RWPromiseKit
Desiciption
A light-weighted Promise library for Objective-C
About Promise
The Promise object is used for deferred and asynchronous computations. A Promise represents an operation that hasn't completed yet, but is expected in the future. Ref
In JavaScript, Promise
handles asynchronising call beatifully:
getJSON("/posts.json").then(function(posts) {
// ...
consume(posts);
}).catch(function(error) {
console.log('something wrong!', error);
});
Usage of RWPromiseKit
Here is a basic example:
RWPromise* p1 = [RWPromise promise:^(ResolveHandler resolve, RejectHandler reject) {
resolve(@"result");
}];
p1.then(^id(NSString* value){
NSLog(@"%@",value); //result
return @"resultOfThen";
}).then(^id(NSString* value){
NSLog(@"%@",value); //resultOfThen
NSException *e = [NSException exceptionWithName:@"name"
reason:@"reason"
userInfo:@{}];
@throw e;
return nil;
}).catch(^(NSError* error){
NSLog(@"%@",[error description]); //error contains exception
});
Using RWPromise is exactly same as using promise in js. resolve
and reject
are provided in initial block as input parameters, these two methods are used to change the state of a promise. Block passed in then
will be invoked when a promise is set to resolved while one in catch
will be invoked when rejected.
For more infomation about the API of promise in js, please reference here
Suppoted API
0.1.0
then
catch
finally
after
retry
timeout
map
filter
reduce
race
all
resolve
reject
0.2.0
progress
Installation
- Cocoapods
pod 'RWPromiseKit', '0.2.0'
- Source code
Copy all source files from directory Class
to your project
Issues and Todo list
-
I simplify the usage of
then
compared with js. Just pass only one handler block to handle when last promise is resolved. To reject, you can raise an expection or return a new promise. -
some other API:map
,filter
,reduce
-
Integrate with 3rd party lib
-
Unit test are not finished -
Complicated test cases.
-
Doc with more detail
License
Licensed under MIT. Full license here »