Build a real-time presence tracker with avatars

One of the first features you’ll likely want to use after setting up Liveblocks in your app is the presence element. Presence lets you track who’s on a page and can be used to create features like:

• Activity indicators: Show which users are currently active or idle.
• Online statuses: Display whether users are online, offline, or away.
• Collaborative editing indicators: Highlight when multiple users are viewing or editing the same document or page.

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What we’ll build

This tutorial covers how we set up presence in the demo app. For the exact setup from this tutorial, visit the tutorial demo editor, or try the live demo.

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Prerequisites

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1. Install and set up the plugin:

If you haven’t already installed the Liveblocks plugin, you can find a step-by-step guide here.

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Database

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2. Set up the database

In this demo, we’ll display users that visit the page. To do this, we need to update the User data type in the database by adding a name and a profile image.

Go to the Data tab and create two new fields:

• name of type text
• profile image of type image

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3. Update the privacy settings

For this demo, we’ll make the user data public to avoid setting up a login system. Go to the Privacy tab and check View all fields and Find in searches for everyone.

⚠️ In a production app, be more careful with privacy settings to protect user data.

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4. Add sample data

Finally, add some user data. You can copy the CSV file and upload it into Bubble if you have a paid plan or trial, or manually add at least three users for this demo.

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Design

Next is a simple design for the page. While not essential for using presence, it’s needed for the demonstration. If you want to skip ahead to the element setup, jump to the section on adding the presence element.

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3. Create a New Page

In your Bubble app, create a new page.

Give the page a name. For this tutorial, I’m calling it presence-tutorial.

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4. Setting up the page

Change the layout of the page. Click on the page until the property editor opens, then go to the Layout tab and select column instead of fixed.

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5. Adding the Liveblocks presence element

Add a hidden popup to house the presence element. This keeps it organized and out of the way.

Drag a popup onto your page and rename it hidden popup.

Search for liveblocks-presence and drag it into the popup to track who’s online.

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6. Add a floating group

Create a floating group that will later house our repeating group for avatars.

Search for floating group in your assets and drag it onto the page. In the Appearance tab, set the following:

• Vertically float relative to: top
• Horizontally float relative to: left
• Floating z-index: above elements

In the Layout tab, uncheck make this element fixed-width and fixed-height. Set the min-width to 100% and min-height to 100px, then check fit height to content.

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7. Add a repeating group

Add a repeating group from the assets to the floating group. Set the type of content to text and the data source to Liveblocks-presence (testing) A's everyone. This data source holds all users in the room, including the local user.

In the Appearance tab, set the following:

• Check set fixed number of rows
• Set rows to 1
• Uncheck set fixed number of columns
• Set minimum width of the column to 20%
• Set separators to none
• Set border to none

In the Layout tab, set the following:

• Set cell's container layout to column
  • Set container alignment to top
• Check element is visible on page load
• Uncheck make this element fixed-width
• Uncheck make this element fixed-height
• Set min height to 0
• Check fit height to content

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8. Create the avatar

Create a group user that will display the profile image of users when they are on the page.

Add a group to the repeating group, name it group user, and set the type of content to user.

Set the data source to do a search for, make the type user, and set the unique id to current cell's text. This data source is a list of user IDs (which we’ll set later), matching Bubble’s unique IDs.

Add an image element to the group user and set the image to Parent group's user's profile image. Enable Imgix and the following settings:

• Check auto enhance the image
• Set quality to 100
• Check resize to fit dimensions by cropping
• Check apply a circle/ellipse mask

Add a border with solid color #177db4e and set a tooltip to display the parent group's user's name.

In the Layout tab, set the width to 50px, check keep element aspect ratio fixed, and set the aspect ratio to 1x1.

That’s it for setting up the design!

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Workflows

Workflows are where most of the interaction with Liveblocks will happen.

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9. Create a room

Create a workflow that runs on page load to create a room for the demo.

On page load, add the Liveblocks - create room action. Set the Room ID to tutorial and the Default Access to public.

Add a new event: When page is loaded.

Then add the Liveblocks - create room action.

Add the Air Alert plugin for confirmation. We’ll use it to show an alert with the room name after the room is created.

Preview the page to confirm that the room was created successfully.

Great! Now that the room is created, we can move on to entering the room.

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10. Workflow to enter a room

You can now disable the on page load workflow—we won’t need it anymore since our room is created.

Create a new page is loaded workflow. We will add an action to set the state of an element. In Bubble, states allow you to store information within elements. For this demo, we’ll use states to store a random user ID from our database to simulate a random user. In a real production app, you’d use the current user’s unique ID, but we’re avoiding login for this tutorial.

Add a new action to set the state of an element:

Set the element in the action’s property editor to presence-tutorial, then create a new custom state:

Call the state User ID and make it of type text.

Add an action to set the state of the element to a random user ID.

Add the authorize user action—this authorizes users in Bubble with Liveblocks.

• For the user ID field, use the User ID state we just created.
• For the Room ID, use the tutorial room you created.
• Set permissions to FULL_ACCESS.

Add the create client action—this creates an instance of Liveblocks in Bubble. The ID token is the result of the user you just authorized. You can leave throttle and lost connection time as is. Learn more about the parameters of the create client action here.

Add the enter room action. This is what joins the user in the room. Enter the Room ID and User ID, and keep the rest as default. Learn more about the advanced settings (e.g., live cursors) in this tutorial.

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Demo

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11. Trying it out

Select preview and you should see the page load with your avatar at the top. Open several tabs to see the users on the page update in real time!

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Next Steps

Now that you’ve got presence running, kick it up a notch with live cursors.