added ability to remove constraint. refactored child constraints

@@ -76,8 +76,10 @@
 
 #pragma mark - MASConstraintDelegate
 
-- (void)addConstraint:(id<MASConstraint>)constraint {
-    [self.delegate addConstraint:constraint];
+- (void)constraint:(id<MASConstraint>)constraint shouldBeReplacedWithConstraint:(id<MASConstraint>)replacementConstraint {
+    int index = [self.childConstraints indexOfObject:constraint];
+    NSAssert(index != NSNotFound, @"Could not find constraint %@", constraint);
+    [self.childConstraints replaceObjectAtIndex:index withObject:replacementConstraint];
 }
 
 #pragma mark - NSLayoutConstraint constant proxies
@@ -165,7 +167,7 @@
 
 - (id<MASConstraint> (^)(id))equalTo {
     return ^id(id attr) {
-        for (id<MASConstraint> constraint in self.childConstraints) {
+        for (id<MASConstraint> constraint in self.childConstraints.copy) {
             constraint.equalTo(attr);
         }
         return self;
@@ -174,7 +176,7 @@
 
 - (id<MASConstraint> (^)(id))greaterThanOrEqualTo {
     return ^id(id attr) {
-        for (id<MASConstraint> constraint in self.childConstraints) {
+        for (id<MASConstraint> constraint in self.childConstraints.copy) {
             constraint.greaterThanOrEqualTo(attr);
         }
         return self;
@@ -183,7 +185,7 @@
 
 - (id<MASConstraint> (^)(id))lessThanOrEqualTo {
     return ^id(id attr) {
-        for (id<MASConstraint> constraint in self.childConstraints) {
+        for (id<MASConstraint> constraint in self.childConstraints.copy) {
             constraint.lessThanOrEqualTo(attr);
         }
         return self;
@@ -211,7 +213,16 @@
 
 #pragma mark - MASConstraint
 
-- (void)commit {
+- (void)installConstraint {
+    for (id<MASConstraint> constraint in self.childConstraints) {
+        [constraint installConstraint];
+    }
+}
+
+- (void)uninstallConstraint {
+    for (id<MASConstraint> constraint in self.childConstraints) {
+        [constraint uninstallConstraint];
+    }
 }
 
 @end

@@ -111,19 +111,23 @@ typedef float MASLayoutPriority;
 @property (nonatomic, copy, readonly) id<MASConstraint> (^key)(id key);
 
 /**
- *	Creates a NSLayoutConstraint. The constraint is added to the first view or the or the closest common superview of the first and second view. 
+ *	Creates a NSLayoutConstraint. The constraint is installed to the first view or the or the closest common superview of the first and second view. 
  */
-- (void)commit;
+- (void)installConstraint;
+
+/**
+ *	Removes previously installed NSLayoutConstraint
+ */
+- (void)uninstallConstraint;
 
 @end
 
 @protocol MASConstraintDelegate <NSObject>
 
 /**
- *	Notifies the delegate when the constraint is has the minimum set of properties.
- *
- *	@param	constraint	a constraint that has at least a NSLayoutRelation and view
+ *	Notifies the delegate when the constraint needs to be replaced with another constraint. For example 
+ *  A MASViewConstraint may turn into a MASCompositeConstraint when an array is passed to one of the equality blocks
  */
-- (void)addConstraint:(id<MASConstraint>)constraint;
+- (void)constraint:(id<MASConstraint>)constraint shouldBeReplacedWithConstraint:(id<MASConstraint>)replacementConstraint;
 
 @end
\ No newline at end of file

@@ -32,15 +32,17 @@
 
 - (void)commit {
     for (id<MASConstraint> constraint in self.constraints) {
-        [constraint commit];
+        [constraint installConstraint];
     }
     [self.constraints removeAllObjects];
 }
 
 #pragma mark - MASConstraintDelegate
 
-- (void)addConstraint:(id<MASConstraint>)constraint {
-    [self.constraints addObject:constraint];
+- (void)constraint:(id<MASConstraint>)constraint shouldBeReplacedWithConstraint:(id<MASConstraint>)replacementConstraint {
+    int index = [self.constraints indexOfObject:constraint];
+    NSAssert(index != NSNotFound, @"Could not find constraint %@", constraint);
+    [self.constraints replaceObjectAtIndex:index withObject:replacementConstraint];
 }
 
 #pragma mark - constraint properties
@@ -49,6 +51,7 @@
     MASViewAttribute *viewAttribute = [[MASViewAttribute alloc] initWithView:self.view layoutAttribute:layoutAttribute];
     MASViewConstraint *constraint = [[MASViewConstraint alloc] initWithFirstViewAttribute:viewAttribute];
     constraint.delegate = self;
+    [self.constraints addObject:constraint];
     return constraint;
 }
 
@@ -104,18 +107,21 @@
 - (id<MASConstraint>)edges {
     MASCompositeConstraint *constraint = [[MASCompositeConstraint alloc] initWithView:self.view type:MASCompositeConstraintTypeEdges];
     constraint.delegate = self;
+    [self.constraints addObject:constraint];
     return constraint;
 }
 
 - (id<MASConstraint>)size {
     MASCompositeConstraint *constraint = [[MASCompositeConstraint alloc] initWithView:self.view type:MASCompositeConstraintTypeSize];
     constraint.delegate = self;
+    [self.constraints addObject:constraint];
     return constraint;
 }
 
 - (id<MASConstraint>)center {
     MASCompositeConstraint *constraint = [[MASCompositeConstraint alloc] initWithView:self.view type:MASCompositeConstraintTypeCenter];
     constraint.delegate = self;
+    [self.constraints addObject:constraint];
     return constraint;
 }
 @end

@@ -14,6 +14,7 @@
 
 @property (nonatomic, strong, readwrite) MASViewAttribute *secondViewAttribute;
 @property (nonatomic, strong, readwrite) MASLayoutConstraint *layoutConstraint;
+@property (nonatomic, weak) UIView *installedView;
 @property (nonatomic, assign) NSLayoutRelation layoutRelation;
 @property (nonatomic, assign) MASLayoutPriority layoutPriority;
 @property (nonatomic, assign) CGFloat layoutMultiplier;
@@ -60,7 +61,7 @@
     self.hasLayoutRelation = YES;
 }
 
-- (BOOL)hasBeenCommitted {
+- (BOOL)hasBeenInstalled {
     return self.layoutConstraint != nil;
 }
 
@@ -146,8 +147,8 @@
 
 - (id<MASConstraint> (^)(CGFloat))percent {
     return ^id(CGFloat percent) {
-        NSAssert(!self.hasBeenCommitted,
-                 @"Cannot modify constraint percent after it has been committed");
+        NSAssert(!self.hasBeenInstalled,
+                 @"Cannot modify constraint percent after it has been installed");
         
         self.layoutMultiplier = percent;
         return self;
@@ -158,8 +159,8 @@
 
 - (id<MASConstraint> (^)(MASLayoutPriority))priority {
     return ^id(MASLayoutPriority priority) {
-        NSAssert(!self.hasBeenCommitted,
-                 @"Cannot modify constraint priority after it has been committed");
+        NSAssert(!self.hasBeenInstalled,
+                 @"Cannot modify constraint priority after it has been installed");
         
         self.layoutPriority = priority;
         return self;
@@ -197,16 +198,15 @@
             for (id attr in attribute) {
                 MASViewConstraint *viewConstraint = [self copy];
                 viewConstraint.secondViewAttribute = attr;
-                [viewConstraint.delegate addConstraint:viewConstraint];
                 [children addObject:viewConstraint];
             }
             MASCompositeConstraint *compositeConstraint = [[MASCompositeConstraint alloc] initWithView:self.firstViewAttribute.view children:children];
             compositeConstraint.delegate = self.delegate;
+            [self.delegate constraint:self shouldBeReplacedWithConstraint:compositeConstraint];
             return compositeConstraint;
         } else {
             self.layoutRelation = relation;
             self.secondViewAttribute = attribute;
-            [self.delegate addConstraint:self];
             return self;
         }
     };
@@ -241,8 +241,8 @@
 
 #pragma mark - MASConstraint
 
-- (void)commit {
-    NSAssert(!self.hasBeenCommitted, @"Cannot commit constraint more than once");
+- (void)installConstraint {
+    NSAssert(!self.hasBeenInstalled, @"Cannot install constraint more than once");
     
     UIView *firstLayoutItem = self.firstViewAttribute.view;
     NSLayoutAttribute firstLayoutAttribute = self.firstViewAttribute.layoutAttribute;
@@ -283,11 +283,18 @@
                  @"couldn't find a common superview for %@ and %@",
                  firstLayoutItem,
                  secondLayoutItem);
+        self.installedView = closestCommonSuperview;
         [closestCommonSuperview addConstraint:self.layoutConstraint];
     } else {
-        
+        self.installedView = firstLayoutItem;
         [firstLayoutItem addConstraint:self.layoutConstraint];
     }
 }
 
+- (void)uninstallConstraint {
+    [self.installedView removeConstraint:self.layoutConstraint];
+    self.layoutConstraint = nil;
+    self.installedView = nil;
+}
+
 @end

@@ -116,7 +116,7 @@ it(@"should complete children", ^{
     expect(viewConstraint.layoutPriority).to.equal(MASLayoutPriorityDefaultLow);
 });
 
-it(@"should not remove on commit", ^{
+it(@"should not remove on install", ^{
     composite = [[MASCompositeConstraint alloc] initWithView:view type:MASCompositeConstraintTypeSize];
     composite.delegate = delegate;
     UIView *newView = UIView.new;
@@ -125,11 +125,22 @@ it(@"should not remove on commit", ^{
     //first equality statement
     composite.equalTo(newView).sizeOffset(CGSizeMake(90, 30));
 
-    [composite commit];
+    [composite installConstraint];
 
     expect(composite.childConstraints).to.haveCountOf(2);
-    expect(delegate.constraints).to.contain(composite.childConstraints[0]);
-    expect(delegate.constraints).to.contain(composite.childConstraints[1]);
+});
+
+it(@"should spawn child composite constraints", ^{
+    composite = [[MASCompositeConstraint alloc] initWithView:view type:MASCompositeConstraintTypeSize];
+    composite.delegate = delegate;
+
+    UIView *otherView = UIView.new;
+    [superview addSubview:otherView];
+    composite.lessThanOrEqualTo(@[@2, otherView]);
+
+    expect(composite.childConstraints).to.haveCountOf(2);
+    expect(composite.childConstraints[0]).to.beKindOf(MASCompositeConstraint.class);
+    expect(composite.childConstraints[1]).to.beKindOf(MASCompositeConstraint.class);
 });
 
 SpecEnd
\ No newline at end of file

@@ -19,8 +19,8 @@
     return self;
 }
 
-- (void)addConstraint:(id<MASConstraint>)constraint {
-    [self.constraints addObject:constraint];
+- (void)constraint:(id<MASConstraint>)constraint shouldBeReplacedWithConstraint:(id<MASConstraint>)replacementConstraint {
+    [self.constraints replaceObjectAtIndex:[self.constraints indexOfObject:constraint] withObject:replacementConstraint];
 }
 
 @end

@@ -10,6 +10,7 @@
 #import "MASConstraint.h"
 #import "UIView+MASAdditions.h"
 #import "MASConstraintDelegateMock.h"
+#import "MASCompositeConstraint.h"
 
 @interface MASViewConstraint ()
 
@@ -21,6 +22,12 @@
 
 @end
 
+@interface MASCompositeConstraint () <MASConstraintDelegate>
+
+@property (nonatomic, strong) NSMutableArray *childConstraints;
+
+@end
+
 SpecBegin(MASViewConstraint)
 
 __block MASConstraintDelegateMock *delegate;
@@ -49,7 +56,6 @@ describe(@"create equality constraint", ^{
         MASViewAttribute *secondViewAttribute = otherView.mas_top;
         MASViewConstraint *newConstraint = (id)constraint.equalTo(secondViewAttribute);
         
-        expect(delegate.constraints).to.contain(constraint);
         expect(newConstraint).to.beIdenticalTo(constraint);
         expect(constraint.secondViewAttribute).to.beIdenticalTo(secondViewAttribute);
         expect(constraint.layoutRelation).to.equal(NSLayoutRelationEqual);
@@ -59,7 +65,6 @@ describe(@"create equality constraint", ^{
         MASViewAttribute *secondViewAttribute = otherView.mas_top;
         MASViewConstraint *newConstraint = (id)constraint.greaterThanOrEqualTo(secondViewAttribute);
 
-        expect(delegate.constraints).to.contain(constraint);
         expect(newConstraint).to.beIdenticalTo(constraint);
         expect(constraint.secondViewAttribute).to.beIdenticalTo(secondViewAttribute);
         expect(constraint.layoutRelation).to.equal(NSLayoutRelationGreaterThanOrEqual);
@@ -69,7 +74,6 @@ describe(@"create equality constraint", ^{
         MASViewAttribute *secondViewAttribute = otherView.mas_top;
         MASViewConstraint *newConstraint = (id)constraint.lessThanOrEqualTo(secondViewAttribute);
 
-        expect(delegate.constraints).to.contain(constraint);
         expect(newConstraint).to.beIdenticalTo(constraint);
         expect(constraint.secondViewAttribute).to.beIdenticalTo(secondViewAttribute);
         expect(constraint.layoutRelation).to.equal(NSLayoutRelationLessThanOrEqual);
@@ -112,11 +116,14 @@ describe(@"create equality constraint", ^{
     
     it(@"should create composite when passed array of views", ^{
         NSArray *views = @[UIView.new, UIView.new, UIView.new];
-        constraint.equalTo(views).priorityMedium().offset(-10);
+        [delegate.constraints addObject:constraint];
+
+        MASCompositeConstraint *composite = (id)constraint.equalTo(views).priorityMedium().offset(-10);
 
-        expect(delegate.constraints).to.haveCountOf(3);
-        for (MASViewConstraint *constraint in delegate.constraints) {
-            int index = [delegate.constraints indexOfObject:constraint];
+        expect(delegate.constraints).to.haveCountOf(1);
+        expect(delegate.constraints[0]).to.beKindOf(MASCompositeConstraint.class);
+        for (MASViewConstraint *constraint in composite.childConstraints) {
+            int index = [composite.childConstraints indexOfObject:constraint];
             expect(constraint.secondViewAttribute.view).to.beIdenticalTo(views[index]);
             expect(constraint.firstViewAttribute.layoutAttribute).to.equal(NSLayoutAttributeWidth);
             expect(constraint.secondViewAttribute.layoutAttribute).to.equal(NSLayoutAttributeWidth);
@@ -127,11 +134,14 @@ describe(@"create equality constraint", ^{
 
     it(@"should create composite when passed array of attributes", ^{
         NSArray *viewAttributes = @[UIView.new.mas_height, UIView.new.mas_left];
-        constraint.equalTo(viewAttributes).priority(60).offset(10);
+        [delegate.constraints addObject:constraint];
+        
+        MASCompositeConstraint *composite = (id)constraint.equalTo(viewAttributes).priority(60).offset(10);
 
-        expect(delegate.constraints).to.haveCountOf(2);
-        for (MASViewConstraint *constraint in delegate.constraints) {
-            int index = [delegate.constraints indexOfObject:constraint];
+        expect(delegate.constraints).to.haveCountOf(1);
+        expect(delegate.constraints[0]).to.beKindOf(MASCompositeConstraint.class);
+        for (MASViewConstraint *constraint in composite.childConstraints) {
+            int index = [composite.childConstraints indexOfObject:constraint];
             expect(constraint.secondViewAttribute.view).to.beIdenticalTo([viewAttributes[index] view]);
             expect(constraint.firstViewAttribute.layoutAttribute).to.equal(NSLayoutAttributeWidth);
             expect(constraint.secondViewAttribute.layoutAttribute).to.equal([viewAttributes[index] layoutAttribute]);
@@ -144,7 +154,7 @@ describe(@"create equality constraint", ^{
 describe(@"multiplier & constant", ^{
 
     it(@"should not allow update of multiplier after layoutconstraint is created", ^{
-        [constraint commit];
+        [constraint installConstraint];
         
         expect(^{
             constraint.percent(0.9);
@@ -152,7 +162,7 @@ describe(@"multiplier & constant", ^{
     });
     
     it(@"should allow update of constant after layoutconstraint is created", ^{
-        [constraint commit];
+        [constraint installConstraint];
         constraint.offset(10);
         
         expect(constraint.layoutConstant).to.equal(10);
@@ -210,7 +220,7 @@ describe(@"multiplier & constant", ^{
     });
 });
 
-describe(@"commit", ^{
+describe(@"install", ^{
 
     it(@"should create layout constraint on commit", ^{
         MASViewAttribute *secondViewAttribute = otherView.mas_height;
@@ -218,7 +228,7 @@ describe(@"commit", ^{
         constraint.percent(0.5);
         constraint.offset(10);
         constraint.priority(345);
-        [constraint commit];
+        [constraint installConstraint];
 
         expect(constraint.layoutConstraint.firstAttribute).to.equal(NSLayoutAttributeWidth);
         expect(constraint.layoutConstraint.secondAttribute).to.equal(NSLayoutAttributeHeight);
@@ -232,6 +242,18 @@ describe(@"commit", ^{
         expect(superview.constraints[0]).to.beIdenticalTo(constraint.layoutConstraint);
     });
 
+    it(@"should uninstall constraint", ^{
+        MASViewAttribute *secondViewAttribute = otherView.mas_height;
+        constraint.equalTo(secondViewAttribute);
+        [constraint installConstraint];
+
+        expect(superview.constraints).to.haveCountOf(1);
+        expect(superview.constraints[0]).to.equal(constraint.layoutConstraint);
+
+        [constraint uninstallConstraint];
+        expect(superview.constraints).to.haveCountOf(0);
+    });
+
 });
 
 SpecEnd
\ No newline at end of file