NSXMLParser简单示例
大多数如何调用NSXMLParser的示例都包含在涉及应用程序的复杂项目中。 什么是演示callback的简单示例。
作为探索NSXMLParser的一部分，我创build了以下非常简单的代码。
的main.m
int main(int argc, const char * argv[]) { @autoreleasepool { NSLog(@"Main Started"); NSError *error = nil; // Load the file and check the result NSData *data = [NSData dataWithContentsOfFile:@"/Users/Tim/Documents/MusicXml/Small.xml" options:NSDataReadingUncached error:&error]; if(error) { NSLog(@"Error %@", error); return 1; } // Create a parser and point it at the NSData object containing the file we just loaded NSXMLParser *parser = [[NSXMLParser alloc] initWithData:data]; // Create an instance of our parser delegate and assign it to the parser MyXmlParserDelegate *parserDelegate = [[MyXmlParserDelegate alloc] init]; [parser setDelegate:parserDelegate]; // Invoke the parser and check the result [parser parse]; error = [parser parserError]; if(error) { NSLog(@"Error %@", error); return 1; } // All done NSLog(@"Main Ended"); } return 0; } MyXmlParserDelegate.h
#import <Foundation/Foundation.h> @interface MyXmlParserDelegate : NSObject <NSXMLParserDelegate> @end
MyXmlParserDelegate.m
#import "MyXmlParserDelegate.h" @implementation MyXmlParserDelegate - (void) parserDidStartDocument:(NSXMLParser *)parser { NSLog(@"parserDidStartDocument"); } - (void)parser:(NSXMLParser *)parser didStartElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName attributes:(NSDictionary *)attributeDict { NSLog(@"didStartElement --> %@", elementName); } -(void) parser:(NSXMLParser *)parser foundCharacters:(NSString *)string { NSLog(@"foundCharacters --> %@", string); } - (void)parser:(NSXMLParser *)parser didEndElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName { NSLog(@"didEndElement --> %@", elementName); } - (void) parserDidEndDocument:(NSXMLParser *)parser { NSLog(@"parserDidEndDocument"); } @end
我已经发布了它，希望它可以帮助别人。
以下是原始Objective-C代码的Swift版本。
它是使用XCode 7.3构build和testing的。 在写代理时，我发现从文档中复制函数原型非常方便。 值得注意的是，Swift目前是一个相当迅速移动的目标。
main.swift
import Foundation // Let's go print("Main: Started") // Try to load the file. Display the description of the error if one occurs var xmlData : NSData do { xmlData = try NSData(contentsOfFile: "/Users/amt/Documents/TestXml/Test.xml", options: .DataReadingMappedIfSafe) } catch let error as NSError { print("Main: \(error.description)") exit(1) } // Create a parser and point it at the NSData object containing // the file we just loaded var parser : NSXMLParser! = NSXMLParser(data: xmlData) // Create a parser delegate object and assign it to the parser // Beware the "weak" reference and don't try to combine the two lines // of code into one unless you like EXC_BAD_ACCESS exceptions var parserDelegate : MyXmlParserDelegate = MyXmlParserDelegate() parser.delegate = parserDelegate // This example also illustrates some of the namespace functions defined in // the delegate protocol so enable namespace reporting to see them invoked parser.shouldReportNamespacePrefixes = true // Parse the document if !parser.parse() { // If parse() returned false then an error occurred so display is location // and details let error = parser.parserError let line = parser.lineNumber let col = parser.columnNumber print("Parsing failed at \(line):\(col): \(error?.localizedDescription)") } // All done print("Main: Ended") exit(0)
MyXmlParserDelegate.swift
import Foundation class MyXmlParserDelegate:NSObject, NSXMLParserDelegate { @objc func parserDidStartDocument(parser: NSXMLParser) { print("parserDidStartDocument") } @objc func parser(parser: NSXMLParser, didStartElement elementName: String, namespaceURI: String?, qualifiedName qName: String?, attributes attributeDict: [String : String]) { print("didStartElement --> \(elementName)") } @objc func parser(parser: NSXMLParser, foundCharacters string: String) { print("foundCharacters --> \(string)") } @objc func parser(parser: NSXMLParser, didEndElement elementName: String, namespaceURI: String?, qualifiedName qName: String?) { print("didEndElement --> \(elementName)") } @objc func parser(parser: NSXMLParser, didStartMappingPrefix prefix: String, toURI namespaceURI: String) { print("didStartMappingPrefix --> Prefix: \(prefix) toURI: \(namespaceURI)") } @objc func parser(parser: NSXMLParser, didEndMappingPrefix prefix: String) { print("didEndMappingPrefix --> Prefix: \(prefix)") } @objc func parserDidEndDocument(parser: NSXMLParser) { print("parserDidEndDocument") } }
Swift 4示例 – parsingXib文件。
import Foundation class XMLTransformer: NSObject { private let parser: XMLParser private var stack = [Node]() private var tree: Node? init(data: Data) { parser = XMLParser(data: data) super.init() parser.delegate = self } } extension XMLTransformer { func transform() throws -> Node? { parser.parse() if let e = parser.parserError { throw e } assert(stack.isEmpty) assert(tree != nil) return tree } } extension XMLTransformer: XMLParserDelegate { func parser(_ parser: XMLParser, didStartElement elementName: String, namespaceURI: String?, qualifiedName qName: String?, attributes attributeDict: [String : String] = [:]) { guard let tag = Tag(rawValue: elementName) else { return } let node = Node(tag: tag, attributes: attributeDict, nodes: []) stack.append(node) } func parser(_ parser: XMLParser, didEndElement elementName: String, namespaceURI: String?, qualifiedName qName: String?) { guard let tag = Tag(rawValue: elementName) else { return } let lastElement = stack.removeLast() assert(lastElement.tag == tag) if let last = stack.last { last.nodes += [lastElement] } else { tree = lastElement } } } extension XMLTransformer { enum Tag: String { case document case objects case tableViewCell, tableViewCellContentView case subviews case mapView case constraints, constraint case connections, outlet } } extension XMLTransformer { class Node { let tag: Tag let attributes: [String : String] var nodes: [Node] init(tag: Tag, attributes: [String : String], nodes: [Node] = []) { self.tag = tag self.attributes = attributes self.nodes = nodes } } }
用法：
let data = try xib(named: "MapTableViewCell") let c = XMLTransformer(data: data) let tree = try c.transform() // Here you have parsed XML in a Tree representation.
