We Keep Coding

Importing old library which imports its modules

In our company we have a library, that is divided into modules. These modules are in separate files and each of this modules have it's dependencies on other modules. Each module has a definition function, which registers it for other modules to use it later and also it can require other modules in its definition function. The require is similar to angular:
modules.require(['authentication', 'data', 'http'], module => console.log('Here is my module: ', module).
The library has a Synchronizer class, which based on this require in each module, handles importing and providing of the required modules. When a module has not yet been required, it creates a <script> tag, set it's src to the required module file and appends it to the body.
Here is the problem, because if I just import the main file of my library and try to require some module, it appends a <script> tag but the path to the file is not correct, because it is all bundled together by webpack.
Is there a way in webpack, to state, that this folder (folder with the plugin) should remain as is, so that I can then make requests to the individual files in this folder?
I have tried using "import" statement, "require" and also I tried to change the library into npm package, but I am not really allowed to change the library, because it has been tested in this format. So keeping the library as is, would be the best.
For example if I put this library into:
./static/js/mylibrary
then our library can produce for modules.require(['data'], onSuccess) a <script> tag with src like:
./static/js/mylibrary/data.js
Can I setup webpack so that the file stays there? In development? In production?
I am using a project created by vue-cli

As I mentioned in the comment simply putting it to the "public" directory in webpack did the trick for both, development and production. Don't know why I didn't try this before.

Make pdf.js 1.5 and require.js play nice together

In my project I have long used require.js together with the pdf.js library. Pdf.js have until recently been putting itself on the global object. I could still use it in my requirejs config by using a shim. The pdfjs library will in turn load another library called pdf.worker. In order to find this module the solution was to add a property to the global PDFJS object called workerSrc and point to the file on disk. This could be done before or after loading the pdfjs library.
The pdfjs library uses the pdf.worker to start a WebWorker and to do so it needs the path to a source file.
When I tried to update the pdfjs library in my project to a new version (1.5.314) the way to load and include the library have changed to use UMD modules and now everything get's a bit tricky.
The pdfjs library checks if the environment is using requirejs and so it defines itself as a module named "pdfjs-dist/build/pdf". When this module loads it checks for a module named "pdfjs-dist/build/pdf.worker". Since I have another folder structure I have added them to my requirejs config object with a new path:
paths: {
"pdfjs-dist/build/pdf": "vendor/pdfjs/build/pdf",
"pdfjs-dist/build/pdf.worker": "vendor/pdfjs/build/pdf.worker"
}
This is to make the module loader to find the modules at all. In development this works great. When I try to use the requirejs optimizer in my grunt build step however, it will put all of my project files into one single file. This step will try to include the pdf.worker module as well and this generates an error:
Error: Cannot uglify2 file: vendor/pdfjs/build/pdf.worker.js. Skipping
it. Error is: RangeError: Maximum call stack size exceeded
Since the worker source needs to be in a single file on disk I don't want this module to be included.
So I've tried two different config-settings in the requirejs config.
The first attempt was to override the paths property in my grunt build options:
paths: {
"pdfjs-dist/build/pdf.worker": "empty:"
}
The second thing to test is to exclude it from my module:
modules: [{
name: "core/app",
exclude: [
"pdfjs-dist/build/pdf.worker"
]
}]
Both techniques should tell the optimizer not to include the module but both attempts ended up with the same error as before. The requirejs optimizer still tries to include the module into the build and the attempt to uglify it ends up with a RangeError.
One could argue that since the uglify step fails it will not be included and I can go about my bussiness, but if the uglify step should happen to start working at a new update of pdfjs - what then?
Can anyone help me figure out why the requirejs config won't just exclude it in the build step and how to make it do so.

I found out what the core of my problem was and now I have a way to solve the problem and make my build process to work. My build step in grunt is using grunt-contrib-requirejs and I needed to override some options in the config for this job.
I didn't want the pdf.worker module to be included in my concatenated and minified production code.
I didn't want r.js to minify it only to later exclude it from the concatenated file.
I tried to solve the first problem thinking that it would mean that the second problem also should be solved. When I figured out the two were separate I finally found a solution.
In the r.js example on github there is a property named fileExclusionRegExp. This is what I now use to tell r.js not to copy the file over to the build folder.
fileExclusionRegExp: /pdf.worker.js/
Second, I need to tell the optimizer to not include this module in the concatenated file. This is done by overriding the paths property for this module to the value of "empty:".
paths: {
"pdfjs-dist/build/pdf.worker": "empty:"
}
Now my grunt build step will work without errors and all is well.
Thanks to async5 for informing me about the bug with uglify and the pdf.worker. The workaround is applied in another grunt task that uglify the worker and copies it into the build-folder separately. The options object for the grunt-contrib-uglify task will need this property in order to not break the pdf.worker file:
compress: {
sequences: false
}
Now my project works great when built for production.

Assemble every module into a single .js file

I want to minimize the number of HTTP requests from the client to load scripts in the browser. This is going to be a pretty general question but I still hope I can get some answers because module management in javascript has been a pain so far.
Current situation
Right now, in development, each module is requested individually from the main html template, like this:
<script src="/libraries/jquery.js"></script>
<script src="/controllers/controllername.js"></script>
...
The server runs on Node.js and sends the scripts as they are requested.
Obviously this is the least optimal way of doing so, since all the models, collections, etc. are also separated into their own files which translates into numerous different requests.
As far as research goes
The libraries I have come across (RequireJS using AMD and CommonJS) can request modules from within the main .js file sent to the client, but require a lot of additional work to make each module compliant with each library:
;(function(factory){
if (typeof define === 'function' && define.amd) define([], factory);
else factory();
}(function(){
// Module code
exports = moduleName;
}));
My goal
I'd like to create a single file on the server that 'concatenates' all the modules together. If I can do so without having to add more code to the already existing modules that would be perfect. Then I can simply serve that single file to the client when it is requested.
Is this possible?
Additionally, if I do manage to build a single file, should I include the open source libraries in it (jQuery, Angular.js, etc.) or request them from an external cdn on the client side?

What you are asking to do, from what I can tell, is concat your js files into one file and then in your main.html you would have this
<script src="/pathLocation/allMyJSFiles.js"></script>
If my assumption is correct, then the answer would be to use one of the two following items
GULP link or GRUNT link
I use GULP.
You can either use gulp on a case by case basis, which means calling gulp from the command line to execute gulp code, or use a watch to do it automatically on save.
Besides getting gulp to work and including the gulp files you need to do what you need, I will only provide a little of what I use to get your answer.
In my gulp file I would have something like this
var gulp = require('gulp');
var concat = require('gulp-concat');
...maybe more.
Then I have the file paths I need to be reduced into one file.
var onlyProductionJS = [
'public/application.js',
'public/directives/**/*.js',
'public/controllers/**/*.js',
'public/factories/**/*.js',
'public/filters/**/*.js',
'public/services/**/*.js',
'public/routes.js'
];
and I use this info in a gulp task like the one below
gulp.task('makeOneFileToRuleThemAll', function(){
return gulp.src(onlyProductionJS)
.pipe(concat('weHaveTheRing.js'))
.pipe(gulp.dest('public/'));
});
I then run the task in my command line by calling
gulp makeOneFileToRuleThemAll
This call runs the associated gulp task which uses 'gulp-concat' to get all the files together into one new file called 'weHaveTheRing.js' and creates that file in the destination 'public/'
Then just include that new file into your main.html
<script src="/pathLocation/weHaveTheRing.js"></script>
As for including all your files into one file, including your vendor files, just make sure that your vendor code runs first. It's probably best to keep those separate unless you have a sure fire way of getting your vendor code to load first without any issues.
UPDATE
Here is my gulp watch task.
gulp.task('startTheWatchingEye', function () {
gulp.watch(productionScripts, ['makeOneFileToRuleThemAll']);
});
Then I start up my server like this (yours may differ)
npm start
// in a different terminal window I then type
gulp startTheWatchfuleye
NOTE: you can use ANY movie or show reference you wish! :)
Now just code it up, every time you make a change in the specified files GULP will run your task(s).
If you want to say run Karma for your test runner...
add the following to your gulp file
var karma = require('karma').server;
gulp.task('karma', function(done){
karma.start({
configFile: __dirname + '/karma.conf.js'
}, done);
});
Then add this task karma to your watch I stated above like this...
gulp.task('startTheWatchingEye', function(){
gulp.watch(productionScripts, ['makeOneFileToRuleThemAll', 'karma']);
});
ALSO
Your specific settings may require a few more gulp modules. Usually, you install Gulp globally, as well as each module. Then use them in your various projects. Just make sure that your project's package.json has the gulp modules you need in dev or whatever.
There are different articles on whether to use Gulp or Grunt. Gulp was made after Grunt with a few additions that Grunt was lacking. I don't know if Grunt lacks them anymore. I like Gulp a lot though and find it very useful with a lot of documentation.
Good luck!

I'd like to create a single file on the server that 'concatenates' all the modules together. If I can do so without having to add more code to the already existing modules that would be perfect.
Sure you can. You can use Grunt or Gulp to do that, more specifically grunt-contrib-concat or gulp-concat
Here's an example of a Gruntfile.js configuration to concat every file under a js directory:
grunt.initConfig({
concat: {
dist: {
files: {
'dist/built.js': ['js/**/**.js'],
},
},
},
});
Also, you can minify everything after concatenating, using grunt-contrib-minify.
Both libraries support source maps so, in the case a bug gets to production, you can easily debug.
You can also minify your HTML files using grunt-contrib-htmlmin.
There's also an extremely useful library called grunt-usemin. Usemin let's you use HTML comments to "control" which files get minified (so you don't have to manually add them).
The drawback is that you have to explicitely include them in your HTML via script tags, so no async loading via javascript (with RequireJS for instance).
Additionally, if I do manage to build a single file, should I include the open source libraries in it (jQuery, Angular.js, etc.) or request them from an external cdn on the client side?
That's debatable. Both have pros and cons. Concatenating vendors assures that, if for some reason, the CDN isn't available, your page works as intended. However the file served is bigger so you consume more bandwidth.
In my personal experience, I tend to include vendor libraries that are absolutely essential for the page to run such as AngularJS for instance.

If I understand you correctly, you could use a task runner such as Grunt to concatenate the files for you.
Have a look at the Grunt Concat plugin.
Example configuration from the docs:
// Project configuration.
grunt.initConfig({
concat: {
dist: {
src: ['src/intro.js', 'src/project.js', 'src/outro.js'],
dest: 'dist/built.js',
}
}
});
Otherwise, as you have stated, a 'module loader' system such as Require JS or Browserify may be the way to go.

How to use gulp to build JavaScript bundles?

I want to use gulp to build bundles of JavaScript files.
For example I have the following structure in my project:
/vendor/vendor1/vendor1.js
/vendor/vendor2/vendor2.js
/js/includes/include1.js
/js/includes/include2.js
/js/bundle1.js
/js/bundle2.js
There are vendor includes (1-2), local includes (3-4), and bundle files (5-6).
Vendor includes are just third-party JavaScript libraries installed with bower or composer. They can be CommonJS, AMD or just a plain-old jQuery plugins.
I want to specify dependencies inside of a bundle files like this:
/js/bundle1.js
(function() {
// Vendor includes.
include('vendor1');
include('vendor2');
// Local includes.
include('includes/include1.js');
include('includes/include2.js');
// Some code here.
})();
I want gulp to process this source file and create a final distribution file (bundle) ensuring that all dependencies (includes) are merged together in a single file. So I can include foo.js from my HTML and all dependencies will be available to it.
I want to have a clear and robust system to manage all dependencies inside of a project and build distribution files.
How can I achieve this?
What format should I use for my own scripts (AMD, CommonJS, other)?
How do I specify dependencies in my source bundle files?
How do I build distribution?

Your question is posed as if there's a single answer, but there isn't. The problem you're trying to solve is one that many people have solved in many different ways, and you've identified two of the major options: AMD and CommonJS. There are other ways, but given that you might be new to Javascript dependency management as well as gulp, I'd recommend going with something that's relatively straightforward (even though this subject is inherently not straightforward).
I think the easiest route for you might be:
use CommonJS to express the dependencies
use browserify to resolve them into bundles
in browserify, use the "UMD" method so that you get a single bundle that will work for apps that use either AMD or CommonJS or are not using either of these dependency management systems
The statement in gulp to run browserify as such might look something like:
var browserify = require('gulp-browserify');
gulp.src('bundles/bundle1.js', {read: false})
.pipe(browserify({
'standalone': true
})
.pipe(rename('bundle1Output.js'))
.pipe(gulp.dest('dist'));
That should give you a dist/bundle1Output.js file.

There is a gulp plugin for this:
https://www.npmjs.com/package/gulp-include
It should do what you want, except that in your bundle file instead of this:
(function() {
// Vendor includes.
include('vendor1');
include('vendor2');
// Local includes.
include('includes/include1.js');
include('includes/include2.js');
// Some code here.
})();
You would have to write:
//=require vendor1/**/*.js
//=require vendor2/**/*.js
//=require includes/include1.js
//=require includes/include2.js
// Some code here

How to include minified library version in RequireJS optimization

My situation is as follows:
My project based on RequireJS.
I am using RequireJS Optimizer for to create a single JS file.
Some of the module use a certain third party library as a dependency.
The third party is NOT included in the optimized file (libName: empty
in the build config).
RequireJS is configured through var require = {} object which appears
on EACH PAGE, right above the RequireJS. The object defines a path to
the unminifed version of the library, among other things.
What i'd like to achieve:
Use the same config file in both development and production (the require={} object is included with tag on each page). During development I'd like modules to use the UNMINIFIED version of the third party.However, after optimization occurs, i would like all the modules to use the minified version of that third party.
I did think of a solution in theory, but it seems a bit messy and Im hopeful cleaner solution exists:
To have the runtime config point to unminified version
var require = {
paths:{
'thirdParty':'lib/thirdParty'
}
}
Create a module which execute (lets call it "PathRewrite" Module):
requirejs.config({
paths:{
'thirdParty':'lib/thirdParty.min'
}
})
In runtime configuration, define path to "PathRewrite" as empty
var require = {
paths:{
'thirdParty':'lib/thirdParty',
'PathRewrite':'empty'
}
}
In the build configuration file define a real Path to "PathRewrite" in order for it to be included in the "main" file (concatenated file after build).
Include "PathRewrite" as a dependency of a module which is executed first.
What I hope that will happen is that during dev, when optimized file is not used, PathRewrite is will not be used, hence the path to unminified third party in the runtime config will be used.
When the project is optimized, PathRewrite will be included and executed. According to RequireJS documentation, it is possible to run RequireJS configuration twice and the configuration will be appended/overwritten. PathRewrite execution will overwrite the path to "thirdParty" to minified, which will thus be used by all the modules.
Hopefully i've provided enough information. I'd be glad hear of other ways to get this done. Thanks in advance.

This topic appears to have been explored a bit in this answer:
Loading min.js files Generated by TypeScript with Require
Don't let the title discourage you. Typescript is not the core issue of the question being answered there. Unfortunately, the discussion reveals that the RequireJS optimizer may be the only way to get decent minification to work, as it seems incapable of selecting alternate paths properly.

Why don't you want to use inbuilt RequireJs optimizer? You may just include this option
optimize : "uglify2"
and all your and third-party code will be minified after concatenation. In this case you don't need to use minified versions of third-party libraries.