Rocket.Chat/app/ui-message/client/messageBox.html

<template name="messageBox">
	<div class="rc-message-box rc-new {{#if isEmbedded}}rc-message-box--embedded{{/if}}">
		{{#unless isAnonymousOrJoinCode}}
			{{> messageBoxTyping rid=_id}}

			{{#if canSend}}
				{{> messagePopupConfig popupConfig}}
				{{> messagePopupSlashCommandPreview popupConfig}}

				{{#if replyMessageData}}
					<div class="reply-preview__wrap message-popup">
					{{#each replyMessageData}}
						{{> messageBoxReplyPreview input=input replyMessageData=.}}
					{{/each}}
					</div>
				{{/if}}

				<label class="rc-message-box__container">
					<span class="rc-message-box__icon emoji-picker-icon {{#unless isEmojiEnabled}}emoji-picker-icon--disabled{{/unless}}">
						{{> icon block="rc-input__icon-svg" icon="emoji"}}
					</span>
					<textarea name="msg" maxlength="{{maxMessageLength}}" placeholder="{{_ 'Message'}}" rows="1" class="rc-message-box__textarea js-input-message"></textarea>
					{{#unless isSendIconDisabled}}
						<span class="rc-message-box__icon rc-message-box__send js-send" data-desktop>
							{{> icon block="rc-input__icon-svg" icon="send"}}
						</span>
					{{else}}
						{{#if subscribed}}
							{{#if isAudioMessageAllowed}}
								{{> messageBoxAudioMessage rid=_id}}
							{{/if}}
							<span class="rc-message-box__action-menu" data-desktop>
								{{#if actions}}
									<span class="rc-message-box__icon">
										{{> icon block="rc-input__icon-svg" icon="plus"}}
									</span>
								{{/if}}
							</span>
						{{else}}
							<span class="rc-message-box__icon">
								<strong><a href="#" class="js-join"> {{_"join"}}</a></strong>
							</span>
						{{/if}}
					{{/unless}}
					<span class="rc-message-box__action-label js-message-actions" data-small>
						{{#each actions}}
							<span class="js-message-action">
								{{> icon block="rc-message-box__action" icon=icon }}
							</span>
						{{/each}}
					</span>
					<span class="rc-message-box__send js-message-action js-send" disabled="{{isSendIconDisabled}}" data-small>
						{{> icon block="rc-message-box__action" icon="send"}}
					</span>
				</label>

				{{#unless isEmbedded}}
					{{#if showFormattingTips}}
						<div class="rc-message-box__toolbar-formatting">
							{{#each formattingButtons}}
								{{#if icon}}
									<button class="rc-message-box__toolbar-formatting-item rc-tooltip js-format" aria-label={{_ label}}>
										{{> icon block="rc-message-box__toolbar-formatting-icon" icon=icon }}
									</button>
								{{else}}
									<span class="rc-message-box__toolbar-formatting-item rc-tooltip" aria-label={{_ label}}>
										<a href="{{link}}" target="_blank" rel="noopener noreferrer" class="rc-message-box__toolbar-formatting-link">{{text}}</a>
									</span>
								{{/if}}
							{{/each}}
						</div>
					{{/if}}
				{{/unless}}
			{{else}}
				<div class="rc-message-box__cannot-send">
					{{#if isBlockedOrBlocker}}
						{{_ "room_is_blocked"}}
					{{else}}
						{{_ "room_is_read_only"}}
					{{/if}}
				</div>
			{{/if}}
		{{else}}
			{{> messageBoxNotSubscribed _id=_id}}
		{{/unless}}
	</div>
</template>