to extract a part of the URl after XML parsing?

Question

Hi Guys..

I am trying to parse an XML file in which an element named "description" is as given below:

 <description><![CDATA[<a href='http://www.okmagazine.com/posts/view/13756/'&gt;&lt;img src='http://www.okmagazine.com/img/photos/thumbs/27044' /></a><br />Ashlee and Pete take their tiny tot to FAO Schwarz in NYC for some new toys. <p> <strong>Pete Wentz</strong> and <strong>Ashlee Simpson Wentz</strong> made the new parent pilgrimage to New York’s FAO Schwarz today, where 6-month old <strong>Bronx Mowgli </strong>was the...]]></description>

What I want is to get the link in the tag <img src='http://www.okmagazine.com/img/photos/thumbs/27044'&gt; using which I can display an image in my image view... How can I separate this string from the contents of description tag?

A part of code when parsing is as given below

- (void)parser:(NSXMLParser *)parser foundCharacters:(NSString *)string{
    //NSLog(@"found characters: %@", string);
    // save the characters for the current item...
    if ([currentElement isEqualToString:@"title"]) {
     [currentTitle appendString:string];
    } else if ([currentElement isEqualToString:@"link"]) {
     [currentLink appendString:string];
    } else if ([currentElement isEqualToString:@"description"]) {
     [currentSummary appendString:string];
    } else if ([currentElement isEqualToString:@"pubDate"]) {
     [currentDate appendString:string];
    }
}

Please help

regards

Arun

Answer 1

I've never used that exact framework, but what you have to keep in mind is that while it will notify you when it finds the CDATA, anything inside is just plain-text to the parser. So it looks like you want to implement foundCDATA. You'll get passed a NSData block, and from there you have to parse the contents. Now, you can use another parser to do that, but it's probably faster just to do manual substring.

Answer 2

Have you thought about using regexp?

Answer 3

NSString *str = @"<![CDATA[<a href='http://www.okmagazine.com/posts/view/13756/'&gt;&lt;img src='http://www.okmagazine.com/img/photos/thumbs/27044' /></a><br />Ashlee and Pete take their tiny tot to FAO Schwarz in NYC for some new toys. <p> <strong>Pete Wentz</strong> and <strong>Ashlee Simpson Wentz</strong> made the new parent pilgrimage to New York’s FAO Schwarz today, where 6-month old <strong>Bronx Mowgli </strong>was the...]]>";


    NSRange range = [str rangeOfString: @"<img src='"];
    str = [str substringFromIndex: range.location + range.length];
    range = [str rangeOfString: @"'"];
    str =[str substringToIndex: range.location];
    CFShow(str);

Answer 4

Attributes are passed in to the didStartElement delegate method of the parser as a dictionary of strings keyed by attribute name. Thus, you can extract the urls you want from the attributes using NSDictionary's objectForKey: with the attribute name as the key. i.e.:

- (void)parser:(NSXMLParser *)parser didStartElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName attributes:(NSDictionary *)attributeDict
{
    if([elementName compare: @"img"] == NSOrderedSame)    // check for <img  ...> element
    {
        NSString* url = [attributeDictionary objectForKey:@"src"]; 
        // url now contains the url you require from the HTML