Add Function to neutralise Mentions (serenity-rs#414)

examples/05_command_framework/src/main.rs

@@ -20,6 +20,7 @@ use serenity::model::gateway::Ready;
 use serenity::model::Permissions;
 use serenity::prelude::Mutex;
 use serenity::prelude::*;
+use serenity::utils::{content_safe, ContentSafeOptions};
 use std::collections::HashMap;
 use std::env;
 use std::fmt::Write;
@@ -175,6 +176,10 @@ fn main() {
             // Make this command use the "complicated" bucket.
             .bucket("complicated")
             .cmd(commands))
+        // Command that will repeat passed arguments and remove user and
+        // role mentions with safe alternative.
+        .command("say", |c| c
+            .cmd(say))
         .group("Emoji", |g| g
             // Sets multiple prefixes for a group.
             // This requires us to call commands in this group
@@ -250,6 +255,32 @@ command!(commands(ctx, msg, _args) {
     }
 });
 
+// Repeats what the user passed as argument but ensures that user and role
+// mentions are replaced with a safe textual alternative.
+// In this example channel mentions are excluded via the `ContentSafeOptions`.
+command!(say(_ctx, msg, args) {
+    let mut settings = if let Some(guild_id) = msg.guild_id {
+       // By default roles, users, and channel mentions are cleaned.
+       ContentSafeOptions::default()
+            // We do not want to clean channal mentions as they
+            // do not ping users.
+            .clean_channel(false)
+            // If it's a guild channel, we want mentioned users to be displayed
+            // as their display name.
+            .display_as_member_from(guild_id)
+    } else {
+        ContentSafeOptions::default()
+            .clean_channel(false)
+            .clean_role(false)
+    };
+
+    let mut content = content_safe(&args.full(), &settings);
+
+    if let Err(why) = msg.channel_id.say(&content) {
+        println!("Error sending message: {:?}", why);
+    }
+});
+
 // A function which acts as a "check", to determine whether to call a command.
 //
 // In this case, this command checks to ensure you are the owner of the message

src/model/channel/channel_id.rs

@@ -14,6 +14,8 @@ use builder::{
 };
 #[cfg(all(feature = "cache", feature = "model"))]
 use CACHE;
+#[cfg(all(feature = "cache", feature = "model"))]
+use Cache;
 #[cfg(feature = "model")]
 use http::{self, AttachmentType};
 #[cfg(feature = "model")]
@@ -293,7 +295,17 @@ impl ChannelId {
     /// [`Channel`]: ../channel/enum.Channel.html
     #[cfg(feature = "cache")]
     #[inline]
-    pub fn to_channel_cached(self) -> Option<Channel> { CACHE.read().channel(self) }
+    pub fn to_channel_cached(self) -> Option<Channel> {
+        self._to_channel_cached(&CACHE)
+    }
+
+    /// To allow testing pass their own cache instead of using the globale one.
+    #[cfg(feature = "cache")]
+    #[inline]
+    pub(crate) fn _to_channel_cached(self, cache: &RwLock<Cache>) -> Option<Channel> {
+        cache.read().channel(self)
+    }
+
 
     /// Search the cache for the channel. If it can't be found, the channel is
     /// requested over REST.

src/model/guild/role.rs

@@ -6,7 +6,7 @@ use builder::EditRole;
 #[cfg(all(feature = "cache", feature = "model"))]
 use internal::prelude::*;
 #[cfg(all(feature = "cache", feature = "model"))]
-use {CACHE, http};
+use {CACHE, Cache, http};
 
 #[cfg(all(feature = "cache", feature = "model", feature = "utils"))]
 use std::str::FromStr;
@@ -182,9 +182,12 @@ impl RoleId {
     /// [`Role`]: ../guild/struct.Role.html
     #[cfg(feature = "cache")]
     pub fn to_role_cached(self) -> Option<Role> {
-        let cache = CACHE.read();
+        self._to_role_cached(&CACHE)
+    }
 
-        for guild in cache.guilds.values() {
+    #[cfg(feature = "cache")]
+    pub(crate) fn _to_role_cached(self, cache: &RwLock<Cache>) -> Option<Role> {
+        for guild in cache.read().guilds.values() {
             let guild = guild.read();
 
             if !guild.roles.contains_key(&self) {