Question

我正在使用NSXMLParser解析以下XML，但是只想根据XML中找到的唯一元素解析某些元素和属性，然后中止解析。

例如，我的XML看起来像这样：

<?xml version="1.0" encoding="UTF-8"?>
<systems>
<system id="system1">
    <game title="game1">
        <checksums>
            <checksum value="checksumvalue1" />
        </checksums>
        <players>
            <player name="name1" description="description1" />
            <player name="name2" description="description2" />
        </players>
    </game>
</system>

我希望能够仅根据players的值返回game中的所有checksum 因此，如果我将checksumvalue1传递给我的方法，我只想使用唯一校验和返回在该players个节点中找到的game。在XML中，将会有其他带校验和的游戏，但校验和将始终是唯一的。

到目前为止，我有一些基本的解析器代码来从校验和值中读取元素和属性，但我不知道从那里去哪里。我也想知道使用XPath NSXMLNode是否更有意义来实现这一目标。

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

if ([elementName isEqualToString:@"checksum"] && [[attributeDict valueForKey:@"value"] isEqualToString:@"checksumvalue1"]) {
    NSString *checksumValue = [attributeDict valueForKey:@"value"];
    NSLog(@"value: %@", checksumValue);

// print players in only one game node that contains the unique checksum value
   }
}

感谢您的帮助！

Answer 1

您必须跟踪您是否已找到校验和以及您遇到的所有玩家。您需要布尔值foundGameChecksum和NSMutableArray* players。不要忘记players = [[NSMutableArray alloc] init];

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

    if ([elementName isEqualToString:@"checksum"] && [[attributeDict valueForKey:@"value"] isEqualToString:@"checksumvalue1"]) {
        NSString *checksumValue = [attributeDict valueForKey:@"value"];
        NSLog(@"value: %@", checksumValue);

        foundGameChecksum = YES;
        // print players in only one game node that contains the unique checksum value
    } else if(foundGameChecksum && [elementName isEqualToString:@"player"]) {
        [players addObject:[attributeDict valueForKey:@"name"]];
    }
}

- (void)parser:(NSXMLParser *)parser didEndElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName
{
    if(foundGameChecksum && [elementName isEqualToString:@"players"]) {
        [parser abortParsing]; // Stop parsing
    }
}

然后在[parser parse];执行后，您将拥有players

中的玩家

即：

<?xml version="1.0" encoding="UTF-8"?>
<systems>
    <system id="system1">
        <game title="game1">
            <checksums>
                <checksum value="checksumvalue1" /> <!-- Found. Start adding -->
            </checksums>
            <players>
                <player name="name1" description="description1" /> <!-- Add -->
                <player name="name2" description="description2" /> <!-- Add -->
            </players> <!-- Stop adding -->
        </game>
    </system>
</systems>

NSXMLParser：根据另一个元素解析特定元素

1 个答案: