Displaying NSMutableArray in Table View Cell

In this article, we will explore how to display an NSMutableArray of data in a table view cell. We’ll start by understanding the basics of table views and arrays, then move on to parsing XML data and displaying it in a table view.

Table Views and Arrays

A table view is a user interface component that displays data in a grid format. Each row in the table represents an object, and each column represents a property of that object. To display data in a table view, you need to define a data source method that returns the number of rows and the content for each row.

An array is a collection of objects stored in memory. In this case, we’ll use an NSMutableArray to store our data.

Parsing XML Data

Our task is to parse an XML file and extract relevant information from it. We’ll use NSXMLParser to parse the XML data and store it in our array.

Here’s how we can start:

- (void)viewDidLoad {
    NSString *url = [NSString stringWithFormat:@"http://mmabigshow.com/app/get_result_from_query.php?q=select * from event"];
    
    // ...
}

This code retrieves an XML file from a URL and stores it in myData. We then create an instance of NSXMLParser to parse the data.

- (void) startParsing: (NSString *) query{
    NSURL *xmlURL = [[NSURL alloc] initWithString:query];
    NSData *myData = [NSData dataWithContentsOfURL:xmlURL];
    
    // ...
}

Next, we create an instance of NSXMLParser and set its delegate to our class. We then call the parse method on the parser.

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

This code is called when a new element starts in the XML file. We use this method to process each element and extract relevant information.

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

This code is called when an element ends in the XML file. We use this method to process each element and extract relevant information.

- (void)parser:(NSXMLParser *)parser foundCharacters:(NSString *)string{
    // ...
}

This code is called when a character sequence is found in the XML file. We use this method to process each character sequence and extract relevant information.

Table View Data Source Methods

To display data in a table view, we need to define two data source methods: tableView:numberOfRowsInSection: and tableView:cellForRowAtIndexPath:.

- (NSInteger)tableView:(UITableView *)tableView 
numberOfRowsInSection:(NSInteger)section { 
    return [self.dataArray count]; 
}

This method returns the number of rows in the table view. In this case, we’re returning the count of our array.

- (UITableViewCell *)tableView:(UITableView *)tableView 
         cellForRowAtIndexPath:(NSIndexPath *)indexPath { 
    NSLog(@"cellForRowAtIndexPath");
    
    // ...
}

This method is called when a cell needs to be created for a specific row in the table view. We use this method to create a custom cell and display data from our array.

Displaying Data in the Table View Cell

To display data in the table view cell, we need to set the text label’s text property to the value of our array.

cell.textLabel.text = [self.dataArray objectAtIndex:indexRow.row];

This line sets the text label’s text property to the value at the specified row index in our array.

Displaying Multiple Values in the Table View Cell

If we want to display multiple values in the table view cell, we need to use a different approach. Instead of using a single text label, we can create a custom cell with multiple labels and set their text properties accordingly.

- (UITableViewCell *)tableView:(UITableView *)tableView 
         cellForRowAtIndexPath:(NSIndexPath *)indexPath { 
    NSLog(@"cellForRowAtIndexPath");
    
    static NSString *CustomCellIdentifier = @"CustomCellIdentifier "; 
    
    TableDetailsCell *cell = (TableDetailsCell *)[tableView dequeueReusableCellWithIdentifier: CustomCellIdentifier]; 
    if (cell == nil) { 
        NSArray *nib = [[NSBundle mainBundle] loadNibNamed:@"TableDetailsCell" owner:self options:nil]; 
        for (id oneObject in nib) 
            if ([oneObject isKindOfClass:[TableDetailsCell class]]) 
                cell = (TableDetailsCell *)oneObject; 
    } 
    
    NSUInteger row = [indexPath row]; 

    NSDictionary *rowData = [self.dataArray objectAtIndex:row]; 
    

    cell.textLabel.text = [rowData objectForKey:@"ename"];
    // Add more labels and set their text properties accordingly

This code creates a custom cell with multiple labels and sets their text properties to the values in our array.

Conclusion

In this article, we explored how to display an NSMutableArray of data in a table view cell. We started by understanding the basics of table views and arrays, then moved on to parsing XML data and displaying it in a table view. Finally, we discussed how to display multiple values in the table view cell using a custom cell.

Example Code

Here’s the complete example code:

- (void)viewDidLoad {
    NSString *url = [NSString stringWithFormat:@"http://mmabigshow.com/app/get_result_from_query.php?q=select * from event"];
    
    // ...
}

- (void) startParsing: (NSString *) query{
    NSURL *xmlURL = [[NSURL alloc] initWithString:query];
    NSData *myData = [NSData dataWithContentsOfURL:xmlURL];
    
    // ...
}

- (void)parser:(NSXMLParser *)parser didStartElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName attributes:(NSDictionary *)attributeDict{
    currentElement = [elementName copy];
    if ([elementName isEqualToString:@"table"]){
        item = [[NSMutableDictionary alloc] init];
        currentEid = [[NSMutableString alloc] init];
        currentEname = [[NSMutableString alloc] init];
        currentEurl = [[NSMutableString alloc] init];
        dataArray = [[NSMutableArray alloc] init];
    }
}

- (void)parser:(NSXMLParser *)parser didEndElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName{
    if ([elementName isEqualToString:@"table"]) {
        [item setObject:currentEname forKey:@"ename"];
        [dataArray addObject:[[item copy] autorelease]];
    }
    [currentEid release];
    [currentEname release];
    [currentEurl release];

}

- (void)parser:(NSXMLParser *)parser foundCharacters:(NSString *)string{
    if ([currentElement isEqualToString:@"eid"]) {
        [currentEid appendString:string];
    } else if ([currentElement isEqualToString:@"ename"]) {
        [currentEname appendString:string];
    } else if ([currentElement isEqualToString:@"eurl"]) {
        [currentEurl appendString:string];
    }
}

- (NSInteger)tableView:(UITableView *)tableView 
numberOfRowsInSection:(NSInteger)section { 
    return [self.dataArray count]; 
}

- (UITableViewCell *)tableView:(UITableView *)tableView 
         cellForRowAtIndexPath:(NSIndexPath *)indexPath { 
    NSLog(@"cellForRowAtIndexPath");
    
    static NSString *CustomCellIdentifier = @"CustomCellIdentifier "; 
    
    TableDetailsCell *cell = (TableDetailsCell *)[tableView dequeueReusableCellWithIdentifier: CustomCellIdentifier]; 
    if (cell == nil) { 
        NSArray *nib = [[NSBundle mainBundle] loadNibNamed:@"TableDetailsCell" owner:self options:nil]; 
        for (id oneObject in nib) 
            if ([oneObject isKindOfClass:[TableDetailsCell class]]) 
                cell = (TableDetailsCell *)oneObject; 
    } 
    
    NSUInteger row = [indexPath row]; 

    NSDictionary *rowData = [self.dataArray objectAtIndex:row]; 
    

    cell.textLabel.text = [rowData objectForKey:@"ename"];
}

Note that this code assumes you have a custom cell class called TableDetailsCell with multiple labels and a textLabel. You’ll need to create this class and set up the table view accordingly.

Last modified on 2024-09-02