解析具有很多子节点的XML到UITableView [英] Parsing XML with a lot of children nodes to UITableView

问题描述

我有一个像这样的XML文件：

I have an xml file that looks like this:

<result>
<trip duration="03:30">
<takeoff date="2010-06-19" time="18:40" city="Moscow"/>
<landing date="2010-06-19" time="20:10" city="Novgorod"/>
<flight carrier="Rossiya" number="8395" eq="320"/>
<price>13429.00</price>
</trip>
<trip duration="03:40">
<takeoff date="2010-06-19" time="09:20" city="Omsk"/>
<landing date="2010-06-19" time="11:15" city="Paris"/>
<flight carrier="AirFrance" number="1145" eq="320"/>
<price>13229.00</price>
</trip>
<trip duration="03:50">
<takeoff date="2010-06-19" time="07:20" city="Omsk"/>
<landing date="2010-06-19" time="14:15" city="Barcelona"/>
<flight carrier="AirFrance" number="1100" eq="320"/>
<price>13329.00</price>
</trip>
</result>

我想获得所有参数，并将它们放在3 UITableViewCells。正如你可以看到有3航班和有关他们的数据。
我一直在尝试在一个TableView中解析它，但我只能得到< price> 的事情。
如何处理解析XML文件中的复杂结构化参数？我的意思是我如何得到起飞日期参数等等？
就我可以得到你不能应用我这样使用的战术：

I'd like to get all the parameters and place them in 3 UITableViewCells. As you can see there are 3 flights and the data about them. I've been trying to parse it in a TableView but I only managed to get the <price> thing going. How would you deal with parsing complex-structured parameters within an XML file? I mean how would I get takeoff date parameter and so on and so forth? As far as I could get you can't apply the tactics I'm using like this one:

- (void) parser:(NSXMLParser *)parser didEndElement:(NSString *)elementname namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName
{
        if ([elementname isEqualToString:@"price"]) 
        {
            currentTweet.dateCreated = currentNodeContent;
        }

任何帮助将非常感激。提前感谢。

Any help would be highly appreciated. Thanks in advance.

推荐答案

这是我经常使用的代码，从一个遵循此基本模型的XML文件构建一个字典的一些明确定义的重复元素（在这种情况下，trip），以及一系列数据元素，其中一些我正在读的标签属性（在这种情况下，起飞，着陆和 code>）和其他我正在读取开始和结束标签之间的数据（在这种情况下，只是price）。

This is the code that I frequently use to build a dictionary from an XML file that follows this basic model of some well defined repeating element (in this case, "trip"), and a series of data elements within that, some of which I'm reading the attributes of the tag (in this case, "takeoff", "landing" and "flight"), and others I'm reading the data between the opening and closing tags (in this case, just "price").

我有以下ivars：

@interface XmlParserViewController () <NSXMLParserDelegate>
{
    NSMutableArray *trips;
    NSMutableDictionary *currentTrip;
    NSMutableString *currentElement;
}
@end

然后代码如下：

- (void)viewDidLoad
{
    [super viewDidLoad];

    trips = [[NSMutableArray alloc] init];

    // I'm getting my xml from my bundle. You get it however you're currently getting it.

    NSString *filename = [[NSBundle mainBundle] pathForResource:@"results" ofType:@"xml"];
    NSData *data = [NSData dataWithContentsOfFile:filename];
    NSXMLParser *parser = [[NSXMLParser alloc] initWithData:data];
    parser.delegate = self;
    [parser parse];
}

#pragma mark - NSXMLParserDelegate methods

#define kRowElementTag @"trip"

- (void)parser:(NSXMLParser *)parser didStartElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qualifiedName attributes:(NSDictionary *)attributeDict
{
    NSArray *attributeElementNames = @[@"takeoff", @"landing", @"flight"];
    NSArray *foundCharacterElementNames = @[@"price"];

    if ([elementName isEqualToString:kRowElementTag])
    {
        currentTrip = [[NSMutableDictionary alloc] init];
        [trips addObject:currentTrip];
        if (attributeDict)
            [currentTrip setObject:attributeDict forKey:elementName];
    }
    else if (currentTrip)
    {
        if ([attributeElementNames containsObject:elementName])
        {
            if (attributeDict)
                [currentTrip setObject:attributeDict forKey:elementName];
        }
        else if ([foundCharacterElementNames containsObject:elementName] && currentElement == nil)
        {
            // you can change this to just grab a few fields ... add whatever fields you want to this

            currentElement = [[NSMutableString alloc] init];
            [currentTrip setObject:currentElement forKey:elementName];
        }
    }
}

- (void)parser:(NSXMLParser *)parser didEndElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName
{
    if ([elementName isEqualToString:kRowElementTag])
    {
        currentTrip = nil;
    }
    else if (currentElement)
    {
        currentElement = nil;
    }
}

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

- (void)parser:(NSXMLParser *)parser parseErrorOccurred:(NSError *)parseError
{
    NSLog(@"%s error=%@", __FUNCTION__, parseError);

    // we should handle the error here
}

- (void)parserDidEndDocument:(NSXMLParser *)parser
{
    NSLog(@"%s trips=%@", __FUNCTION__, trips);

    // generally I immediately kick off the reload of the table, but maybe 
    // you want to grok the trips dictionary first.
    //        
    // [self.tableView reloadData];
}

正如你可以猜到的，我试图结束那种嵌套数组/字典结构，我们已经用来解析JSON文件。显然，我不喜欢这样的事实，我必须在我的代码前面确定一些XML文件的结构（外部数组trip标签，takeoff，landing和flight code>有属性，但价格没有）等，但这是一个比我第一次尝试在XML解析硬编码的值在所有地方更好一点。叹息。

As you can guess, I'm trying to end up with that sort of nested array/dictionary structure that we've gotten used to parsing JSON files. Clearly, I don't like the fact that I have to identify some of the structure of the XML file up front in my code (the fact that the outer array has "trip" tags, that "takeoff", "landing", and "flight" have attributes but "price"` doesn't), etc. But this is a little better than my first attempts at XML parsing that hardcoded values all over the place. Sigh.

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