Question

I have a file xml as this:

<data>
    <first>
        <city>
            city
        </city>
        <people>
            400
        </people>
    </first>
    <size>
        <width>
            340
        </width>
        <height>
            120
        </height>
    </size>
    <description>
        <temp>
            sunny
        </temp>
        <people>
            45
        </people>
    </description>
    <description>
        <temp>
            cloudy
        </temp>
        <people>
                90
        </people>
    </description>

I use for parsing this code:

- (void)parser:(NSXMLParser *)parser didStartElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName attributes:(NSDictionary *)attributeDict{            

    currentElement = [elementName copy];
    if ([elementName isEqualToString:@"first"]) {
        firstType = [[NSMutableDictionary alloc] init];
        currentCity = [[NSMutableString alloc] init];
        currentPeople = [[NSMutableString alloc] init];
    }

    if ([elementName isEqualToString:@"size"]){
        currentSize = [[NSMutableDictionary alloc] init];
        width = [[NSMutableString alloc]init];
        height = [[NSMutableString alloc]init];
    }

    if ([elementName isEqualToString:@"description"]){
        desc1 = [[NSMutableDictionary alloc] init];
        temp1 = [[NSMutableString alloc]init];
        people1 = [[NSMutableString alloc]init];
    }

    if ([elementName isEqualToString:@"description"]){
        desc2 = [[NSMutableDictionary alloc] init];
        temp2 = [[NSMutableString alloc]init];
        people2 = [[NSMutableString alloc]init];
    }
}

- (void)parser:(NSXMLParser *)parser didEndElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName{     

    if ([elementName isEqualToString:@"first"]) {

        [firstType setObject:currentType forKey:@"city"];
        [firstType setObject:currentQuery forKey:@"people"];
                [feed addObject:[firstType copy]];
    }
    if ([elementName isEqualToString:@"size"]){

        [currentSize setObject:tempC forKey:@"width"];
        [currentSize setObject:tempF forKey:@"height"];
        [feed addObject:[currentSize copy]];
    }
    if ([elementName isEqualToString:@"description"]){

        [desc1 setObject:temp1 forKey:@"temp1"];
        [desc1 setObject:people1 forKey:@"people1"];
        [feed addObject:[desc1 copy]];
    }

    if ([elementName isEqualToString:@"description"]){

        [desc2 setObject:temp1 forKey:@"temp2"];
        [desc2 setObject:people1 forKey:@"people2"];
        [feed addObject:[desc2 copy]];
    }
}

- (void)parser:(NSXMLParser *)parser foundCharacters:(NSString *)string{
    NSLog(@"found");
    if ([currentElement isEqualToString:@"city"]){
        [currentCity appendString:string];
    } 
    else if ([currentElement isEqualToString:@"people"]) {
        [currentPeople appendString:string];
    } 
    else if ([currentElement isEqualToString:@"width"]){
        [width appendString:string];
    }
    else if ([currentElement isEqualToString:@"height"]){
        [height appendString:string];
    }
    else if ([currentElement isEqualToString:@"temp"]){
        [temp1 appendString:string];
    }
    else if ([currentElement isEqualToString:@"temp"]){
        [temp2 appendString:string];
    }
    else if ([currentElement isEqualToString:@"people"]){
        [people1 appendString:string];
    }
    else if ([currentElement isEqualToString:@"people"]){
        [people2 appendString:string];
    }

}

- (void) parserDidEndDocument:(NSXMLParser *)parser {

    NSLog(@"feed:%@",feed);
}

the result of nslog is:

feed:(
        {
        city = city;
        people = 4004590;
    },
        {
        width = 340;
        height = 120;
    },
        {
        temp = sunny;
        people = "";
    },
        { ///???? here there is an empty space
    },
        {
        temp = cloudy;
        people = "";
    },
        {
    }
)

Now I don’t understand why there is a space between first dictionary of desc 1 and desc2, and I don’t know how “people” take the result of people1 and people2 in a single string

Can you help me?

Answer 1

You need to keep track of whether you are parsing the first occurrence of description within the data tag, or the second. This can easily be done with a boolean (if there are only two), or an integer (for multiple) that indicates which of the tags you are currently processing. Then, in the parser:didEndElement: method, you can assign the accumulated data to the correct dictionary based on the flag/counter.

The other possibility, which I use in my XML parsing, is to accumulate characters for one tag at a time, then when I encounter the closing element for that tag, store the characters into the containing element’s Dictionary right then. In other words, when I encounter the endTag for temp, I will immediately assign it to the current description tag’s dictionary. Then, when I encounter the ending tag for the description tag itself, I can close out that dictionary, set the flag/increment the counter, and continue on with the next tag that is to be parsed.

- (void)parser:(NSXMLParser *)parser didStartElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName attributes:(NSDictionary *)attributeDict
{
    // ... SNIP ...

    if ( [ elementName isEqualToString:@"description" ] )
    {
        curDescription = [ [ NSMutableDictionary alloc ] init ] ;
    }

    // ... SNIP ...

    accumulatedCharacters = [ [ NSMutableString alloc ] init ] 
}

- (void)parser:(NSXMLParser *)parser didEndElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName    
{
    // ... SNIP ...

    if ( [ elementName isEqualToString:@"temp" ] )
    {
        [ curDescription setValue:accumulatedCharacters forKey:@"temp" ] ;
    }
    if ( [ elementName isEqualToString:@"description" ] )
    {
        // Save the curDescription object, then clear it for reuse on the next 
        // occurrence of the tag
        [ curDescription release ] ;
        curDescription = nil ;
    }

    // ... SNIP ...

    [ accumulatedCharacters release ] ;
    accumulatedCharacters = nil ;
}

- (void)parser:(NSXMLParser *)parser foundCharacters:(NSString *)string{
{
    [ accumulatedCharacters appendString:string ] ;
}