HTML解析：如何从远程站点获取链接标记

Question

I have a site (for example apple.com ) which contain link tag, for example

<link rel="alternate" type="application/rss+xml" title="RSS" href="http://images.apple.com/main/rss/hotnews/hotnews.rss" />

So how I can get title "RSS" and href from it?

Update 1: I've tried to convert site into string using

NSData *data = [NSURLConnection sendSynchronousRequest:[NSURLRequest requestWithURL:[NSURL URLWithString:@"http://apple.com/"]] returningResponse:NULL error:NULL];
NSString *HTMLWithFeeds = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];

But I dont know what to do now...

Update 2:

It is not clear from my post, but in addition in should find at this site link with type="application/rss+xml"

Answer 1

you might try using regular expressions

NSError *error = NULL;
NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:@"<link.*?href="(.*?)".*?>"
                                                                           options:NSRegularExpressionCaseInsensitive
                                                                             error:&error];

NSArray *matches = [regex matchesInString:string
                                  options:0
                                    range:NSMakeRange(0, [string length])];
for (NSTextCheckingResult *match in matches) {
     NSRange matchRange = [match range];
     NSRange firstHalfRange = [match rangeAtIndex:1];
     NSRange secondHalfRange = [match rangeAtIndex:2];
}

Apples documentation has some examples about how to further use and access the matches:

https://developer.apple.com/library/ios/#documentation/Foundation/Reference/NSRegularExpression_Class/Reference/Reference.html

eg something like the following regex should do for the hrefs:

<link.*?href="(.*?)".*?>

Answer 2

if you using jquery, $("link").attr("title"） --> print "RSS" $("link").attr("href") --> print http:// *

if you want to get the href content, using jquery ajax. $.get("http:// * ", function(result){});

Answer 3

Create an NSXMLDocument using -initWithContentsOfURL:options:error: with the NSXMLDocumentTidyHTML option. Then, you can navigate the hierarchy of nodes starting with -rootElement . Or, you can use XPath, like [doc nodesForXPath:@"//link@title"] .