数据类型和XMLParser

Question

我将我的网站上的数据同步到我的应用程序，我正在使用NSXMLParser来执行此操作。问题是我把我的数据库中的所有字段定义为字符串。当所有内容都是字符串时，同步过程可以正常工作，但是当我尝试将这些数据用于其他目的时，这会让我心痛不已。

谁能帮我确定我的领域具有正确的数据类型的同步过程，下面的代码：

.M

// Array for WORKOUT. 
    NSMutableString *currentID, *currentUserID, *currentWalkID, *currentDate, *currentDistance, *currentRepeats, *currentType, *currentIntensity, 
    *currentComments, *currentTime, *currentWeight, *currentHeight; 

我知道它是与此的NSMutableString，显然一切被定义为一个字符串。

.H

- (void)parser:(NSXMLParser *)parser didStartElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName attributes:(NSDictionary *)attributeDict 
{   
    currentElement = [elementName copy]; 

    // Check for the WORKOUT details in the XML feed. 
    if ([elementName isEqualToString:@"workout"]) 
    { 
     // clear out our workout item caches... 
     item = [[NSMutableDictionary alloc] init]; 
     currentID = [[NSMutableString alloc] init]; 
     currentUserID = [[NSMutableString alloc] init]; 
     currentWalkID = [[NSMutableString alloc] init]; 
     currentDate = [[NSMutableString alloc] init]; 
     currentDistance = [[NSMutableString alloc] init]; 
     currentRepeats = [[NSMutableString alloc] init]; 
     currentType = [[NSMutableString alloc] init]; 
     currentIntensity = [[NSMutableString alloc] init]; 
     currentComments = [[NSMutableString alloc] init]; 
     currentTime = [[NSMutableString alloc] init]; 
     currentWeight = [[NSMutableString alloc] init]; 
     currentHeight = [[NSMutableString alloc] init]; 
    } 
} 


- (void)parser:(NSXMLParser *)parser didEndElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName 
{  
    if ([elementName isEqualToString:@"workout"]) 
    { 
     Workout *newWorkout = [NSEntityDescription insertNewObjectForEntityForName:@"Workout" inManagedObjectContext: self.managedObjectContext]; 

     // save values to an item, then store that item into the array... 
     [item setObject:currentID forKey:@"workout_id"]; 
     [item setObject:currentUserID forKey:@"workout_user_id"]; 
     [item setObject:currentWalkID forKey:@"workout_walk_id"]; 
     [item setObject:currentDate forKey:@"workout_date"]; 
     [item setObject:currentDistance forKey:@"workout_distance"]; 
     [item setObject:currentRepeats forKey:@"workout_repeats"]; 
     [item setObject:currentType forKey:@"workout_type"]; 
     [item setObject:currentIntensity forKey:@"workout_intensity"]; 
     [item setObject:currentComments forKey:@"workout_comments"]; 
     [item setObject:currentTime forKey:@"workout_time"]; 
     [item setObject:currentWeight forKey:@"workout_weight"]; 
     [item setObject:currentHeight forKey:@"workout_height"]; 

     newWorkout.workout_id = currentID; 
     newWorkout.workout_user_id = currentUserID; 
     newWorkout.workout_walk_id = currentWalkID; 
     newWorkout.workout_date = currentDate; 
     newWorkout.workout_distance = currentDistance; 
     newWorkout.workout_repeats = currentRepeats; 
     newWorkout.workout_type = currentType; 
     newWorkout.workout_intensity = currentIntensity; 
     newWorkout.workout_comments = currentComments; 
     newWorkout.workout_time = currentTime; 
     newWorkout.workout_weight = currentWeight; 
     newWorkout.workout_height = currentHeight; 
     [self.workoutArray addObject:newWorkout]; 
    } 
} 

- (void)parser:(NSXMLParser *)parser foundCharacters:(NSString *)string{ 
    // save the characters for the current item... 
    if ([currentElement isEqualToString:@"workout_id"]) { 
     [currentID appendString:string]; 
    } else if ([currentElement isEqualToString:@"workout_user_id"]) { 
     [currentUserID appendString:string]; 
    } else if ([currentElement isEqualToString:@"workout_walk_id"]) { 
     [currentWalkID appendString:string]; 
    } else if ([currentElement isEqualToString:@"workout_date"]) { 
     [currentDate appendString:string]; 
    } else if ([currentElement isEqualToString:@"workout_distance"]) { 
     [currentDistance appendString:string]; 
    } else if ([currentElement isEqualToString:@"workout_repeats"]) { 
     [currentRepeats appendString:string]; 
    } else if ([currentElement isEqualToString:@"workout_type"]) { 
     [currentType appendString:string]; 
    } else if ([currentElement isEqualToString:@"workout_intensity"]) { 
     [currentIntensity appendString:string]; 
    } else if ([currentElement isEqualToString:@"workout_comments"]) { 
     [currentComments appendString:string]; 
    } else if ([currentElement isEqualToString:@"workout_time"]) { 
     [currentTime appendString:string]; 
    } else if ([currentElement isEqualToString:@"workout_weight"]) { 
     [currentWeight appendString:string]; 
    } else if ([currentElement isEqualToString:@"workout_height"]) { 
     [currentHeight appendString:string]; 
} 

Answer 1

XML只能携带字符串。 Wheather它是元素的内部文本或属性的值，最后，一切都只是一个字符串。

如果要通过XML发送其他任何内容，发送端必须将其编码为一个字符串，并且接收端必须解码该字符串。为了这一点，双方必须就格式达成一致，例如对于整数值，一种可能性是将125编码为“125”，或将浮点数2.5编码为“2.5”。如果你使用这种格式的数字，你可以使用NSString的integerValue和floatValue对它们进行解码。

float test = [@"2.5" floatValue]; 

有在xsd定义，你可以使用一些标准格式，但不会帮助你对它们进行解码，如果你没有一个解析器，这是否适合你。 （NSXMLParser不是这样） 如果您使用其他格式请看NSScanner。对于日期和时间，你想看看NSDateFormatter。

如果您需要帮助转换，请发布您使用的格式，即XML的摘录。