develop. The most common is grunt, with gulp close behind.
You configure grunt tasks, like grunt-contrib-uglify and grunt-contrib-copy, and put those tasks under a grunt-contrib-watch task. Have the grunt watch task watch the files you modify, and every time a change is detected those .min files are automatically generated.
These build tools have no impact on your application, they are run before the files are servered. You were correct to assume there was an easy way to do this. I suggest you look at grunt getting started, a sample gruntfile, or a project that uses grunt - here's mine, it does minification like you requested. Clone my repo, run sudo npm install, then sudo grunt. I don't have watch set up in my project but grunt is very well documented.

Related

Version control strategy for webpack-encore project

I'm learning to use webpack-encore and noticed it is installed only as a dev dependency. Does that mean I should compile my js and css files on development and push them to the repository, and then to production?
That seems to me what the docs are implying, but wouldn't that mean a merge-conflict hell? Compiled files would be impossible to merge.
Also wouldn't that be contrary to version control philosophy? As far as I know, you don't publish binaries in compiled languages (i.e. C/C++), you push the code and expect the server to compile them. I know this isn't the same type of "compilation" in javascript, but what is the expected behavior of the production server in this case? To receive the files ready to serve them, or to compile them at the time of release?
Thanks in advance
Does that mean I should compile my js and css files on development and push them to the repository, and then to production?
Not exactly - it depends on how you deploy.
When you deploy, you need to run ./node_modules/.bin/encore production to build your assets. Once you've done this, only your built assets (e.g. web/build) need to be transferred to production.
You could run this command locally (or on some "build" server) and the transfer all the files to production. Or, you could use a git pull on production, and then run this command on production (the downside being that you would need Node.js installed on production).
You shouldn't / don't need to commit your built files to your repository. But... if it simplifies your deploy (i.e. you want to do a git pull and be done), there's no real problem with that.
I just added a PR to answer these in the FAQ (http://symfony.com/doc/current/frontend/encore/faq.html) - here's the PR until it's deployed: https://github.com/symfony/symfony-docs/pull/8109
Cheers!
Solution 1:
Run yarn run encore production locally
Check out which files have been created / modified
Add them to VCS
Commit
Push / deploy
Solution 2:
Push / deploy
Run yarn run encore production remotely during deployment
To my eyes the 2nd solution is way better, because you don't need an extra human-checking before deployment, everything is automated.
But this has a strong drawback: building assets can be a slow process, and when I deploy, my production is down during 5 to 20 seconds until assets are built.
Here's the HTTP 500 error:
An exception has been thrown during the rendering of a template ("Asset manifest file "[...]/web/build/manifest.json" does not exist.").
It looks like the manifest.json file is deleted at the beginning of the process, and created from scratch later on.
Something that should be improved?

What is "npm run build" in create-react-app?

I could not find any explanation regarding the work of "npm run build",
It is simple and easy to use and i get the "build" folder that works great,
But, in create-react-app, what happens exactly behind the scene?
Is it a complete different use of a build tool?
If not, is it utilizing other build tools?
Developers often break JavaScript and CSS out into separate files. Separate files let you focus on writing more modular chunks of code that do one single thing. Files that do one thing decrease your cognitive load as maintaining them is a quite cumbersome task.
What happens exactly behind the scene?
When it’s time to move your app to production, having multiple JavaScript or CSS files isn’t ideal. When a user visits your site, each of your files will require an additional HTTP request, making your site slower to load.
So to remedy this, you can create a “build” of our app, which merges all your CSS files into one file, and does the same with your JavaScript. This way, you minimize the number and size of files the user gets. To create this “build”, you use a “build tool”. Hence the use of npm run build.
As you have rightly mentioned that running the command (npm run build) creates you a build directory. Now suppose you have a bunch of CSS and JS files in your app:
css/
mpp.css
design.css
visuals.css
...
js/
service.js
validator.js
container.js
...
After you run npm run build your build directory will be:
build/
static/
css/
main.css
js/
main.js
Now your app has very few files. The app is still the same but got compacted to a small package called build.
Final Verdict:
You might wonder why a build is even worth it, if all it does is save your users a few milliseconds of load time. Well, if you’re making a site just for yourself or a few other people, you don’t have to bother with this. Generating a build of your project is only necessary for high traffic sites (or sites that you hope will be high traffic soon).
If you’re just learning development, or only making sites with very low traffic, generating a build might not be worth your time.
It's briefly explained here: https://github.com/facebookincubator/create-react-app#npm-run-build-or-yarn-build.
It correctly bundles React in production mode and optimizes the build for the best performance.
The build is minified and the filenames include the hashes.
Behind the scenes, it uses babel to transpile your code and webpack as the build tool to bundle up your application.

Any good idea or software in obfuscating my ASP.NET framework 4 application?

For about 2 weeks i have been surfing the internet for finding any idea or a software to help me obfuscating my asp project i couldn't find any helpful way cause my main need is to obfuscate the .JS files in my project and i didn't find any build in tool for VS2010, cause i want to have an automated build including obfuscating however i have also tried searching a tool for javascript files obfuscating including a command line way to communicate with the tool so i can call it in pre build event.
also if you can explain for me how to handle the injected javascript code in my c# code or no need to do this step.
I really appreciate your helps.
Actually there is a plenty of different way to obfuscating javascript. One of the best solution is gulp
Gulp is a task/build runner for development. It allows you to do a lot of stuff within your development workflow. You can compile sass files, uglify and compress js files and much more. The kicker for gulp is that its a streaming build system which doesn't write temp files.
It's really usefull tool to static files management. I suggest you to dive into it.
For example; lets look at following gulp definitian.
elixir(function(mix) {
mix.styles([
"font.css",
"bootstrap.css",
"custom.css"
], 'public/css/production.css').
scripts([
"jquery-2.2.4.min.js",
"bootstrap.min.js",
"app.js"
], 'public/js/production.js')
});
It concatenates font.css, bootstrap.css and custom.css files in order. And same for js files.Then performs compression and obfuscation.
You just need to run gulp --production for that.
There is a very good detailed documentation about using gulp with asp.net.
https://docs.asp.net/en/latest/client-side/using-gulp.html

How to set up a ASP.NET API / AngularJS project

I am starting my own Angular web application. I have experience coding in c# and angular but I have never had to set up my own project/solution. In this case, I would like to set up an ASP.NET Web API that will communicate to an Angular SPA front end in JSON (although it should be agnostic to the front end, any application that speaks JSON should be able to communicate with it).
Additionally, I have heard good things about grunt and so I would like to incorporate it into the project (at the very least to compile LESS and minify and combine my angular files).
I am working with visual studio professional 2013. I began by creating a Web API project and downloading the WebEssentials plugin.
I am just a little confused on how to continue here. Should I split out my angular into a separate project in the same solution? How do I include grunt?
How do I use grunt in the context of visual studio to include my angular files in my index.html file?
The project comes with a Scripts folder and a Views folder. I know that it is preferable to structure the angular files by function so that the controllers and views are housed together. Should I be including my views in the scripts folder? How does that affect my build procedure?
I realize these may be very naive questions. Please bear with me, I am a complete beginner when it comes to these kinds of tasks. All I have done in the past is basically code.
Let's go step by step:
Visual Studio Solution with Web Api and Angular JS
You can store both Web Api and Angular code in same solution and project.
In this case you can arrange structure like this:
Content
Controllers
Models
Scripts (with app/ folder and vendor scripts like angular, jquery, etc.)
Views
index.html for angular application you can put into Scripts/app folder.
And all views for Angular you can put into Scripts/app/views folder.
Using Grunt/Gulp
Grunt/Gulp/Cake/Broccoli - those tools are simply an a javascript task runners, which allows you to to various things like combine your vendor scripts into one file, minify and combine your scripts into one file, transform your LESS to CSS, etc.
To use those task runners you can use Project Build Events. In project build events you can run Grant/Gulp tasks, which will do all the magic for you.
Also there is an extension for Visual Studio called Task Runner. This extension lets you execute any Grunt/Gulp task or target inside Visual Studio by adding a Task Runner Explorer window.
Example of using Gulp in Visual Studio Project by using Task Runner
To run your Gulp tasks by Task Runner automatically you need to add a line into start of your gulpfile.js
/// <vs AfterBuild='<here is a name of your Gulp task>' />
This line will force your task to run after each rebuild of your project.
Useful Info
To get additional info about Apps with AngularJS on ASP.NET you can check video by John Papa: "Building Rich Apps with AngularJS on ASP.NET"
Usefull Gulp modules:
gulp-useref - Parse build blocks in HTML files to replace references to non-optimized scripts or stylesheets.
gulp-less - Less for Gulp.
gulp-uglify - Minify files with UglifyJS.

Dependency management and build tool for JavaScript

I have many JS snippets and files shared across multiple projects. I have to either copy-past them into a single file for each project, or serve them as individual files on cdn. Both are bad ideas.
Is there any dependency management and build tool like Maven for JavaScript? Ideally it would take a set of js dependencies and build a single js file which can be served on cdn.
I can write a script to do that. But I'm looking to find if anything comparable to Maven exists for JS.
Update 2014: Based on answers here and my research following are most popular tools:
Bower, NPM, RequireJS, Browserify, Webpack, Grunt, Gulp
There's RequireJS, but that's kind of a different thing than Maven, and what you're asking it to do is different than Maven too. There are any number of JS combiner/minifiers, like jekyll-combiner and a zillion others.
If you're using Maven, the JavaScript Maven Tools might be of interest. If you're not, I don't know of a unified way to specifiy, download, combine, etc. for arbitrary build systems. Some of the node.js stuff might be useful, but I've never used that outside of a node.js context, so I'm not sure.
http://webjars.org/ packages JS libraries as JAR files and makes them available under Maven.
RequireJS is not a replacement to WebJars; it complements it.RequireJS will use public JS files (on CDNs) at runtime, whereas Webjars will download the necessary files at build-time and have you host them yourself.
Because most JS files are not hosted on CDNs, I use Webjars to download the necessary JS files at build-time, and reference them using RequireJS. That way I get the best of both worlds.
Take a look to grunt. It's very flexible build tool for javascript projects. Used by jquery team and other big projects. It combine, minify, test, lint js files, wtitten in javascript, have dozens plugins for whatever you want

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