A fast & lightweight XML & HTML parser in Swift with XPath & CSS support

by iOS Example

Fuzi (斧子)

A fast & lightweight XML/HTML parser in Swift that makes your life easier. [Documentation]

Fuzi is based on a Swift port of Mattt Thompson's Ono(斧), using most of its low level implementaions with moderate class & interface redesign following standard Swift conventions, along with several bug fixes.

Fuzi(斧子) means "axe", in homage to Ono(斧), which in turn is inspired by Nokogiri (鋸), which means "saw".

A Quick Look

let xml = "..."
// or
// let xmlData = <some NSData or Data>
do {
  let document = try XMLDocument(string: xml)
  // or
  // let document = try XMLDocument(data: xmlData)
  
  if let root = document.root {
    // Accessing all child nodes of root element
    for element in root.children {
      print("\(element.tag): \(element.attributes)")
    }
    
    // Getting child element by tag & accessing attributes
    if let length = root.firstChild(tag:"Length", inNamespace: "dc") {
      print(length["unit"])     // `unit` attribute
      print(length.attributes)  // all attributes
    }
  }
  
  // XPath & CSS queries
  for element in document.xpath("//element") {
    print("\(element.tag): \(element.attributes)")
  }
  
  if let firstLink = document.firstChild(css: "a, link") {
    print(firstLink["href"])
  }
} catch let error {
  print(error)
}

Features

Inherited from Ono

  • Extremely performant document parsing and traversal, powered by libxml2
  • Support for both XPath and CSS queries
  • Automatic conversion of date and number values
  • Correct, common-sense handling of XML namespaces for elements and attributes
  • Ability to load HTML and XML documents from either String or NSData or [CChar]
  • Comprehensive test suite
  • Full documentation

Improved in Fuzi

  • Simple, modern API following standard Swift conventions, no more return types like AnyObject! that cause unnecessary type casts
  • Customizable date and number formatters
  • Some bugs fixes
  • More convenience methods for HTML Documents
  • Access XML nodes of all types (Including text, comment, etc.)
  • Support for more CSS selectors (yet to come)

Requirements

  • iOS 8.0+ / Mac OS X 10.9+
  • Xcode 8.0+

Use version 0.4.0 for Swift 2.3.

Installation

There are 4 ways you can install Fuzi to your project.

Using CocoaPods

You can use CocoaPods to install Fuzi by adding it to your to your Podfile:

platform :ios, '8.0'
use_frameworks!

target 'MyApp' do
	pod 'Fuzi', '~> 1.0.0'
end

Then, run the following command:

$ pod install

Using Swift Package Manager

The Swift Package Manager is now built-in with Xcode 11 (currently in beta). You can easily add Fuzi as a dependency by choosing File > Swift Packages > Add Package Dependency... or in the Swift Packages tab of your project file and clicking on +.
Simply use https://github.com/cezheng/Fuzi as repository and Xcode should automatically resolve the current version.

Manually

  1. Add all *.swift files in Fuzi directory into your project.
  2. In your Xcode project Build Settings:
    1. Find Search Paths, add $(SDKROOT)/usr/include/libxml2 to Header Search Paths.
    2. Find Linking, add -lxml2 to Other Linker Flags.

Using Carthage

Create a Cartfile or Cartfile.private in the root directory of your project, and add the following line:

github "cezheng/Fuzi" ~> 1.0.0

Run the following command:

$ carthage update

Then do the followings in Xcode:

  1. Drag the Fuzi.framework built by Carthage into your target's General -> Embedded Binaries.
  2. In Build Settings, find Search Paths, add $(SDKROOT)/usr/include/libxml2 to Header Search Paths.

Usage

XML

import Fuzi

let xml = "..."
do {
  // if encoding is omitted, it defaults to NSUTF8StringEncoding
  let document = try XMLDocument(string: html, encoding: String.Encoding.utf8)
  if let root = document.root {
    print(root.tag)
    
    // define a prefix for a namespace
    document.definePrefix("atom", defaultNamespace: "http://www.w3.org/2005/Atom")
    
    // get first child element with given tag in namespace(optional)
    print(root.firstChild(tag: "title", inNamespace: "atom"))

    // iterate through all children
    for element in root.children {
      print("\(index) \(element.tag): \(element.attributes)")
    }
  }
  // you can also use CSS selector against XMLDocument when you feels it makes sense
} catch let error as XMLError {
  switch error {
  case .noError: print("wth this should not appear")
  case .parserFailure, .invalidData: print(error)
  case .libXMLError(let code, let message):
    print("libxml error code: \(code), message: \(message)")
  }
}

HTML

HTMLDocument is a subclass of XMLDocument.

import Fuzi

let html = "<html>...</html>"
do {
  // if encoding is omitted, it defaults to NSUTF8StringEncoding
  let doc = try HTMLDocument(string: html, encoding: String.Encoding.utf8)
  
  // CSS queries
  if let elementById = doc.firstChild(css: "#id") {
    print(elementById.stringValue)
  }
  for link in doc.css("a, link") {
      print(link.rawXML)
      print(link["href"])
  }
  
  // XPath queries
  if let firstAnchor = doc.firstChild(xpath: "//body/a") {
    print(firstAnchor["href"])
  }
  for script in doc.xpath("//head/script") {
    print(script["src"])
  }
  
  // Evaluate XPath functions
  if let result = doc.eval(xpath: "count(/*/a)") {
    print("anchor count : \(result.doubleValue)")
  }
  
  // Convenient HTML methods
  print(doc.title) // gets <title>'s innerHTML in <head>
  print(doc.head)  // gets <head> element
  print(doc.body)  // gets <body> element
  
} catch let error {
  print(error)
}

I don't care about error handling

import Fuzi

let xml = "..."

// Don't show me the errors, just don't crash
if let doc1 = try? XMLDocument(string: xml) {
  //...
}

let html = "<html>...</html>"

// I'm sure this won't crash
let doc2 = try! HTMLDocument(string: html)
//...

I want to access Text Nodes

Not only text nodes, you can specify what types of nodes you would like to access.

let document = ...
// Get all child nodes that are Element nodes, Text nodes, or Comment nodes
document.root?.childNodes(ofTypes: [.Element, .Text, .Comment])

Migrating From Ono?

Looking at example programs is the swiftest way to know the difference. The following 2 examples do exactly the same thing.

Ono Example

Fuzi Example

Accessing children

Ono

[doc firstChildWithTag:tag inNamespace:namespace];
[doc firstChildWithXPath:xpath];
[doc firstChildWithXPath:css];
for (ONOXMLElement *element in parent.children) {
  //...
}
[doc childrenWithTag:tag inNamespace:namespace];

Fuzi

doc.firstChild(tag: tag, inNamespace: namespace)
doc.firstChild(xpath: xpath)
doc.firstChild(css: css)
for element in parent.children {
  //...
}
doc.children(tag: tag, inNamespace:namespace)

Iterate through query results

Ono

Conforms to NSFastEnumeration.

// simply iterating through the results
// mark `__unused` to unused params `idx` and `stop`
[doc enumerateElementsWithXPath:xpath usingBlock:^(ONOXMLElement *element, __unused NSUInteger idx, __unused BOOL *stop) {
  NSLog(@"%@", element);
}];

// stop the iteration at second element
[doc enumerateElementsWithXPath:XPath usingBlock:^(ONOXMLElement *element, NSUInteger idx, BOOL *stop) {
  *stop = (idx == 1);
}];

// getting element by index 
ONOXMLDocument *nthElement = [(NSEnumerator*)[doc CSS:css] allObjects][n];

// total element count
NSUInteger count = [(NSEnumerator*)[document XPath:xpath] allObjects].count;

Fuzi

Conforms to Swift's SequenceType and Indexable.

// simply iterating through the results
// no need to write the unused `idx` or `stop` params
for element in doc.xpath(xpath) {
  print(element)
}

// stop the iteration at second element
for (index, element) in doc.xpath(xpath).enumerate() {
  if idx == 1 {
    break
  }
}

// getting element by index 
if let nthElement = doc.css(css)[n] {
  //...
}

// total element count
let count = doc.xpath(xpath).count

Evaluating XPath Functions

Ono

ONOXPathFunctionResult *result = [doc functionResultByEvaluatingXPath:xpath];
result.boolValue;    //BOOL
result.numericValue; //double
result.stringValue;  //NSString

Fuzi

if let result = doc.eval(xpath: xpath) {
  result.boolValue   //Bool
  result.doubleValue //Double
  result.stringValue //String
}

License

Fuzi is released under the MIT license. See LICENSE for details.

GitHub

https://github.com/cezheng/Fuzi