refactored the template experiment1 implementation to add i18n support of numbers & dates

libraries/stdlib/src/kotlin/template/experiment1/Templates.kt

@@ -3,6 +3,12 @@ package kotlin.template.experiment1
 import org.w3c.dom.Node
 import kotlin.dom.toXmlString
 
+import java.lang.Number
+import java.text.DateFormat
+import java.text.NumberFormat
+import java.util.Date
+import java.util.Locale
+
 fun StringBuilder.text(value : String) : Unit {
     this.append(value)
 }
@@ -22,43 +28,61 @@ fun format(fn : (StringBuilder) -> Unit) : String {
 }
 
 
-abstract class TextBuilder<T>(val output: Appendable) {
+abstract class TextBuilder(val output : Appendable) {
 
-/*
+    /*
     */
-/**
-     * Converts the given string template to a String
+    /**
+         * Converts the given string template to a String
 
-    fun toString(fn: (T) -> Unit): String = toString(ToStringFormatter, fn)
+        fun toString(fn: (T) -> Unit): String = toString(ToStringFormatter, fn)
 
-    fun toString(formatter : ValueFormatter, fn: (T) -> Unit): String {
-        fn(this)
-        return output.toString() ?: ""
-    }
-*/
+        fun toString(formatter : ValueFormatter, fn: (T) -> Unit): String {
+            fn(this)
+            return output.toString() ?: ""
+        }
+    */
 
-    fun text(value: String): Unit {
+    fun text(value : String) : Unit {
         output.append(value)
     }
-
 }
 
-class HtmlBuilder(output: Appendable) : TextBuilder<HtmlBuilder>(output) {
-    var nullText : String = ""
+open class I18nBuilder(output : Appendable, val formatter : I18nFormatter) : TextBuilder(output) {
 
-    fun expression(value: Node): Unit {
+    fun expression(value : Any?) : Unit {
+        escape(formatter.format(value))
+    }
+
+    fun expression(value : Number) : Unit {
+        escape(formatter.formatNumber(value))
+    }
+
+    fun expression(value : Date) : Unit {
+        escape(formatter.formatDate(value))
+    }
+
+    /**
+     * By default does no escaping but inherited classes may escape text
+     */
+    open fun escape(text : String) : Unit {
+        output.append(text)
+    }
+}
+
+open class HtmlBuilder(output : Appendable, formatter : I18nFormatter) : I18nBuilder(output, formatter) {
+
+    /**
+     * Nodes are assumed to already be properly HTML/XML encoded so don't escape
+     */
+    fun expression(value : Node) : Unit {
         text(value.toXmlString())
     }
 
-    fun expression(value: Any?): Unit {
-        if (value == null) {
-            output.append(nullText)
-        } else {
-            escape(value.toString() ?: "")
-        }
-    }
-
-    fun escape(text : String) : Unit {
+    /**
+     * Escapes text using HTML escaping of sensitive tokens
+     */
+    override fun escape(text : String) : Unit {
         for (c in text) {
             if (c == '<') output.append("&lt;")
             else if (c == '>') output.append("&gt;")
@@ -75,22 +99,57 @@ class HtmlBuilder(output: Appendable) : TextBuilder<HtmlBuilder>(output) {
  * different types for different kinds of language
  */
 trait ValueFormatter {
-    fun format(buffer : Appendable, val value : Any?) : Unit
+    fun format(val value : Any?) : String
 }
 
-object ToStringFormatter : ValueFormatter {
+open class ToStringFormatter : ValueFormatter {
 
-    fun toString() = "ToStringFormatter"
+    var nullText : String = "null"
 
-    override fun format(buffer : Appendable, value : Any?) {
-        val text = if (value == null) "null" else value.toString()
-        buffer.append(text)
+    open fun toString() = "ToStringFormatter"
+
+    override fun format(value : Any?): String {
+        return if (value == null) nullText else value.toString()
     }
 }
 
-fun toHtml(fn: (HtmlBuilder) -> Unit): String {
-    val buffer = StringBuilder()
-    val html = HtmlBuilder(buffer)
-    fn(html)
-    return buffer.toString() ?: ""
+open class I18nFormatter(val locale : Locale = Locale.getDefault().sure()): ToStringFormatter() {
+
+    override fun toString() = "I18nFormatter"
+
+    public var numberFormat : NumberFormat = NumberFormat.getInstance(locale).sure()
+
+    public var dateFormat : DateFormat = DateFormat.getDateTimeInstance(DateFormat.DEFAULT, DateFormat.DEFAULT, locale).sure()
+
+    fun formatNumber(number : Number): String {
+        return numberFormat.format(number) ?: ""
+    }
+
+    fun formatDate(date : Date): String {
+        return dateFormat.format(date) ?: ""
+    }
+
+    /**
+     * Generates the internationalised text for this formatter
+     */
+    fun toString(fn : (I18nBuilder) -> Unit) : String {
+        val buffer = StringBuilder()
+        val builder = I18nBuilder(buffer, this)
+        fn(builder)
+        return buffer.toString() ?: ""
+    }
+
+    /**
+     * Generates the HTML for the given function
+     */
+    fun toHtml(fn : (HtmlBuilder) -> Unit) : String {
+        val buffer = StringBuilder()
+        val html = HtmlBuilder(buffer, this)
+        fn(html)
+        return buffer.toString() ?: ""
+    }
 }
+
+
+
+