Ecosyste.ms: Awesome

An open API service indexing awesome lists of open source software.

https://github.com/yonaskolb/Stylist

Define UI styles for iOS apps in a hot-reloadable yaml or json file
https://github.com/yonaskolb/Stylist

css hot-reload ios style styling swift tvos ui yaml

Last synced: about 1 month ago
JSON representation

Define UI styles for iOS apps in a hot-reloadable yaml or json file

Lists

README 

        
#  Stylist 🎨



[![Build Status](https://img.shields.io/circleci/project/github/yonaskolb/Stylist.svg?style=for-the-badge)](https://circleci.com/gh/yonaskolb/Stylist)

![Platforms](https://img.shields.io/cocoapods/p/Stylist.svg?style=for-the-badge)

[![Carthage compatible](https://img.shields.io/badge/Carthage-compatible-4BC51D.svg?style=for-the-badge)](https://github.com/Carthage/Carthage) [![CocoaPods version](https://img.shields.io/cocoapods/v/Stylist.svg?style=for-the-badge)](https://cocoapods.org/pods/Stylist)

[![license](https://img.shields.io/github/license/yonaskolb/Stylist.svg?style=for-the-badge)](https://github.com/yonaskolb/Stylist/blob/master/LICENSE)



Stylist lets you define UI styles for iOS apps in a hot-reloadable external yaml or json theme file



- ✅ Define styles in **external theme files**

- ✅ Apply styles **programmatically** or via **Interface Builder**

- ✅ **Hotload** themes to see results immediately without recompiling

- ✅ Apply styles to any **UIView**, **UIViewController**, **UITabBar**, and your own **custom** classes

- ✅ Apply styles by style **names** or **classes**

- ✅ Apply styles when contained in certain view **hierarchies**

- ✅ **Swap** entire themes on the fly

- ✅ Built in style properties for all popular **UIKit** classes

- ✅ Reference **Theme variables** for commonly used values

- ✅ Include styles **within other styles**

- ✅ Define **custom** strongly typed properties and custom parsing to dynamically set any property



Example theme:



```yaml

variables:

  primaryColor: "DB3B3B" # hex color

  headingFont: Ubuntu # reference loaded font

styles:

  MyApp.MyViewController: # applied to MyViewController class

    view: # access the view

      tintColor: $primaryColor # reference a variable

    navigationBar: # access the navigation bar

      barTintColor: red # use color name

      titleColor: white

  UIButton:

    backgroundImage: buttonBack # set image

    backgroundImage:highlighted: buttonBack-highlighted # for highlighted control state

  MyApp.Section:

    styles: [themed] # include other styles

    axis(horizontal:regular): horizontal # restrict by size class

    axis(horizontal:compact): vertical

  MyApp.Section UIStackView UILabel: # View containment selector

    textAlignment: right # use enums

  primaryButton:

    textColor: "55F" # shorted hex value

    contentEdgeInsets: [10,5] # set simplified UIEdgeInsets

    font(device:iphone): $headingFont:16 # reference font variable and change size

    font(device:ipad): $headingFont:22 # restrict to device

  secondaryButton:

    cornerRadius: 10 # set layer properties

    textColor: customColor # use named color

    font: 20 # use system font

    contentEdgeInsets: 6 # set UIEdgeInsets using a single value

  sectionHeading:

    font: title 2 # use UIFontTextStyle

    font: darGray:0.5 # built in color with alpha

  content:

    font: Arial:content # Use custom font with UIFontTextStyle

  themed: # style is referenced in other styles

    tintColor: $primaryColor

```

- [⬇️ Installing](#installing)

- [⚒ Usage](#usage)

  - [Loading a Theme](#loading-a-theme)

  - [Setting a Style](#setting-a-style)

  - [Hot Reloading](#hot-reloading)

- [🎨 Theme](#theme)

  - [Style Selectors](#style-selectors)

  - [Styles References](#style-references)

  - [View hierarchy styles](#view-hierarchy-styles)

  - [Style Context](#style-context)

- [🖌 Style Properties](#style-properties)

- [⚙️ Custom Properties](#custom-properties)

- [⚙️ Custom Styleable class](#custom-styleable-class)



## ⬇️ Installing



### Cocoapods

Add the following to your `podfile`



```sh

pod 'Stylist'

```



### Carthage

Add the following to your `Cartfile`

```sh

github "yonaskolb/Stylist"

```



## ⚒ Usage



Make sure to import Stylist



```swift

import Stylist

```



### Loading a Theme

To load a Theme use:



```swift

Stylist.shared.load(path: pathToFile)

```



You can load multiple themes, and they will all be applied as long as they have different paths.



You can also load a Theme manually and then add it by name, allowing you to swap themes at runtime.



```swift

let theme = try Theme(path: pathToTheme)

Stylist.shared.addTheme(theme, name: "mainTheme")

```



### Setting a Style

Class styles will be applied to `UIView` when they are added to a superview, and to `UIViewController` when `viewDidLoad()` is called.



To set a custom style on a Styleable class, simply set its `style` property. You can set multiple styles by comma separating them.



#### Programmatically



```swift

myView.style = "myStyle"

otherView.style = "myStyle,otherStyle"

```



#### Interface Builder



Styles can be set in Interface Builder in the property inspector






### Hot Reloading

You can choose to watch a Theme files which means that whenever that file is changed the styles are reloaded. These changes can also be animated!



Themes can live at a remote url allowing you to update styles remotely.



Hotloading can be very useful while developing, as you can make changes to your styles on the fly without recompiling and see the results animate in instantly! To watch a file simply call `watch` on stylist and pass in a URL to a local file on disk or a remote url:



```swift

Stylist.shared.watch(url: fileOrRemoteURL, animateChanges: true) { error in

  print("An error occurred while loading or parsing the file: \(error)")

}

```

If an error occurs at any time the `parsingError` callback will be called with a `ThemeError`, which will tell you exactly what went wrong including any formatting errors or invalid references. This means if you accidentally save an invalid theme you don't have to worry that your app will blow up.



To stop watching the file, you can call `stop()` on the `FileWatcher` that is returned.



> Note that if a style property was present and you then remove it, Stylist cannot revert the change so that property will remain in the previous state.



## 🎨 Theme



A Theme file has a list of `variables` and a list of `styles`.

Variables can be referenced in styles using `$variableName`.



Styles are defined by [selector](#selectors), and are a map of [properties](Docs/StyleProperties.MD#properties) to [values](Docs/StyleProperties.MD#types)



```yml

variables:

  primaryColor: "DB3B3B"

styles:

  primary:

    color: $primaryColor

```



### Style Selectors

Styles are defined using one or more selectors. Selectors can be a class or a style name or both. Custom classes must be prefixed by the module name. Style names must start with a lowercase.



For example:



- `UIButton` all UIButtons

- `MyApp.MyView` all MyView classes in the MyApp Module

- `UITabBar.primary` all tab bars with the primary style

- `primary` all styleables with the primary style



There can be multiple selectors separated by a space, which then check if the later selectors are contained in the earlier selectors. This only applies to UIViews and UIViewControllers. The containers don't have to be direct superviews but can be further up the responder chain.



For example, the following style will be applied to any `UIButton` that is contained within a view with a `section` style, that is within a `UIStackView` with the `main` style, and then within a `UINavigationController`.



```yaml

styles:

  UINavigationController UIStackView.main section UIButton:

    font: title3

```



Styles will be applied in order of specificity, so the more specific a style is (more selectors), the later it will be applied.



### Style references



Each style may also have a `styles` array that is an array of other inherited styles, who's properties will also be applied without overwriting anything.



```yml

styles:

  primary:

    styles: [themed]

  themed:

    tintColor: red

    backgroundColor: EEEEEE

```



### View hierarchy styles



Styles can reference the view hierarchy and then style that with its own properties. This is really useful for testing or accessing parts of the view hierarchy easily (`UIViewController.view` for example)



The sub styles are available on the following types:



- **UIView**

	- `superview`: The superview

	- `next`: The next sibling view

	- `previous`: The previous sibling view

	- `viewController`: The view controller the view belongs to

- **UIViewController**

	- `view`: The root view

	- `parent`: The parent view controller

	- `navigationController`: The UINavigationController this is contained in

	- `tabBarController`: The UITabBarController this is contained in

	- `tabBar`: The UITabBar for this view controller. Can be accessed on any child view controller

	- `navigationBar`: The UINavigationBar for this view controller. Can be accessed on any child view controller



```yml

styles:

  MyApp.MyViewController:

    view:

      tintColor: red

    navigationBar:

      tintColor: red

```



### Style Context

Style properties can be restricted to a certain context, for example a certain control state or trait collection. This is similar to how CSS media queries work. See [Context](Docs/StyleProperties.MD#context) for more info



```yml

styles:

  UIButton.primary:

    backgroundImage: buttonBack

    backgroundImage:highlighted: buttonBack-highlighted

  UIStackView.main:

    axis(horizontal:regular): horizontal

    axis(horizontal:compact): vertical

  title:

    font(device:iphone): $headingFont:16

    font(device:ipad): $headingFont:22

```



## 🖍 Style Properties

Many UIKit views and bar buttons have built in properties that you can set. These can be viewed in [Style Properties](Docs/StyleProperties.MD).



## ⚙️ Custom Properties

Custom properties and parsers can also be added to let you configure anything you wish in a strongly typed way.



To create a `StyleProperty` pass a name and a generic closure that sets the property. Make sure to provide types for the styleable class and the generic `PropertyValue`.



```swift

// creates a new property that is applies a TextTransform to a MyLabel

// access the property context and value via the PropertyValue

let property = StyleProperty(name: "textTransform") { (view: MyLabel, value: PropertyValue) in

    view.textTransform = value.value

}



// adds the custom property to Stylist

Stylist.shared.addProperty(property)

```



The value must conform to `StyleValue` which is a simple protocol:



```swift

public protocol StyleValue {

    associatedtype ParsedType

    static func parse(value: Any) -> ParsedType?

}

```



The `PropertyValue` will have a `value` property containing your parsed value. It also has a `context` which contains the [property context](Docs/StyleProperties.MD#context) like device type, UIControlState, UIBarMetrics, size classes..etc.



When a theme is loaded or when a style is set on a view, these custom properties will be applied if the view type and property name match.



Many different types of properties are already supported and listed here in [Style Property Types](Docs/StyleProperties.MD#types)



## ⚙️ Custom Styleable class

By default `UIView`, `UIViewController` and `UIBarItem` are styleable. You can make any custom class styleable as well by conforming to the `Styleable` protocol.

The inbuilt `Styleable` classes automatically call `applyStyles`, so you will have to do that automatically in your `styles` setter.



```swift

public protocol Styleable: class {

    var styles: [String] { get set }

}



extension Styleable {



    func applyStyles() {

        Stylist.shared.style(self)

    }

}

```



## 👥 Attributions



This tool is powered by:



- [KZFileWatchers](https://github.com/krzysztofzablocki/KZFileWatchers)

- [Yams](https://github.com/jpsim/Yams)



## 👤 Contributions

Pull requests and issues are welcome



## 📄 License



Stylist is licensed under the MIT license. See [LICENSE](LICENSE) for more info.