add HttpExchange.fileName() method

CHANGELOG.md

@@ -1,5 +1,6 @@
 # Unreleased
 * jdbc: DB_READONLY=true env var can be used to make the whole app read-only (e.g. when migrating the DB, instead of Heroku maintenance mode)
+* HttpExchange.fileName() added for setting of Content-Disposition
 
 # 1.5.5
 * jdbc: support reading of collections of Decimal from DB array columns

server/src/klite/HttpExchange.kt

@@ -90,6 +90,11 @@ open class HttpExchange(
     get() = responseHeaders["Content-type"]?.firstOrNull()
     set(value) { value?.let { header("Content-type", MimeTypes.withCharset(it)) } }
 
+  fun fileName(fileName: String, attachment: Boolean = true) {
+    header("Content-disposition", (if (attachment) "attachment" else "inline") + "; filename=\"$fileName\"")
+    responseType = MimeTypes.typeFor(fileName)
+  }
+
   val accept get() = Accept(header("Accept"))
 
   fun render(code: StatusCode, body: Any?) {
@@ -103,9 +108,10 @@ open class HttpExchange(
    * Sends response headers and provides the stream
    * @param length 0 -> no response, null -> use chunked encoding
    */
-  fun startResponse(code: StatusCode, length: Long? = null, contentType: String? = null): OutputStream {
+  fun startResponse(code: StatusCode, length: Long? = null, contentType: String? = null, fileName: String? = null): OutputStream {
     sessionStore?.save(this, session)
-    responseType = contentType
+    fileName?.let { fileName(it) }
+    contentType?.let { responseType = it }
     val bodyNotAllowed = method == HEAD || method == OPTIONS
     original.sendResponseHeaders(code.value, if (length == 0L || bodyNotAllowed) -1 else length ?: 0)
     if (bodyNotAllowed) throw BodyNotAllowedException()

server/test/klite/HttpExchangeTest.kt

@@ -63,6 +63,31 @@ class HttpExchangeTest {
     verify { original.responseHeaders.add("Set-Cookie", "LANG=et; Domain=angryip.org; SameSite=Strict") }
   }
 
+  @Test fun `response content-type`() {
+    exchange.responseType = MimeTypes.csv
+    verify { original.responseHeaders.set("Content-type", "application/csv; charset=UTF-8") }
+
+    exchange.responseType = "text/hello; charset=ISO-8859-1"
+    verify { original.responseHeaders.set("Content-type", "text/hello; charset=ISO-8859-1") }
+
+    exchange.responseType = MimeTypes.pdf
+    verify { original.responseHeaders.set("Content-type", "application/pdf") }
+  }
+
+  @Test fun `response content-disposition`() {
+    exchange.fileName("hello.xml")
+    verify {
+      original.responseHeaders.set("Content-disposition", "attachment; filename=\"hello.xml\"")
+      original.responseHeaders.set("Content-type", "text/xml; charset=UTF-8")
+    }
+
+    exchange.fileName("mega.pdf", attachment = false)
+    verify {
+      original.responseHeaders.set("Content-disposition", "inline; filename=\"mega.pdf\"")
+      original.responseHeaders.set("Content-type", "application/pdf")
+    }
+  }
+
   @Test fun `body as text`() {
     every { exchange.requestType } returns null
     every { original.requestBody } answers { "123".byteInputStream() }