### ASRatioLayoutSpec Objective-C Example

Source: https://texturegroup.org/docs/layout2-layoutspec-types.html

Lays out a component at a fixed 0.5 aspect ratio.

```Objective-C
- (ASLayoutSpec *)layoutSpecThatFits:(ASSizeRange)constrainedSize
{
  // Half Ratio
  ASStaticSizeDisplayNode *subnode = ASDisplayNodeWithBackgroundColor([UIColor greenColor], CGSizeMake(100, 100));
  return [ASRatioLayoutSpec ratioLayoutSpecWithRatio:0.5 child:subnode];
}
```

--------------------------------

### ASRatioLayoutSpec Swift Example

Source: https://texturegroup.org/docs/layout2-layoutspec-types.html

Lays out a component at a fixed 0.5 aspect ratio in Swift.

```Swift
override func layoutSpecThatFits(_ constrainedSize: ASSizeRange) -> ASLayoutSpec
{
  // Half Ratio
  let subnode = ASDisplayNodeWithBackgroundColor(UIColor.green, CGSize(width: 100, height: 100.0))
  let ratioSpec = ASRatioLayoutSpec(ratio: 0.5, child: subnode)
  return ratioSpec
}
```

--------------------------------

### Run pod install

Source: https://texturegroup.org/docs/installation.html

Run 'pod install' in the project directory after quitting Xcode completely.

```bash
> pod install

```

--------------------------------

### Create ASDimension instances

Source: https://texturegroup.org/docs/layout2-conversion-guide.html

Examples of using handy functions to create ASDimension objects in Objective-C.

```Objective-C
// 2.0:
// Handy functions to create ASDimensions
ASDimension dimensionInPoints;
dimensionInPoints = ASDimensionMake(ASDimensionTypePoints, 5.0)
dimensionInPoints = ASDimensionMake(5.0)
dimensionInPoints = ASDimensionMakeWithPoints(5.0)
dimensionInPoints = ASDimensionMake("5.0pt");

ASDimension dimensionInFractions;
dimensionInFractions = ASDimensionMake(ASDimensionTypeFraction, 0.5)
dimensionInFractions = ASDimensionMakeWithFraction(0.5)
dimensionInFractions = ASDimensionMake("50%");
```

--------------------------------

### Creating ASDimension values

Source: https://texturegroup.org/docs/layout2-api-sizing.html

Examples of creating ASDimension instances representing relative percentages or fixed point values.

```Objective-C
**// dimension returned is relative (%)**
ASDimensionMake(@"50%");  
ASDimensionMakeWithFraction(0.5);

**// dimension returned in points**
ASDimensionMake(@"70pt");
ASDimensionMake(70);      
ASDimensionMakeWithPoints(70);
```

--------------------------------

### Creating ASDimension values in Swift

Source: https://texturegroup.org/docs/layout2-api-sizing.html

Examples of creating ASDimension instances representing relative percentages or fixed point values in Swift.

```Swift
**// dimension returned is relative (%)**
ASDimensionMake("50%")
ASDimensionMakeWithFraction(0.5)

**// dimension returned in points**
ASDimensionMake("70pt")
ASDimensionMake(70)
ASDimensionMakeWithPoints(70)
```

--------------------------------

### Initialize ASScrollNode with layoutSpecBlock

Source: https://texturegroup.org/docs/scroll-node.html

Example showing how to initialize an ASScrollNode, enable automatic subnode and content size management, and define a layoutSpecBlock.

```objective-c
// NOTE: If you are using a horizontal stack, set scrollNode.scrollableDirections.
ASScrollNode *scrollNode = [[ASScrollNode alloc] init];
scrollNode.automaticallyManagesSubnodes = YES;
scrollNode.automaticallyManagesContentSize = YES;

scrollNode.layoutSpecBlock = ^(ASDisplayNode *node, ASSizeRange constrainedSize){
  ASStackLayoutSpec *stack = [ASStackLayoutSpec verticalStackLayoutSpec];
  // Add children to the stack.
  return stack;
};
```

--------------------------------

### ASRelativeDimension Example (Objective-C)

Source: https://texturegroup.org/docs/layout-api-sizing.html

Uses flexBasis with ASRelativeDimensionMakeWithPercent to set two child nodes of a horizontal stack to share width 40/60.

```objectivec
leftSideStack.flexBasis = ASRelativeDimensionMakeWithPercent(0.4f);
self.detailLabel.flexBasis  = ASRelativeDimensionMakeWithPercent(0.6f);
[horizontalStack setChildren:@[leftSideStack, self.detailLabel]];

```

--------------------------------

### ASRelativeDimension Example (Swift)

Source: https://texturegroup.org/docs/layout-api-sizing.html

Uses flexBasis with ASDimensionMake to set two child nodes of a horizontal stack to share width 40/60.

```swift
leftSideStack.style.flexBasis = ASDimensionMake("40%")
detailsLabel.style.flexBasis = ASDimensionMake("60%")
horizontalStack.children = [leftSideStack, detailsLabel]

```

--------------------------------

### Configure ASTextNode with line spacing in Swift

Source: https://texturegroup.org/docs/text-node.html

Example of setting up an ASTextNode with NSParagraphStyle line spacing, which may cause layout issues.

```Swift
let someLongString = "..."

let paragraphStyle = NSMutableParagraphStyle()
paragraphStyle.lineSpacing = 10.0

let font = UIFont(name: "SomeFontName", size: 15.0)

let attributes = [
    NSFontAttributeName: font,
    NSParagraphStyleAttributeName: paragraphStyle
]

let textNode = ASTextNode()
textNode.maximumNumberOfLines = 4
textNode.attributedText = NSAttributedString(string: someLongString, attributes: attributes)
```

--------------------------------

### Configure ASTextNode with line spacing in Objective-C

Source: https://texturegroup.org/docs/text-node.html

Example of setting up an ASTextNode with NSParagraphStyle line spacing, which may cause layout issues.

```Objective-C
// ...
NSString *someLongString = @"...";

NSMutableParagraphStyle *paragraphStyle = [[NSMutableParagraphStyle alloc] init];
paragraphStyle.lineSpacing = 10.0;

UIFont *font = [UIFont fontWithName:@"SomeFontName" size:15];

NSDictionary *attributes = @{
	NSFontAttributeName : font,
	NSParagraphStyleAttributeName: paragraphStyle
};

ASTextNode *textNode = [[ASTextNode alloc] init];
textNode.maximumNumberOfLines = 4;
textNode.attributedText = [[NSAttributedString	alloc] initWithString:someLongString
												   attributes:attributes];
// ...
```

--------------------------------

### ASCornerLayoutSpec Objective-C Example

Source: https://texturegroup.org/docs/layout2-layoutspec-types.html

Demonstrates using ASCornerLayoutSpec to position a badge node at the top right corner of an avatar node in Objective-C.

```objective-c
- (ASLayoutSpec *)layoutSpecThatFits:(ASSizeRange)constrainedSize
{
  ...
  // Layout the center of badge to the top right corner of avatar.
  ASCornerLayoutSpec *cornerSpec = [ASCornerLayoutSpec cornerLayoutSpecWithChild:self.avatarNode corner:self.badgeNode location:ASCornerLayoutLocationTopRight];
  // Slightly shift center of badge inside of avatar.
  cornerSpec.offset = CGPointMake(-3, 3);
  ...
}
```

--------------------------------

### ASCornerLayoutSpec Swift Example

Source: https://texturegroup.org/docs/layout2-layoutspec-types.html

Demonstrates using ASCornerLayoutSpec to position a badge node at the top right corner of an avatar node in Swift.

```swift
override func layoutSpecThatFits(_ constrainedSize: ASSizeRange) -> ASLayoutSpec
{
  ...
  // Layout the center of badge to the top right corner of avatar.
  let cornerSpec = ASCornerLayoutSpec(child: avatarNode, corner: badgeNode, location: .topRight)
  // Slightly shift center of badge inside of avatar.
  cornerSpec.offset = CGPoint(x: -3, y: 3)
  ...
}
```

--------------------------------

### Configure autoplay, autorepeat, and muting (Objective-C)

Source: https://texturegroup.org/docs/video-node.html

Set shouldAutoplay, shouldAutorepeat, and muted properties to control video behavior. This example configures a node to play once silently.

```Objective-C
videoNode.shouldAutoplay = YES;
videoNode.shouldAutorepeat = NO;
videoNode.muted = YES;

```

--------------------------------

### Configure autoplay, autorepeat, and muting (Swift)

Source: https://texturegroup.org/docs/video-node.html

Set shouldAutoplay, shouldAutorepeat, and muted properties to control video behavior. This example configures a node to play once silently.

```Swift
videoNode.shouldAutoplay = true
videoNode.shouldAutorepeat = false
videoNode.muted = true

```

--------------------------------

### Thread-safe node block example (Objective-C)

Source: https://texturegroup.org/docs/containers-ascollectionnode.html

Shows how to access the data model outside the node block to ensure thread safety. The index is used to fetch the model before creating the block.

```objectivec
- (ASCellNodeBlock)collectionNode:(ASCollectionNode *)collectionNode nodeBlockForItemAtIndexPath:(NSIndexPath *)indexPath
{
    PhotoModel *photoModel = [_photoFeed objectAtIndex:indexPath.row];
    
    // this may be executed on a background thread - it is important to make sure it is thread safe
    ASCellNode *(^cellNodeBlock)() = ^ASCellNode *() {
        PhotoCellNode *cellNode = [[PhotoCellNode alloc] initWithPhoto:photoModel];
        cellNode.delegate = self;
        return cellNode;
    };
    
    return cellNodeBlock;
}
  
```

--------------------------------

### ASDisplayNode keep alive reference example

Source: https://texturegroup.org/docs/faq.html

Shows creating an ASTextNode, setting its attributed string, and adding it as a subnode. The retain cycle output is shown, which is intentionally created when the node's view is in a live view hierarchy. This behavior should not be relied upon in good application design.

```objective-c
ASTextNode *title=[[ASTextNode alloc]init];
title.attributedString=Text;
[self addSubnode:title];

retain cycles
(
"-> _keepalive_node -> ASTextNode ",
"-> _view -> _ASDisplayView "
)
```

--------------------------------

### ASDKViewController init with ASCollectionNode (Objective-C)

Source: https://texturegroup.org/docs/containers-ascollectionnode.html

Shows how to create an ASCollectionNode and assign it to an ASDKViewController using initWithNode:.

```objectivec
- (instancetype)init
{
  _flowLayout = [[UICollectionViewFlowLayout alloc] init];
  _collectionNode = [[ASCollectionNode alloc] initWithCollectionViewLayout:_flowLayout];
  
  self = [super initWithNode:_collectionNode];
  if (self) {
    _flowLayout.minimumInteritemSpacing = 1;
    _flowLayout.minimumLineSpacing = 1;
  }
  
  return self;
}

```

--------------------------------

### Initialize ASDisplayNode in Swift

Source: https://texturegroup.org/docs/display-node.html

Basic initialization of an ASDisplayNode and setting its properties in Swift.

```swift
let node = ASDisplayNode()
node.backgroundColor = .orange
node.bounds = CGRect(x: 0, y: 0, width: 100, height: 100)

print("Underlying view: \(node.view)")
```

--------------------------------

### ASInsetLayoutSpec implementation

Source: https://texturegroup.org/docs/layout2-layoutspec-types.html

Examples of using ASInsetLayoutSpec to apply insets to a child node in Objective-C and Swift.

```objective-c
- (ASLayoutSpec *)layoutSpecThatFits:(ASSizeRange)constrainedSize
{
  ...
  UIEdgeInsets *insets = UIEdgeInsetsMake(10, 10, 10, 10);
  ASInsetLayoutSpec *headerWithInset = [ASInsetLayoutSpec insetLayoutSpecWithInsets:insets child:textNode];
  ...
}
```

```swift
override func layoutSpecThatFits(_ constrainedSize: ASSizeRange) -> ASLayoutSpec
{
  ...
  let insets = UIEdgeInsets(top: 10.0, left: 10.0, bottom: 10.0, right: 10.0)
  let headerWithInset = ASInsetLayoutSpec(insets: insets, child: textNode)
  ...
}
```

--------------------------------

### ASStackLayoutSpec Swift Implementation

Source: https://texturegroup.org/docs/layout2-layoutspec-types.html

Example of creating an ASStackLayoutSpec in Swift with horizontal direction and constrained dimensions.

```swift
override func layoutSpecThatFits(_ constrainedSize: ASSizeRange) -> ASLayoutSpec 
{
  let mainStack = ASStackLayoutSpec(direction: .horizontal,
                                    spacing: 6.0,
                                    justifyContent: .start,
                                    alignItems: .center,
                                    children: [titleNode, subtitleNode])

  // Set some constrained size to the stack
  mainStack.style.minWidth = ASDimensionMakeWithPoints(60.0)
  mainStack.style.maxHeight = ASDimensionMakeWithPoints(40.0)

  return mainStack
}
```

--------------------------------

### ASStackLayoutSpec Objective-C Implementation

Source: https://texturegroup.org/docs/layout2-layoutspec-types.html

Example of creating an ASStackLayoutSpec in Objective-C with horizontal direction and constrained dimensions.

```objective-c
- (ASLayoutSpec *)layoutSpecThatFits:(ASSizeRange)constrainedSize
{
  ASStackLayoutSpec *mainStack = [ASStackLayoutSpec stackLayoutSpecWithDirection:ASStackLayoutDirectionHorizontal
                       spacing:6.0
                justifyContent:ASStackLayoutJustifyContentStart
                    alignItems:ASStackLayoutAlignItemsCenter
                      children:@[_iconNode, _countNode]];

  // Set some constrained size to the stack
  mainStack.style.minWidth = ASDimensionMakeWithPoints(60.0);
  mainStack.style.maxHeight = ASDimensionMakeWithPoints(40.0);

  return mainStack;
}
```

--------------------------------

### ASDKViewController init with ASCollectionNode (Swift)

Source: https://texturegroup.org/docs/containers-ascollectionnode.html

Shows how to create an ASCollectionNode and assign it to an ASDKViewController using init(node:).

```swift
init() {
  flowLayout = UICollectionViewFlowLayout()
  collectionNode = ASCollectionNode(collectionViewLayout: flowLayout)

  super.init(node: collectionNode)

  flowLayout.minimumInteritemSpacing = 1
  flowLayout.minimumLineSpacing = 1
}

```

--------------------------------

### Enable Subtree Rasterization

Source: https://texturegroup.org/docs/subtree-rasterization.html

Enables precompositing for the entire node hierarchy starting from the root node.

```swift
rootNode.enableSubtreeRasterization()
```

--------------------------------

### Basic ASVideoNode usage with AVAsset (Swift)

Source: https://texturegroup.org/docs/video-node.html

Initialize an ASVideoNode and assign an AVAsset from a URL. Requires linking AVFoundation. This is the Swift version.

```Swift
let videoNode = ASVideoNode()

let asset = AVAsset(url: URL(string: "http://www.w3schools.com/html/mov_bbb.mp4")!)
videoNode.asset = asset

```

--------------------------------

### Enable Subtree Rasterization

Source: https://texturegroup.org/docs/subtree-rasterization.html

Enables precompositing for the entire node hierarchy starting from the root node.

```objective-c
[rootNode enableSubtreeRasterization];
```

--------------------------------

### Wrap a UIView with initWithViewBlock in Swift

Source: https://texturegroup.org/docs/display-node.html

Initializes a node with a block that returns a view in Swift.

```swift
let node = ASDisplayNode { () -> UIView in
	let view = SomeView()
	return view
}
```

--------------------------------

### ASAbsoluteLayoutSpec implementation in Objective-C

Source: https://texturegroup.org/docs/layout2-layoutspec-types.html

Example of defining an absolute layout by setting layoutPosition and preferredSize for child nodes.

```Objective-C
- (ASLayoutSpec *)layoutSpecThatFits:(ASSizeRange)constrainedSize
{
  CGSize maxConstrainedSize = constrainedSize.max;

  // Layout all nodes absolute in a static layout spec
  guitarVideoNode.style.layoutPosition = CGPointMake(0, 0);
  guitarVideoNode.style.preferredSize = CGSizeMake(maxConstrainedSize.width, maxConstrainedSize.height / 3.0);

  nicCageVideoNode.style.layoutPosition = CGPointMake(maxConstrainedSize.width / 2.0, maxConstrainedSize.height / 3.0);
  nicCageVideoNode.style.preferredSize = CGSizeMake(maxConstrainedSize.width / 2.0, maxConstrainedSize.height / 3.0);

  simonVideoNode.style.layoutPosition = CGPointMake(0.0, maxConstrainedSize.height - (maxConstrainedSize.height / 3.0));
  simonVideoNode.style.preferredSize = CGSizeMake(maxConstrainedSize.width/2, maxConstrainedSize.height / 3.0);

  hlsVideoNode.style.layoutPosition = CGPointMake(0.0, maxConstrainedSize.height / 3.0);
  hlsVideoNode.style.preferredSize = CGSizeMake(maxConstrainedSize.width / 2.0, maxConstrainedSize.height / 3.0);

  return [ASAbsoluteLayoutSpec absoluteLayoutSpecWithChildren:@[guitarVideoNode, nicCageVideoNode, simonVideoNode, hlsVideoNode]];
}
```

--------------------------------

### ASCenterLayoutSpec Objective-C Example

Source: https://texturegroup.org/docs/layout2-layoutspec-types.html

Centers a subnode within the layout spec using XY centering options.

```Objective-C
- (ASLayoutSpec *)layoutSpecThatFits:(ASSizeRange)constrainedSize
{
  ASStaticSizeDisplayNode *subnode = ASDisplayNodeWithBackgroundColor([UIColor greenColor], CGSizeMake(70, 100));
  return [ASCenterLayoutSpec centerLayoutSpecWithCenteringOptions:ASCenterLayoutSpecCenteringXY
                                                    sizingOptions:ASCenterLayoutSpecSizingOptionDefault
                                                            child:subnode]
}
```

--------------------------------

### Initialize ASDisplayNode

Source: https://texturegroup.org/docs/display-node.html

Basic initialization of an ASDisplayNode and setting its properties.

```objective-c
ASDisplayNode *node = [[ASDisplayNode alloc] init];
node.backgroundColor = [UIColor orangeColor];
node.bounds = CGRectMake(0, 0, 100, 100);

NSLog(@"Underlying view: %@", node.view);
```

--------------------------------

### ASOverlayLayoutSpec implementation

Source: https://texturegroup.org/docs/layout2-layoutspec-types.html

Examples of using ASOverlayLayoutSpec to layer a foreground node over a background node in Objective-C and Swift.

```objective-c
- (ASLayoutSpec *)layoutSpecThatFits:(ASSizeRange)constrainedSize
{
  ASDisplayNode *backgroundNode = ASDisplayNodeWithBackgroundColor([UIColor blueColor]);
  ASDisplayNode *foregroundNode = ASDisplayNodeWithBackgroundColor([UIColor redColor]);
  return [ASOverlayLayoutSpec overlayLayoutSpecWithChild:backgroundNode overlay:foregroundNode];
}
```

```swift
override func layoutSpecThatFits(_ constrainedSize: ASSizeRange) -> ASLayoutSpec
{
  let backgroundNode = ASDisplayNodeWithBackgroundColor(UIColor.blue)
  let foregroundNode = ASDisplayNodeWithBackgroundColor(UIColor.red)
  return ASOverlayLayoutSpec(child: backgroundNode, overlay: foregroundNode)
}
```

--------------------------------

### Basic ASImageNode Usage (Swift)

Source: https://texturegroup.org/docs/image-node.html

Initialize an ASImageNode and set its image and content mode using Swift.

```swift
let imageNode = ASImageNode()

imageNode.image = UIImage(named: "someImage")
imageNode.contentMode = .scaleAspectFill
```

--------------------------------

### Thread-safe nodeBlockForRowAt implementation

Source: https://texturegroup.org/docs/containers-astablenode.html

Example of accessing the data model outside the block to ensure thread safety.

```Swift
func tableNode(_ tableNode: ASTableNode, nodeBlockForRowAt indexPath: IndexPath) -> ASCellNodeBlock {
  guard photoFeed.count > indexPath.row else { return { ASCellNode() } }
    
  let photoModel = photoFeed[indexPath.row]
    
  // this may be executed on a background thread - it is important to make sure it is thread safe
  let cellNodeBlock = { () -> ASCellNode in
    let cellNode = PhotoCellNode(photo: photoModel)
    cellNode.delegate = self
    return cellNode
  }
    
  return cellNodeBlock
}
```

--------------------------------

### Thread-safe nodeBlockForRowAtIndexPath implementation

Source: https://texturegroup.org/docs/containers-astablenode.html

Example of accessing the data model outside the block to ensure thread safety.

```Objective-C
- (ASCellNodeBlock)tableNode:(ASTableNode *)tableNode nodeBlockForRowAtIndexPath:(NSIndexPath *)indexPath
{
    PhotoModel *photoModel = [_photoFeed objectAtIndex:indexPath.row];
    
    // this may be executed on a background thread - it is important to make sure it is thread safe
    ASCellNode *(^cellNodeBlock)() = ^ASCellNode *() {
        PhotoCellNode *cellNode = [[PhotoCellNode alloc] initWithPhoto:photoModel];
        cellNode.delegate = self;
        return cellNode;
    };
    
    return cellNodeBlock;
}
```

--------------------------------

### Placeholder Text - Swift

Source: https://texturegroup.org/docs/editable-text-node.html

Set the attributedPlaceholderText property to display a placeholder that disappears when the user starts typing.

```swift
editableTextNode.attributedPlaceholderText = NSAttributedString(string: "Type something here...")

```

--------------------------------

### Placeholder Text - Objective-C

Source: https://texturegroup.org/docs/editable-text-node.html

Set the attributedPlaceholderText property to display a placeholder that disappears when the user starts typing.

```objectivec
editableTextNode.attributedPlaceholderText = [[NSAttributedString alloc] initWithString:@"Type something here..."];

```

--------------------------------

### Basic ASVideoNode usage with AVAsset (Objective-C)

Source: https://texturegroup.org/docs/video-node.html

Initialize an ASVideoNode and assign an AVAsset from a URL. Requires linking AVFoundation. This is the Objective-C version.

```Objective-C
ASVideoNode *videoNode = [[ASVideoNode alloc] init];

AVAsset *asset = [AVAsset assetWithURL:[NSURL URLWithString:@"http://www.w3schools.com/html/mov_bbb.mp4"]];
videoNode.asset = asset;

```

--------------------------------

### ASAbsoluteLayoutSpec implementation in Swift

Source: https://texturegroup.org/docs/layout2-layoutspec-types.html

Example of defining an absolute layout by setting layoutPosition and preferredSize for child nodes in Swift.

```Swift
override func layoutSpecThatFits(_ constrainedSize: ASSizeRange) -> ASLayoutSpec
{
  let maxConstrainedSize = constrainedSize.max

  // Layout all nodes absolute in a static layout spec
  guitarVideoNode.style.layoutPosition = CGPoint.zero
  guitarVideoNode.style.preferredSize = CGSize(width: maxConstrainedSize.width, height: maxConstrainedSize.height / 3.0)

  nicCageVideoNode.style.layoutPosition = CGPoint(x: maxConstrainedSize.width / 2.0, y: maxConstrainedSize.height / 3.0)
  nicCageVideoNode.style.preferredSize = CGSize(width: maxConstrainedSize.width / 2.0, height: maxConstrainedSize.height / 3.0)

  simonVideoNode.style.layoutPosition = CGPoint(x: 0.0, y: maxConstrainedSize.height - (maxConstrainedSize.height / 3.0))
  simonVideoNode.style.preferredSize = CGSize(width: maxConstrainedSize.width / 2.0, height: maxConstrainedSize.height / 3.0)

  hlsVideoNode.style.layoutPosition = CGPoint(x: 0.0, y: maxConstrainedSize.height / 3.0)
  hlsVideoNode.style.preferredSize = CGSize(width: maxConstrainedSize.width / 2.0, height: maxConstrainedSize.height / 3.0)

  return ASAbsoluteLayoutSpec(children: [guitarVideoNode, nicCageVideoNode, simonVideoNode, hlsVideoNode])
}
```

--------------------------------

### Configure ASLayoutElement sizing with ASDimensionUnitAuto

Source: https://texturegroup.org/docs/layout2-conversion-guide.html

Demonstrates how to use ASDimensionUnitAuto for intrinsic sizing versus setting explicit sizes for nodes without intrinsic content.

```Objective-C
// 2.0:
// No specific size needs to be set as the imageNode's size 
// will be calculated from the content (the image in this case)
ASImageNode *imageNode = [ASImageNode new];
imageNode.image = ...;

// Specific size must be set for ASLayoutElement objects that
// do not have an intrinsic content size (ASVideoNode does not
// have a size until it's video downloads)
ASVideoNode *videoNode = [ASVideoNode new];
videoNode.style.preferredSize = CGSizeMake(200, 100);
```

--------------------------------

### Setting ASDisplayNode and ASLayoutSpec size

Source: https://texturegroup.org/docs/layout2-conversion-guide.html

Demonstrates setting width and preferred size using the 2.0 style API compared to 1.x limitations.

```Objective-C
// 1.x:
// no good way to set an intrinsic size

// 2.0:
ASDisplayNode *ASDisplayNode = ...;

// width 100 points, height: auto
displayNode.style.width = ASDimensionMakeWithPoints(100);

// width 50%, height: auto
displayNode.style.width = ASDimensionMakeWithFraction(0.5);

ASLayoutSpec *layoutSpec = ...;

// width 100 points, height 100 points
layoutSpec.style.preferredSize = CGSizeMake(100, 100);
```

--------------------------------

### ASRelativeLayoutSpec Swift Implementation

Source: https://texturegroup.org/docs/layout2-layoutspec-types.html

Example of using ASRelativeLayoutSpec in Swift to position a foreground node within a background node.

```swift
override func layoutSpecThatFits(_ constrainedSize: ASSizeRange) -> ASLayoutSpec
{
  ...
  let backgroundNode = ASDisplayNodeWithBackgroundColor(UIColor.blue)
  let foregroundNode = ASDisplayNodeWithBackgroundColor(UIColor.red, CGSize(width: 70.0, height: 100.0))

  let relativeSpec = ASRelativeLayoutSpec(horizontalPosition: .start,
                                          verticalPosition: .start,
                                          sizingOption: [],
                                          child: foregroundNode)

  let backgroundSpec = ASBackgroundLayoutSpec(child: relativeSpec, background: backgroundNode)
  ...
}
```

--------------------------------

### ASRelativeLayoutSpec Objective-C Implementation

Source: https://texturegroup.org/docs/layout2-layoutspec-types.html

Example of using ASRelativeLayoutSpec in Objective-C to position a foreground node within a background node.

```objective-c
- (ASLayoutSpec *)layoutSpecThatFits:(ASSizeRange)constrainedSize
{
  ...
  ASDisplayNode *backgroundNode = ASDisplayNodeWithBackgroundColor([UIColor redColor]);
  ASStaticSizeDisplayNode *foregroundNode = ASDisplayNodeWithBackgroundColor([UIColor greenColor], CGSizeMake(70, 100));

  ASRelativeLayoutSpec *relativeSpec = [ASRelativeLayoutSpec relativePositionLayoutSpecWithHorizontalPosition:ASRelativeLayoutSpecPositionStart
                                  verticalPosition:ASRelativeLayoutSpecPositionStart
                                      sizingOption:ASRelativeLayoutSpecSizingOptionDefault
                                             child:foregroundNode]

  ASBackgroundLayoutSpec *backgroundSpec = [ASBackgroundLayoutSpec backgroundLayoutSpecWithChild:relativeSpec background:backgroundNode];
  ...
}
```

--------------------------------

### Initialize and Set URL for ASNetworkImageNode (Swift)

Source: https://texturegroup.org/docs/network-image-node.html

Initialize an ASNetworkImageNode and set its url property to load a remote image.

```swift
let imageNode = ASNetworkImageNode()
imageNode.url = URL(string: "https://someurl.com/image_uri")
```

--------------------------------

### Constructing exact size range (ASRelativeSizeRangeMakeWithExactCGSize and ASSizeRangeMake)

Source: https://texturegroup.org/docs/layout-api-sizing.html

Shows the Objective-C and Swift convenience functions for constructing an exact size range (min = max = no range) when relative values are not needed.

```objective-c
ASRelativeSizeRangeMakeWithExactCGSize(CGSize exact);
```

```swift
public func ASSizeRangeMake(_ exactSize: CGSize) -> ASSizeRange
```

--------------------------------

### ASCenterLayoutSpec Swift Example

Source: https://texturegroup.org/docs/layout2-layoutspec-types.html

Centers a subnode within the layout spec using XY centering options in Swift.

```Swift
override func layoutSpecThatFits(_ constrainedSize: ASSizeRange) -> ASLayoutSpec
{
  let subnode = ASDisplayNodeWithBackgroundColor(UIColor.green, CGSize(width: 60.0, height: 100.0))
  let centerSpec = ASCenterLayoutSpec(centeringOptions: .XY, sizingOptions: [], child: subnode)
  return centerSpec
}
```

--------------------------------

### Run carthage update

Source: https://texturegroup.org/docs/installation.html

Run 'carthage update' in Terminal to fetch dependencies and build frameworks.

```bash
> carthage update

```

--------------------------------

### Add Target-Action Pair (Swift)

Source: https://texturegroup.org/docs/button-node.html

Adds a target-action pair to respond to touch-up-inside events. This is the Swift version of the target-action example.

```swift
buttonNode.addTarget(self, action: #selector(buttonPressed), forControlEvents: .touchUpInside)

```

--------------------------------

### Initialize ASMultiplexImageNode in ASCellNode

Source: https://texturegroup.org/docs/multiplex-image-node.html

Initialize the node, set downloadsIntermediateImages to true, and define the imageIdentifiers array in descending order of quality.

```Objective-C
- (instancetype)initWithURLs:(NSDictionary *)urls
{
    ...
     _imageURLs = urls;          // something like @{@"thumb": "/smallImageUrl", @"medium": ...}

    _multiplexImageNode = [[ASMultiplexImageNode alloc] initWithCache:nil 
                                                           downloader:[ASBasicImageDownloader sharedImageDownloader]];
    _multiplexImageNode.downloadsIntermediateImages = YES;
    _multiplexImageNode.imageIdentifiers = @[ @"original", @"medium", @"thumb" ];

    _multiplexImageNode.dataSource = self;
    _multiplexImageNode.delegate   = self;
    ...
}
```

```Swift
init(urls: [String: NSURL]) {
    imageURLs = urls

    multiplexImageNode = ASMultiplexImageNode(cache: nil, downloader: ASBasicImageDownloader.shared())
    multiplexImageNode.downloadsIntermediateImages = true
    multiplexImageNode.imageIdentifiers = ["original", "medium", "thumb" ]

    multiplexImageNode.dataSource = self
    multiplexImageNode.delegate   = self
    ...
}
```

--------------------------------

### Add Target-Action Pair (Objective-C)

Source: https://texturegroup.org/docs/button-node.html

Adds a target-action pair to respond to touch-up-inside events. This is the Objective-C version of the target-action example.

```objectivec
[buttonNode addTarget:self action:@selector(buttonPressed:) forControlEvents:ASControlNodeEventTouchUpInside];

```

--------------------------------

### Create a Simple Header Layout in Swift

Source: https://texturegroup.org/docs/automatic-layout-examples-2.html

Uses a vertical ASStackLayoutSpec for text, a horizontal ASStackLayoutSpec for the header, and an ASInsetLayoutSpec for padding.

```Swift
override func layoutSpecThatFits(_ constrainedSize: ASSizeRange) -> ASLayoutSpec {
  let nameLocationStack = ASStackLayoutSpec.vertical()
  nameLocationStack.style.flexShrink = 1.0
  nameLocationStack.style.flexGrow = 1.0

  if postLocationNode.attributedText != nil {
    nameLocationStack.children = [userNameNode, postLocationNode]
  } else {
    nameLocationStack.children = [userNameNode]
  }

  let headerStackSpec = ASStackLayoutSpec(direction: .horizontal,
                                          spacing: 40,
                                          justifyContent: .start,
                                          alignItems: .center,
                                          children: [nameLocationStack, postTimeNode])

  return ASInsetLayoutSpec(insets: UIEdgeInsets(top: 0, left: 10, bottom: 0, right: 10), child: headerStackSpec)
}
```

--------------------------------

### Set Attributed Title (Swift)

Source: https://texturegroup.org/docs/button-node.html

Sets an attributed title for a control state. This is the Swift version of the attributed string example.

```swift
buttonNode.setAttributedTitle(attributedTitle, for: .normal)

```

--------------------------------

### Create a Simple Header Layout in Objective-C

Source: https://texturegroup.org/docs/automatic-layout-examples-2.html

Uses a vertical ASStackLayoutSpec for text, a horizontal ASStackLayoutSpec for the header, and an ASInsetLayoutSpec for padding.

```Objective-C
- (ASLayoutSpec *)layoutSpecThatFits:(ASSizeRange)constrainedSize
{
  // when the username / location text is too long, 
  // shrink the stack to fit onscreen rather than push content to the right, offscreen
  ASStackLayoutSpec *nameLocationStack = [ASStackLayoutSpec verticalStackLayoutSpec];
  nameLocationStack.style.flexShrink = 1.0;
  nameLocationStack.style.flexGrow = 1.0;
  
  // if fetching post location data from server, 
  // check if it is available yet and include it if so
  if (_postLocationNode.attributedText) {
    nameLocationStack.children = @[_usernameNode, _postLocationNode];
  } else {
    nameLocationStack.children = @[_usernameNode];
  }
  
  // horizontal stack
  ASStackLayoutSpec *headerStackSpec = [ASStackLayoutSpec stackLayoutSpecWithDirection:ASStackLayoutDirectionHorizontal
                                                                               spacing:40
                                                                        justifyContent:ASStackLayoutJustifyContentStart
                                                                            alignItems:ASStackLayoutAlignItemsCenter
                                                                              children:@[nameLocationStack, _postTimeNode]];
  
  // inset the horizontal stack
  return [ASInsetLayoutSpec insetLayoutSpecWithInsets:UIEdgeInsetsMake(0, 10, 0, 10) child:headerStackSpec];
}
```

--------------------------------

### Set Attributed Title (Objective-C)

Source: https://texturegroup.org/docs/button-node.html

Sets an attributed title for a control state. This is the Objective-C version of the attributed string example.

```objectivec
[self.buttonNode setAttributedTitle:attributedTitle forState:ASControlStateNormal];

```