From cafff103e51ce658d536b66149dd048d6696803f Mon Sep 17 00:00:00 2001
From: diamondburned <datutbrus@gmail.com>
Date: Thu, 8 Apr 2021 13:09:10 -0700
Subject: [PATCH] Bot: Add ErrorReplier

This commit adds the ErrorReplier callback into Context, which allows
the user to implement a custom way to format errors, such as putting
them into an embed.
---
 bot/ctx.go      | 9 +++++++++
 bot/ctx_call.go | 8 ++++++--
 2 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/bot/ctx.go b/bot/ctx.go
index 864983e..07cdbb1 100644
--- a/bot/ctx.go
+++ b/bot/ctx.go
@@ -127,6 +127,15 @@ type Context struct {
 	// MessageCreate events.
 	ReplyError bool
 
+	// ErrorReplier is an optional function that allows changing how the error
+	// is replied. It overrides ReplyError and is only used for MessageCreate
+	// events.
+	//
+	// Note that errors that are passed in here will bypas FormatError; in other
+	// words, the implementation might only care about ErrorReplier and leave
+	// FormatError as it is.
+	ErrorReplier func(err error, src *gateway.MessageCreateEvent) api.SendMessageData
+
 	// EditableCommands when true will also listen for MessageUpdateEvent and
 	// treat them as newly created messages. This is convenient if you want
 	// to quickly edit a message and re-execute the command.
diff --git a/bot/ctx_call.go b/bot/ctx_call.go
index 4519154..20b129a 100644
--- a/bot/ctx_call.go
+++ b/bot/ctx_call.go
@@ -114,14 +114,18 @@ func (ctx *Context) callMessageCreate(
 		return nil
 	}
 
-	if err != nil && !ctx.ReplyError {
+	if err != nil && !ctx.ReplyError && ctx.ErrorReplier == nil {
 		return err
 	}
 
 	var data api.SendMessageData
 
 	if err != nil {
-		data.Content = ctx.FormatError(err)
+		if ctx.ErrorReplier != nil {
+			data = ctx.ErrorReplier(err, mc)
+		} else {
+			data.Content = ctx.FormatError(err)
+		}
 	} else {
 		switch v := v.(type) {
 		case string: