Syncfusion aspnetmvc chat ui

Syncfusion ASP.NET MVC Chat UI

The Syncfusion ASP.NET MVC Chat UI (Syncfusion.EJ2.InteractiveChat.ChatUI) is a feature-rich conversational interface component for building real-time chat applications, AI assistants, and bot integrations. It supports structured messages, user avatars, typing indicators, file attachments, mention tagging, markdown rendering, and extensive template customization.

Navigation Guide

Getting Started

📄 Read: references/getting-started.md

• NuGet package installation (Syncfusion.EJ2.MVC5)
• Namespace, stylesheet, and script references
• Script manager registration
• Basic Chat UI rendering with @Html.EJS().ChatUI()
• Configuring initial messages and current user

Messages

📄 Read: references/messages.md

• ChatUIMessage model: Text, Id, Author, Timestamp, Status, AttachedFile
• Pinned messages, reply-to threading (ChatUIReplyTo with Timestamp, TimestampFormat, MentionUsers), forwarded messages
• Compact mode, auto-scroll, quick reply suggestions
• Message toolbar with MessageToolbarItemClickedEventArgs (item, message, cancel, event)
• Message status: IconCss, Text, Tooltip usage
• Markdown content rendering with marked + DOMPurify

User Configuration

📄 Read: references/user-configuration.md

• ChatUIUser model: Id, User, AvatarUrl, AvatarBgColor, CssClass, StatusIconCss
• Defining the current user with the User property
• Avatar images, fallback initials, background color
• Presence status icons (online, offline, busy, away)

Header and Toolbar

📄 Read: references/header-and-toolbar.md

• Show/hide header (ShowHeader), header text and icon
• ChatUIToolbarSettings — header toolbar items
• Toolbar item properties: IconCss, Type, Text, Visible, Disabled, Tooltip, CssClass, Align, TabIndex, Template
• ItemClicked event handler

Footer and Templates

📄 Read: references/footer-and-templates.md

• Show/hide footer (ShowFooter), custom footer template
• Empty chat template, message template, suggestion template
• Typing users template, time break template
• Template context variables (message, index, users, messageDate, suggestion)

Events and Methods

📄 Read: references/events-and-methods.md

• Created, MessageSend, UserTyping events with full event args (cancel, isTyping, message, user, itemData)
• addMessage() — add message as string or object
• updateMessage() — edit an existing message by ID
• scrollToBottom() — programmatic scroll to latest message
• scrollToMessage(messageId) — scroll to a specific message by ID
• focus() — programmatically focus the chat input textarea
• Accessing the ChatUI instance via ej.base.getInstance()

Appearance and Layout

📄 Read: references/appearance-and-layout.md

• Placeholder, Width, Height, CssClass
• Timestamps (ShowTimeStamp, TimeStampFormat)
• Time breaks (ShowTimeBreak, TimeBreakTemplate)
• Typing indicator (TypingUsers)
• Load on demand (LoadOnDemand) for long conversation histories
• Persistence (EnablePersistence) — save and restore state across page reloads

File Attachments

📄 Read: references/file-attachments.md

• Enable file attachments (EnableAttachments)
• AttachmentSettings: SaveUrl, RemoveUrl, AllowedFileTypes, MaxFileSize, SaveFormat, Path
• Drag-and-drop, maximum file count
• Custom attachment and preview templates
• Pre-populating attachments on messages at initial render (AttachedFile)
• Attachment lifecycle events and ChatAttachmentClickEventArgs (file, cancel, event)

Mentions and Globalization

📄 Read: references/mentions-and-globalization.md

• MentionUsers list, @ mention trigger popup
• Custom trigger character (MentionTriggerChar)
• Predefined mentions in message text using {0}, {1} placeholders
• MentionSelect event
• Localization (Locale, ej.base.L10n.load) and RTL (EnableRtl)

Bot Integrations and Speech-to-Text

📄 Read: references/bot-integrations.md

• Microsoft Bot Framework (Direct Line) integration
• Google Dialogflow integration
• Speech-to-Text via Web Speech API + SpeechToText component
• Secure token server pattern
• MessageSend + addMessage() integration pattern
• Troubleshooting common bot connection issues

---

Quick Start Example

Controller (HomeController.cs):

using Syncfusion.EJ2.InteractiveChat;

public ActionResult Index()
{
    var currentUser = new ChatUIUser { Id = "user1", User = "Albert" };
    var otherUser   = new ChatUIUser { Id = "user2", User = "Michale Suyama" };

    var messages = new List<ChatUIMessage>
    {
        new ChatUIMessage { Text = "Hi Michale, are we on track for the deadline?", Author = currentUser },
        new ChatUIMessage { Text = "Yes, the design phase is complete.", Author = otherUser },
        new ChatUIMessage { Text = "I'll review it and send feedback by today.", Author = currentUser }
    };

    ViewBag.CurrentUser = currentUser;
    ViewBag.Messages    = messages;
    return View();
}

View (Index.cshtml):

@using Syncfusion.EJ2.InteractiveChat

<div style="height:400px; width:450px;">
    @Html.EJS().ChatUI("chatUI")
        .User(ViewBag.CurrentUser)
        .Messages(ViewBag.Messages)
        .HeaderText("Team Chat")
        .Render()
</div>

Required layout references (_Layout.cshtml):

<head>
    <link rel="stylesheet" href="https://cdn.syncfusion.com/ej2/{{ site.ej2version }}/fluent.css" />
    <script src="https://cdn.syncfusion.com/ej2/{{ site.ej2version }}/dist/ej2.min.js"></script>
</head>
<body>
    ...
    @Html.EJS().ScriptManager()
</body>

---

Common Patterns

Programmatically Add a Message (Bot Reply)

function onMessageSend(args) {
    var chatUI = ej.base.getInstance(document.getElementById('chatUI'), ejs.interactivechat.ChatUI);
    fetch('/api/bot/reply', {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({ text: args.message.text })
    })
    .then(r => r.json())
    .then(data => chatUI.addMessage({ text: data.reply, author: botUser }));
}

Enable File Attachments

@Html.EJS().ChatUI("chatUI")
    .User(ViewBag.CurrentUser)
    .EnableAttachments(true)
    .AttachmentSettings(new ChatUIFileAttachmentSettings {
        SaveUrl = Url.Content("https://services.syncfusion.com/aspnet/production/api/FileUploader/Save"),
        RemoveUrl = Url.Content("https://services.syncfusion.com/aspnet/production/api/FileUploader/Remove")
    })
    .Render()

Show Typing Indicator (Client-Side)

function onCreated() {
    var chatUI = ej.base.getInstance(document.getElementById('chatUI'), ejs.interactivechat.ChatUI);
    chatUI.typingUsers = [{ id: "user2", user: "Michale Suyama" }];
    chatUI.dataBind();
}

---

Key Properties Reference

Property	Type	Default	Description
User	ChatUIUser	—	Current logged-in user
Messages	List<ChatUIMessage>	[]	Initial message collection
HeaderText	string	—	Text shown in header
HeaderIconCss	string	—	CSS class for header icon
ShowHeader	bool	true	Show or hide the header
ShowFooter	bool	true	Show or hide the footer
Placeholder	string	"Type your message…"	Textarea placeholder
Width	string	"100%"	Component width
Height	string	"100%"	Component height
CssClass	string	—	Custom CSS class
AutoScrollToBottom	bool	false	Auto-scroll on new message
ShowTimeStamp	bool	true	Show message timestamps
TimeStampFormat	string	"dd/MM/yyyy hh:mm a"	Global timestamp format
ShowTimeBreak	bool	false	Show date separators
EnableCompactMode	bool	false	Align all messages left
LoadOnDemand	bool	false	Lazy-load messages on scroll
EnablePersistence	bool	false	Persist state across page reloads via localStorage
EnableAttachments	bool	false	Enable file attachments
MentionUsers	List<ChatUIUser>	—	Users available for @ mention
TypingUsers	List<ChatUIUser>	—	Users currently typing
EnableRtl	bool	false	Right-to-left layout
Locale	string	"en"	Localization culture code