Merge pull request #175 from iZettle/text-editor-accessibility-value

PLT-2650 Add the Ability to Supply an `accessibilityValue` to `ValueField` Through `TextEditor`

CHANGELOG.md

@@ -1,3 +1,7 @@
+# 3.3.0
+
+- Added (backwards compatible) support for supplying an `accessibilityValue` to `ValueField` through `TextEditor`.
+
 # 3.2.0
 
 - Xcode 13.0 compatibility

Form/TextEditor.swift

@@ -26,6 +26,13 @@ public protocol TextEditor {
     /// The current formatted text of value and the index into text where insertions happen, useful for placing cursors etc.
     var textAndInsertionIndex: (text: String, index: String.Index) { get }
 
+    /// The current accessibility value of the edited text.
+    ///
+    /// Depending on the kind of value being edited, and the UI surrounding it,
+    /// it might be desirable to have a slightly different string representation
+    /// exposed to an assistive technology. Defaults to the value of `text`.
+    var accessibilityValue: String { get }
+
     mutating func insertCharacter(_ char: Character)
 
     mutating func deleteBackward()
@@ -39,6 +46,10 @@ public extension TextEditor {
         return textAndInsertionIndex.text
     }
 
+    var accessibilityValue: String {
+        return text
+    }
+
     var insertionIndex: String.Index {
         return textAndInsertionIndex.index
     }
@@ -84,6 +95,10 @@ public class AnyTextEditor<Value>: TextEditor {
         set { fatalError() }
     }
 
+    public var accessibilityValue: String {
+        fatalError()
+    }
+
     public var defaultValue: Value {
         fatalError()
     }
@@ -172,6 +187,10 @@ private final class _AnyTextEditor<Editor: TextEditor>: AnyTextEditor<Editor.Val
         set { editor.value = newValue }
     }
 
+    public override var accessibilityValue: String {
+        editor.accessibilityValue
+    }
+
     public override var shouldResetOnInsertion: Bool {
         get { return editor.shouldResetOnInsertion }
         set { editor.shouldResetOnInsertion = newValue }

Form/ValueEditor.swift

@@ -12,6 +12,7 @@ import UIKit
 public struct ValueEditor<Value>: TextEditor {
     private let isValidCharacter: ((Character) -> Bool)
     private let valueToText: (Value) -> String
+    private let valueToAccessibilityValue: (Value) -> String
     private let _textAndInsertionIndex: (Value) -> (String, String.Index)
     private let textToValue: (String) -> Value?
     private let minCharacters: Int
@@ -25,23 +26,39 @@ public struct ValueEditor<Value>: TextEditor {
     /// Parameters:
     ///   - defaultValue: The value to use when resetting the editor.
     ///   - valueToText: How to convert a `Value` to the editable text representation part of the value.
+    ///   - valueToAccessibilityValue: How to convert a `Value` into a string representation for the editor's
+    ///     `accessibilityValue`. Defaults to the text returned by `textAndInsertionIndex`.
     ///   - textToValue: How to convert the editable text representation part of value back to a `Value`.
     ///   - isValidCharacter: Whether a character is a valid input to build a value.
     ///   - minCharacters: Min characters of the editable text representation of value, defaults to zero
     ///   - maxCharacters: Max characters of the editable text representation of value, defaults to `.max`
     ///   - textAndInsertionIndex: Format a value for display (adding potential prefix, postfix or other formatting)
     ///       and the index for insertions, useful for placing cursors etc.
-    public init(value: Value, defaultValue: Value, valueToText: @escaping (Value) -> String, textToValue: @escaping (String) -> Value?, isValidCharacter: @escaping ((Character) -> Bool), minCharacters: Int = 0, maxCharacters: Int = .max, textAndInsertionIndex: @escaping (Value) -> (String, String.Index)) {
+    public init(
+        value: Value,
+        defaultValue: Value,
+        valueToText: @escaping (Value) -> String,
+        valueToAccessibilityValue: ((Value) -> String)? = nil,
+        textToValue: @escaping (String) -> Value?,
+        isValidCharacter: @escaping ((Character) -> Bool),
+        minCharacters: Int = 0, maxCharacters: Int = .max,
+        textAndInsertionIndex: @escaping (Value) -> (String, String.Index)
+    ) {
         self.value = value
         self.defaultValue = defaultValue
         self.valueToText = valueToText
+        self.valueToAccessibilityValue = valueToAccessibilityValue ?? { textAndInsertionIndex($0).0 }
         self.textToValue = textToValue
         _textAndInsertionIndex = textAndInsertionIndex
         self.isValidCharacter = isValidCharacter
         self.minCharacters = minCharacters
         self.maxCharacters = maxCharacters
     }
 
+    public var accessibilityValue: String {
+        valueToAccessibilityValue(value)
+    }
+
     public var textAndInsertionIndex: (text: String, index: String.Index) {
         return _textAndInsertionIndex(value)
     }

Form/ValueField.swift

@@ -169,11 +169,11 @@ public final class ValueField<Value>: UIControl, UIKeyInput {
     }
 
     public override var accessibilityValue: String? {
-        get { return label.text }
-        set {
-            guard let text = newValue else { return }
-            label.value = text
+        get {
+            editor.accessibilityValue
         }
+        //swiftlint:disable:next unused_setter_value
+        set { /* accessibilityValue is always read from the editor. */ }
     }
 
     public override var inputView: UIView? {

FormTests/ValueEditorTests.swift

@@ -87,4 +87,22 @@ class ValueEditorTests: XCTestCase {
         test(editor, "1234567890", "12345", 0)
         test(editor, "123456R3", "3", 0)
     }
+
+    func testComputesCorrectAccessibilityValue() {
+        let defaultEditor = ValueEditor<String>(value: "test")
+        let customEditor = ValueEditor(
+            value: "test",
+            defaultValue: "",
+            valueToText: { $0 },
+            valueToAccessibilityValue: { $0 + " modified" },
+            textToValue: { $0 },
+            isValidCharacter: { _ in true },
+            minCharacters: 0,
+            maxCharacters: .max,
+            textAndInsertionIndex: { ($0, $0.endIndex) }
+        )
+
+        XCTAssertEqual(defaultEditor.accessibilityValue, defaultEditor.text)
+        XCTAssertEqual(customEditor.accessibilityValue, "test modified")
+    }
 }

FormTests/ValueFieldTests.swift

@@ -153,4 +153,23 @@ class ValueFieldTests: XCTestCase {
 
         wait(for: [fieldBecameFirstResponder], timeout: 1)
     }
+
+    func testUsesEditorAccessibilityValue() {
+        let expectedAccessibilityValue = "accessibility value"
+        let editor = ValueEditor<String>(
+            value: "",
+            defaultValue: "",
+            valueToText: { $0 },
+            valueToAccessibilityValue: { _ in expectedAccessibilityValue },
+            textToValue: { $0 },
+            isValidCharacter: { _ in true },
+            minCharacters: 0,
+            maxCharacters: .max,
+            textAndInsertionIndex: { ($0, $0.endIndex) }
+        )
+
+        let field = ValueField(value: "", editor: editor)
+
+        XCTAssertEqual(field.accessibilityValue, expectedAccessibilityValue)
+    }
 }

Package.resolved

@@ -6,8 +6,8 @@
         "repositoryURL": "https://github.com/izettle/Flow.git",
         "state": {
           "branch": null,
-          "revision": "0563b5bc4b3a5a4869f9d7ff498a8de5031e3dc5",
-          "version": "1.8.3"
+          "revision": "3bc56e13c29cfbcc77cdae6193bbad697ee95799",
+          "version": "1.10.0"
         }
       }
     ]