Guide Guide Creating Bypass Handler's

[Deazer]

Introduction
Bypass Handler is a handler for commands that come from the client when clicking on links in HTML windows/Interfaces (NPC dialogues, Community Board, tutorials, etc.).

Quick start
Step 1: Create handler class

package handler.bypass;

import l2.gameserver.model.Player;
import l2.gameserver.model.instances.NpcInstance;

public class MyBypassHandler extends ScriptBypassHandler
{
  @Override
  public void handle(Player player, NpcInstance npc, String bypass, String params)
  {
    // Your logic here
    player.sendMessage("Bypass works! Params: " + params);
  }

  @Override
  public String[] getBypassPrefixes()
  {
    return new String[]{"_mybypass"};
  }
}

Step 2: Add to the config ONLY if you need to call this bypass directly from the interface. If it is called from HTML - DO NOT, this is important!
File: config/altsettins.properties
AltSimpleBypassAllowed = ...,_mybypass

Step 3: Use in HTML
<a action="bypass _mybypass">Press me</a>
<a action="bypass _mybypass param1 param2">With parameters</a>

Registration types
Prefix matching (getBypassPrefixes)
Used when bypass starts with a specific string:

@Override
public String[] getBypassPrefixes()
{
  return new String[]{"_myprefix"};
}

Exact match (getBypassCommands)
Used when an exact string match is required

@Override
public String[] getBypassCommands()
{
  return new String[]{"my_exact_command"};
}

Working with NPCs
requiresNpc()
If the handler requires NPC:

@Override
public boolean requiresNpc()
{
  return true; // bypass will not execute if npc == null
}

requiresNpcCheck()
If a check of the distance to the NPC is needed:

@Override
public boolean requiresNpcCheck()
{
  return true; // will check NpcInstance.canBypassCheck(player, npc)
}

Examples
Example 1: Simple informational bypass

package handler.bypass;

import l2.gameserver.model.Player;
import l2.gameserver.model.instances.NpcInstance;

/**
 * Shows character information
 * HTML: <a action="bypass _charinfo">My information</a>
 */
public class CharInfoBypassHandler extends ScriptBypassHandler
{
  @Override
  public void handle(Player player, NpcInstance npc, String bypass, String params)
  {
    player.sendMessage("Your level: " + player.getLevel());
    player.sendMessage("Your class: " + player.getClassId().name());
    player.sendMessage("Adena: " + player.getAdena());
  }

  @Override
  public String[] getBypassCommands()
  {
    return new String[]{"_charinfo"};
  }
}

Example 2: Bypass with parameters

package handler.bypass;

import l2.gameserver.model.Player;
import l2.gameserver.model.instances.NpcInstance;

/**
 * Teleport to Coordinates
 * HTML: <a action="bypass _quicktele 82698 148638 -3473">To Giran Town</a>
 */
public class QuickTeleportBypassHandler extends ScriptBypassHandler
{
  @Override
  public void handle(Player player, NpcInstance npc, String bypass, String params)
  {
    String[] args = params.trim().split(" ");
    if(args.length < 3)
    {
      player.sendMessage("Incorrect coordinates");
      return;
    }
 
    try
    {
      int x = Integer.parseInt(args[0]);
      int y = Integer.parseInt(args[1]);
      int z = Integer.parseInt(args[2]);
      player.teleToLocation(x, y, z);
    }
    catch(NumberFormatException e)
    {
      player.sendMessage("Coordinate parsing error");
    }
  }

  @Override
  public String[] getBypassPrefixes()
  {
    return new String[]{"_quicktele "};
  }
}

Example 3: Bypass with NPC check

package handler.bypass;

import l2.gameserver.model.Player;
import l2.gameserver.model.instances.NpcInstance;

/**
 * Purchasing buff from NPC
 * HTML: <a action="bypass _buybuff 1204 5">Buff Wind Walk</a>
 */
public class BuyBuffBypassHandler extends ScriptBypassHandler
{
  @Override
  public void handle(Player player, NpcInstance npc, String bypass, String params)
  {
    String[] args = params.trim().split(" ");
    if(args.length < 2)
      return;

    int skillId = Integer.parseInt(args[0]);
    int skillLvl = Integer.parseInt(args[1]);
    int price = 10000;

    if(player.getAdena() < price)
    {
      player.sendMessage("Insufficient adena");
      return;
    }

    player.reduceAdena(price, true);
    npc.broadcastPacket(new MagicSkillUse(npc, player, skillId, skillLvl, 0, 0));
    player.altOnMagicUse(player, SkillTable.getInstance().getInfo(skillId, skillLvl));
  }

  @Override
  public boolean requiresNpc()
  {
    return true;
  }

  @Override
  public boolean requiresNpcCheck()
  {
    return true;
  }

  @Override
  public String[] getBypassPrefixes()
  {
    return new String[]{"_buybuff "};
  }
}

Example 4: Multiple commands in one handler

package handler.bypass;

import l2.gameserver.model.Player;
import l2.gameserver.model.instances.NpcInstance;

/**
 * Pet management
 * HTML: <a action="bypass pet_feed">Feed</a>
 *       <a action="bypass pet_dismiss">Release</a>
 */
public class PetControlBypassHandler extends ScriptBypassHandler
{
  @Override
  public void handle(Player player, NpcInstance npc, String bypass, String params)
  {
    if(player.getPet() == null)
    {
      player.sendMessage("You do not have a pet");
      return;
    }

    switch(bypass)
    {
      case "pet_feed":
        // feeding logic
        player.sendMessage("The pet is fed");
        break;
      case "pet_dismiss":
        // release logic
        player.getPet().unSummon();
        player.sendMessage("Pet released");
        break;
    }
  }

  @Override
  public String[] getBypassCommands()
  {
    return new String[]{"pet_feed", "pet_dismiss"};
  }
}

Example 5: GM-only bypass

package handler.bypass;

import l2.gameserver.model.Player;
import l2.gameserver.model.instances.NpcInstance;

/**
 * GM Only
 * HTML: <a action="bypass _gmspawn 20001">Spawn mob</a>
 */
public class GmSpawnBypassHandler extends ScriptBypassHandler
{
  @Override
  public void handle(Player player, NpcInstance npc, String bypass, String params)
  {
    if(!player.isGM())
    {
      player.sendMessage("For GM Only");
      return;
    }

    int npcId = Integer.parseInt(params.trim());
    // spawn logic
    player.sendMessage("NPC " + npcId + " spawned");
  }

  @Override
  public String[] getBypassPrefixes()
  {
    return new String[]{"_gmspawn "};
  }
}

 

[rihosedemon]

Thank you

 

[fa1thDEV]

great guide, thx

 

[Telol]

Great

 

[Nunes]

Thx