Preworker is a tool to help you do work in your application before it is needed. You'll often have times in your application where it may be useful to build a product of some data before it is needed to allow a better user experience. A few examples are:
- Build a complex path that represents a users run before they tap into it.
- Download a large version of an image before the user views the full size.
- Apply a filters to an image before the user taps it so it immediately renders.
- Package a document before it the user saves it.
Units of work are defined in a closure so you don't need to do any subclassing to start using Preworker. Each work closure is passed an object, called a Preworker Context, to enable progress tracking and asynchronous work to be done within the closure as well.
You can track the progress of the work being done and be notified as the work progresses.
Preworker makes use of libdispatch to support multiple units of work within the main unit of work. This makes downloads possible, among other things. Here's an example:
var downloadWorker = Preworker<NSData> { context in
let session = NSURLSession(configuration: NSURLSessionConfiguration.defaultSessionConfiguration())
context++ // Tells the context we are starting an operation
var downloadData: NSData?
var downloadError: NSError?
let task = session.dataTaskWithURL(NSURL(string: "http://ipv4.download.thinkbroadband.com/100MB.zip")) { data, response, error in
downloadData = data
downloadError = error
context-- // Tells the context we finished an operation
}
task.resume()
// This asks the context to wait until all operations have been finished.
context.waitForPendingOperations()
return (downloadData, downloadError)
}.start()- Download Preworker and check out the example operations in the sample application
- Start using Preworker by copying the files in the Sources directory to your own project.
We'll include support for Cocoapods when it's possible to!
Preworker is built using Swift, and makes heavy use of the advanced features of Swift, so it isn't available in Objective-C. It supports iOS 7.0+, or Mac OS X 10.10+.
Preworker is used to create units of work. They can be any type of work that you may want done separately, but usually it would be done in the background.
Check out the Using Preworker document to see some examples on how you could use Preworker.
- If you need help or have a general question use Stack Overflow
- If you've found a bug or have a feature request open an issue
Copyright (c) 2014, James Richard All rights reserved.
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