javascript tutorial

Question

Hello,

I need to do some scripts in java script. I am working on it but couldn't find a few solutions to a few problems.

First of all I need a GOOD tutorial, but not for an internet page but for a DESKTOP script.

Things couldn't find out like : 1) I wanted a simple message box inorder to debug my program, I used: var name = prompt("What is your name","Type Name Here");

When running it I get error of "Object expected"

2) Couldn't find how to open a file

Answer 1

This question might be of interest to you: http://stackoverflow.com/questions/109399/can-you-do-desktop-development-using-javascript

Answer 2

The latest prerelease of Opera acts as a runtime for JS applications.

They have tutorials describing how to use it.

I used: var name = prompt("What is your name","Type Name Here");

When running it I get error of "Object expected"

Presumably your runtime doesn't implement prompt that in a way that is compatible with those arguments.

2) Couldn't find how to open a file

This depends on the runtime you use. JS itself doesn't have anything built in to read files (or display a prompt). You need an environment that provides those objects.

Answer 3

I have to ask: why is JavaScript the right tool for the job? Why not use a scripting language intended to be used this way, such as Python, Ruby, Lua, ... etc?

If you are using Microsoft's JScript (and it sounds like you are), look to the MSDN web site for help. The page here looks fairly good. Google can also help with that.

Assuming you don't mind using Java, you could also use the Mozilla Rhino shell. But it doesn't look like there is a standard way of reading from the console in JavaScript. (presumably since this is not something typically required in a JavaScript application...) The built in JavaScript functions in the shell seem fairly basic, but you can read a file.

There area also examples of using Rhino, which may be helpful. You can interface with the Java API to do whatever else you need to do.

Answer 4

Based on your comments, I guess that you are attempting to run a JavaScript file directly on Windows. Double-clicking on a .js file in windows will (probably) run it in Windows Script Host.
The prompt() function will not work this way, since WSH provides a completely different API than browser-embedded engines.

The following code should accomplish your intentions. However if you want anything more than a simple popup, HTAs are the only way to do complex GUIs with JScript on the desktop.

var fso, ws, ts;
fso = new ActiveXObject('Scripting.FileSystemObject');
ws = WScript.CreateObject('WScript.Shell');

var ForWriting= 2;
ts = fso.OpenTextFile('foo.txt', ForWriting, true);
ts.WriteLine(new Date().getTime());
ts.Close();

ws.Popup('Wrote to file!');

var ForReading= 1;
ts = fso.OpenTextFile('foo.txt', ForReading, false);
var fileContents = ts.ReadLine();
ts.Close();

ws.Popup('The file contained: ' + fileContents);

WScript.Quit();

Answer 5

Try this link. I found it invaluable.