Deno Objective-C

Objective-C Runtime Bridge for Deno.

import objc from "https://deno.land/x/objc@0.1.0/mod.ts";

objc.import("AppKit");

const { NSPasteboard } = objc.classes;

const pasteboard = NSPasteboard.generalPasteboard();

const result = pasteboard.stringForType("public.utf8-plain-text");
// or
const result = objc
  .send`${pasteboard} stringForType:${"public.utf8-plain-text"}`;

// Convert to JS String
console.log(result.UTF8String());

Usage

This is mainly for interfacing with macOS Frameworks, but it can also be used with GNUstep libobjc2.

By default, libobjc.dylib, libobjc.so or objc.dll will be loaded depending on the platform.

If you want to override that, use DENO_OBJC_PATH env variable.

API

To retrieve a class, use objc.classes:

const { NSPasteboard } = objc.classes;

To retrieve a protocol, use objc.protocols:

const { NSPasteboardReading } = objc.protocols;

In Obj-C, take the following method:

- (void)setString:(NSString *)string;

Now to send it, you do

[self setString:@"Hello World"];

But in JavaScript, you can do it in two ways. One is using the proxied method:

self.setString_("Hello World");
// or
self.setString("Hello World");

Alternative way is to use objc.send:

objc.send`${self} setString:${"Hello World"}`;

When sending a message, the types of course need to be converted into native ones. For example, by default the native string type in Obj-C is actually just null terminated C string. So the JS string will be converted to that if the method needs.

Otherwise, if we find that the method takes an id type, we will try to convert it to NSString instead.

Importing frameworks at runtime is done via NSBundle. By default, only Foundation framework is loaded.

Security

Since this module makes heavy use of FFI, it is inherently unsafe and gives access to low level system primitives.

As such, to use this module you need to pass these flags:

• --allow-env: To check for a possible DENO_OBJC_PATH value
• --allow-ffi: To load ObjC runtime dynamic library
• --unstable: The FFI API in Deno is an unstable API (it can change)

The allow-ffi permission basically breaks through entire security sandbox, so you can also just pass -A/--allow-all.

License

Apache-2.0 licensed.

Copyright 2022 © DjDeveloperr