More formatter work.

Implement functions, add test.

Functions don't hugely need to be optional, we can just carry on
if the function is invalid.

src/com/dmdirc/ui/messages/EventFormatter.java

  * a <code>.</code> character, e.g. <code>{{user.hostname}}</code>. One or more functions can
  * be applied to the result of this, to change the appearance of the output. Functions are
  * separated from their argument with a <code>|</code> character,
- * e.g. <code>{{user.hostname|toCapitals}}</code>.
+ * e.g. <code>{{user.hostname|uppercase}}</code>.
  *
  * <p>Properties and functions are case-insensitive.
  */
 
         String value = target.toString();
         for (int i = 1; i < functionParts.length; i++) {
-            final Optional<String> result = propertyManager.applyFunction(value, functionParts[i]);
-            if (result.isPresent()) {
-                value = result.get();
-            } else {
-                return ERROR_STRING;
-            }
+            value = propertyManager.applyFunction(value, functionParts[i]);
         }
 
         return value;

src/com/dmdirc/ui/messages/EventPropertyManager.java

 import com.dmdirc.logger.ErrorLevel;
 
 import java.lang.reflect.Method;
+import java.util.HashMap;
+import java.util.Map;
 import java.util.Optional;
+import java.util.function.Function;
 
 import javax.inject.Inject;
 
 public class EventPropertyManager {
 
     private final DMDircMBassador eventBus;
+    private final Map<String, Function<String, String>> functions = new HashMap<>();
 
     @Inject
     public EventPropertyManager(final DMDircMBassador eventBus) {
         this.eventBus = eventBus;
+
+        functions.put("uppercase", String::toUpperCase);
+        functions.put("lowercase", String::toLowerCase);
+        functions.put("trim", String::trim);
     }
 
     public <S> Optional<Object> getProperty(final S object, final Class<? extends S> type,
             final Method method = type.getMethod(methodName);
             return Optional.ofNullable(method.invoke(object));
         } catch (ReflectiveOperationException ex) {
-            eventBus.publish(new UserErrorEvent(ErrorLevel.MEDIUM, ex,
+            eventBus.publishAsync(new UserErrorEvent(ErrorLevel.MEDIUM, ex,
                     "Unable to format event: could not retrieve property " + property,
                     ex.getMessage()));
         }
         return Optional.empty();
     }
 
-    public Optional<String> applyFunction(final String input, final String function) {
-        return Optional.empty();
+    public String applyFunction(final String input, final String function) {
+        if (functions.containsKey(function)) {
+            return functions.get(function).apply(input);
+        }
+        eventBus.publishAsync(new UserErrorEvent(ErrorLevel.LOW, null,
+                "Unable to format event: no such function " + function, null));
+        return input;
     }
 
 }

test/com/dmdirc/ui/messages/EventFormatterTest.java

     @Before
     public void setup() {
         formatter = new EventFormatter(propertyManager, templateProvider);
+    }
+
+    @Test
+    public void testBasicFormat() {
         messageEvent = new ChannelMessageEvent(channel, null, null);
 
         when(templateProvider.getTemplate(ChannelMessageEvent.class))
                 .thenReturn(Optional.ofNullable("Template {{channel}} meep"));
         when(propertyManager.getProperty(messageEvent, ChannelMessageEvent.class, "channel"))
                 .thenReturn(Optional.of("MONKEY"));
+
+        assertEquals("Template MONKEY meep", formatter.format(messageEvent).orElse(null));
     }
 
     @Test
-    public void testBasicFormat() {
-        assertEquals("Template MONKEY meep", formatter.format(messageEvent).orElse(null));
+    public void testFormatWithFunction() {
+        messageEvent = new ChannelMessageEvent(channel, null, null);
+
+        when(templateProvider.getTemplate(ChannelMessageEvent.class))
+                .thenReturn(Optional.ofNullable("Template {{channel|lowercase}} meep"));
+        when(propertyManager.getProperty(messageEvent, ChannelMessageEvent.class, "channel"))
+                .thenReturn(Optional.of("MONKEY"));
+        when(propertyManager.applyFunction("MONKEY", "lowercase")).thenReturn("monkey");
+
+        assertEquals("Template monkey meep", formatter.format(messageEvent).orElse(null));
     }
 
 }