Interface Builder: Typed segues on a per scene basis

Sources/SwiftGenCLI/templates/ib/scenes-swift4.stencil

@@ -42,7 +42,7 @@ import {{module}}
     {% set sceneClass %}{% call className storyboard.initialScene %}{% endset %}
     {{accessModifier}} static let initialScene = InitialSceneType<{{sceneClass}}>(storyboard: {{storyboardName}}.self)
     {% endif %}
-    {% for scene in storyboard.scenes %}
+    {% for scene in storyboard.scenes where scene.identifier %}
 
     {% set sceneID %}{{scene.identifier|swiftIdentifier:"pretty"|lowerFirstWord|escapeReservedKeywords}}{% endset %}
     {% set sceneClass %}{% call className scene %}{% endset %}

Sources/SwiftGenCLI/templates/ib/scenes-swift5.stencil

@@ -42,7 +42,7 @@ import {{module}}
     {% set sceneClass %}{% call className storyboard.initialScene %}{% endset %}
     {{accessModifier}} static let initialScene = InitialSceneType<{{sceneClass}}>(storyboard: {{storyboardName}}.self)
     {% endif %}
-    {% for scene in storyboard.scenes %}
+    {% for scene in storyboard.scenes where scene.identifier %}
 
     {% set sceneID %}{{scene.identifier|swiftIdentifier:"pretty"|lowerFirstWord|escapeReservedKeywords}}{% endset %}
     {% set sceneClass %}{% call className scene %}{% endset %}

Sources/SwiftGenCLI/templates/ib/segues-swift4.stencil

@@ -16,10 +16,100 @@ import {{module}}
 // MARK: - Storyboard Segues
 
 // swiftlint:disable explicit_type_interface identifier_name line_length type_body_length type_name
-{{accessModifier}} enum {{param.enumName|default:"StoryboardSegue"}} {
+{% macro moduleName item %}{% filter removeNewlines %}
+  {% if item.moduleIsPlaceholder %}
+    {{ env.PRODUCT_MODULE_NAME|default:param.module }}
+  {% else %}
+    {{ item.module }}
+  {% endif %}
+{% endfilter %}{% endmacro %}
+{% macro className item %}{% filter removeNewlines %}
+  {% set module %}{% call moduleName item %}{% endset %}
+  {% if module and ( not param.ignoreTargetModule or module != env.PRODUCT_MODULE_NAME and module != param.module ) %}
+    {{module}}.
+  {% endif %}
+  {{item.type}}
+{% endfilter %}{% endmacro %}
+{% set enumName %}{{param.enumName|default:"StoryboardSegue"}}{% endset %}
+{% set unnamedSegue %}{{param.unnamedSegueCaseName|default:"unnamedSegue"}}{% endset %}
+{% for scene in customSceneTypes where scene.segues %}
+{% set sceneClass %}{% call className scene %}{% endset %}
+{{accessModifier}} extension {{sceneClass}} {
+  {{accessModifier}} enum {{enumName}}: String {
+    {% for segue in scene.segues where segue.identifier %}
+    {% set segueID %}{{segue.identifier|swiftIdentifier:"pretty"|lowerFirstWord}}{% endset %}
+    case {{segueID|escapeReservedKeywords}}{% if segueID != segue.identifier %} = "{{segue.identifier}}"{% endif %}
+    {% endfor %}
+  }
+
+  {{accessModifier}} func perform(segue: {{enumName}}, sender: Any? = nil) {
+    let identifier = {% if isAppKit %}NSStoryboardSegue.Identifier({% endif %}segue.rawValue{% if isAppKit %}){% endif %}
+    performSegue(withIdentifier: identifier, sender: sender)
+  }
+
+  {{accessModifier}} enum Typed{{enumName}} {
+    {% set hasUnnamedSegue %}{% for segue in scene.segues where not scene.identifier %}1{% endfor %}{% endset %}
+    {% for segue in scene.segues where segue.identifier %}
+    {% set segueID %}{{segue.identifier|swiftIdentifier:"pretty"|lowerFirstWord}}{% endset %}
+    case {{segueID|escapeReservedKeywords}}{% filter removeNewlines:"leading" %}
+      {% if segue.customClass or segue.destination %}(
+        {% if segue.destination %}destination: {% call className segue.destination %}{% endif %}
+        {% if segue.customClass and segue.destination %}, {% endif %}
+        {% if segue.customClass %}segue: {% call className segue %}{% endif %}
+      ){% endif %}
+    {% endfilter %}
+    {% endfor %}
+    {% if hasUnnamedSegue %}
+    case {{unnamedSegue}}
+    {% endif %}
+
+    // swiftlint:disable cyclomatic_complexity
+    init(segue: {{prefix}}StoryboardSegue) {
+      switch segue.identifier{% if isAppKit %}?.rawValue{% endif %} ?? "" {
+      {% for segue in scene.segues where segue.identifier %}
+      case "{{segue.identifier}}":
+        {% if segue.customClass %}
+        {% set segueClass %}{% call className segue %}{% endset %}
+        guard let segue = segue as? {{segueClass}} else {
+          fatalError("Segue '{{segue.identifier}}' is not of the expected type {{segueClass}}.")
+        }
+        {% endif %}
+        {% if segue.destination %}
+        {% set destinationClass %}{% call className segue.destination %}{% endset %}
+        {% if destinationClass != "UIKit.UIViewController" %}
+        guard let vc = segue.destination{% if isAppKit %}Controller{% endif %} as? {{destinationClass}} else {
+          fatalError("Destination of segue '{{segue.identifier}}' is not of the expected type {{destinationClass}}.")
+        }
+        {% else %}
+        let vc = segue.destination{% if isAppKit %}Controller{% endif %}
+        {% endif %}
+        {% endif %}
+        {% set segueID %}{{segue.identifier|swiftIdentifier:"pretty"|lowerFirstWord}}{% endset %}
+        self = .{{segueID|escapeReservedKeywords}}{% filter removeNewlines:"leading" %}
+          {% if segue.customClass or segue.destination %}(
+            {% if segue.destination %}destination: vc{% endif %}
+            {% if segue.customClass and segue.destination %}, {% endif %}
+            {% if segue.customClass %}segue: segue{% endif %}
+          ){%endif %}
+        {% endfilter %}
+      {% endfor %}
+      {% if hasUnnamedSegue %}
+      case "":
+        self = .{{unnamedSegue}}
+      {% endif %}
+      default:
+        fatalError("Unrecognized segue '\(segue.identifier{% if isAppKit %}?.rawValue{% endif %} ?? "")' in {{sceneClass}}")
+      }
+    }
+    // swiftlint:enable cyclomatic_complexity
+  }
+}
+
+{% endfor %}
+{{accessModifier}} enum {{enumName}} {
   {% for storyboard in storyboards where storyboard.segues %}
   {{accessModifier}} enum {{storyboard.name|swiftIdentifier:"pretty"|escapeReservedKeywords}}: String, SegueType {
-    {% for segue in storyboard.segues %}
+    {% for segue in storyboard.segues where segue.identifier %}
     {% set segueID %}{{segue.identifier|swiftIdentifier:"pretty"|lowerFirstWord}}{% endset %}
     case {{segueID|escapeReservedKeywords}}{% if segueID != segue.identifier %} = "{{segue.identifier}}"{% endif %}
     {% endfor %}

Sources/SwiftGenCLI/templates/ib/segues-swift5.stencil

@@ -16,10 +16,99 @@ import {{module}}
 // MARK: - Storyboard Segues
 
 // swiftlint:disable explicit_type_interface identifier_name line_length type_body_length type_name
-{{accessModifier}} enum {{param.enumName|default:"StoryboardSegue"}} {
+{% macro moduleName item %}{% filter removeNewlines %}
+  {% if item.moduleIsPlaceholder %}
+    {{ env.PRODUCT_MODULE_NAME|default:param.module }}
+  {% else %}
+    {{ item.module }}
+  {% endif %}
+{% endfilter %}{% endmacro %}
+{% macro className item %}{% filter removeNewlines %}
+  {% set module %}{% call moduleName item %}{% endset %}
+  {% if module and ( not param.ignoreTargetModule or module != env.PRODUCT_MODULE_NAME and module != param.module ) %}
+    {{module}}.
+  {% endif %}
+  {{item.type}}
+{% endfilter %}{% endmacro %}
+{% set enumName %}{{param.enumName|default:"StoryboardSegue"}}{% endset %}
+{% set unnamedSegue %}{{param.unnamedSegueCaseName|default:"unnamedSegue"}}{% endset %}
+{% for scene in customSceneTypes where scene.segues %}
+{% set sceneClass %}{% call className scene %}{% endset %}
+{{accessModifier}} extension {{sceneClass}} {
+  {{accessModifier}} enum {{enumName}}: String {
+    {% for segue in scene.segues where segue.identifier %}
+    {% set segueID %}{{segue.identifier|swiftIdentifier:"pretty"|lowerFirstWord}}{% endset %}
+    case {{segueID|escapeReservedKeywords}}{% if segueID != segue.identifier %} = "{{segue.identifier}}"{% endif %}
+    {% endfor %}
+  }
+
+  {{accessModifier}} func perform(segue: {{enumName}}, sender: Any? = nil) {
+    performSegue(withIdentifier: segue.rawValue, sender: sender)
+  }
+
+  {{accessModifier}} enum Typed{{enumName}} {
+    {% set hasUnnamedSegue %}{% for segue in scene.segues where not scene.identifier %}1{% endfor %}{% endset %}
+    {% for segue in scene.segues where segue.identifier %}
+    {% set segueID %}{{segue.identifier|swiftIdentifier:"pretty"|lowerFirstWord}}{% endset %}
+    case {{segueID|escapeReservedKeywords}}{% filter removeNewlines:"leading" %}
+      {% if segue.customClass or segue.destination %}(
+        {% if segue.destination %}destination: {% call className segue.destination %}{% endif %}
+        {% if segue.customClass and segue.destination %}, {% endif %}
+        {% if segue.customClass %}segue: {% call className segue %}{% endif %}
+      ){% endif %}
+    {% endfilter %}
+    {% endfor %}
+    {% if hasUnnamedSegue %}
+    case {{unnamedSegue}}
+    {% endif %}
+
+    // swiftlint:disable cyclomatic_complexity
+    init(segue: {{prefix}}StoryboardSegue) {
+      switch segue.identifier ?? "" {
+      {% for segue in scene.segues where segue.identifier %}
+      case "{{segue.identifier}}":
+        {% if segue.customClass %}
+        {% set segueClass %}{% call className segue %}{% endset %}
+        guard let segue = segue as? {{segueClass}} else {
+          fatalError("Segue '{{segue.identifier}}' is not of the expected type {{segueClass}}.")
+        }
+        {% endif %}
+        {% if segue.destination %}
+        {% set destinationClass %}{% call className segue.destination %}{% endset %}
+        {% if destinationClass != "UIKit.UIViewController" %}
+        guard let vc = segue.destination{% if isAppKit %}Controller{% endif %} as? {{destinationClass}} else {
+          fatalError("Destination of segue '{{segue.identifier}}' is not of the expected type {{destinationClass}}.")
+        }
+        {% else %}
+        let vc = segue.destination{% if isAppKit %}Controller{% endif %}
+        {% endif %}
+        {% endif %}
+        {% set segueID %}{{segue.identifier|swiftIdentifier:"pretty"|lowerFirstWord}}{% endset %}
+        self = .{{segueID|escapeReservedKeywords}}{% filter removeNewlines:"leading" %}
+          {% if segue.customClass or segue.destination %}(
+            {% if segue.destination %}destination: vc{% endif %}
+            {% if segue.customClass and segue.destination %}, {% endif %}
+            {% if segue.customClass %}segue: segue{% endif %}
+          ){%endif %}
+        {% endfilter %}
+      {% endfor %}
+      {% if hasUnnamedSegue %}
+      case "":
+        self = .{{unnamedSegue}}
+      {% endif %}
+      default:
+        fatalError("Unrecognized segue '\(segue.identifier ?? "")' in {{sceneClass}}")
+      }
+    }
+    // swiftlint:enable cyclomatic_complexity
+  }
+}
+
+{% endfor %}
+{{accessModifier}} enum {{enumName}} {
   {% for storyboard in storyboards where storyboard.segues %}
   {{accessModifier}} enum {{storyboard.name|swiftIdentifier:"pretty"|escapeReservedKeywords}}: String, SegueType {
-    {% for segue in storyboard.segues %}
+    {% for segue in storyboard.segues where segue.identifier %}
     {% set segueID %}{{segue.identifier|swiftIdentifier:"pretty"|lowerFirstWord}}{% endset %}
     case {{segueID|escapeReservedKeywords}}{% if segueID != segue.identifier %} = "{{segue.identifier}}"{% endif %}
     {% endfor %}

Sources/SwiftGenKit/Parsers/InterfaceBuilder/CustomType.swift

@@ -0,0 +1,77 @@
+//
+// SwiftGenKit
+// Copyright © 2020 SwiftGen
+// MIT Licence
+//
+
+import Foundation
+
+extension InterfaceBuilder {
+  struct CustomType: InterfaceBuilderSwiftType {
+    let type: String
+    let module: String?
+    let moduleIsPlaceholder: Bool
+    var segues = Set<Segue>()
+    var destinations = [Segue: Scene]()
+
+    init(scene: Scene) {
+      type = scene.type
+      module = scene.moduleIsPlaceholder ? "<placeholder>" : scene.module
+      moduleIsPlaceholder = scene.moduleIsPlaceholder
+    }
+
+    mutating func add(segue: Segue, destination: Scene?, warningHandler: Parser.MessageHandler?) {
+      segues.insert(segue)
+
+      // store destination, or check it's at least the same type
+      if let destination = destination {
+        if let current = destinations[segue] {
+          if !areEqual(current, destination) {
+            let message = "warning: The segue with identifier '\(segue.identifier)' in \(module ?? "").\(type) has " +
+              "multiple destination types: \(destination.module ?? "").\(destination.type) and " +
+              "\(destination.module ?? "").\(destination.type)."
+            warningHandler?(message, #file, #line)
+          }
+        } else {
+          destinations[segue] = destination
+        }
+      }
+    }
+
+    private func areEqual(_ lhs: Scene, _ rhs: Scene) -> Bool {
+      lhs.tag != rhs.tag ||
+        lhs.customClass != rhs.customClass ||
+        lhs.customModule != rhs.customModule
+    }
+  }
+}
+
+extension InterfaceBuilder.Parser {
+  var customSceneTypes: [InterfaceBuilder.CustomType] {
+    var result: [String: InterfaceBuilder.CustomType] = [:]
+
+    // collect scenes by custom type
+    for storyboard in storyboards {
+      for scene in storyboard.scenes where scene.customClass != nil {
+        let key = InterfaceBuilder.Parser.identifier(for: scene)
+        var customType = result[key] ?? InterfaceBuilder.CustomType(scene: scene)
+
+        for segue in scene.segues {
+          let destination = self.destination(for: segue.destination, in: storyboard)
+          customType.add(segue: segue, destination: destination, warningHandler: warningHandler)
+        }
+
+        result[key] = customType
+      }
+    }
+
+    return result
+      .sorted { $0.0 < $1.0 }
+      .map { _, value in value }
+  }
+
+  private static func identifier(for scene: InterfaceBuilder.Scene) -> String {
+    let module = scene.moduleIsPlaceholder ? "<placeholder>" : scene.module
+    return "\(module ?? "").\(scene.type)"
+  }
+}

Sources/SwiftGenKit/Parsers/InterfaceBuilder/InterfaceBuilderParser.swift

@@ -64,5 +64,26 @@ public enum InterfaceBuilder {
         return platforms.first
       }
     }
+
+    func destination(for sceneID: String, in storyboard: Storyboard) -> Scene? {
+      // directly to a scene
+      if let scene = storyboard.scenes.first(where: { $0.sceneID == sceneID }) {
+        return scene
+      }
+
+      // to a scene placeholder
+      if let placeholder = storyboard.placeholders.first(where: { $0.sceneID == sceneID }),
+        let storyboard = storyboards.first(where: { $0.name == placeholder.storyboardName }) {
+        // can be either a scene by identifier, or the initial scene
+        if let referencedIdentifier = placeholder.referencedIdentifier,
+          let scene = storyboard.scenes.first(where: { $0.identifier == referencedIdentifier }) {
+          return scene
+        } else if placeholder.referencedIdentifier == nil {
+          return storyboard.initialScene
+        }
+      }
+
+      return nil
+    }
   }
 }

Sources/SwiftGenKit/Parsers/InterfaceBuilder/InterfaceBuilderSwiftType.swift

@@ -0,0 +1,13 @@
+//
+// SwiftGenKit
+// Copyright © 2020 SwiftGen
+// MIT Licence
+//
+
+import Foundation
+
+protocol InterfaceBuilderSwiftType {
+  var type: String { get }
+  var module: String? { get }
+  var moduleIsPlaceholder: Bool { get }
+}