How to parse Multiple .xml files in iphone?

问题:

Its my first experience with xmls so please don't be harsh on me if my question is low quality. I am working on app where I retrieve all data using xml files from server.

Before posting question here I read some Tutorials about xml file parsing. But when I start to implement it in my app, then I am totally confused at the point when I am trying to parse the second Xml file and so on.

Now I want to explain my app flow using some screenshot so that it become easy for everyone that what I want.

1. First view
2. Second view
3. Third view

Now when I click in any row in first view it goes to second view and show all related data in second view and when I click any item in Second view it goes to the third view and show detail information about that particular item.

After explanation of app flow, now I show my code what I tried so far. Following a tutorial I just simply drag classes (XMLParser, Book) to my app for testing purpose.

Code:

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
 {
NSURL *url = [[NSURL alloc] initWithString:@"Firstviewxmlurl"];
NSXMLParser *xmlParser = [[NSXMLParser alloc] initWithContentsOfURL:url];
XMLParser *parser = [[XMLParser alloc] initXMLParser];
[xmlParser setDelegate:parser];
BOOL success = [xmlParser parse];
if(success)
    NSLog(@"No Errors");
else
    NSLog(@"Error Error Error!!!");
 }

Now my XMLParser.m code is

- (XMLParser *) initXMLParser {

[super init];

appDelegate = (AppDelegate *)[[UIApplication sharedApplication] delegate];

return self;
  }

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

if([elementName isEqualToString:@"Collections"]) {
    //Initialize the array.
    appDelegate.books = [[NSMutableArray alloc] init];
}
else if([elementName isEqualToString:@"Collection"]) {

    //Initialize the book.
    aBook = [[Book alloc] init];

    //Extract the attribute here.
    aBook.bookID = [[attributeDict objectForKey:@"id"] integerValue];

    NSLog(@"Reading id value :%i", aBook.bookID);
}

NSLog(@"Processing Element: %@", elementName);
    }

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

if(!currentElementValue) 
    currentElementValue = [[NSMutableString alloc] initWithString:string];
else
    [currentElementValue appendString:string];

NSLog(@"Processing Value: %@", currentElementValue);
}

 - (void)parser:(NSXMLParser *)parser didEndElement:(NSString *)elementName 
   namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName {
if([elementName isEqualToString:@"Collections"])
    return;
if([elementName isEqualToString:@"Collection"]) {
    [appDelegate.books addObject:aBook];

    [aBook release];
    aBook = nil;
}
else 
    [aBook setValue:currentElementValue forKey:elementName];

[currentElementValue release];
currentElementValue = nil;
  }

Finaly my First view Class code is

    #pragma mark Table Methods

  - (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
  {
return 1;
  }


- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section 
 {
//return [tblViewData count];
return [appDelegate.books count];
 }

  - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath 
    {
static NSString *CellIdentifier = @"SimpleTableIdentifier";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];

if (cell == nil)
{
    cell=[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleValue1 reuseIdentifier:CellIdentifier];
    cell.selectionStyle=UITableViewCellSelectionStyleGray;
    cell.accessoryType=UITableViewCellAccessoryDisclosureIndicator;
}
//cell.textLabel.text=[[tblViewData objectAtIndex:indexPath.row]
                    // stringByReplacingOccurrencesOfString:@"*" withString:@""];
   Book *aBook = [appDelegate.books objectAtIndex:indexPath.row];

cell.textLabel.text = aBook.title;

if([deviceType isEqualToString:@"ipad"])
{
    [cell.textLabel setFont:[UIFont fontWithName:@"Helvetica-Bold" size:20]];
}
//cell.textLabel.font=[UIFont fontWithName:@"Walkway_SemiBold" size:16];
return cell;
   }

After implementation of all the above Code i got the result in form of this Now at this point i confuse how can i pass my Second view xml file url and then third view url.my xml files are in this format

First xml file

 <?xml version="1.0" encoding="UTF-8"?>
<Collections> <Collection id="5"><title>Allegroo</title> </Collection>

Second xml file

 <?xml version="1.0" encoding="UTF-8"?>
 <Collection id="5"><colletciontitle>Allegroo</colletciontitle>  <weaveimage>"imageurl"   </weaveimage><Rug id="48"><Rugthumb>"firstimageurl"</Rugthumb><RugSku>AL-637</RugSku></Rug><Rug id="51"><Rugthumb>"Secondimageurl"</Rugthumb><RugSku>AL-641</RugSku></Rug>

Third xml file

  <?xml version="1.0" encoding="UTF-8"?>
 <Rug id="47"><Rugmainimage>"imageurl"</Rugmainimage> <Rugtitle>AL-636 Aged Indigo / Vintage Beige</Rugtitle> <Rugdiscription>Hand Knotted
  Distressed Wool Pile / Cotton Foundation </Rugdiscription><Availablesizes><Size>10x14</Size><Size>12x15</Size><Size>2x3</Size><Size>3x5</Size><Size>4x6</Size><Size>6x9</Size><Size>8x10</Size><Size>9x12</Size><Runner>2'6"x10'</Runner><Runner>2'6"x12'</Runner><Runner>2'6"x8'</Runner></Availablesizes></Rug>

Any help in the form of link or sample code releated to my issue and suggestion will be highly appriated.Thanks

回答1:

I have added some of the code to make you understand. Try to implement according to your condition. Below code is just to refer as i havn't made all the changes u need to understand first and then implement accordingly

//int i = 0;   // in AppDelegate

Code:

//Or ViewDidLoad Method
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
 int = 1;    //For First View
NSURL *url = [[NSURL alloc] initWithString:@"Firstviewxmlurl"];
NSXMLParser *xmlParser = [[NSXMLParser alloc] initWithContentsOfURL:url];
XMLParser *parser = [[XMLParser alloc] initXMLParser];
[xmlParser setDelegate:parser];
BOOL success = [xmlParser parse];
if(success)
    NSLog(@"No Errors");
else
    NSLog(@"Error Error Error!!!");
 }

XMLParser.m

- (XMLParser *) initXMLParser 
    {  
      [super init];
      appDelegate = (AppDelegate *)[[UIApplication sharedApplication] delegate]; 
      return self;
    }

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

    if([elementName isEqualToString:@"Collections"]) 
   {
        //Initialize the array.
      if (int == 1)
        appDelegate.books = [[NSMutableArray alloc] init];

      else if (int == 2)
        appDelegate.secondArray = [[NSMutableArray alloc] init];

      else if (int == 3)
        appDelegate.thirdArray = [[NSMutableArray alloc] init];
    }

    else if([elementName isEqualToString:@"Collection"]) 
  {
         if (i == 1)
        {
          //Initialize the book.
          aBook = [[Book alloc] init];

          //Extract the attribute here.
          aBook.bookID = [[attributeDict objectForKey:@"id"] integerValue];

          NSLog(@"Reading id value :%i", aBook.bookID);
        }

         else if (i == 2)
        {
           //Second Xml 
        }

        else if (i == 3)
       {
           //Third Xml
       }

    }

  NSLog(@"Processing Element: %@", elementName);
 }


- (void)parser:(NSXMLParser *)parser foundCharacters:(NSString *)string { 
    //Check condition 
    if(!currentElementValue) 
        currentElementValue = [[NSMutableString alloc] initWithString:string];
    else
        [currentElementValue appendString:string];

    NSLog(@"Processing Value: %@", currentElementValue);
    }

     - (void)parser:(NSXMLParser *)parser didEndElement:(NSString *)elementName 
       namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName {
//Check COndition
    if([elementName isEqualToString:@"Collections"])
        return;
    if([elementName isEqualToString:@"Collection"]) {
        [appDelegate.books addObject:aBook];

        [aBook release];
        aBook = nil;
    }
    else 
        [aBook setValue:currentElementValue forKey:elementName];

    [currentElementValue release];
    currentElementValue = nil;
      }

回答2:

Hmm, So Defining long story short, you want to parse multiple urls in sequence ?

So here is the answer,

1. Use a variable / identifier in appDelegate that tells you which xml is being parsed.
2. Use your xml parser as delegate class object

3. Use delegate method to swich to next xml parsing

    - (void)parserDidEndDocument:(NSXMLParser *)parser {
        // Change URL accordingly 
        NSURL *url = [[NSURL alloc] initWithString:@"Firstviewxmlurl"];
        NSXMLParser *xmlParser = [[NSXMLParser alloc] initWithContentsOfURL:url];
        XMLParser *parser = [[XMLParser alloc] initXMLParser];
        [xmlParser setDelegate:parser];
         BOOL success = [xmlParser parse];
   }