How to create a Gatsby source plugin with sourceNodes API

Gatsby is a popular and powerful static site generator that allows developers to build fast and efficient websites using modern web technologies. One of the key features of Gatsby is its ability to pull in data from external sources, such as CMSs, databases, APIs, and more, using its source plugins.

In this article, we will explore how to create a Gatsby source plugin using Gatsby’s sourceNodes API. The sourceNodes API allows us to create nodes in Gatsby’s internal GraphQL data layer, which can then be queried and used to build our website.

Step 1: Set up a new Gatsby project

The first step in creating a Gatsby source plugin is to set up a new Gatsby project. If you don’t already have Gatsby installed, you can do so by running the following command in your terminal:

npm install -g gatsby-cli

Once Gatsby is installed, create a new Gatsby project using the following command:

gatsby new my-source-plugin

Step 2: Create a new source plugin

Next, navigate to the root of your Gatsby project and create a new directory for your source plugin. In this example, we’ll call our source plugin “my-source-plugin”.

mkdir my-source-plugin

Now, create a new file in your source plugin directory called gatsby-node.js. This is where we will define our source plugin using Gatsby’s sourceNodes API.

Step 3: Define your sourceNodes API

Inside your gatsby-node.js file, you can use the following code to define a simple source plugin that fetches data from an API and creates nodes in Gatsby’s data layer:

   
const fetch = require('node-fetch');

exports.sourceNodes = async ({ actions, createNodeId, createContentDigest }) => {
  const { createNode } = actions;

  // Fetch data from your API
  const response = await fetch('https://api.example.com/data');
  const data = await response.json();

  // Create nodes for each item in the data
  data.forEach(item => {
    const node = {
      ...item,
      id: createNodeId(`my-source-plugin-${item.id}`),
      internal: {
        type: 'MySourcePlugin',
        contentDigest: createContentDigest(item),
      },
    };
    createNode(node);
  });
};
   
   

Step 4: Add your source plugin to your Gatsby project

Finally, you will need to add your source plugin to your Gatsby project’s gatsby-config.js file. Add the following code to the plugins array in your gatsby-config.js file:

   
module.exports = {
  plugins: [
    {
      resolve: 'my-source-plugin',
      options: {
        // Add any options here
      },
    },
  ],
};
   
   

Once you’ve added your source plugin to your gatsby-config.js file, you can run gatsby develop to start your Gatsby project. Your source plugin will now be fetching data from your API and creating nodes in Gatsby’s data layer!

Creating a Gatsby source plugin with the sourceNodes API can be a powerful way to pull in data from external sources and use it to build your website. By following the steps outlined in this article, you can create custom source plugins to fetch data from any source and integrate it into your Gatsby project.