Fixed #336: Add support for Html Entities

Author: davesmith00000

build.sbt

@@ -139,6 +139,7 @@ lazy val tyrianTags =
       commonSettings ++ publishSettings,
       Compile / sourceGenerators += codeGen("tyrian", TagGen.gen).taskValue,
       Compile / sourceGenerators += codeGen("tyrian", AttributeGen.gen).taskValue,
+      Compile / sourceGenerators += codeGen("tyrian", HtmlEntityGen.gen).taskValue,
       Compile / sourceGenerators += codeGen("CSS", "tyrian", CSSGen.gen).taskValue
     )
     .jsSettings(

project/CompleteHtmlEntityLists.scala

@@ -0,0 +1,47 @@
+import sbt.*
+import scala.sys.process.*
+
+object HtmlEntityGen {
+
+  def template(moduleName: String, fullyQualifiedPath: String, contents: String): String =
+    s"""package $fullyQualifiedPath
+    |
+    |// GENERATED by HtmlEntityGen.scala - DO NOT EDIT
+    |trait $moduleName {
+    |$contents
+    |}
+    """.stripMargin
+
+  def gen(fullyQualifiedPath: String, sourceManagedDir: File): Seq[File] = {
+
+    val name = "HtmlEntities"
+
+    val file: File =
+      sourceManagedDir / s"$name.scala"
+
+    if (!file.exists()) {
+      println("Generating Html Entities")
+
+      val contents: String = {
+        val all =
+          CompleteHtmlEntityLists.all.map { case (safeName, entityValue) =>
+            s"""  val _${safeName}_ = HtmlEntity("$entityValue")"""
+          }
+
+        s"""
+        |${all.mkString("\n")}
+        |""".stripMargin
+      }
+
+      val newContents: String =
+        template(name, fullyQualifiedPath, contents)
+
+      IO.write(file, newContents)
+
+      println("Written: " + file.getCanonicalPath)
+    }
+
+    Seq(file)
+  }
+
+}

project/HtmlEntityGen.scala

@@ -5,6 +5,7 @@ import tyrian.CustomHtml
 import tyrian.Elem
 import tyrian.Empty
 import tyrian.Html
+import tyrian.HtmlEntity
 import tyrian.RawTag
 import tyrian.Tag
 import tyrian.Text
@@ -102,4 +103,7 @@ object HtmlRoot:
         case c: CustomHtml[GlobalMsg] =>
           List(c)
 
+        case e: HtmlEntity =>
+          List(e)
+
     Batch.fromList(rec(target))

tyrian-next/src/main/scala/tyrian/next/HtmlRoot.scala

@@ -9,10 +9,11 @@ private val spacer = (str: String) => if str.isEmpty then str else " " + str
 extension [Msg](elem: Elem[Msg])
   def render: String =
     elem match
-      case _: Empty.type    => ""
-      case t: Text          => t.value
-      case h: Html[?]       => h.render
-      case c: CustomElem[?] => c.toElems.mkString
+      case _: Empty.type     => ""
+      case t: Text           => t.value
+      case h: Html[?]        => h.render
+      case c: CustomElem[?]  => c.toElems.mkString
+      case HtmlEntity(value) => value
 
 extension [Msg](html: Html[Msg])
   def render: String =
@@ -27,10 +28,11 @@ extension [Msg](html: Html[Msg])
           spacer(tag.attributes.map(_.render).filterNot(_.isEmpty).mkString(" "))
 
         val children = tag.children.map {
-          case _: Empty.type    => ""
-          case t: Text          => t.value
-          case h: Html[?]       => h.render
-          case c: CustomElem[?] => c.render
+          case _: Empty.type     => ""
+          case t: Text           => t.value
+          case h: Html[?]        => h.render
+          case c: CustomElem[?]  => c.render
+          case HtmlEntity(value) => value
         }.mkString
 
         s"""<${tag.name}$attributes>$children</${tag.name}>"""

tyrian-tags/shared/src/main/scala/tyrian/HTMLRendering.scala

@@ -49,7 +49,7 @@ sealed trait Html[+M] extends Elem[M]:
 
 /** Object used to provide Html syntax `import tyrian.Html.*`
   */
-object Html extends HtmlTags with HtmlAttributes with AttributeSyntax:
+object Html extends HtmlTags with HtmlAttributes with AttributeSyntax with HtmlEntities:
 
   def tag[M](name: String)(attributes: Attr[M]*)(children: Elem[M]*): Html[M] =
     Tag(name, attributes.toList, children.toList)
@@ -164,3 +164,6 @@ object RawTag:
 
 trait CustomHtml[+M] extends Html[M]:
   def toHtml: Html[M]
+
+final case class HtmlEntity(value: String) extends Elem[Nothing]:
+  def map[N](f: Nothing => N): HtmlEntity = this

tyrian-tags/shared/src/main/scala/tyrian/Html.scala

@@ -145,4 +145,17 @@ class HTMLRenderingTests extends munit.FunSuite {
     assertEquals(actual, expected)
   }
 
+  test("Can render an nbsp html entity") {
+    val view: Model => Html[Msg] =
+      _ => span(p("Hello,"), _nbsp_, text("world!"))
+
+    val actual =
+      view(model).render
+
+    val expected =
+      "<span><p>Hello,</p>&nbsp;world!</span>"
+
+    assertEquals(actual, expected)
+  }
+
 }

tyrian-tags/shared/src/test/scala/tyrian/HTMLRenderingTests.scala

@@ -147,6 +147,7 @@ object Rendering:
       case t: Text            => List(VNode.text(t.value))
       case subHtml: Html[Msg] => List(toVNode(subHtml, onMsg, router))
       case c: CustomElem[Msg] => c.toElems.flatMap(cc => elemToVNodes(cc, onMsg, router))
+      case HtmlEntity(value)  => List(VNode.text(value))
 
   private lazy val patch: Patch =
     snabbdom.init(