Nate Cook Nate Cook - 1 year ago 63
Objective-C Question

How can I retrieve Swift "header" files for Cocoa APIs?

The way I know I can view the automatically-translated Swift versions of Cocoa APIs is by command-clicking a Cocoa type in Xcode. For example, here's what is generated for UITableViewController:

class UITableViewController : UIViewController, UITableViewDelegate, NSObjectProtocol, UIScrollViewDelegate, UITableViewDataSource {

init(style: UITableViewStyle)

var tableView: UITableView!
var clearsSelectionOnViewWillAppear: Bool // defaults to YES. If YES, any selection is cleared in viewWillAppear:

var refreshControl: UIRefreshControl!

Is there an alternate way to make Xcode generate this Swift version? Preferably from the command line?

Answer Source

The Swift REPL includes a helper :print_decl <name> - print the AST representation of the named declarations

This blog post explains how you can write a simple script to help you use this to generate documentation for a specific type. I updated the script to allow using either OS X

#! /bin/sh
# usage: <shellscript> [--osx] typename

if [ "$1" = "--osx" ] ; then
    echo "import Cocoa\n:print_decl $2" | xcrun swift -deprecated-integrated-repl
    sdk_path=$(echo `xcrun --show-sdk-path` | sed 's#MacOSX.platform/Developer/SDKs/MacOSX10.10.sdk#iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator8.0.sdk#')
    echo "import UIKit\n:print_decl $1" | xcrun swift -deprecated-integrated-repl -sdk "$sdk_path"

Note 1: The script defaults to using the iOS SDK. If you want to use the OS X SDK use the "--osx" option as the first parameter

Note 2: I prefer to leave out the file output that is part of the blog post so that I can use this script in other ways than just file generation