Attributed：便捷、实用的属性字符串扩展

A Modern interface for attributed strings.

Usage

This library aims to be a drop in replacement to the current programming interface of NSAttributedString. The existing interface to using attributed strings has a few flaws, namely if you dont know the Key and type of value needed to set a certain attribute, you have spend time checking documentation or the reading the comments for NSAttributedString. Another concern is safety, passing a dictionary of type [String: Any] to the constructor of NSAttributedString is a potential crash at runtime waiting to happen.

Say for example one wished to create a attributed string with text colored red, a font of Chalkduster and to have the string underlined.

Given the existing API that would look something like this:

let attributes: [String: Any] = [
    NSForegroundColorAttributeName: UIColor.red,
    NSFontAttributeName: UIFont(name: "Chalkduster", size: 24.0)!,
    NSUnderlineStyleAttributeName: 1,
]

let text = NSAttributedString(string: "Hello", attributes: attributes)

To produce the exact same string using this library one could write the following:

let attributes = Attributes {
    return $0.foreground(color: .red)
             .font(UIFont(name: "Chalkduster", size: 24.0)!)
             .underlineStyle(.styleSingle)
}

"Hello".attributed(with: attributes)

Attributes

The [String: Any] attributes dictionary that was passed to the NSAttributedString constructor as in NSAttributedString(string: "Hello", attributes: attributes) has been made an actual type Attributes.

There are two intefaces for working with the Attributes type. The suggested interface is the Constructor interface that accepts a closure that returns an Attributes object.

let attributes = Attributes {
    return $0.foreground(color: .red)
             .font(UIFont(name: "Chalkduster", size: 24.0)!)
             .underlineStyle(.styleSingle)
}

The second way of working with Attribute objects is to set properties one method call at a time. The benefit of this interface is a base set of attributes can be created and then that base set of attributes can then be freely modified. Since Attributes is of type struct there is zero chance of corrupting the original base Attributes object by working this way.

let baseAttributes = Attributes().font(UIFont(name: "Chalkduster", size: 24.0)!)

let accentedAttributes = baseAttribues.foreground(color: .red) 
                                      .underlineStyle(.styleSingle)

Extensions to String

Two extensions have been made to the type String. The first is: attributed(with: attributes) where attributes is an object of type Attributes. This function will return an NSAttributedString from an object of type String.

"Hello".attributed(with: attributes)

The second interface is similar but takes closure given a blank Attributes that the user can modify and return to be used in constructing an NSAttributedString.

let nameLabel.attributedText = "Steve".attributed {
                                      return $0.font(UIFont(name: "Chalkduster", size: 24.0)!)
                                               .foreground(color: .red)
                                               .underlineStyle(.styleSingle)
                               }

Installation

Carthage

If you use Carthage to manage your dependencies, simply add Attributed to your Cartfile:

github "Nirma/Attributed"

If you use Carthage to build your dependencies, make sure you have added Attributed.framework to the "Linked Frameworks and Libraries" section of your target, and have included Attributed.framework in your Carthage framework copying build phase.

CocoaPods

If you use CocoaPods to manage your dependencies, simply add Attributed to your Podfile:

pod 'AttributedLib'

Requirements

• Xcode 8.0
• Swift 3.0+

Contribution

Contributions are more than welcome!

License

Attributed is free software, and may be redistributed under the terms specified in the LICENSE file.