is require.js the right tool (for the job) for "normal" web sites" - requirejs

I have started building a web site and have used Require.js for selectively loading scripts which I require to implement functionality. What I am experiencing is:
the "main" script has not finished executing (or even downloading) before some of my code uses "require" to load dependencies. What this means is that the require.js config has not run and does not know the locations of my scripts.
because the require.js config has not run by the time my code needs to use it, the "shim" mechanism has not been initialised and cannot be used.
The Common Errors page along with a lot of the issues I seem to be reading about online while trying to solve my own problems seem to suggest that this is not the right tool for the job.
This seems to be useful for single page applications or node.js applications, but not traditional sites where other scripts could be running before require.js has been initialised.
If require.js is not the right tool for the job, is there a right tool for this job? If so then what is?

Are you loading the require.js script asynchronously (with an async='async')? You want requirejs to load synchronously. Once it's loaded, it will load further scripts, like your main.js file, asynchronously. They may all load out of order, but the code will actually get executed in the right order (respecting the declared dependencies).
So in your page template, you would have this:
<script src="/Scripts/require.js" type="text/javascript" data-main="main.js"></script>
That will load RequireJS, and once it's loaded it starts loading your main.js asynchronously. Typically main.js does not define any modules, it just makes use of modules defined in other files. These dependencies are listed in the require() call:
require(["moduleA", "moduleB"], function(A, B){
// Do something with A and B
A.someFunction();
B.someOtherFunction();
});
The files moduleA.js and moduleB.js must wrap their contents inside a define(). In moduleA.js (which depends on module C):
define(["moduleC"], function () {
// Build up an A
var A = ....;
return A;
});
I wonder now if you're wrapping your modules in a define call. Not doing that could explain the out-of-order execution you're experiencing.
RequireJS is a perfectly valid tool on a traditional site, not just on a single-page site.

Related

Sails.js: can't find variable require (react-bootstrap-datetimepicker)

I'm using Sails js and I want to use a nodejs module.
I also use React js.
I want to use react-bootstrap-datetimepicker in my javascript script.
react-bootstrap-datetimepicker
I installed my module with npm install react-bootstrap-datetimepicker
I tried in config/boostrap.js to add this line var DateTimeField = require('react-bootstrap-datetimepicker');, but DateTimeField isn't recognised in my js script.
Uncaught ReferenceError: DateTimeField is not defined
I also tried to add this line directly in my script, but I have this error:
ReferenceError: Can't find variable: require
And also this one in my script: import DateTimeField from "react-bootstrap-datetimepicker";
I have all these errors in the navigator console.
EDIT 1:
I understand what you said, thank you for your answer.
BUT, for example with react-bootstrap, I can use:
var Input = ReactBootstrap.Input;
var ButtonInput = ReactBootstrap.ButtonInput;
There is exactly the same architecture with react-bootstrap-datetimepicker, so I maybe I can do the same?
var DateTimePicker = ... . DateTimePicker
I tried to include like you said, but it doesn't recognise DateTimePicker.
Here is the doc:
Installation :
npm install react-bootstrap-datetimepicker
Then
javascript
var DateTimeField = require('react-bootstrap-datetimepicker');
render: function() {
return <DateTimeField />;
}
See (examples/) for more details.
And in examples/, the line is:
import DateTimeField from "react-bootstrap-datetimepicker";
Ok, first you have to understand the division of server side and client side javascript, even thought you are using the same language, and you can share libraries, bare in mind, that for client side js you need to supply the user browser with the libraries and scripts it needs, so those have to be in the html you serve the user. When you require any module in sails bootstrap or similar, you are loading the script into the server memory, not serving it to the users browser, that means you can use in the server code, but not in client code.
For you use case, you have to download the library code, and put it in your assets/js folder and if you have the script tags in the layout, sails will automatically inject it there for you, but if not or you are using other template engine like jade, just manually add it.
example:
<html>
....
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/<react-version>/react.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/<react-version>/react-dom.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react-bootstrap/<version>/react-bootstrap.min.js">
<script src='/js/react-bootstrap-datetimepicker.min.js'></script>
// The other js files that depend on datetimepicker go here
</html>
Now just to be clear, require is a node.js function, node.js is not the same as javascript, its a piece of software with its own functions, thats why you are getting an error related to it when trying to use it in the browser, there is no require method there, so you can't use it, at least not directly. You can use browserify to sort of emulate the node workflow, where you have a node_modules folder and use require on those, browserify will bundle (search for the modules and merge them) and give you a javascript file that you can then link in your html code. That is more setup work, and unless you really need it, because you have a lot of files, i think is not worth the effort.. lets say for just one file using require.
So i think you were misguided by that github repo, because it says npm-install. Just ignore it (unless you use browsefify like i said) and download the link i gave you above ( the .min.js).
So to sumarize, you issue have nothing to do with sails, just link the library in the html you provide to the user, like any other client side script.

Why can't I require files which are available due to app.use?

If a directory has been made available to a node application in the server.js file which sits in the main directory using:
app.use("/scripts",express.static(__dirname + "/scripts"));
and I attempt to use require from a file inside of that directory (/scripts/custom.js) using:
var Testing123 = require('../app/models/article');
Is there a reason this is not possible? and is there a solution to that problem?
Edit: In one of my views (views/tree.ejs) I use:
<script type="text/javascript" src="../scripts/custom.js"></script>
to access my Custom script which sits inside my scripts folder which is made available using express.static, Custom uses a web scraper to scrape articles and present them in circles (in the form of an image, title and link) on views/tree.ejs, I now want custom.js to save each article it creates to a mongodb database but to do so, it needs access to things like my Article Schema hence the problem above.
You cannot because Node.js scripts and browser scripts do not run in the same context. Your app.use call just exposes a /scripts route that serves assets statically on your HTTP Server.
Your scripts/custom.js script seems to be a browser-side script (Because you load it with a script tag inside an ejs view) but you want to use require inside it and this will not work as this is a Node.js function.
Have a look at LearnYouNode which is an excellent Node beginner tutorial so that you will understand how modules work in Node and know a bit more about the separation between server-side and client-side JS.

Including remote library with Node.js?

I've noticed that every time I want to use a package in Node I need to "npm install" it locally and then use the require keyword. I wanted to know if there's a way I could include a remote library kind of like that way we can include remote files using client side html when we use a CDN:
<head>
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.11.0/jquery.min.js"></script>
</head>
require() in node core is synchronous, so there is no way to do it natively (since network i/o is async in node). You'd have to write some function to fetch the resource first and then require() it.
You can't actually supply a URL to "require", but you can of course fetch a remote resource from a URL, including a javascript resource. And then load it locally.
The following answer even links to a "remote_require" that someone wrote to do another kludgy version of this.
how to require from URL in Node.js
If you are trying to use other JavaScript files in your application, you will need to export all of the functions defined by those JavaScript files.
You would export a function like so:
exports.nameOfExport = function(x, y, z) {
// Function content
};
You would then require this file in the file you are trying to use it in with this line:
var myFileName = require('./routes/folder1/myFileName'); // Relative path to required file
If this doesn't answer your question, I suggest going to https://www.npmjs.org/ to search for a package that does what you are trying to do.

Grunt task to optionally include an AMD module for different environment

I'm developing a web app using Require.js for AMD and amplify.request to abstract away my AJAX calls. The other advantage to amplify.request is that I've defined an alternative module containing mocked versions of my requests that I can use for testing purposes. Currently, I'm switching between the two versions of my request module by simply commenting/un-commenting the module reference in my main.js file.
What I'd love to do is use Grunt to create different builds of my app depending on which module I wanted included. I could also use it to do things like turn my debug mode on or off. I'm picturing something similar to usemin, only for references inside JavaScript, not HTML.
Anyone know of a plugin that does this, or have a suggestion about how I could do it with Grunt?
On our current project we have a few different environments. For each of them, we can specify different configuration settings for the requirejs build.
To distinguish between these different environments, I've used a parameter target.
You can simply pass this to grunt by appending it to your call like
grunt --target=debug
And you can access this parameter in the Gruntfile, by using grunt.option, like
var target = (grunt.option('target') || 'debug').toLowerCase();
The line above will default to debug. You could then make use of the paths configuration setting of requirejs to point the build to the correct module. Example code below.
requirejs: {
compile: {
options: {
paths: {
"your/path/to/amplify/request": target === "debug" ? "path/to/mock" : "path/to/real",
}
}
}
}

How to test an AngularJS/SocketStream/Node.js app using Karma

I am working on an AngularJS application that is delivered by a SocketStream/node.js server.
I have an AngularJS service that calls api functions on the SocketStream server and progress has been good so far.
But now the time has come to start writing the first tests and the first testing framework that came to mind is Karma/Jasmine, since this is the recommend AngularJS set up.
So far so good, but since my AngularJS modules are imported using 'require' (SocketStream's version, not require.js) and server api calls are part of the test, I need to configure Karma to load SocketStream (at least its client side).
I took a good look at 'https://github.com/yiwang/angular-phonecat-livescript-socketstream' but when I run this example I get run time errors, possibly because I have later versions of variuous dependencies installed.
I managed to get 'required' resolved by packing my SocketStream app by adding 'ss.client.packAssets()' to app.js and run 'SS_PACK=1 node app.js', but when I start karma it logs an error message saying:
'Chrome 23.0 (Linux) ERROR
Uncaught TypeError: undefined is not a function
at /the...path/client/static/assets/app/1368026081351.js:25'
'1368026081351.js' is the SocketStream packed assets file. If I don't load it the error message is something like 'require is undefined', so my best guess is that the error is happening somewhere inside the SocketStream require code. Also because I run karma in DEBUG mode and can see all the files being served.
I have been trying different approaches as to find out what is happening but to now avail. So my questions are:
Is anybody else successfully testing AngularJS/SocketStream using Karma?
Does anybody have any suggestions as to how I can fix, or at least debug this problem?
Are there any alternatives/better solutions?
Time to answer, sort of, my own question:
Sort of, because I came to the conclusion that Karma and node.js/SocketStream have a lot of overlap, so I decided to see if I can omit Karma altogether and deliver the Jasmine testing platform through SocketStream. It turns out that that is possible and here's how I did it:
I defined a new SocketStream route and client in my 'app.js' file:
ss.client.define( 'test', {
view: 'SpecRunner.html',
css: ['libs/test'],
code: ['libs', 'tests', 'app'],
tmpl: 'none'
});
ss.http.route( '/test', function(req, res) {
res.serveClient( 'test' );
});
I downloaded jasmine-standalone-1.3.1.zip and copied 'SpecRunner.html' to the 'client/views' folder. I then edited it to make it load AngularJS and all SocketStream client files, like all other views:
<script src="//ajax.googleapis.com/ajax/libs/angularjs/1.0.6/angular.min.js"></script>
<script src="//ajax.googleapis.com/ajax/libs/angularjs/1.0.6/angular-resource.min.js"></script>
<SocketStream/>
I removed the 'script' tags that import the sample source files ( 'Player.js' and 'Song.js' ) and specs but let the last 'script' block in place unmodified.
I then created a new folder inside 'client/css/libs' called 'test' and copied 'jasmine.css' in there unmodified.
Then I copied 'jasmine.js' and 'jasmine-html.js' renamed to '01-jasmine.js' and '02-jasmine-html.js' but otherwise unmodified, into '/client/code/libs'.
Now Jasmine is in place and will be invoked by using the '/test' route. The slightly unsatisfactory bit is that I haven't found an elegant place to store my spec files. They only work so far if I place them inside the 'libs' folder. Anywhere else and they are served by SocketStream as modules and are not run.
But I can live with that for now. I can run Jasmine tests without having to configure a special Karma setup.

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