[Packager] Add option for remote packager in info.plist

[ghost]

Add an option to add a ReactServer key to info.plist that specifies a location to a remote server running the packager. This allows you to easily change the location of the packager for on-device debugging without having to root around in various parts of the code, namely AppDelegate.m and RCTWebSocketExecutor.m (if you want debugging).

[amasad]

@frantic can you take a look?

[brentvatne]

• Should follow styleguide - curly braces for all if statements, space between if and paren
• Any change here would need to include a corresponding change to the docs in docs/Debugging.md and perhaps other places

cc @tobyhughes @frantic

[frantic]

@tobyhughes - if you are still interested in working on that, please consider @brentvatne's suggestions about code style and docs. Potentially (in separate PR) we could also provide a script that at build time writes laptop's IP address into Info.plist to make everything "just work".

[ghost]

Will do :) I'll update the PR tonight.

[frantic]

Just looked at the codebase, and seems like there are few more places where the URL is hardcoded. Would be nice to change those refs too:

• Libraries/WebSocket/RCTWebSocketExecutor.m
• React/Base/RCTRedBox.m
• Libraries/RCTTest/RCTTestRunner.m

You can also extract this logic into some util function to not have to do this manually in different places, something like RCTServerURLWithPath(@"/index.bundle")

[ide]

Could you generalize this so it's programmatically configurable and reads from the Info.plist by default but doesn't require it? Ex: [RCTConfiguration sharedConfiguration][@"scriptHost"] = ipAddress.

[sahrens]

cc @nicklockwood - were you planning on adding this to the dev menu? would be nice to move what we have internally to OSS with the bonjour stuff and app link support (rn://ip:X.X.X.X)

[jtremback]

Is there any way I can help with this? I've got to debug on device because my app uses the camera, and this stuff is a pain.

[frantic]

nit: space after )

[frantic]

I'm getting this in shortly :)

[nicklockwood]

Yeah, this isn't the right right way to handle URLs in iOS. You should probably do something like:

NSString *server = [[NSBundle mainBundle] objectForInfoDictionaryKey:@"ReactServer"];
if (server == nil) {
    server = @"http://localhost:8081";
}
NSURL *baseURL = [NSURL URLWithString:server];
NSURL *fullURL = [NSURL URLWithString:bundlePath relativeToURL:baseURL];

Although that also isn't completely bulletproof. Probably worth writing some unit tests with various combinations of missing or redundant prefixes and suffixes.

It may be worth using [RCTConvert NSURL:server] instead of [NSURL URLWithString:server] actually, as that handles a whole bunch of bad inputs gracefully already, and already has some tests.

[frantic]

@nicklockwood has a great point

[brentvatne]

@tobyhughes - any interest in updating this or can we close?