Natalie

Natalie - Storyboard Code Generator (for Swift)

Synopsis

Script generate Swift code based on storyboard files to make work with Storyboards and segues easier. Generated file reduce usage of Strings as identifiers for Segues or Storyboards.

This is a proof of concept to address the String issue for strongly typed Swift language. Natalie is a Swift script (written in Swift) that produces a single .swift file with a bunch of extensions to project classes along the generated Storyboard enum.

Since Natalie is a Swift script, that means it is written in Swift and requires Swift to run. The project uses SWXMLHash as a dependency to parse XML and due to framework limitations all code is in a single file.

###Enumerate Storyboards Generated enum Storyboards with convenient interface (drop-in replacement for UIStoryboard).

struct Storyboards {
    struct Main {...}
    struct Second {...}
    ...

Instantiate initial view controller for storyboard

let vc = Storyboards.Main.instantiateInitialViewController()

Instantiate ScreenTwoViewController in storyboard, using storyboard id

let vc = Storyboards.Main.instantiateScreenTwoViewController()

example usage for prepareForSegue()

override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
  if segue == MainViewController.Segue.ScreenOneSegue {	
	let viewController = segue.destinationViewController as? MyViewController
    viewController?.view.backgroundColor = UIColor.yellowColor()
  }
}

...it could be switch { } statement, but it's broken.

###Segues

Perform segue

self.performSegue(MainViewController.Segue.ScreenOneSegue, sender:nil)

Each custom view controller is extended with this code and provide list of available segues and additional informations from Storyboard.

Segue enumeration contains list of available segues

kind property represent types Segue

destination property return type of destination view controller.

extension MainViewController { 

    enum Segue: String, Printable, SegueProtocol {
        case ScreenOneSegueButton = "Screen One Segue Button"
        case ScreenOneSegue = "ScreenOneSegue"

        var kind: SegueKind? {
            ...
        }

        var destination: UIViewController.Type? {
            switch (self) {
            case ScreenOneSegueButton:
                return ScreenOneViewController.self
            case ScreenOneSegue:
                return ScreenOneViewController.self
            default:
                assertionFailure("Unknown destination")
                return nil
            }
        }

        var identifier: String { return self.description } 
        var description: String { return self.rawValue }
    }
}

###Reusable Views To Improve Performance

Collections and tables views use reuseidentifier on cell to recycle a view.

If you define it, their custom view controllers will be extended with an Reusable enumeration, which contains list of available reusable identifiers

example to dequeue a view with Reusable enumeration with UITableView:

func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
    let cell = tableView.dequeueReusableCell(ScreenTwoViewController.Reusable.MyCell, forIndexPath: indexPath) as! UITableViewCell
    cell.textLabel?.text = "\(indexPath.row)"
    return cell
}

Before dequeuing your view, you must register a class or a xib for each identifier. If your cell view has custom class defined in storyboard, in your controller you can call directly

override func viewDidLoad()  {
    tableView.registerReusableCell(MainViewController.Reusable.MyCell)
}

You can pass the view instead - the view must define the reuseidentifier

    tableView.registerReusableCell(tableViewCell)

If your custom reusable view, you can also execute code according to reusable values

class MyCustomTableViewCell: UITableViewCell {
    override func prepareForReuse() {
        if self == MyCustomTableViewController.Reusable.MyCell {
            ...
        }
        else if self == MyCustomTableViewController.Reusable.mySecondCellId {
            ...
        }
    }
}

##Installation

There is no need to do any installation, however if you want easy Xcode integration you may want to install the script to be easily accessible for any application from /usr/local/bin

$ brew install natalie

$ git clone https://github.com/krzyzanowskim/Natalie.git
$ sudo cp natalie.swift /usr/local/bin/natalie.swift

You can also put natalie.swift file at the root of your project folder and keep it under version control like this everyone even your CI will be able to generate the files.

###Xcode Integration

Natalie can be integrated with Xcode in such a way that the Storyboards.swift file will be updated with every build of the project, so you don't have to do it manually every time.

This is my setup created with New Run Script Phase on Build Phase Xcode target setting. It is important to move this phase above Compilation phase because this file is expected to be up to date for the rest of the application.

echo "Natalie Generator: Determining if generated Swift file is up-to-date."

NATALIE_PATH="/usr/local/bin/natalie.swift"
#If you put natalie.swift on the project folder
# NATALIE_PATH="$PROJECT_DIR/natalie.swift"

if [ -f $NATALIE_PATH ]; then
    BASE_PATH="$PROJECT_DIR/$PROJECT_NAME"
    //
    OUTPUT_PATH="$BASE_PATH/Storyboards.swift"
    
    if [ ! -e "$OUTPUT_PATH" ] || [ -n "$(find "$BASE_PATH" -type f -name "*.storyboard" -newer "$OUTPUT_PATH" -print -quit)" ]; then
        echo "Natalie Generator: Generated Swift is out-of-date; re-generating..."

        /usr/bin/chflags nouchg "$OUTPUT_PATH"
        "$NATALIE_PATH" "$BASE_PATH" > "$OUTPUT_PATH"
        /usr/bin/chflags uchg "$OUTPUT_PATH"

        echo "Natalie Generator: Done."
    else
        echo "Natalie Generator: Generated Swift is up-to-date; skipping re-generation."
    fi
fi

Don't forget to add Storyboards.swift to the project.

##Usage:

Download Natalie from Github: https://github.com/krzyzanowskim/Natalie and use it in the console, for example like this:

$ git clone https://github.com/krzyzanowskim/Natalie.git
$ cd Natalie

The script expects one of two types of parameters:

path to a single .storyboard file
path to a folder

If the parameter is a Storyboard file, then this file will be used. If a path to a folder is provided Natalie will generate code for every storyboard found inside.

$ natalie.swift NatalieExample/NatalieExample/Base.lproj/Main.storyboard > NatalieExample/NatalieExample/Storyboards.swift

##Contribution

Please submit Pull Request against current development branch (today it is Swift2 branch)

Author and contact

Marcin Krzyżanowski

Licence

The MIT License (MIT)

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

slangley/Natalie

Natalie

Synopsis

Author and contact

Licence