devxoul/slots

Dynamic contents management for Swift.

Slots

Dynamic contents management for Swift.

At a Glance

let slots = Slots()
slots.pattern = ["Month", "Picture", "Picture", "Month", "Picture"]
slots["Month"] = ["Nov 2014", "Dec 2014", "Jan 2015"]
slots["Picture"] = [Picture(1), Picture(2), Picture(3)]

Then:

slots.contents // "Nov 2014", Picture(1), Picture(2), "Dec 2014", Picture(3), "Jan 2015"
slots[2] // Picture(2)
slots.type(at: 3) // "Month"

Installation

• For iOS 8+ projects with CocoaPods:

  pod 'Slots'

• For iOS 8+ projects with Carthage:

  github "devxoul/Slots" ~> 2.0
  

• For iOS 7 projects with CocoaSeeds:

  github 'devxoul/Then', '2.0.0', :files => 'Slots/*.swift'

Getting Started

Storing Contents

Slots can store all kind of contents. Each type of contents must be an unique string value.

This code below describes a basic example for storing some alphabet letters and numbers:

let slots = Slots()
slots["alphabet"] = ["a", "b", "c"]
slots["number"] = [1, 2, 3, 4, 5]

Using Pattern

Slots can sort stored contents according to specified pattern. You can assign array of content types to pattern property to specify contents pattern.

For example, when contents pattern is set to ["alphabet", "number"], Slots will sort contents of "alphabet" and those of "number" to be alternated with each other.

slots.pattern = ["alphabet", "number"]
slots["alphabet"] = ["a", "b", "c"]
slots["number"] = [1, 2, 3, 4, 5]
slots.contents // ["a", 1, "b", 2, "c", 3]

Although there are 5 objects in "alphabet", but slots.contents returns array that contains only 3 numbers because there is no more objects in "alphabet" after 3 time alternated. You can check the number of elements in sorted contents with count property.

slots.count // 6

Same content type can appear more than once.

slots.pattern = ["alphabet", "number", "number"]
slots.contents // ["a", 1, 2, "b", 3, 4, "c", 5]

Repeatables

You can assign repeatable content types to repeatables property. Content types specified in repeatables will be repeated until the contents are all exhausted.

slots.pattern = ["alphabet", "number"]
slots.repeatables = ["number"] // make repeatable
slots["alphabet"] = ["a", "b", "c"]
slots["number"] = [1, 2, 3, 4, 5]
slots.contents // ["a", 1, "b", 2, "c", 3, 4, 5]

Getting Contents

Slots provides the easy way to get contents. Let's assume that the slots declared like this:

slots.pattern = ["alphabet", "number", "number"]
slots["alphabet"] = ["a", "b", "c"]
slots["number"] = [1, 2, 3, 4, 5]

Then we can get 7th content in the slots with subscription, like an array.

slots[6] // "c"

If we attempt to get value of non-existing index, it'll return nil.

slots[6] // "c"
slots[7] // 5
slots[8] // nil

We can get Slice with subrange.

slots[0..<4] // "a", 1, 2, "b"

Real-World Example

Let's apply Slots to real world situation. Assume that we have to make a newsfeed like StyleShare's stylefeed. There are many content types in a feed, such as: style, featured user, featured collection, advertisements, etc.

// declare content types as constant
struct ContentType {
    static let style = "style"
    static let advertisement = "advertisement"
}

func viewDidLoad() {
    super.viewDidLoad()

    // each advertisements appear after 3 styles
    self.slots.pattern = [
        ContentType.style, ContentType.style, ContentType.style
        ContentType.advertisement
    ]
    
    // styles must be repeated even if there's no advertisements.
    self.slots.repeatables = [ContentType.style]
}

func fetchStyles() {
    self.slots[ContentType.style] = // styles from API response
    self.tableView.reloadData()
}

func fetchAdvertisements() {
    self.slots[ContentType.advertisement] = // advertisements from API response
    self.tableView.reloadData()
}

func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
    return self.slots.count
}

func tableView(_ tableView: UITableView, cellForRowAt indexPath: NSIndexPath) -> UITableViewCell {
    let contentType = self.slots.type(at: indexPath.row)
    let content = self.slots[indexPath.row]
    
    switch contentType {
        case ContentType.style:
            let cell = // ...
            cell.style = content as Style
            return cell

        case ContentType.advertisement:
            let cell = // ...
            cell.advertisement = content as Advertisement
            return cell
    }
}

License

Slots is under MIT license. See the LICENSE file for more information.