subscribe() is out, bind() is in

Author: icanzilb

Assets/slack.png

@@ -1,8 +1,8 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<document type="com.apple.InterfaceBuilder3.CocoaTouch.Storyboard.XIB" version="3.0" toolsVersion="14854.2" targetRuntime="iOS.CocoaTouch" propertyAccessControl="none" useAutolayout="YES" useTraitCollections="YES" useSafeAreas="YES" colorMatched="YES" initialViewController="cqX-1O-xhM">
+<document type="com.apple.InterfaceBuilder3.CocoaTouch.Storyboard.XIB" version="3.0" toolsVersion="14865.1" targetRuntime="iOS.CocoaTouch" propertyAccessControl="none" useAutolayout="YES" useTraitCollections="YES" useSafeAreas="YES" colorMatched="YES" initialViewController="cqX-1O-xhM">
     <device id="retina6_1" orientation="portrait" appearance="light"/>
     <dependencies>
-        <plugIn identifier="com.apple.InterfaceBuilder.IBCocoaTouchPlugin" version="14806.4"/>
+        <plugIn identifier="com.apple.InterfaceBuilder.IBCocoaTouchPlugin" version="14819.2"/>
         <capability name="Safe area layout guides" minToolsVersion="9.0"/>
         <capability name="collection view cell content view" minToolsVersion="11.0"/>
         <capability name="documents saved in the Xcode 8 format" minToolsVersion="8.0"/>
@@ -25,7 +25,7 @@
                                             <rect key="frame" x="0.0" y="0.0" width="342.5" height="50"/>
                                             <autoresizingMask key="autoresizingMask"/>
                                             <subviews>
-                                                <label opaque="NO" multipleTouchEnabled="YES" contentMode="left" insetsLayoutMarginsFromSafeArea="NO" text="Plain list" textAlignment="natural" lineBreakMode="tailTruncation" baselineAdjustment="alignBaselines" adjustsFontSizeToFit="NO" id="dE9-Yq-PRN">
+                                                <label opaque="NO" multipleTouchEnabled="YES" contentMode="left" insetsLayoutMarginsFromSafeArea="NO" text="Static plain list" textAlignment="natural" lineBreakMode="tailTruncation" baselineAdjustment="alignBaselines" adjustsFontSizeToFit="NO" id="dE9-Yq-PRN">
                                                     <rect key="frame" x="20" y="0.0" width="314.5" height="50"/>
                                                     <autoresizingMask key="autoresizingMask"/>
                                                     <fontDescription key="fontDescription" type="system" pointSize="17"/>
@@ -284,12 +284,12 @@
                                     <label opaque="NO" userInteractionEnabled="NO" contentMode="left" horizontalHuggingPriority="251" verticalHuggingPriority="251" text="Status" textAlignment="natural" lineBreakMode="tailTruncation" baselineAdjustment="alignBaselines" adjustsFontSizeToFit="NO" translatesAutoresizingMaskIntoConstraints="NO" id="2nN-q1-dXy">
                                         <rect key="frame" x="121" y="67.5" width="72" height="31.5"/>
                                         <fontDescription key="fontDescription" style="UICTFontTextStyleTitle1"/>
-                                        <color key="textColor" systemColor="linkColor" red="0.0" green="0.47843137254901963" blue="1" alpha="1" colorSpace="custom" customColorSpace="sRGB"/>
+                                        <color key="textColor" systemColor="linkColor" red="0.0" green="0.47843137250000001" blue="1" alpha="1" colorSpace="custom" customColorSpace="sRGB"/>
                                         <nil key="highlightedColor"/>
                                     </label>
                                     <button opaque="NO" contentMode="scaleToFill" contentHorizontalAlignment="center" contentVerticalAlignment="center" buttonType="roundedRect" lineBreakMode="middleTruncation" translatesAutoresizingMaskIntoConstraints="NO" id="fbr-Gc-rOl">
                                         <rect key="frame" x="37" y="135" width="240" height="46"/>
-                                        <color key="backgroundColor" systemColor="linkColor" red="0.0" green="0.47843137254901963" blue="1" alpha="1" colorSpace="custom" customColorSpace="sRGB"/>
+                                        <color key="backgroundColor" systemColor="linkColor" red="0.0" green="0.47843137250000001" blue="1" alpha="1" colorSpace="custom" customColorSpace="sRGB"/>
                                         <constraints>
                                             <constraint firstAttribute="height" constant="46" id="6r8-B6-yiH"/>
                                             <constraint firstAttribute="width" constant="240" id="kUK-LS-l4G"/>
@@ -310,7 +310,7 @@
                                     </button>
                                     <button opaque="NO" contentMode="scaleToFill" contentHorizontalAlignment="center" contentVerticalAlignment="center" buttonType="roundedRect" lineBreakMode="middleTruncation" translatesAutoresizingMaskIntoConstraints="NO" id="eGM-4g-fqO">
                                         <rect key="frame" x="37" y="217" width="240" height="46"/>
-                                        <color key="backgroundColor" systemColor="systemGrayColor" red="0.55686274509803924" green="0.55686274509803924" blue="0.57647058823529407" alpha="1" colorSpace="custom" customColorSpace="sRGB"/>
+                                        <color key="backgroundColor" systemColor="systemGrayColor" red="0.5568627451" green="0.5568627451" blue="0.57647058819999997" alpha="1" colorSpace="custom" customColorSpace="sRGB"/>
                                         <fontDescription key="fontDescription" style="UICTFontTextStyleTitle2"/>
                                         <state key="normal" title="Reload">
                                             <color key="titleColor" systemColor="systemBackgroundColor" cocoaTouchSystemColor="whiteColor"/>
@@ -399,7 +399,7 @@
                                                     <nil key="highlightedColor"/>
                                                 </label>
                                             </subviews>
-                                            <color key="backgroundColor" systemColor="tertiarySystemGroupedBackgroundColor" red="0.94901960784313721" green="0.94901960784313721" blue="0.96862745098039216" alpha="1" colorSpace="custom" customColorSpace="sRGB"/>
+                                            <color key="backgroundColor" systemColor="tertiarySystemGroupedBackgroundColor" red="0.94901960780000005" green="0.94901960780000005" blue="0.96862745100000003" alpha="1" colorSpace="custom" customColorSpace="sRGB"/>
                                             <constraints>
                                                 <constraint firstItem="b97-Y7-dI9" firstAttribute="top" secondItem="Elw-G5-4Vf" secondAttribute="bottom" constant="8" id="3dE-Sl-j8Z"/>
                                                 <constraint firstAttribute="bottom" secondItem="b97-Y7-dI9" secondAttribute="bottom" constant="7" id="5gd-yF-ve0"/>
@@ -461,7 +461,7 @@
                                                 <label opaque="NO" userInteractionEnabled="NO" contentMode="left" horizontalHuggingPriority="251" verticalHuggingPriority="251" text="Label" textAlignment="natural" lineBreakMode="tailTruncation" baselineAdjustment="alignBaselines" adjustsFontSizeToFit="NO" translatesAutoresizingMaskIntoConstraints="NO" id="l3U-52-thG">
                                                     <rect key="frame" x="20" y="21" width="334" height="21"/>
                                                     <fontDescription key="fontDescription" style="UICTFontTextStyleTitle2"/>
-                                                    <color key="textColor" systemColor="linkColor" red="0.0" green="0.47843137254901963" blue="1" alpha="1" colorSpace="custom" customColorSpace="sRGB"/>
+                                                    <color key="textColor" systemColor="linkColor" red="0.0" green="0.47843137250000001" blue="1" alpha="1" colorSpace="custom" customColorSpace="sRGB"/>
                                                     <nil key="highlightedColor"/>
                                                 </label>
                                             </subviews>

Example/Example/Base.lproj/Main.storyboard

@@ -30,7 +30,7 @@ class GitHubSearchViewController: UIViewController, UISearchBarDelegate {
       .map { $0.items }
       .replaceError(with: [])
       .receive(on: DispatchQueue.main)
-      .subscribe(retaining: tableView.rowsSubscriber(cellIdentifier: "Cell", cellType: UITableViewCell.self, cellConfig: { (cell, ip, repo) in
+      .bind(subscriber: tableView.rowsSubscriber(cellIdentifier: "Cell", cellType: UITableViewCell.self, cellConfig: { (cell, ip, repo) in
         cell.textLabel!.text = repo.name
         cell.detailTextLabel!.text = repo.description
       }))

Example/Example/GitHubSearchViewController.swift

@@ -57,17 +57,16 @@ class ViewController: UIViewController {
     switch demo {
     case .plain:
       // A plain list with a single section -> Publisher<[Person], Never>
-      data
-        .map { $0[0] }
-        .subscribe(retaining: tableView.rowsSubscriber(cellIdentifier: "Cell", cellType: PersonCell.self, cellConfig: { cell, indexPath, model in
+      first.publisher
+        .bind(subscriber: tableView.rowsSubscriber(cellIdentifier: "Cell", cellType: PersonCell.self, cellConfig: { cell, indexPath, model in
           cell.nameLabel.text = "\(indexPath.section+1).\(indexPath.row+1) \(model.name)"
         }))
         .store(in: &subscriptions)
 
     case .multiple:
       // Table with sections -> Publisher<[[Person]], Never>
       data
-        .subscribe(retaining: tableView.sectionsSubscriber(cellIdentifier: "Cell", cellType: PersonCell.self, cellConfig: { cell, indexPath, model in
+        .bind(subscriber: tableView.sectionsSubscriber(cellIdentifier: "Cell", cellType: PersonCell.self, cellConfig: { cell, indexPath, model in
           cell.nameLabel.text = "\(indexPath.section+1).\(indexPath.row+1) \(model.name)"
         }))
         .store(in: &subscriptions)
@@ -80,7 +79,7 @@ class ViewController: UIViewController {
             return Section(header: "Header", items: persons, footer: "Footer")
           }
         }
-        .subscribe(retaining: tableView.sectionsSubscriber(cellIdentifier: "Cell", cellType: PersonCell.self, cellConfig: { cell, indexPath, model in
+        .bind(subscriber: tableView.sectionsSubscriber(cellIdentifier: "Cell", cellType: PersonCell.self, cellConfig: { cell, indexPath, model in
           cell.nameLabel.text = "\(indexPath.section+1).\(indexPath.row+1) \(model.name)"
         }))
         .store(in: &subscriptions)
@@ -93,7 +92,7 @@ class ViewController: UIViewController {
       controller.animated = false
 
       data
-        .subscribe(retaining: tableView.sectionsSubscriber(controller))
+        .bind(subscriber: tableView.sectionsSubscriber(controller))
         .store(in: &subscriptions)
     }
 

Example/Example/ViewController.swift

@@ -2,7 +2,7 @@
 
 **CombineDataSources** provides custom Combine subscribers that act as table and collection view controllers and bind a stream of element collections to table or collection sections with cells.  
 
-⚠️⚠️⚠️ **Note**: The package is currently work in progress.
+⚠️⚠️⚠️ **Note** 🚨🚨🚨: The package is currently work in progress.
 
 ### Table of Contents
 
@@ -14,9 +14,7 @@
 
 1.2 [Customize the table controller](#customize-the-table-controller)
 
-1.3 [Subscribing a completing publisher](#subscribing-a-completing-publisher)
-
-1.4 [List loaded in batches](#list-loaded-in-batches)
+1.3 [List loaded in batches](#list-loaded-in-batches)
 
 2. [**Installation**](#installation)
 
@@ -38,9 +36,10 @@ The repo contains a demo app in the *Example* sub-folder that demonstrates visua
 var data = PassthroughSubject<[Person], Never>()
 
 data
-  .subscribe(subscriber: tableView.rowsSubscriber(cellIdentifier: "Cell", cellType: PersonCell.self, cellConfig: { cell, indexPath, model in
+  .bind(subscriber: tableView.rowsSubscriber(cellIdentifier: "Cell", cellType: PersonCell.self, cellConfig: { cell, indexPath, model in
     cell.nameLabel.text = model.name
   }))
+  .store(in: &subscriptions)
 ```
 
 ![Plain list updates with CombineDataSources](https://github.com/combineopensource/CombineDataSources/raw/master/Assets/plain-list.gif)
@@ -49,10 +48,11 @@ Respectively for a collection view:
 
 ```swift
 data
-  .subscribe(collectionView.itemsSubscriber(cellIdentifier: "Cell", cellType: PersonCollectionCell.self, cellConfig: { cell, indexPath, model in
+  .bind(subscriber: collectionView.itemsSubscriber(cellIdentifier: "Cell", cellType: PersonCollectionCell.self, cellConfig: { cell, indexPath, model in
     cell.nameLabel.text = model.name
     cell.imageURL = URL(string: "https://api.adorable.io/avatars/100/\(model.name)")!
   }))
+  .store(in: &subscriptions)
 ```
 
 ![Plain list updates for a collection view](https://github.com/combineopensource/CombineDataSources/raw/master/Assets/plain-collection.gif)
@@ -63,9 +63,10 @@ data
 var data = PassthroughSubject<[Section<Person>], Never>()
 
 data
-  .subscribe(subscriber: tableView.sectionsSubscriber(cellIdentifier: "Cell", cellType: PersonCell.self, cellConfig: { cell, indexPath, model in
+  .bind(subscriber: tableView.sectionsSubscriber(cellIdentifier: "Cell", cellType: PersonCell.self, cellConfig: { cell, indexPath, model in
     cell.nameLabel.text = model.name
   }))
+  .store(in: &subscriptions)
 ```
 
 ![Sectioned list updates with CombineDataSources](https://github.com/combineopensource/CombineDataSources/raw/master/Assets/sections-list.gif)
@@ -83,27 +84,10 @@ controller.animated = false
 // More custom controller configuration ...
 
 data
-  .subscribe(subscriber: tableView.sectionsSubscriber(controller))
-```
-
-#### Subscribing a completing publisher
-
-Sometimes you'll bind a publisher to your table or collection view and it will complete at a point. When you use `subscribe(_)` the completion event will release the CombineDataSource subscriber as well and that will likely render the table/collection empty.
-
-In such case you can use the custom operator included in **CombineDataSources** `subscribe(retaining:)` that will give you an `AnyCancellable` to retain the subscriber, like so:
-
-```swift
-var subscriptions = [AnyCancellable]()
-...
-Just([Person(name: "test"])
-  .subscribe(retaining: tableView.rowsSubscriber(cellIdentifier: "Cell", cellType: UITableViewCell.self, cellConfig: { (cell, ip, person) in
-    cell.textLabel!.text = person.name
-  }))
+  .subscribe(bind: tableView.sectionsSubscriber(controller))
   .store(in: &subscriptions)
 ```
 
-This will keep the subscriber and the data source alive until you cancel the subscription manually or it is released from memory.
-
 #### List loaded in batches
 
 A common pattern for list views is to load a very long list of elements in "batches" or "pages". (The distinction being that pages imply ordered, equal-length batches.)
@@ -186,6 +170,10 @@ Add the following dependency to your **Package.swift** file:
 
 CombineOpenSource is available under the MIT license. See the LICENSE file for more info.
 
+## Combine Open Source
+
+Join ![Combine Slack channel](Assets/slack.png) [https://combineopensource.slack.com](https://combineopensource.slack.com) for Combine related talk.
+
 ## Credits
 
 Created by Marin Todorov for [CombineOpenSource](https://github.com/combineopensource).

README.md

@@ -73,7 +73,7 @@ public class TableViewBatchesController<Element: Hashable> {
     // Display items in table view.
     batchesDataSource.output.$items
       .receive(on: DispatchQueue.main)
-      .subscribe(retaining: tableView.rowsSubscriber(itemsController))
+      .bind(subscriber: tableView.rowsSubscriber(itemsController))
       .store(in: &subscriptions)
 
     // Show/hide spinner.

Sources/CombineDataSources/TableView/TableViewBatchesController.swift

@@ -6,14 +6,17 @@
 import Foundation
 import Combine
 
+public typealias Binding = Subscriber
+
 public extension Publisher where Failure == Never {
-  func subscribe<S: Subscriber>(retaining subscriber: S) -> AnyCancellable
-    where S.Failure == Never, S.Input == Output {
-    
-    sink(receiveCompletion: { (completion) in
-      subscriber.receive(completion: completion)
-    }) { (value) in
-      _ = subscriber.receive(value)
-    }
+  func bind<B: Binding>(subscriber: B) -> AnyCancellable
+    where B.Failure == Never, B.Input == Output {
+
+      handleEvents(receiveSubscription: { subscription in
+        subscriber.receive(subscription: subscription)
+      })
+      .sink { value in
+        _ = subscriber.receive(value)
+      }
   }
 }

Sources/CombineDataSources/etc/Publisher+SubscribeRetaining.swift

@@ -1,5 +1,6 @@
 import XCTest
 import UIKit
+import Combine
 @testable import CombineDataSources
 
 final class MemoryManagementTests: XCTestCase {
@@ -23,4 +24,35 @@ final class MemoryManagementTests: XCTestCase {
     dataSource = nil
     XCTAssertNotNil(ctr!.dataSource)
   }
+    
+  func testBind() {
+    let expectation1 = expectation(description: "subscribed")
+    let expectation2 = expectation(description: "value")
+
+    var subscriptions = [AnyCancellable]()
+    var sub: AnySubscriber<String, Never>?
+    
+    sub = AnySubscriber<String, Never>(
+      receiveSubscription: { sub in
+        expectation1.fulfill()
+      },
+      receiveValue: { value -> Subscribers.Demand in
+        expectation2.fulfill()
+        return .unlimited
+      })
+    { (completion) in
+      XCTFail("Binding sent completion event")
+    }
+    
+    DispatchQueue.main.async {
+      let data = PassthroughSubject<String, Never>()
+      data
+        .bind(subscriber: sub!)
+        .store(in: &subscriptions)
+
+      data.send("asdasd") // will be passed on
+      data.send(completion: .finished) // will be filtered
+    }
+    wait(for: [expectation1, expectation2], timeout: 1)
+  }
 }

Tests/CombineDataSourcesTests/MemoryManagementTests.swift

@@ -0,0 +1,15 @@
+//
+//  File.swift
+//  
+//
+//  Created by Marin Todorov on 8/30/19.
+//
+
+import UIKit
+import Combine
+import XCTest
+
+final class TableViewBatchesControllerTests: XCTestCase {
+  // TODO: add
+  
+}