Add warning message when post is rejected

plugin.json

@@ -18,6 +18,14 @@
         "type": "bool",
         "help_text": "If set the plugin will reject posts containing profanity instead of censoring."
       },
+      {
+        "key": "WarningMessage",
+        "display_name": "Warning Message",
+        "type": "text",
+        "help_text": "If Reject Posts is enabled, this message will be sent to the user to warn him. Use `%s` in the message if you want to cite the forbidden word. Markdown formatted.",
+        "placeholder": "Ex. Your post has been rejected by the Profanity Filter, because the following word is not allowed: `%s`.",
+        "default": "Your post has been rejected by the Profanity Filter, because the following word is not allowed: `%s`."
+      },
       {
         "key": "CensorCharacter",
         "display_name": "Censor Character",
@@ -37,4 +45,4 @@
     "header": "",
     "footer": ""
   }
-}
+}

server/configuration.go

@@ -22,6 +22,7 @@ type configuration struct {
 	RejectPosts     bool
 	CensorCharacter string
 	BadWordsList    string
+	WarningMessage  string `json:"WarningMessage"`
 }
 
 // Clone shallow copies the configuration. Your implementation may require a deep copy if

server/plugin.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"fmt"
 	"strings"
 	"sync"
 	"unicode"
@@ -39,6 +40,11 @@ func (p *Plugin) FilterPost(post *model.Post) (*model.Post, string) {
 	for i, word := range words {
 		if p.WordIsBad(word) {
 			if configuration.RejectPosts {
+				p.API.SendEphemeralPost(post.UserId, &model.Post{
+					ChannelId: post.ChannelId,
+					Message:   fmt.Sprintf(configuration.WarningMessage, word),
+					RootId:    post.RootId,
+				})
 				return nil, "Profane word not allowed: " + word
 			}
 			words[i] = strings.Repeat(configuration.CensorCharacter, len(word))