I'm trying to implement some complex business validation logic via JS in DMN using java embedded camunda with spring boot. To avoid usage of deprecated Nashorn and add ES6 support, I've added to project graal js engine. It seems it works pretty well, but I have no idea how to add custom functions into context of js-script engine. Let's say I have index.js in my resource folder with exported functions, how can I register such extension to be able to use it into camunda?
Graal.js already works to a certain extent, but official support for it is only added in 7.16. Please see: https://jira.camunda.com/browse/CAM-13516
Specifically the point of allowing to load external scripts by default is in discussion there. You may explain your use case in a comment on the ticket.
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Im angular developer.
In our front & back exists some magic calculation methods.
Classes same, but when anyone find bug in calculation need to fix it in two different projects.
maybe there is a way to create a generic codebase (maby function) that can be converted to js(or ts) & java and update two libraries based on the two results obtained
You could try to use kotlin.
Kotlin transpiles to JavaScript and also compiles to java bytecode.
However, you can only access kotlin utilities and neither access java or JS/TS types if you want to use the code in both java and ts/js code but you can use the kotlin stdlib.
But if it really is just a calculation, you may not need java/js specific classes/functions.
However, as VLAZ mentioned in the comments, you should consider doing the calculation only once in the backend.
Setting this up in IntelliJ
You can create such a project in IntelliJ by sekecting Kotlin in the New Project Window and using the project template Library.
Make sure you have the targets common, jvm and js. Since you didn't say you would do native stuff, you don't need the native target.
You can then use the kotlin library in both JavaScript (e.g. Angular) and Java projects as a dependency.
From a Java project, you can reference KOTLIN_PROJECT/build/classes/kotlin/jvm/main (this directory contains compiled Java classes).
From a JavaScript (e.g. Angular) project, you can reference KOTLIN_PROJECT/build/js/packages/kotlinToJavaAndJS.
As a proof of concept, I have made this repository on GitHub.
We have a large ecosystem of Javascript websites, actually Angular, that we don't plan to rewrite in c# any time soon. So the goal here is to be able to use a vendor dll in our javascript to add new features. This is a proprietary system, we don't have any alternative, either we use their dll, either we don't have the feature. I'm putting a lot of hope in webassembly here because this looked like the silver bullet to use that dll without having to rewrite the whole project in a new language.
Problem: all the examples I can find are more about using Blazor to write a website or call javascript from Blazor, I can't find anything to include some ad-hoc C# code into an existing project. I would have thought it would be a great use case though because being able to leverage C# threadpool on a webpage sounds pretty good to me!
Anyone has done something similar or know some examples/tutorials I could follow?
As Tuan says Angular and C# don't really live together in the way you suggest.
I would say there are 2 separate approaches here.
Have an C#.NET MVC app but adjust the routing so the Angular App Handles some pages and the .NET app handles others. This is OK but there are so many pitfalls such as the fact that you can not share bundled CSS and JS or maintain the structure of your Angular controllers (amongst others).
A better way would be keep your lovely Angular app the way it is but have a separate Web API application/project and use the angular app to call the dll (reference in the project) within the correct context as a REST API (via a simple POST or GET call).
It's not too clear exactly what you want to do when you say "... able to use a vendor dll in our javascript to add new features ..." but you can find info on writing and implementing C# as a Web API in .NET core here
https://learn.microsoft.com/en-us/aspnet/core/tutorials/first-web-api?view=aspnetcore-3.1&tabs=visual-studio
In my CakePHP app, I am defining a Wizard vendor that outputs the HTML for a multistep Wizard type plugin, along with its relevant Javascript code. I'm wanting to use the JsHelper so that I can buffer my code to the bottom of the page.
Everything else is working, including my Javascript code if I just output it directly with the HTML. I just can't quite figure out how to use the JsHelper. Do I use a App:Uses or App:Import statement? When using it in a View, I can just define it on the controller level, but that doesn't work here.
$this->Js->buffer("
$('.mws-wizard').wizard({
buttonContainerClass: 'mws-button-row',
orientation: '$orientation',
forwardOnly: $forwardOnly
});
");
If you are developing this 'vendor' package yourself, you should not develop it as a 'vendor', but as a plugin.
The vendor folders are meant for including third-party libraries that are not developed with CakePHP in mind (for example to use parts of the Zend Framework in your application).
From the manual:
Note: Loading vendors usually means you are loading packages that do not follow conventions. For most vendor packages using App::import() is recommended.
Create a plugin not a vendor
To develop re-usable code that can be used with different projects/applications, develop your code as a Plugin. Plugins are basically 'mini CakePHP applications'. Classes from a plugin can be used inside your application and vice-versa; a plugin can use CakePHP helpers the same way as you use them in your application.
See Creating Your Own Plugins
Regarding the JsHelper
Contrary to the comment placed by Sam Delaney, your usage of the JsHelper looks fine to me. Adding some script to the Js buffer to output it in the layout seems useful. Just don't try to use it for extended blocks of JavaScript; that should be put in external .js files.
I do recommend to write the JavaScript code yourself and not have the JsHelper generate the code for you (e.g. Don't use $this->Js->get('#foo')->event('click', $eventCode);). This may be personal, but IMO this makes it harder to track/debug your JavaScript and isn't any more readable than just $('#foo').click('event code');
I've personally never found any use for the JavaScript helper in CakePHP as if you're not careful, you end with getting <script> tags littering your markup, which sometimes makes it quite difficult to debug. From what you describe, you have the JavaScript aggregated and appended at the bottom of your HTML so it isn't as bad as the situation I highlight previously.
Is it not possible to relocate all your JavaScript to .js files to encapsulate all the function for your wizard plugin/vendor? If you could do this, it would be in keeping with MVC principles where you could logically separate the view markup and presentation logic.
I am in the process of choosing ScriptSharp for coding all my javascripts. I already use JQuery and it is great that there is built-in support for this.
But what about YUI? I need it in particular for the editor control..
How can I code the part for the editor control within Script# framework? Is there a place to enter custom javascript when a certain library is not supported or something similar?
Are there any future plans to add YUI to ScriptSharp?
It would be interesting to have YUI support, but there aren't specific plans to add support for it right now, at least not at the top of the priority list.
However, if folks in the community want to get it going and contribute, I can help with questions that come up.
The general idea is you create an import library (there is an Import Library project template when you install Script#), which defines a c# API corresponding to the OM that you program against. The C# API consists of classes and stub methods that define the signatures (think of this as a header file of sorts). There are a few metadata attributes to customize generation of script that references those APIs to get various transforms to happen ... so you can create a working, and often times more natural c# interface that then maps to runtime script constructs and APIs you are targeting.
When I see the sample at http://yuilibrary.com/ I see a bunch of parallels to jQuery, so I imagine building support for it is likely possible at a technical level.
The best way to understand how to do this would be to look at the sources of mscorlib.dll (represents the core script objects) Script.Web.dll (represents the DOM) and Script.jQuery.dll (represents core jQuery API). All of these are in the Script# repository on github ... https://github.com/nikhilk/scriptsharp ... if you haven't already seen them.
We are creating an import library for OpenLayers (http://openlayers.org) and I can say it is incredible easy to do. We started just doing what NikhilK says, inspecting the source code. The results are just great. YUI is a very well designed and documented api, so I think it would be stratightforward. You could just create the import clases you need for your project.
I am working on a Yahoo! App which requires certain external Javascript Frameworks to be loaded and used. Also in the Yahoo! App Best Practices Guide, it is also mentioned that the sources should be externalized, however, externalization isn't working for me.
I am using the standard procedure to load the external JS file like the following:
<script src="http://www.google.com/js/nxsl.1.js"></script>
But the above statement is giving me an error that external sources are not allowed.
Is there any way to use external JS files as I don't want to include all of my JS Login inline, it doesn't make sense to me and majorly my code won't be re-usable.
Any thoughts ?
Take a look at Yahoo's Get utility. It's part of their YUI library. It enables cross-site loading and is easy to use. You can read about it here:
http://developer.yahoo.com/yui/get/