ios - 带空格的字符串无法转换为 NSURL - Mantle

Question

想知道我们是否可以解决在 Mantle 中将带空格的字符串转换为 NSURL 失败的问题？

我遇到了 Mantle 错误:

Error Domain=MTLTransformerErrorHandlingErrorDomain Code=1 “无法将字符串转换为 URL” UserInfo=0x7ff9e8de4090 {MTLTransformerErrorHandlingInputValueErrorKey= https://x.com/dev-pub-image-md/x-img/02020-x yy z@2X.png, NSLocalizedDescription=无法将字符串转换为 URL，NSLocalizedFailureReason=输入 URL 字符串 https://x.com/dev-pub-image-md/x-img/02020-x yy z@2X.png 格式错误

类文件下方；

.h-

#import "Mantle.h"

@interface Place : MTLModel <MTLJSONSerializing>

@property (strong, nonatomic) NSString *placeId;
@property (strong, nonatomic) NSURL *logoURL;

@end

.m-

#import "Place.h"

@implementation Place

+ (NSDictionary *)JSONKeyPathsByPropertyKey {
    return @{@"placeId": @"placeId",
             @"logoURL":@"circleImage"
             };
}

+ (NSValueTransformer *)logoURLJSONTransformer {
    return [NSValueTransformer valueTransformerForName:MTLURLValueTransformerName];
}

@end

提前致谢!

Answer 1

发生这种情况是因为您的字符串未经过 URL 结尾编码(URL 不能包含空格)。

首先 - 使用以下方法对您的字符串进行 URL 编码。来源:Stackoverflow

- (NSString *)urlencodeString:(NSString*)string {
    NSMutableString *output = [NSMutableString string];
    const unsigned char *source = (const unsigned char *)[self UTF8String];
    int sourceLen = strlen((const char *)source);
    for (int i = 0; i < sourceLen; ++i) {
        const unsigned char thisChar = source[i];
        if (thisChar == ' '){
            [output appendString:@"+"];
        } else if (thisChar == '.' || thisChar == '-' || thisChar == '_' || thisChar == '~' || 
                   (thisChar >= 'a' && thisChar <= 'z') ||
                   (thisChar >= 'A' && thisChar <= 'Z') ||
                   (thisChar >= '0' && thisChar <= '9')) {
            [output appendFormat:@"%c", thisChar];
        } else {
            [output appendFormat:@"%%%02X", thisChar];
        }
    }
    return output;
}

然后将其转换为 URL。

在您的特定场景中，您使用的是 Mantle JSON 转换器。所以你能做的是；

+ (NSValueTransformer *)logoURLJSONTransformer {
    return [MTLValueTransformer transformerUsingReversibleBlock:^id(NSString *str, BOOL *success, NSError *__autoreleasing *error) {
        if (success) {
            NSString *urlEncodedString  = [self urlencodeString:str];
            return [NSURL URLWithString:urlEncodedString];
        }else{
            return @"";
        }

    }];
}