https://github.com/drewag/property-bindings
Property Bindings for Objective-C
https://github.com/drewag/property-bindings
Last synced: about 1 month ago
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Property Bindings for Objective-C
- Host: GitHub
- URL: https://github.com/drewag/property-bindings
- Owner: drewag
- License: mit
- Created: 2013-01-27T23:25:19.000Z (over 12 years ago)
- Default Branch: master
- Last Pushed: 2014-06-20T00:15:20.000Z (almost 11 years ago)
- Last Synced: 2025-03-26T13:11:19.318Z (about 2 months ago)
- Language: C++
- Homepage:
- Size: 1.87 MB
- Stars: 19
- Watchers: 2
- Forks: 1
- Open Issues: 3
-
Metadata Files:
- Readme: README.md
- Changelog: CHANGELOG.md
- License: LICENSE
Awesome Lists containing this project
README
Property Bindings for Objective-C
The Bindings extension on NSObject provide a mechanism to bind the
property of one object to the property of another's through KVO.
Integration
===========
After cloning the repository run "git submodule update --init" from within the root directory of the product.
Add the bindings.xcodeproject to your project and add bindings.a library to your target's "Link Binary With Libraries" build phase.
Usage
======
Basic Bindings
--------------
Import the header for the Bindings extension:
```objective-c
#import "bindings/NSObject+Binding.h"
```
# Basics
The Bindings extension provides the following methods to all NSObjects:
- (void)bindProperty:(NSString *)observingKeyPath
toObserved:(NSObject *)observed
withKeyPath:(NSString *)observedKeyPath;
- (void)unbindProperty:(NSString *)keyPath;
- (void)unbindAll;
If you want an object's property to always be equal to another object's property you can bind it using the `-bindProperty:toObservered:withKeyPath:` method. This automatically sets up the necessary observers and removes the observer if the source object or destination object is destroyed.
```objective-c
[destinationObject bindProperty:@"stringProperty" toObserved:sourceObject withKeyPath:@"stringProperty"];
```
You can also manually remove a binding by calling the `-unbindProperty:` or `-unbindAll` methods.
If you want to stop the binding do the following:
```objective-c
[destinationObject unbindProperty:@"stringProperty"];
```
# Transforming Values
Sometimes you may want to bind a property to the property of a different type. For example, you might want to bind a date property to a string property.
To do this, create a setter on the destination object that takes the source objects property types, convert the object, and then set it on the real property. For example:
```objective-c
- (void)setDate:(NSDate *)date {
self.dateString = date.description;
}
```
In the example above you would bind to the "date" key path.
See the spec file for more example usage: specs/BindingSpec.mm
For a description of the implementation please see my [blog post](http://drewag.me/posts/objective-c-bindings?source=github) about it.
Specialty Bindings
------------------
# Binding A Table View to an NSArray
Instead of needing to implement a UITableViewDataSource object you can bind a table view directly to an NSArray. The syntax looks like the following:
```objective-c
[tableView
bindToObserved:sourceObject
withArrayKeyPath:@"names"
cellCreationBlock:^UITableViewCell *(NSString *name) {
UITableViewCell *cell = [self.tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (!cell) {
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];
[cell autorelease];
}
cell.textLabel.text = name;
return cell;
}];
```
The cellCreationBlock will be called every time the table needs a new cell.
**Note:** in order to handle insertions, deletions, and modifications you must ensure that the property triggers granular KVO notifications which an NSArray does not do automatically.
Contribution
=============
I encourage anybody with ideas or bug fixes to make changes and submit pull requests. If you do, please follow the [CAAG Commit Style](http://drewag.me/posts/changes-at-a-glance?source=github).