Help with xml web service

[imsatasia]

Hello Friends,

I'm learning implementing web-services for iPhone.

Anyone please help me out to get data from following Webservice URL:

Request (HTTP GET)

http://api.stlouisfed.org/fred/category?category_id=125&api_key=78da607fc8224651eca5653e65a4be5e

Response:

<?xml version="1.0" encoding="utf-8" ?>
<categories>
<category id="125" name="Trade Balance" parent_id="13"/>
</categories>

I want to display category-name from the response in a UILabel.

Thanks.

[itzdark]

NSXMLParser

codesofa Make NSXMLParser your friend..

[imsatasia]

Originally Posted by itzdark

NSXMLParser

codesofa Make NSXMLParser your friend..

Hi itzdark,

Thanks for link.

I'm new to Web services.

Will you please help me to write following methods for my demo web service.

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

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

- (void)parser:(NSXMLParser *)parser foundCharacters:(NSString *)string

Thanks again.

[imsatasia]

This is How I have written my code:

- (void)parser:(NSXMLParser *)parser didStartElement:(NSString *)elementName 
  namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName attributes:(NSDictionary *)attributeDict
{
	currentElement = [[elementName copy] autorelease];
	NSLog(currentElement);
	if ([elementName isEqualToString:@"category"]) 
	{
		lbl1.text = [attributeDict valueForKey:@"name"];
		NSLog([attributeDict valueForKey:@"name"]);

		hello = FALSE;
	}
}
	
- (void)parser:(NSXMLParser *)parser foundCharacters:(NSString *)string
{
		if (hello) {
			[currnetCategory appendString:string];
		}
}


- (void)parser:(NSXMLParser *)parser didEndElement:(NSString *)elementName 
namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName
{
	currentElement = [[elementName copy] autorelease];
	NSLog(currentElement);
	if ([elementName isEqualToString:@"categories"])
	{
		return;
	}
	
	else if([elementName isEqualToString:@"category"]) 
		{
			NSLog(lbl1.text);
			hello = FALSE;
		
		}
}

it is giving me the correct value for NSLog([attributeDict valueForKey:@"name"]); in gdb.

- But at the end of xml file it was giving me error "EXC_BAD_ACCESS".

[imsatasia]

Here is my Log:

<?xml version="1.0" encoding="utf-8" ?>
<categories>
<category id="125" name="Trade Balance" parent_id="13"/>
</categories>
2010-03-10 13:25:12.788 testxml[11864:207] categories
2010-03-10 13:25:12.789 testxml[11864:207] category
2010-03-10 13:25:12.789 testxml[11864:207] Trade Balance
2010-03-10 13:25:12.790 testxml[11864:207] category
2010-03-10 13:25:12.790 testxml[11864:207] Trade Balance
2010-03-10 13:25:12.791 testxml[11864:207] categories

then the app was terminated.

Thanks

[itzdark]

Run it again, when it crashes click the little spraypaint can button next to the gdb button this will show you the line it crashed it on. This well help point you in the right direction.

EXC_BAD_ACCESS indicates you tried to use a variable that has been released or wasn't initialized properly

[imsatasia]

Originally Posted by itzdark

Run it again, when it crashes click the little spraypaint can button next to the gdb button this will show you the line it crashed it on. This well help point you in the right direction.

EXC_BAD_ACCESS indicates you tried to use a variable that has been released or wasn't initialized properly

It was stopping at the end of this method:

- (void)parser:(NSXMLParser *)parser didEndElement:(NSString *)elementName 
namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName
{
	currentElement = [[elementName copy] autorelease];
	NSLog(currentElement);
	if ([elementName isEqualToString:@"categories"])
	{
		return;
	}
	
	else if([elementName isEqualToString:@"category"]) 
		{
			NSLog(lbl1.text);
			hello = FALSE;
		
		}
}

Thanks.