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

Question

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".

libxml is for xml parsing and for that you need to see TouchXML. — Ayaz Alavi
– Ayaz Alavi, Commented Jun 11, 2010 at 7:56
Even though I'm using HTMLparser.h? I'll take a look at TouchXML thanks. — StuR
– StuR, Commented Jun 11, 2010 at 8:37
@Ayaz: libxml2 supports HTML4 parsing. From the sparse documentation of TouchXML, it seems it doesn't, so it's not appropriate in this instance. — JeremyP
– JeremyP, Commented Jun 11, 2010 at 10:17
touchXML contains CXMLDocumentTidyHTML property in their CXMLDocument.h file, inferring from that this problem could be solved using touchXML also you can see KissXML which is inspired from touchXML. For pure HTML parser I just found a link touchtank.wordpress.com/element-parser .. see if it fits for your needs — Ayaz Alavi
– Ayaz Alavi, Commented Jun 11, 2010 at 10:29
github.com/zootreeves/Objective-C-HMTL-Parser Did what I wanted, thanks v much for your help. — StuR
– StuR, Commented Jun 11, 2010 at 14:12

StuR · Accepted Answer · 2012-10-24 10:46:45Z

19

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];

edited Oct 24, 2012 at 10:46

answered Jun 11, 2010 at 14:11

StuR

12.3k9 gold badges47 silver badges66 bronze badges

Sign up to request clarification or add additional context in comments.

3 Comments

clarky Over a year ago

I know this is old, but I'm pretty sure he wants "allContents" and not "rawContents"

Dejell Over a year ago

@StuR does his library work for iphone development io6 as well?

StuR Over a year ago

@Odelya I should think so, although I haven't tested it. You may need to set a no arc compiler flag.

ElPiter · Accepted Answer · 2012-02-26 21:42:51Z

1

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>

answered Feb 26, 2012 at 21:42

ElPiter

4,33210 gold badges60 silver badges82 bronze badges

Collectives™ on Stack Overflow

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

2 Answers 2

3 Comments

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

3 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related