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Get data from the collection

Page 4 out of 10

Connect to your Astra DB via the API that will call your Netlify serverless functions. You will get data from your Astra DB collection and display it on the UI.

Clarice Bouwer

Software Engineering Team Lead and Director of Cloudsure

Sunday, 23 October 2022 · Estimated 2 minute read

Handler

You need to create a GET handler that will get all data from the collection and handle certain error cases. his verb is encapsulated in the find function of the getCollection function.

./netlify/functions/getTodos.js
Copy 
const { getCollection } = require('./astraClient');

exports.handler = async (event, context) => {
  try {
    const todos = await getCollection();
    try {
      const res = await todos.find({});
      return {
        statusCode: 200,
        body: JSON.stringify(Object.values(res.data)),
      };
    } catch (e) {
      const code = e.toString().indexOf("Request failed with status code 404") > -1
        ? 404
        : 400;
      return {
        statusCode: code,
        body: JSON.stringify(e.message),
      };
    }
  } catch (error) {
    return {
      statusCode: 500,
      body: JSON.stringify(error.message),
    };
  }
};

API

The API exposes endpoints that will fetch from ./netlify/functions/<endpoint>. The endpoints are handlers in the ./netlify/functions directory in the root of the app. This location is to be configured in netlify.toml.

To understand this new-age magic, you will need to understand Netlify functions. These bad boys deploy server-side code that will work as an API endpoint without the need for running your own server or VM or pod. It runs on Netlify automatically in response to events and can process jobs in the background.

./src/api.js
Copy 
const throwError = (response, message) => {
  throw new Error({
    status: response.status,
    message,
    response,
  });
};

const respond = (response) => {
  if (response.status >= 500) {
    throwError(response, 'Internal Server Error');
  }
  if (response.status === 404) {
    throwError(response, 'Not Found');
  }
  if (response.status >= 400) {
    throwError(response, 'Bad Request');
  }
  return response.json();
};

const getTodos = async () => {
  const response = await fetch(`/.netlify/functions/getTodos`);
  return await respond(response);
};

const api = {
  getTodos,
};

export default api;

List tasks in the User Interface

./src/App.js
Copy 
import React, { useEffect, useState } from 'react';
import api from './api';

const App = () => {
  // Optimization strategy:
  // Store todos in an array on the state. Once interacted on, change the state
  // instead of getting all todos from the DB each time.
  const [todos, setTodos] = useState([]);

  useEffect(() => {
    // Load all todos in a useEffect so that there isn't
    // a stack overflow with infinite rerenders.
    // https://www.robinwieruch.de/react-hooks-fetch-data/
    const loadTodos = async () => {
      const data = await api.getTodos()
      setTodos(data);
    };
    loadTodos();
  }, []);

  return (
    <>
      {todos && todos.length === 0 && <div>There is nothing to do.</div>}
      {todos &&
        todos.length > 0 &&
        todos.map((todo) => {
          return <div key={todo.id}>{todo.id} | {todo.text}</div>;
        })}
    </>
  );
};

export default App;

✋ Important to note

At this point the collection does not exist so you should get a 404 response from the API in your network tab. Let's go add some stuff.

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