Simple libxml2 HTML parsing example, using Objective-c, Xcode, and HTMLparser.h

问题

Please can somebody show me a simple example of parsing some HTML using libxml.

#import <libxml2/libxml/HTMLparser.h>

NSString *html = @"<ul>"
    "<li><input type=\"image\" name=\"input1\" value=\"string1value\" /></li>"
    "<li><input type=\"image\" name=\"input2\" value=\"string2value\" /></li>"
  "</ul>"
  "<span class=\"spantext\"><b>Hello World 1</b></span>"
  "<span class=\"spantext\"><b>Hello World 2</b></span>";

1) Say I want to parse the value of the input whose name = input2.

Should output "string2value".

2) Say I want to parse the inner contents of each span tag whose class = spantext.

Should output: "Hello World 1" and "Hello World 2".

回答1:

I used Ben Reeves' HTML Parser to achieve what I wanted:

NSError *error = nil;
NSString *html = 
    @"<ul>"
        "<li><input type='image' name='input1' value='string1value' /></li>"
        "<li><input type='image' name='input2' value='string2value' /></li>"
    "</ul>"
    "<span class='spantext'><b>Hello World 1</b></span>"
    "<span class='spantext'><b>Hello World 2</b></span>";
HTMLParser *parser = [[HTMLParser alloc] initWithString:html error:&error];

if (error) {
    NSLog(@"Error: %@", error);
    return;
}

HTMLNode *bodyNode = [parser body];

NSArray *inputNodes = [bodyNode findChildTags:@"input"];

for (HTMLNode *inputNode in inputNodes) {
    if ([[inputNode getAttributeNamed:@"name"] isEqualToString:@"input2"]) {
        NSLog(@"%@", [inputNode getAttributeNamed:@"value"]); //Answer to first question
    }
}

NSArray *spanNodes = [bodyNode findChildTags:@"span"];

for (HTMLNode *spanNode in spanNodes) {
    if ([[spanNode getAttributeNamed:@"class"] isEqualToString:@"spantext"]) {
        NSLog(@"%@", [spanNode allContents]); //Answer to second question
    }
}

[parser release];

回答2:

As Vladimir said, for the second point it's important to replace rawContents with Contents. rawContents will print the complete raw text node, i.e.:

<span class='spantext'><b>Hello World 1</b></span>

来源：https://stackoverflow.com/questions/3020849/simple-libxml2-html-parsing-example-using-objective-c-xcode-and-htmlparser-h

标签

objective-c

xcode

html-parsing

libxml2