Appwrite Functions is all about flexibility. Behind the simple workflow hides some useful examples that can help you accomplish your goals faster. Take a look at the following.
Currency conversion API
Here's a currency conversion API that converts from Euros and Indian Rupees to US Dollars. We'll use an external API to get the latest exchange rates and query it using a dependency specific to each runtime.
Prerequisites
Run the following bash command to create a package.json file. This file is used to manage your Node.js project's dependencies.
npm init -y
Install the undici library. This library includes a fetch function that you can use to make HTTP requests.
npm install undici
Finally, add npm install to your function's build commands in the Appwrite Console.
Run the following bash command to create a composer.json file. This file is used to manage your PHP project's dependencies.
composer init -y
Install the guzzlehttp/guzzle library. This library includes a get function that you can use to make HTTP requests.
composer require guzzlehttp/guzzle
Finally, add composer install to your function's build commands in the Appwrite Console.
Run the following bash command to create a requirements.txt file. This file is used to manage your Python project's dependencies.
touch requirements.txt
Install the requests library. This library includes a get function that you can use to make HTTP requests.
echo "requests" >> requirements.txt
pip install -r requirements.txt
Finally, add pip install -r requirements.txt to your function's build commands in the Appwrite Console.
Create a pubspec.yaml file with the following contents. This file is used to manage your Dart project's dependencies.
name: appwrite_function
description: Appwrite Function
version: 1.0.0
environment:
sdk: '>=2.12.0 <3.0.0'
Install the http library. This library includes a get function that you can use to make HTTP requests.
pub install http
Finally, add pub get to your function's build commands in the Appwrite Console.
Create a Gemfile file with the following contents. This file is used to manage your Ruby project's dependencies.
source 'https://rubygems.org'
Install the httparty library. This library includes a get function that you can use to make HTTP requests.
echo "gem 'httparty'" >> Gemfile
bundle install
Finally, add bundle install to your function's build commands in the Appwrite Console.
Code
import { fetch } from 'undici';
export default async function ({ req, res }) {
if (req.path === '/eur') {
const amountInEuros = Number(req.query.amount);
const response = await fetch('https://api.exchangerate.host/latest?base=EUR&symbols=USD');
const data = await response.json();
const amountInDollars = amountInEuros * data.rates.USD;
return res.text(amountInDollars.toString());
}
if (req.path === '/inr') {
const amountInRupees = Number(req.query.amount);
const response = await fetch('https://api.exchangerate.host/latest?base=INR&symbols=USD');
const data = await response.json();
const amountInDollars = amountInRupees * data.rates.USD;
return res.text(amountInDollars.toString());
}
return res.text('Invalid path');
};
Voting system
Here's a simple voting system that allows users to vote on various topics. Appwrite Functions and the server SDK are used to enforce voting rules and prevent multiple votes from the same user for a single topic.
Prerequisites
Create a Topics collection with the following attributes:
Name | Type | Description |
title | string | The name of the topic |
description | string | Long form description of the topic |
Create a Votes collection with the following attributes:
Name | Type | Description |
userId | string | The ID of the user who cast the vote |
topicId | string | The ID of the topic that was voted on |
vote | string | The vote cast by the user. Must be either "yes" or "no" |
Code
import { Client, Databases, Query } from 'node-appwrite';
export default async function ({ req, res }) {
const vote = {
userId: req.query.userId,
topicId: req.query.topicId,
vote: req.query.vote
};
if (vote.vote !== 'yes' && vote.vote !== 'no') {
return res.json({ ok: false, message: 'You must vote yes or no.' }, 400);
}
// Set project and set API key
const client = new Client();
client
.setProject(process.env.APPWRITE_FUNCTION_PROJECT_ID)
.setKey(req.headers['x-appwrite-key']);
const database = new Database(client);
const existingVotes = await database.listDocuments('[VOTES_COLLECTION_ID]', [
Query.equals('userId', vote.userId),
Query.equals('topicId', vote.topicId)
]);
if (existingVotes.total > 0) {
return res.json({ ok: false, message: 'You have already voted on this topic.' }, 400);
}
const voteDocument = await database.createDocument('[VOTES_COLLECTION_ID]', {
userId,
topicId,
vote,
});
return res.json({ ok: true, message: 'Vote cast.', vote: voteDocument });
};
Use the function by navigating to the function URL in the browser. The URL should contain the required parameters. For example, <YOUR_FUNCTION_URL>/?userId=<USER_ID>&topicId=<TOPIC_ID>&vote=yes to cast a vote.
HTML contact form
Here's a simple form page that handles form submissions, and can be used to store a user's message in a collection. The form is submitted to the function using the POST method and the form data is sent as a URL-encoded string in the request body.
Prerequisites
Create a Messages collection with the following attributes:
Name | Type | Description |
name | string | The name of the message author |
string | The email of the message author | |
content | string | The content of the message |
Code
import { Client, Databases, Query, ID } from 'node-appwrite';
import querystring from 'node:querystring';
const html = `<!doctype html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>Contact Form</title>
</head>
<body>
<form action="/" method="POST">
<input type="text" id="name" name="name" placeholder="Name" required>
<input type="email" id="email" name="email" placeholder="Email" required>
<textarea id="content" name="content" placeholder="Message" required></textarea>
<button type="submit">Submit</button>
</form>
</body>
</html>`
export default async function ({ req, res }) {
if (req.method === 'GET') {
return res.text(html, 200, {'content-type': 'text/html'});
}
if (req.method === 'POST' && req.headers['content-type'] === 'application/x-www-form-urlencoded') {
const formData = querystring.parse(req.body);
const message = {
name: formData.name,
email: formData.email,
content: formData.content
};
// Set project and set API key
const client = new Client()
.setProject(process.env.APPWRITE_FUNCTION_PROJECT_ID)
.setKey(req.headers['x-appwrite-key']);
const databases = new Databases(client);
const document = await databases.createDocument('<DATABASE_ID>', '[MESSAGES_COLLECTION_ID]', ID.unique(), message);
return res.text("Message sent");
}
return res.text('Not found', 404);
}
Use the function by navigating to the function URL in the browser. Submit the form to store the message in the collection.