Tagging system for Masonry

UIView+MasonryTagging.h

#import <UIKit/UIKit.h>
#import <Masonry/Masonry.h>

@interface UIView (MasonryTagging)

- (void)prepareConstraintsWithTag:(NSString *)tag block:(void (^)(MASConstraintMaker *make))block;
- (void)removePreparedConstraintsWithTag:(NSString *)tag;
- (void)installConstraintsWithTag:(NSString *)tag;
- (void)installConstraintsWithTag:(NSString *)tag recursive:(BOOL)recursive;
- (void)uninstallConstraintsWithTag:(NSString *)tag;
- (void)uninstallConstraintsWithTag:(NSString *)tag recursive:(BOOL)recursive;

@end

UIView+MasonryTagging.m

#import "UIView+MasonryTagging.h"
#import <objc/message.h>

@implementation UIView (MasonryTagging)

- (NSMutableDictionary *)mas_constraintsByTag {
    static const void *mas_constraintsByTagKey = &mas_constraintsByTagKey;
    NSMutableDictionary *d = objc_getAssociatedObject(self, mas_constraintsByTagKey);;
    if(!d) {
        d = [NSMutableDictionary dictionary];
        objc_setAssociatedObject(self, mas_constraintsByTagKey, d, OBJC_ASSOCIATION_RETAIN_NONATOMIC);
    }
    return d;
}

- (void)prepareConstraintsWithTag:(NSString *)tag block:(void (^)(MASConstraintMaker *make))block {
    NSParameterAssert(tag);
    NSParameterAssert(block);
    NSArray *constraints = [self makeConstraints:block];
    for(MASConstraint *constraint in constraints) {
        [constraint uninstall];
    }
    
    NSMutableArray *taggedConstraints = [self mas_constraintsByTag][tag];
    if(!taggedConstraints) {
        taggedConstraints = [constraints mutableCopy];
        [self mas_constraintsByTag][tag] = taggedConstraints;
    } else {
        [taggedConstraints addObjectsFromArray:constraints];
    }
}
- (void)removePreparedConstraintsWithTag:(NSString *)tag {
    [self uninstallConstraintsWithTag:tag];
    [[self mas_constraintsByTag][tag] removeAllObjects];
}
- (void)installConstraintsWithTag:(NSString *)tag {
    NSArray *taggedConstraints = [self mas_constraintsByTag][tag];
    [taggedConstraints makeObjectsPerformSelector:@selector(install)];
}
- (void)installConstraintsWithTag:(NSString *)tag recursive:(BOOL)recursive {
    [self installConstraintsWithTag:tag];
    if(recursive) {
        for(UIView *subivew in self.subviews) {
            [subivew installConstraintsWithTag:tag recursive:recursive];
        }
    }
}
- (void)uninstallConstraintsWithTag:(NSString *)tag {
    NSArray *taggedConstraints = [self mas_constraintsByTag][tag];
    [taggedConstraints makeObjectsPerformSelector:@selector(uninstall)];
}
- (void)uninstallConstraintsWithTag:(NSString *)tag recursive:(BOOL)recursive {
    [self uninstallConstraintsWithTag:tag];
    if(recursive) {
        for(UIView *subivew in self.subviews) {
            [subivew uninstallConstraintsWithTag:tag recursive:recursive];
        }
    }
}

@end

Usage is as such:

[view prepareConstraintsWithTag:@"keyboard" block:^(MASConstraintMaker *make) {
   make.centerY.equalTo(otherView).with.offset(50.0);
}];

[view installConstraintsWithTag:@"keyboard" recursive:YES];