Merge pull request #2242 from RomanPodymov/feature/result_builders

@formbuilder

Author: mlorenze

README.md

@@ -228,6 +228,22 @@ form +++ {
 }
 ```
 
+#### @FormBuilder
+```swift
+@FormBuilder
+var form: Form {
+    Section("Section A") { section in
+        section.tag = "Section_A"
+    }
+    if true {
+        Section("Section B") { section in
+            section.tag = "Section_B"
+        }
+    }
+    NameRow("NameRow_f1") { $0.title = "Name" }
+}
+```
+
 ### Using the callbacks
 
 Eureka includes callbacks to change the appearance and behavior of a row.

Source/Core/ResultBuilders.swift

@@ -35,6 +35,22 @@ extension Array: RowsProvider where Element == BaseRow {
     public var rows: [BaseRow] { self }
 }
 
+public protocol SectionsProvider {
+    var sections: [Section] { get }
+}
+
+extension Section: SectionsProvider {
+    public var sections: [Section] { [self] }
+}
+
+extension Array: SectionsProvider where Element == Section {
+    public var sections: [Section] { self }
+}
+
+extension BaseRow: SectionsProvider {
+    public var sections: [Section] { [.init([self])] }
+}
+
 @resultBuilder
 public struct SectionBuilder {
     public static func buildBlock(_ components: RowsProvider...) -> [BaseRow] {
@@ -57,8 +73,35 @@ public struct SectionBuilder {
         components?.flatMap { $0.rows } ?? []
     }
 
-    public static func buildExpression(_ expression: BaseRow?) -> [BaseRow] {
-        expression.flatMap { [$0] } ?? []
+    public static func buildExpression(_ expression: RowsProvider?) -> [BaseRow] {
+        expression.flatMap { $0.rows } ?? []
+    }
+}
+
+@resultBuilder
+public struct FormBuilder {
+    public static func buildBlock(_ components: SectionsProvider...) -> [Section] {
+        components.flatMap { $0.sections }
+    }
+    
+    public static func buildFinalResult(_ components: [Section]) -> Form {
+        .init(components)
+    }
+    
+    public static func buildEither(first components: [SectionsProvider]) -> [Section] {
+        components.flatMap { $0.sections }
+    }
+    
+    public static func buildEither(second components: [SectionsProvider]) -> [Section] {
+        components.flatMap { $0.sections }
+    }
+    
+    public static func buildOptional(_ components: [SectionsProvider]?) -> [Section] {
+        components?.flatMap { $0.sections } ?? []
+    }
+    
+    public static func buildExpression(_ expression: SectionsProvider?) -> [Section] {
+        expression.flatMap { $0.sections } ?? []
     }
 }
 #endif

Tests/ResultBuildersTests.swift

@@ -35,40 +35,87 @@ class ResultBuildersTests: BaseEurekaTests {
         }
         DecimalRow("DecimalRow_f1") { $0.title = "Decimal" }
     }
+
+    @FormBuilder
+    var form: Form {
+        Section("Section A") { section in
+            section.tag = "Section_A"
+        }
+        if true {
+            Section("Section B") { section in
+                section.tag = "Section_B"
+            }
+        }
+        NameRow("NameRow_f1") { $0.title = "Name" }
+    }
     #endif
 
+    private var checkBuildEither = false
+    private var checkBuildExpressionBaseRowOptional = false
+
     func testSectionBuilder() {
         #if swift(>=5.4)
-        var checkBuildEither = false
+        setupManySectionsForm()
+        addMoreItemsToManySectionsForm()
+
+        XCTAssertNotNil(manySectionsForm.rowBy(tag: "NameRow_f1"))
+        XCTAssertNotNil(manySectionsForm.rowBy(tag: "IntRow_f1"))
+        XCTAssertNotNil(manySectionsForm.rowBy(tag: "DecimalRow_f1"))
+        XCTAssertNotNil(manySectionsForm.rowBy(tag: "UrlRow_f1"))
+        XCTAssertNotNil(manySectionsForm.rowBy(tag: "TwitterRow_f1"))
+        XCTAssertNil(manySectionsForm.rowBy(tag: "TwitterRow_f2"))
+        XCTAssertNil(manySectionsForm.rowBy(tag: "EmailRow_f1"))
+        XCTAssertNotNil(manySectionsForm.rowBy(tag: "AccountRow_f1"))
+        XCTAssertNotNil(manySectionsForm.rowBy(tag: "PhoneRow_f1"))
+        XCTAssertNil(manySectionsForm.rowBy(tag: "PhoneRow_f2"))
+        XCTAssertNotNil(manySectionsForm.rowBy(tag: "ZipCodeRow_f1"))
+        XCTAssertNotNil(manySectionsForm.rowBy(tag: "PasswordRow_f1"))
+        #endif
+    }
+
+    private func setupManySectionsForm() {
+        checkBuildEither = false
+        checkBuildExpressionBaseRowOptional = true
         manySectionsForm = (section1 +++ {
             URLRow("UrlRow_f1") { $0.title = "Url" }
             if checkBuildEither {
                 TwitterRow("TwitterRow_f2") { $0.title = "Twitter" }
             } else {
                 TwitterRow("TwitterRow_f1") { $0.title = "Twitter" }
             }
+            if checkBuildExpressionBaseRowOptional {
+                nil
+            } else {
+                EmailRow("EmailRow_f1") { $0.title = "Email" }
+            }
             AccountRow("AccountRow_f1") { $0.title = "Account" }
         })
-        checkBuildEither = true
+    }
+
+    private func addMoreItemsToManySectionsForm() {
+        checkBuildEither.toggle()
+        checkBuildExpressionBaseRowOptional.toggle()
         manySectionsForm +++ {
             if checkBuildEither {
                 PhoneRow("PhoneRow_f1") { $0.title = "Phone" }
             } else {
                 PhoneRow("PhoneRow_f2") { $0.title = "Phone" }
             }
+            if checkBuildExpressionBaseRowOptional {
+                nil
+            } else {
+                ZipCodeRow("ZipCodeRow_f1") { $0.title = "Zip Code" }
+            }
             PasswordRow("PasswordRow_f1") { $0.title = "Password" }
         }
-        
+    }
+
+    func testFormBuilder() {
+        #if swift(>=5.4)
+        manySectionsForm = form
+        XCTAssertNotNil(manySectionsForm.sectionBy(tag: "Section_A"))
+        XCTAssertNotNil(manySectionsForm.sectionBy(tag: "Section_B"))
         XCTAssertNotNil(manySectionsForm.rowBy(tag: "NameRow_f1"))
-        XCTAssertNotNil(manySectionsForm.rowBy(tag: "IntRow_f1"))
-        XCTAssertNotNil(manySectionsForm.rowBy(tag: "DecimalRow_f1"))
-        XCTAssertNotNil(manySectionsForm.rowBy(tag: "UrlRow_f1"))
-        XCTAssertNotNil(manySectionsForm.rowBy(tag: "TwitterRow_f1"))
-        XCTAssertNil(manySectionsForm.rowBy(tag: "TwitterRow_f2"))
-        XCTAssertNotNil(manySectionsForm.rowBy(tag: "AccountRow_f1"))
-        XCTAssertNotNil(manySectionsForm.rowBy(tag: "PhoneRow_f1"))
-        XCTAssertNil(manySectionsForm.rowBy(tag: "PhoneRow_f2"))
-        XCTAssertNotNil(manySectionsForm.rowBy(tag: "PasswordRow_f1"))
         #endif
     }
 }