I have played a little with Dart and I think it's great. I understand that it can output native JS and that the VM will likely be supported by Google in their browser. As it is possible that other browser suppliers won't support the Dart VM, is it at all possible to install the Dart VM on client machines for use in foreign browsers?
is it at all possible to install the Dart VM on client machines for use in foreign browsers?
It is, however it is easier to supply the Dart VM yourself.
Javascript is perfectly able to:
Find a script of a specific type
Convert the script into Javascript
Execute the compiled script
While this is technically not a Dart Virtual Machine, it will get your Dart code executed at full speed. However, you do have to wait for the compilation to complete. The usual way is to do the compilation on the server (once), and only send the compiled javascript to clients.
Another option is interpreted code. Instead of compiling to javascript, the Dart instructions are executed one-by-one. Dart is not a machine-level language, so it needs parsing, but what follows is interpretation. The downside is reduced performance. This will get you as close to having a full-blown virtual machine (separate from the Javascript one) as possible.
Normally, you don't care which one you get (maybe you'll even get a just-in-time compiler), but it does make a difference in terms of a Dart virtual machine being present (rather than just getting your code executed).
The Dart compiler needs to be present on the page somehow (unless you precompile).
The easiest way is to just write <script src="path/to/your/dart-compiler.js"></script> into the head.
The Dartium browser does support Dart natively, but it is not designed for common use. Wikipedia says:
In the Dartium Browser: The Dart SDK ships with a version of the Chromium web browser modified to include a Dart virtual machine. This browser can run Dart code directly without compilation to Javascript. It is currently not intended for general-purpose use, but rather as a development tool for Dart applications.[7] When embedding Dart code into web apps, the current recommended procedure is to load a bootstrap JavaScript file, "dart.js", which will detect the presence or absence of the Dart VM and load the corresponding Dart or compiled Javascript code, respectively,[8] therefore guaranteeing browser compatibility with or without the custom Dart VM.
If you want the ability to run Dart be dependent on the client machine rather than on the page, there are a few ways too.
One way is to include the compiler as a user-script. This will work in all both modern desktop browsers. However, I'm not sure if there's an existing way to add user-script support to Internet Explorer.
One way is to add a browser extension. All modern desktop browsers support extensions, and Internet Explorer has Browser Helper Objects.
All of these will require the extra Javascript step. If you want native interpretation that bypasses Javascript, you need a plugin. Plugins require a specific mime-type to run (not sure if the script type counts), but you can install an extension that will trigger the use of the plugin. However, DOM manipulation still needs the extra Javascript step. There is no way around it.
A desktop installer can definitely install a plugin into a browser. Indeed, this is the way plugins normally get installed. Installing extensions from a desktop installer might be possible as well, but I can't confirm or deny this last claim for now.
As far as I know there is no way to just simply install a plugin (like Flash) for Dart. For Internet Explorer one could install Chrome-frame, but I haven't seen something similar for Firefox and Safari.
Related
I'm trying to get a number of Chrome extensions working in an Electron app. Electron only supports dev tools extensions, so I'm writing code to handle regular extensions more-or-less from scratch. But, I'm getting stuck figuring out what's involved in getting the content scripts to run in the same way they do in Chrome.
In the existing Electron implementation, which is expressly limited to development tool extensions, I traced the code to here, specifically, line 392:
win.devToolsWebContents.executeJavaScript(Extensions.extensionServer._addExtension(${JSON.stringify(extensionInfo)}))
Finding the next step in this process has proved very challenging. I think, but am not certain, that HERE is the corresponding Chromium code, but this seems like it's for development tools extensions in particular (what with the calls to InspectorFrontendHost and the use of iframes).
Could anyone point me in the right direction? Where is the code where Chromium loads the content scripts for regular extensions? Or is this that code?
I want to compile dart code to JS on-the-fly without invoking dart2js at the command line. Eg., (written in Dart) read in some dart code from a file and transform it to JS (must be in memory, filesystem is not writable).
I thought maybe dart2js would effectively just be a cli over a pub package I can call manually, but I can't find any information on doing this at runtime :(
(note: I know this idea sucks and it'll be very slow; it's just for something I'm prototyping and will ultimately use dart2js normally, I just can't address that yet)
https://try-dart-lang.appspot.com/ does this. The source is available. Its basically dart2js run through dart2js.
Not sure if this is the right repository https://github.com/peter-ahe-google/orphan-try
I guess Peter would be ok with pinging him about more information.
The project was replaced by pub.dartlang.org which uses a service running on the server https://github.com/dart-lang/dart-services where source is posted to for dart2js translation.
electron, node-webkit, brackets-shell and atom-shell are frameworks that allow a user to create stand alone executables that use HTML, CSS, and JavaScript (Node) for all code in the app. They don't require any prior installation of any software, as I understand it. I want to use Dart instead of JavaScript. I don't want a chrome app because that requires the installation of Chrome, if I understand correctly. Is it possible to make a stand-alone application using Dart? Will DartToJs be able to do this for me?
You need to have a Dart-VM (Dart-Runtime) installed in order to be able to execute Dart applications on the command line/server.
As far as I know there is no way to create a standalone executable, at least no easy one.
It is technically possible to create an executable that contains the Dart-VM but there are no tools available yet that generate that for you.
I don't think the path using Dart2JS will help much. Dart2JS aims primarily at browsers but I have heard that some try to use Dart2JS to run Dart code with Node.js but I don't know if that really works.
This similar question contains some links that may be of interest to you: Embedding Dart into application
dart2js + node-webkit will definitely do this for you. Just compile your webapp to js, make a proper package.json file and follow the standard directions on the node-webkit github page.
There's even a pub package that let's you use the node-webkit API from dart (filesystem access, window controls, and whatnot).
Search pub for node_webkit and you'll find it.
Good luck.
Story:
I have written a HTML Merge Compiler that can merge resource's/assets into one single HTML file (minify it to the max) and compiles Javascript with the google enclosure compiler. I have written this compiler to speed up loading and interpreting the code and to obfuscate the code to protect a little bit (script kiddie protection). Major reason was/is speed and to make it compact.
This is working OK with reliable results and i use this in PhoneGap applications/games. I have also written a javascript library that encapsulate all platforms that works with standard HTML/CSS without the need to change the code, it works also in the browser, with a touchscreen or without or on any device or operating system. Write once, publish many ;-). The idea around it is that is working always, always operate the same but can use device specific things when available but does never fail (when something is not there, for example a vibrate functionality).
Anyway, most frameworks (like PhoneGap) concentrate on Mobile Platforms but i want to port it also to desktop platforms like Windows, OSX and maybe Linux. For Windows I have wrote an Delphi Application that loads the HTML in a TEmbeddedWB object (is Internet Explorer actually) but the 'problem' is that it is only suitable to Windows and IE is not the fastest browser around, especially when it is embedded (do not why it is slower than the browser itself). For example, when i load the compiled code in Firefox and/or Google Chrome it is blazing fast (you do not notice it is javascript ;-)).
EDIT:
Pre release of IE10 for Windows 7 is just launched, installed it and lag is gone!
You can download it from here:
http://www.microsoft.com/en-us/download/details.aspx?id=35709
Introduction to my question:
I have tried XULRunner of Mozilla a long time ago but the first time was not a pleasure to me and also i tried it today again but can't get it to work. Get a parse error in the main xul file of the project, window is an undefined entity. ??? I create a sample project like: http://mdn.beonex.com/en/Getting_started_with_XULRunner.html
I do not know what to do about this error. Also i think documentation is not up-to-date? Most documentation is from around 2006.
The question, what i want to know:
Before i am going to waste my time (see also introduction), is it
possible to create frameless (full-screen) desktop executables with
use of XULRunner like with PhoneGap?
Is it possible to create cross-platform applications with XULRunner, i mean, does it really work seamless. Where can i find a ready-to-publish example of a XULRunner project and is it possible to load local HTML file(s) like in PhoneGap?
It is possible and allowed to access external resources?
Long story, but maybe there is somebody that have tried this before and can lead me to choose the right direction.
is it possible to create frameless (full-screen) desktop executables with use of XULRunner like with PhoneGap?
Yes. You use disablechrome attribute to remove the window frame and sizemode="maximized" to have it open full-screen. Alternatively you can use the full-screen API if you want your application to run in a normal window and only switch to full-screen mode on request.
Is it possible to create cross-platform applications with XULRunner
Yes. There are things like menus that work very differently on OS X but most of the time you don't need to care what operating system your application runs on (Windows, Linux and Mac OS X supported).
Where can i find a ready-to-publish example of a XULRunner project
See documentation for a XULRunner application example. For "ready-to-publish" you would need an installer which doesn't come with the platform.
is it possible to load local HTML file(s) like in PhoneGap?
Yes. The top-level window has to be XUL but you can use some very minimal code here - essentially a single <iframe flex="1"/> tag. You can load HTML pages into that frame then.
It is possible and allowed to access external resources?
Yes, XULRunner applications have full privileges and can access files on disk as well as web resources without any restrictions.
Just read news that Google had announced an early preview of the new web programming language Dart. The documentation on the dartlang.org states:
You will be able to run Dart code in several ways:
Translate Dart code to JavaScript that can run in any modern browser:
Chrome, Safari 5+, and Firefox 4+ (more browser support coming
shortly).
Execute Dart code directly in a VM on the server side
Use Dartboard to write, modify, and execute small Dart programs
within any browser window
And I'm curious is there already VM available to run Dart code? Can't find it anyway, maybe it is available through some beta program?
A pre-built binary of the Dart VM is available in the Dart SDK. Alternatively, you can checkout the source to the whole Dart project, which includes the VM.
Dartium, Chromium with a Dart VM, is now available.
http://www.dartlang.org/dartium/
You can download precompiled binary runtime for Windows, Linux and Mac from Dart Force. Another way is to run node.js-style HTTP server using Fling.