Add commandPreProcessFunction to CommandClient

Author: Chew

command/src/main/java/com/jagrosh/jdautilities/command/CommandClientBuilder.java

@@ -46,6 +46,7 @@ public class CommandClientBuilder
     private String altprefix;
     private String[] prefixes;
     private Function<MessageReceivedEvent, String> prefixFunction;
+    private Function<MessageReceivedEvent, Boolean> commandPreProcessFunction;
     private String serverInvite;
     private String success;
     private String warning;
@@ -73,7 +74,7 @@ public class CommandClientBuilder
      */
     public CommandClient build()
     {
-        CommandClient client = new CommandClientImpl(ownerId, coOwnerIds, prefix, altprefix, prefixes, prefixFunction, activity, status, serverInvite,
+        CommandClient client = new CommandClientImpl(ownerId, coOwnerIds, prefix, altprefix, prefixes, prefixFunction, commandPreProcessFunction, activity, status, serverInvite,
                                                      success, warning, error, carbonKey, botsKey, new ArrayList<>(commands), useHelp,
                                                      shutdownAutomatically, helpConsumer, helpWord, executor, linkedCacheSize, compiler, manager);
         if(listener!=null)
@@ -171,7 +172,23 @@ public CommandClientBuilder setPrefixFunction(Function<MessageReceivedEvent, Str
         this.prefixFunction = prefixFunction;
         return this;
     }
-    
+
+    /**
+     * Sets the pre-process function. This code is executed before every command.<br>
+     * Returning "true" will allow processing to proceed.<br>
+     * Returning "false" or "null" will prevent the Command from executing.
+     *
+     * @param commandPreProcessFunction
+     *        The function to execute
+     *
+     * @return This builder
+     */
+    public CommandClientBuilder setCommandPreProcessFunction(Function<MessageReceivedEvent, Boolean> commandPreProcessFunction)
+    {
+        this.commandPreProcessFunction = commandPreProcessFunction;
+        return this;
+    }
+
     /**
      * Sets whether the {@link com.jagrosh.jdautilities.command.CommandClient CommandClient} will use
      * the builder to automatically create a help command or not.

command/src/main/java/com/jagrosh/jdautilities/command/impl/CommandClientImpl.java

@@ -75,6 +75,7 @@ public class CommandClientImpl implements CommandClient, EventListener
     private final String altprefix;
     private final String[] prefixes;
     private final Function<MessageReceivedEvent, String> prefixFunction;
+    private final Function<MessageReceivedEvent, Boolean> commandPreProcessFunction;
     private final String serverInvite;
     private final HashMap<String, Integer> commandIndex;
     private final ArrayList<Command> commands;
@@ -97,7 +98,7 @@ public class CommandClientImpl implements CommandClient, EventListener
     private CommandListener listener = null;
     private int totalGuilds;
 
-    public CommandClientImpl(String ownerId, String[] coOwnerIds, String prefix, String altprefix, String[] prefixes, Function<MessageReceivedEvent, String> prefixFunction, Activity activity, OnlineStatus status, String serverInvite,
+    public CommandClientImpl(String ownerId, String[] coOwnerIds, String prefix, String altprefix, String[] prefixes, Function<MessageReceivedEvent, String> prefixFunction, Function<MessageReceivedEvent, Boolean> commandPreProcessFunction, Activity activity, OnlineStatus status, String serverInvite,
                              String success, String warning, String error, String carbonKey, String botsKey, ArrayList<Command> commands,
                              boolean useHelp, boolean shutdownAutomatically, Consumer<CommandEvent> helpConsumer, String helpWord, ScheduledExecutorService executor,
                              int linkedCacheSize, AnnotatedModuleCompiler compiler, GuildSettingsManager manager)
@@ -124,6 +125,7 @@ public CommandClientImpl(String ownerId, String[] coOwnerIds, String prefix, Str
         this.altprefix = altprefix==null || altprefix.isEmpty() ? null : altprefix;
         this.prefixes = prefixes==null || prefixes.length == 0 ? null : prefixes;
         this.prefixFunction = prefixFunction;
+        this.commandPreProcessFunction = commandPreProcessFunction==null ? event -> true : commandPreProcessFunction;
         this.textPrefix = prefix;
         this.activity = activity;
         this.status = status;
@@ -592,7 +594,10 @@ else if(event.isFromType(ChannelType.PRIVATE) || event.getTextChannel().canTalk(
                     if(listener != null)
                         listener.onCommand(cevent, command);
                     uses.put(command.getName(), uses.getOrDefault(command.getName(), 0) + 1);
-                    command.run(cevent);
+                    if(commandPreProcessFunction.apply(event))
+                    {
+                        command.run(cevent);
+                    }
                     return; // Command is done
                 }
             }