Imagine engaging users and creating a lively community within your app. Think about gathering useful feedback with one simple feature. What if you could do that? This guide shows you how.

Many apps lack good ways for users to share their thoughts. This can lead to users losing interest. It also makes you miss chances to improve. We’ll build a real-time upvote/downvote system. It will be just like Reddit. We’ll use Angular and Firebase. This makes a fun, interactive experience.

Modeling Data in Firebase for Votes

This part is about how to set up your database. It needs to store and get vote data efficiently. The structure we pick is important. It makes sure things run smoothly and can grow easily.

Understanding the Data Requirements

Our database must answer some important questions. “What does a user think of something?” and “How many total votes does it have?” are key questions.

Structuring the NoSQL Database

We’ll make collections based on item IDs. We’ll store user IDs with the votes they made. Firebase data security rules will keep things safe.

Querying and Aggregating Votes

We can ask the database about user votes. We’ll also find the total votes for each item. Firebase makes it quick to get the data.

Building the Angular Service

Here, we make the Angular service. It talks to the Firebase database.

Setting Up the Firebase Object Observable

We create a Firebase tool. It watches a specific item ID. This lets us see data updates as they happen.

Implementing the updateUserVote Function

This function sends vote data to Firebase. It sends the user ID and their vote.

Handling Vote Values (-1, 0, 1)

Each vote value has a meaning. -1 is a downvote. 0 means no vote. 1 is an upvote. We store these values in the database.

Creating the Upvote/Downvote Component

This is about the Angular part. It shows the buttons and handles what users do.

Defining Input Variables (Item ID, User ID)

We send the item and user IDs to the component. They become input variables.

Using the ngOnInit Lifecycle Hook

We watch the Firebase data in the ngOnInit part. This helps us get the vote data when the component loads.

Calculating the Total Vote Count

A library like Lodash can count votes fast. Or, use regular JavaScript to do the same job.

Implementing the Upvote and Downvote Logic

Now, we’ll build the functions. They handle the upvoting and downvoting.

Creating Separate Functions for Upvote and Downvote

We make upvote and downvote functions. They are almost the same. One uses a positive vote and the other uses a negative vote.

Allowing Users to Cancel Their Vote

Users can undo votes easily. Clicking the same button again cancels their vote. A simple line of code makes this happen.

Handling Unauthenticated Users

Consider sending unauthenticated users to a login page. This can easily be implemented.

Styling and Displaying the Vote Status

This covers how it looks. We want to show users their vote status.

Using Arrow Icons for Upvote and Downvote

We use arrow icons. They show the upvote and downvote buttons.

Highlighting Active Votes with Color

The ngClass helps us change button colors. Green means upvote. Red means downvote.

Ensuring Accessibility

Add ARIA attributes. This makes it better for everyone to use.

Conclusion

We’ve built an upvote/downvote system. It uses Angular and Firebase. This system boosts user fun. It gets useful feedback. It grows community interaction. Try adding this to your own app.