Support for XML request body and response body

Sources/_OpenAPIGeneratorCore/Translator/CommonTypes/Constants.swift

@@ -371,6 +371,9 @@ enum Constants {
 
         /// The substring used in method names for the multipart coding strategy.
         static let multipart: String = "Multipart"
+
+        /// The substring used in method names for the XML coding strategy.
+        static let xml: String = "XML"
     }
 
     /// Constants related to types used in many components.

Sources/_OpenAPIGeneratorCore/Translator/Content/CodingStrategy.swift

@@ -30,6 +30,9 @@ enum CodingStrategy: String, Hashable, Sendable {
     /// A strategy using multipart/form-data.
     case multipart
 
+    /// A strategy using optional CustomCoder.
+    case xml
+
     /// The name of the coding strategy in the runtime library.
     var runtimeName: String {
         switch self {
@@ -38,6 +41,7 @@ enum CodingStrategy: String, Hashable, Sendable {
         case .binary: return Constants.CodingStrategy.binary
         case .urlEncodedForm: return Constants.CodingStrategy.urlEncodedForm
         case .multipart: return Constants.CodingStrategy.multipart
+        case .xml: return Constants.CodingStrategy.xml
         }
     }
 }

Sources/_OpenAPIGeneratorCore/Translator/Content/ContentInspector.swift

@@ -21,8 +21,9 @@ extension FileTranslator {
     ///
     /// Priority:
     /// 1. JSON
-    /// 2. text
-    /// 3. binary
+    /// 2. XML
+    /// 3. text
+    /// 4. binary
     ///
     /// - Parameters:
     ///   - map: The content map from the OpenAPI document.
@@ -109,8 +110,9 @@ extension FileTranslator {
     ///
     /// Priority:
     /// 1. JSON
-    /// 2. text
-    /// 3. binary
+    /// 2. XML
+    /// 3. text
+    /// 4. binary
     ///
     /// - Parameters:
     ///   - map: The content map from the OpenAPI document.
@@ -128,7 +130,7 @@ extension FileTranslator {
         let mapWithContentTypes = try map.map { key, content in try (type: key.asGeneratorContentType, value: content) }
 
         let chosenContent: (type: ContentType, schema: SchemaContent, content: OpenAPI.Content)?
-        if let (contentType, contentValue) = mapWithContentTypes.first(where: { $0.type.isJSON }) {
+        if let (contentType, contentValue) = mapWithContentTypes.first(where: { $0.type.isJSON || $0.type.isXML }) {
             chosenContent = (contentType, .init(contentType: contentType, schema: contentValue.schema), contentValue)
         } else if !excludeBinary,
             let (contentType, contentValue) = mapWithContentTypes.first(where: { $0.type.isBinary })
@@ -161,6 +163,7 @@ extension FileTranslator {
     ///
     /// Priority of checking for known MIME types:
     /// 1. JSON
+    /// 2. XML
     /// 2. text
     /// 3. binary
     ///
@@ -189,6 +192,7 @@ extension FileTranslator {
             )
         }
         if contentType.isJSON { return .init(contentType: contentType, schema: contentValue.schema) }
+        if contentType.isXML { return .init(contentType: contentType, schema: contentValue.schema) }
         if contentType.isUrlEncodedForm { return .init(contentType: contentType, schema: contentValue.schema) }
         if contentType.isMultipart {
             guard isRequired else {

Sources/_OpenAPIGeneratorCore/Translator/Content/ContentType.swift

@@ -56,9 +56,14 @@ struct ContentType: Hashable {
         /// The type is encoded as an async sequence of parts.
         case multipart
 
+        /// A content type for XML.
+        ///
+        /// The bytes are provided to a CustomCoder.
+        case xml
+
         /// Creates a category from the provided type and subtype.
         ///
-        /// First checks if the provided content type is a JSON, then text,
+        /// First checks if the provided content type is a JSON, then XML, then text,
         /// and uses binary if none of the two match.
         /// - Parameters:
         ///   - lowercasedType: The first component of the MIME type.
@@ -68,6 +73,10 @@ struct ContentType: Hashable {
             if (lowercasedType == "application" && lowercasedSubtype == "json") || lowercasedSubtype.hasSuffix("+json")
             {
                 self = .json
+            } else if (lowercasedType == "application" && lowercasedSubtype == "xml")
+                || lowercasedSubtype.hasSuffix("+xml")
+            {
+                self = .xml
             } else if lowercasedType == "application" && lowercasedSubtype == "x-www-form-urlencoded" {
                 self = .urlEncodedForm
             } else if lowercasedType == "multipart" && lowercasedSubtype == "form-data" {
@@ -84,6 +93,7 @@ struct ContentType: Hashable {
             case .binary: return .binary
             case .urlEncodedForm: return .urlEncodedForm
             case .multipart: return .multipart
+            case .xml: return .xml
             }
         }
     }
@@ -215,11 +225,17 @@ struct ContentType: Hashable {
     /// is a multipart form.
     var isMultipart: Bool { category == .multipart }
 
+    /// A Boolean value that indicates whether the content type
+    /// is a type of XML.
+    var isXML: Bool { category == .xml }
+
     /// The content type `text/plain`.
     static var textPlain: Self { try! .init(string: "text/plain") }
 
     /// The content type `application/json`.
     static var applicationJSON: Self { try! .init(string: "application/json") }
+    /// The content type `application/xml`.
+    static var applicationXML: Self { try! .init(string: "application/xml") }
 
     /// The content type `application/octet-stream`.
     static var applicationOctetStream: Self { try! .init(string: "application/octet-stream") }

Sources/_OpenAPIGeneratorCore/Translator/Multipart/translateMultipart.swift

@@ -353,7 +353,7 @@ extension FileTranslator {
             ])
         let bodyExpr: Expression
         switch codingStrategy {
-        case .json, .uri, .urlEncodedForm:
+        case .json, .xml, .uri, .urlEncodedForm:
             // Buffering.
             bodyExpr = .try(.await(converterExpr))
         case .binary, .multipart:

Sources/_OpenAPIGeneratorCore/Translator/RequestBody/translateRequestBody.swift

@@ -275,7 +275,7 @@ extension ServerFileTranslator {
                 )
             let bodyExpr: Expression
             switch codingStrategy {
-            case .json, .uri, .urlEncodedForm:
+            case .json, .xml, .uri, .urlEncodedForm:
                 // Buffering.
                 bodyExpr = .try(.await(converterExpr))
             case .binary, .multipart:

Sources/_OpenAPIGeneratorCore/Translator/Responses/translateResponseOutcome.swift

@@ -267,7 +267,7 @@ extension ClientFileTranslator {
                     )
                 let bodyExpr: Expression
                 switch codingStrategy {
-                case .json, .uri, .urlEncodedForm:
+                case .json, .xml, .uri, .urlEncodedForm:
                     // Buffering.
                     bodyExpr = .try(.await(converterExpr))
                 case .binary, .multipart:

Sources/swift-openapi-generator/Documentation.docc/Articles/Supported-OpenAPI-features.md

@@ -24,7 +24,9 @@ For any other formats, the payload is provided as raw bytes (using the `HTTPBody
     - when content type is `application/x-www-form-urlencoded`
 - [x] multipart
     - for details, see [SOAR-0009](https://swiftpackageindex.com/apple/swift-openapi-generator/main/documentation/swift-openapi-generator/soar-0009)
-- [ ] XML
+- [X] XML
+    - when content type is `application/xml` or ends with `+xml`
+    - xmlCoder must be provided to `OpenAPIRuntime.Configuration`
 
 ### OpenAPI specification features
 

Sources/swift-openapi-generator/Documentation.docc/Development/Converting-between-data-and-Swift-types.md

@@ -26,10 +26,13 @@ At the time of writing, the list of coders used is as follows.
 | Format | Encoder | Decoder | Supported in |
 | ------ | ------- | ------- | ----- |
 | JSON | `Foundation.JSONEncoder` | `Foundation.JSONDecoder` | Bodies, headers |
-| URI (†) | `OpenAPIRuntime.URIEncoder` | `OpenAPIRuntime.URIDecoder` | Path, query, headers |
+| XML (†) | `OpenAPIRuntime.CustomCoder` | `OpenAPIRuntime.CustomCoder` | Bodies |
+| URI (††) | `OpenAPIRuntime.URIEncoder` | `OpenAPIRuntime.URIDecoder` | Path, query, headers |
 | Plain text | `OpenAPIRuntime.StringEncoder` | `OpenAPIRuntime.StringDecoder` | Bodies |
 
-> †: Configurable implementation of variable expansion from URI Template (RFC 6570), the `application/x-www-form-urlencoded` serialization from RFC 1866, and OpenAPI 3.0.3. For details of the supported combinations, review <doc:Supported-OpenAPI-features>.
+> †: XML support is optional, and not enabled by default. Encoding and decoding requires providing a `OpenAPIRuntime.CustomCoder` to the `OpenAPIRuntime.Configuration` initializer.
+
+> ††: Configurable implementation of variable expansion from URI Template (RFC 6570), the `application/x-www-form-urlencoded` serialization from RFC 1866, and OpenAPI 3.0.3. For details of the supported combinations, review <doc:Supported-OpenAPI-features>.
 
 While the generator attempts to catch invalid inputs at generation time, there are still combinations of `Codable` types and locations that aren't compatible, and will only get caught at runtime by the specific coder implementation. For example, one could ask the `StringEncoder` to encode an array, but the encoder will throw an error, as containers are not supported in that encoder.
 
@@ -50,6 +53,9 @@ Below is a list of the "dimensions" across which the helper methods differ:
     - `JSON`
         - example content type: `application/json` and any with the `+json` suffix
         - `{"color": "red", "power": 24}`
+    - `XML`
+        - example content type: `application/xml` and any with the `+xml` suffix
+        - `<root><color>red</color><power>24</power></root>`
     - `URI`
         - example: query, path, header parameters
         - `color=red&power=24`
@@ -93,24 +99,30 @@ method parameters: value or type of value
 | client | set | request query | URI | both | setQueryItemAsURI |
 | client | set | request body | JSON | optional | setOptionalRequestBodyAsJSON |
 | client | set | request body | JSON | required | setRequiredRequestBodyAsJSON |
+| client | set | request body | XML | optional | setOptionalRequestBodyAsXML |
+| client | set | request body | XML | required | setRequiredRequestBodyAsXML |
 | client | set | request body | binary | optional | setOptionalRequestBodyAsBinary |
 | client | set | request body | binary | required | setRequiredRequestBodyAsBinary |
 | client | set | request body | urlEncodedForm | optional | setOptionalRequestBodyAsURLEncodedForm | 
 | client | set | request body | urlEncodedForm | required | setRequiredRequestBodyAsURLEncodedForm | 
 | client | set | request body | multipart | required | setRequiredRequestBodyAsMultipart | 
 | client | get | response body | JSON | required | getResponseBodyAsJSON |
+| client | get | response body | XML | required | getResponseBodyAsXML |
 | client | get | response body | binary | required | getResponseBodyAsBinary |
 | client | get | response body | multipart | required | getResponseBodyAsMultipart |
 | server | get | request path | URI | required | getPathParameterAsURI |
 | server | get | request query | URI | optional | getOptionalQueryItemAsURI |
 | server | get | request query | URI | required | getRequiredQueryItemAsURI |
 | server | get | request body | JSON | optional | getOptionalRequestBodyAsJSON |
 | server | get | request body | JSON | required | getRequiredRequestBodyAsJSON |
+| server | get | request body | XML | optional | getOptionalRequestBodyAsXML |
+| server | get | request body | XML | required | getRequiredRequestBodyAsXML |
 | server | get | request body | binary | optional | getOptionalRequestBodyAsBinary |
 | server | get | request body | binary | required | getRequiredRequestBodyAsBinary |
 | server | get | request body | urlEncodedForm | optional | getOptionalRequestBodyAsURLEncodedForm |
 | server | get | request body | urlEncodedForm | required | getRequiredRequestBodyAsURLEncodedForm |
 | server | get | request body | multipart | required | getRequiredRequestBodyAsMultipart |
 | server | set | response body | JSON | required | setResponseBodyAsJSON |
+| server | set | response body   | XML | required | setResponseBodyAsXML |
 | server | set | response body | binary | required | setResponseBodyAsBinary |
 | server | set | response body | multipart | required | setResponseBodyAsMultipart |

Tests/OpenAPIGeneratorCoreTests/Translator/Content/Test_ContentType.swift

@@ -46,9 +46,13 @@ final class Test_ContentType: Test_Core {
                 ), ("text/plain", .binary, "text", "plain", "", "text/plain", "text/plain", "text/plain"),
                 ("*/*", .binary, "*", "*", "", "*/*", "*/*", "*/*"),
                 (
-                    "application/xml", .binary, "application", "xml", "", "application/xml", "application/xml",
+                    "application/xml", .xml, "application", "xml", "", "application/xml", "application/xml",
                     "application/xml"
                 ),
+                (
+                    "application/custom-type", .binary, "application", "custom-type", "", "application/custom-type", "application/custom-type",
+                    "application/custom-type"
+                ),
                 (
                     "application/octet-stream", .binary, "application", "octet-stream", "", "application/octet-stream",
                     "application/octet-stream", "application/octet-stream"