Is there a way to have some code run in the browser after coffeescript has compiled and run all the script files in the header?
Something like:
coffee.onCompiled () -> console.log "I've finished loading all the coffee files"
How else can I get this behaviour? (please don't suggest setTimeout)
At first I thought you were asking about how to attach a callback to window.onload from CoffeeScript (which is, of course, very straightforward, since "It's just JavaScript"), but now I realize that you're asking how you ensure that code runs after all
<script type="text/coffeescript" src="..."></script>
tags have been executed when using coffee-script.js.
One solution is to put a callback in the last CoffeeScript you load. Since 1.1.0, coffee-script.js has ensured that all CoffeeScript script tags are run in order (though note that they'll only run after all JavaScript script tags have run). So, for instance, if you put
<script type="text/coffeescript">
onReady()
</script>
after all your other script tags, and define window.onReady somewhere else, then that function will be called after all scripts have loaded. If you made it
$ -> onReady()
(with jQuery), then you'd ensure that the DOM is ready as well as all scripts.
Update: I posted that this is "one solution" because I wasn't 100% sure whether there's a callback that coffee-script.js invokes after all scripts have been run. But after checking the source, I can confidently say that it doesn't, so the only solution is to put code in the last <script type="text/coffeescript"> tag. (Whether it's inline or in a .coffee file doesn't matter.)
Related
I've spent more time on this than I care to admit but was hoping for some help in understanding the cause of the problem. I have a basic HTML web resource in Dynamics 365 (v9.1.0.9228) and in order to get the global context I must include the following:
<script src="ClientGlobalContext.js.aspx" type="text/javascript"></script>
https://learn.microsoft.com/en-us/powerapps/developer/model-driven-apps/clientapi/reference/getglobalcontext-clientglobalcontext.js.aspx
The problem is that when I do... the Chrome debugger loses its place in the document. The execution stops at the breakpoint(s) but the current line is not highlighted this means no way to step into/over the lines or indeed know what line we are on at any given point. I can see however that the code is being executed due to my output to console (See code in footer).
I have tested this across:
Multiple D365 online instances (v9.1.0.9228)
Multiple development machines running Chrome (v77.0.3865.90)
Literally stripped back the code to very basic HTML. Interestingly, this issue does not occur in IE? The only workaround I have found is rather than having inline JS within the head tags place it a separate file instead and reference from the HTML web resource, Chrome then seems to have no issues in stopping on right line and highlighting the correct line as we debug BUT only functions within that library. If the HTML web resource has inline script the issue will still be present within that scope.
head
<script type="text/javascript" src="ClientGlobalContext.js.aspx"></script>
<script type="text/javascript">
function registerEvents() {
debugger;
console.log("in registerEvents v2.0.3");
testButton = document.getElementById("test");
testButton.onclick = test;
}
function test() {
debugger;
console.log("in Test v2.0.3");
}
</script>
body
<script type="text/javascript">
registerEvents();
</script>
<p>In chrome debugger v2.0.3</p>
<button id="test">Test</button>
I would like to understand if I am doing something wrong here as it seems to be a bug within Chrome DevTools itself given this works on all other browsers when debugging? The actual code here is almost irrelevant as the issue occurs whenever "ClientGlobalContext.js.aspx" is referenced, if we comment out that line the Chrome debugger works as expected.
My React based app contains a form and somewhere along the way it stopped working, the onSubmit even was no longer fired and the form was just simply submitted with a new http request. While trying to isolate the problem I stripped my whole app to the following snippet (which is actually this jsfiddle taken from another question):
import React from 'react'
var OnSubmitTest = React.createClass({
render: function () {
var doSomething = function () {
alert('it works!');
}
return <form onSubmit={doSomething}>
<button>Click me</button>
</form>;
}
});
React.render(<OnSubmitTest/>, document.body);
The script on jsfiddle works as it should: the message is alerted just before the form is actually submitted. I get no alert in my app, though.
If I add e.preventDefault() the jsfiddle form is not submitted at all, my form is.
The difference is that I build my app using webpack and babel from es6 but it's hard to believe that this could have any impact on this matter.
Any idea what might be the reason? What should I try next to debug that?
Update: JSFiddle showing the problem. The linked file is the webpack output (not uglified in any way to keep it readable, that's why it's so huge). You can find my code (compiled) starting on the line 53.
Mystery solved: I forgot to mark the node_modules directory as excluded (I use IntelliJ IDEA) so when I used refactoring to change some variable name form to something else, the IDE eagerly refactored the whole React and replaced all occurrences of form with the new value.
I fixed it by reinstalling all npm dependencies.
I am brand new to NancyFX and currently enthralled by its low-ceremony approach to web application development. Throwing myself in at the deep-end, I also want to use CoffeeScript and investigate the benefits of Sass.
The Set-Up
To enable this combination I have created a new Empty Web Application using the VS2010 template (found in the Nancy Accessories project). I have then used the VS PackageManager to Nancify my application and add the SassAndCoffee support:
PM> Install-Package Nancy
PM> Install-Package Nancy.SassAndCoffee
So far so good. I then created an ~/Content/scripts folder and in there I have placed a file called home.coffee containing the following line of CoffeeScript.
alert "Hello Nancy!"
Now things start to get a bit fuzzy. I want to run this script on the client so I create an view called ~/Views/home.sshtml (and associated NancyModule with Get["/"] route - not shown). The view's html looks like this:
<head>
<title>Hello Nancy</title>
<script type="text/javascript" src="/content/scripts/home.js"></script>
</head>
<body>
<p>Hello #Model.User</p>
</body>
</html>
The view works just fine but the link to the home.js file just returns a 404: Not Found.
I am hoping that somehow Nancy will magically work out that I need my CoffeeScript compiled to JavaScript when it looks for the referenced home.js file and finds the home.coffee instead. This didn't work - so much for inspired guesswork.
If I change the script tag above to point to the existing home.coffee instead then the file is found but processed as a normal JavaScript file giving errors concerning the lack of tiresome ceremony namely: "unexpected string"
The Question
Now you know my set-up and simple requirements, here then is my question:
How do I get CoffeeScript to 'just work' using the NancyFX framework?
Thank you
Update
Steven Robbins (below) has answered this question by pointing to the demo code. But just in case you don't want to pull MBs of source from GitHub, here are the lines required to get things going. First add a class called Bootstrapper.cs to your project. Now add the following code (it worked like a charm for me):
public class Bootstrapper : DefaultNancyBootstrapper
{
protected override void ApplicationStartup(TinyIoCContainer container, IPipelines pipelines)
{
base.ApplicationStartup(container, pipelines);
StaticConfiguration.DisableErrorTraces = false;
Hooks.Enable(pipelines, new InMemoryCache(), container.Resolve<IRootPathProvider>());
}
}
The SassAndCoffee project doesn't hook into the static content bit in Nancy, it (or something similar) may in the future, but at the moment it's just a separate pipeline hook.
If you take a look at the sample project on github:
https://github.com/NancyFx/Nancy.SassAndCoffee/tree/master/src/Nancy.SassAndCoffee.Demo
That should show you how to get it going.
Can someone explain what happens after the java code is converted to Javascript by the GWT compiler?
how will the compiled javascript reach the client browser and when does this happen.
Well from your server, you serve a html page which should contain a tag that points to your compiled javascript.
Example of what the script tag would look like
<script type="text/javascript" language="javascript" src="http://example.com/js/project/project.nocache.js"></script>
The GWT compiler generates output files as described here.
At a very high level. There is a very tiny loader file (the .nocache.) which you should include in a script tag in your page. This file's only job is to determine the correct compiled application code files to request from the server. This load happens asynchronously after the nocache script has loaded.
I've encountered what seems like a chicken & egg problem, and have what I think is a logical solution. However, it occurred to me that others must have encountered something similar, so I figured I'd float it out there for the masses.
The situation is that I want to use dojo's addOnLoad function to queue up a number of callbacks which should be executed after the DOM has completed rendering on the client side. So what I'm doing is as follows:
<html>
<head>
<script type="text/javascript" src="dojo.xd.js"></script>
...
</head>
<body>
...
<script type="text/javascript">
dojo.addOnLoad( ... );
dojo.addOnLoad( ... );
...
</script>
</body>
</html>
Now, the issue is that I seem to be calling dojo.addOnLoad before the entire Dojo library has been downloaded the browser. This makes sense in a way, because the inline SCRIPT contents should be executed before the entire DOM is loaded (and the normal body onload callback is triggered).
My question is this - is my approach sound, or would it make more sense to register a normal/standard body onload JavaScript callback to call a function, which does the same work that each of the dojo.addOnLoads is doing in the SCRIPT block. Of course, this begs the question, why would you ever then use dojo.addOnLoad if you're not guaranteed that the Dojo library will be loaded prior to using the library?
Hopefully this situation makes sense to someone other than me. Seems like someone else may have encountered this situation.
Thoughts?
Best Regards,
Adam Rice
You're doing it correctly. External Javascript files are loaded and executed synchronously in order, so by the time it reaches your dojo.addOnLoad( ... ); Dojo has loaded. Use dojo.addOnLoad instead of window.onload for two reasons:
it fires earlier, because it utilizes DOMContentLoaded
it handles asynchronous loading of dojo.require by postponing the execution until all required scripts have been read
Explained in DojoCampus as (dojo.addOnLoad):
dojo.addOnLoad is a fundamental aspect
of using Dojo. Passing addOnLoad a
function will register the function to
run when the Dom is ready. This
differs slightly from document.ready
and body.onload in that addOnLoad
waits until all dojo.require() (and
their recursive dependencies) have
loaded before firing.
This might have nothing to do with your problem, but ive just had a case where I had the same symptoms. For me everything worked fine for Firefox, Chrome etc, but not IE8.
I was getting what looked like dojo not being loaded, an error in IE8 saying that dojo was undefined (but not all the time) and i could strip everything down to just style sheets and importing dojo and still get the error.
I was running a local google app engine development server. This looks to be based on pythons SimpleHTTPServer which in turn uses SocketServer.BaseServer. This has BaseServer.request_queue_size which defaults to 5 - i couldn't find anything in app engine which overrode this value so i guess the development google app engine server has an upper limit of 5 connections.
Using regedit and going to HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings
“MaxConnectionsPerServer”=dword:00000010
“MaxConnectionsPer1_0Server”=dword:0000010
This shows that IE was going to try and open up to 10 simultaneous connections. I edited these two keys and made them 2 and restarted the computer, the problem went away.