Skip to main content

Spreadsheets in GatsbyJS Sites

GatsbyJS is a framework for creating websites. It uses React components for page templates and GraphQL for loading data.

SheetJS is a JavaScript library for reading and writing data from spreadsheets.

This demo uses GatsbyJS and SheetJS (through the gatsby-transformer-excel1 transformer) to pull data from a spreadsheet and display the content in a page.

The "Complete Example" section includes a complete website powered by an XLSX spreadsheet.

gatsby-transformer-excel is maintained by the Gatsby core team and all bugs should be directed to the main Gatsby project. If it is determined to be a bug in the parsing logic, issues should then be raised with the SheetJS team.

gatsby-transformer-excel uses an older version of the library. It can be overridden through a package.json override in the latest versions of NodeJS:

package.json (add highlighted lines)
{
  "overrides": {
    "xlsx": "https://cdn.sheetjs.com/xlsx-0.20.1/xlsx-0.20.1.tgz"
  }
}
Telemetry

GatsbyJS collects telemetry by default. The telemetry subcommand can disable it:

npx gatsby telemetry --disable

Integration Details​

In the GatsbyJS data system, source plugins read from data sources and generate nodes represent raw data. Transformer plugins transform these nodes into other nodes that represent processed data for use in pages.

This example uses gatsby-source-filesystem2 to read files from the filesystem and gatsby-transformer-excel transformer to perform the transform.

Installation​

The SheetJS NodeJS module will be referenced by gatsby-transformer-excel.

Before installing, to ensure that the transformer uses the latest version of the library, the overrides section must be added to package.json:

package.json (add highlighted lines)
{
  "overrides": {
    "xlsx": "https://cdn.sheetjs.com/xlsx-0.20.1/xlsx-0.20.1.tgz"
  }
}

gatsby-transformer-excel and gatsby-source-filesystem should be installed after installing SheetJS modules:

npx gatsby telemetry --disable
yarn add https://cdn.sheetjs.com/xlsx-0.20.1/xlsx-0.20.1.tgz
yarn add gatsby-transformer-excel gatsby-source-filesystem

GraphQL details​

Under the hood, gatsby-transformer-excel uses the SheetJS read3 method to parse the workbook into a SheetJS workbook4. Each worksheet is extracted from the workbook. The sheet_to_json method5 generates row objects using the headers in the first row as keys.

Consider the following worksheet:

pres.xlsx

Assuming the file name is pres.xlsx and the data is stored in "Sheet1", the following nodes will be created:

[
  { Name: "Bill Clinton", Index: 42, type: "PresXlsxSheet1" },
  { Name: "GeorgeW Bush", Index: 43, type: "PresXlsxSheet1" },
  { Name: "Barack Obama", Index: 44, type: "PresXlsxSheet1" },
  { Name: "Donald Trump", Index: 45, type: "PresXlsxSheet1" },
  { Name: "Joseph Biden", Index: 46, type: "PresXlsxSheet1" },
]

The type is a proper casing of the file name concatenated with the sheet name.

The following query pulls the Name and Index fields from each row:

{
  allPresXlsxSheet1 { # "all" followed by type
    edges {
      node { # each line in this block should be a field in the data
        Name
        Index
      }
    }
  }
}

Complete Example​

Tested Deployments

This demo was tested on 2023 December 04 against [email protected]. The generated project used [email protected] and [email protected].

Project setup​

0) Disable GatsbyJS telemetry:

npx gatsby telemetry --disable

1) Create a template site:

npm init gatsby -- -y sheetjs-gatsby

2) Follow the on-screen instructions for starting the local development server:

cd sheetjs-gatsby
npm run develop

Open a web browser to the displayed URL (typically http://localhost:8000/)

3) Edit package.json and add the highlighted lines in the JSON object:

package.json (add highlighted lines)
{
  "overrides": {
    "xlsx": "https://cdn.sheetjs.com/xlsx-0.20.1/xlsx-0.20.1.tgz"
  },
  "name": "sheetjs-gatsby",
  "version": "1.0.0",

4) Install the library and plugins:

npm i --save https://cdn.sheetjs.com/xlsx-0.20.1/xlsx-0.20.1.tgz
npm i --save gatsby-transformer-excel gatsby-source-filesystem

5) Make a src/data directory, download https://sheetjs.com/pres.xlsx, and move the downloaded file into the new folder:

mkdir -p src/data
curl -L -o src/data/pres.xlsx https://sheetjs.com/pres.xlsx

6) Edit gatsby-config.js and add the following lines to the plugins array:

gatsby-config.js (add highlighted lines)
module.exports = {
  siteMetadata: {
    title: `sheetjs-gatsby`,
    siteUrl: `https://www.yourdomain.tld`,
  },
  plugins: [
    {
      resolve: `gatsby-source-filesystem`,
      options: {
        name: `data`,
        path: `${__dirname}/src/data/`,
      },
    },
    `gatsby-transformer-excel`,
  ],
}

Stop and restart the development server process (npm run develop).

GraphiQL test​

7) Open the GraphiQL editor. The output of the previous step displayed the URL (typically http://localhost:8000/___graphql )

There is an editor in the left pane. Paste the following query into the editor:

GraphQL Query (paste into editor)
{
  allPresXlsxSheet1 {
    edges {
      node {
        Name
        Index
      }
    }
  }
}

Press the Execute Query button (▶) and data should show up in the right pane:

GraphiQL Screenshot

React page​

8) Create a new file src/pages/pres.js that uses the query and displays the result:

src/pages/pres.js
import { graphql } from "gatsby"
import * as React from "react"

export const query = graphql`query {
  allPresXlsxSheet1 {
    edges {
      node {
        Name
        Index
      }
    }
  }
}`;

const PageComponent = ({data}) => {
  return ( <pre>{JSON.stringify(data, 2, 2)}</pre> );
};
export default PageComponent;

After saving the file, access http://localhost:8000/pres in the browser. The displayed JSON is the data that the component receives:

Expected contents of /pres
{
  "allPresXlsxSheet1": {
    "edges": [
      {
        "node": {
          "Name": "Bill Clinton",
          "Index": 42
        }
      },
  // ....

9) Change PageComponent to display a table based on the data:

src/pages/pres.js
import { graphql } from "gatsby"
import * as React from "react"

export const query = graphql`query {
  allPresXlsxSheet1 {
    edges {
      node {
        Name
        Index
      }
    }
  }
}`;

const PageComponent = ({data}) => {
  const rows = data.allPresXlsxSheet1.edges.map(r => r.node);
  return ( <table>
    <thead><tr><th>Name</th><th>Index</th></tr></thead>
    <tbody>{rows.map(row => ( <tr>
      <td>{row.Name}</td>
      <td>{row.Index}</td>
    </tr> ))}</tbody>
  </table> );
};

export default PageComponent;

Going back to the browser, http://localhost:8000/pres will show a table:

Data in Table

Live refresh​

10) Open the file src/data/pres.xlsx in Excel or another spreadsheet editor. Add a new row at the end of the file, setting cell A7 to "SheetJS Dev" and cell B7 to 47. The sheet should look like the following screenshot:

New Row in File

Save the file and observe that the table has refreshed with the new data:

Updated Table

Static site​

11) Stop the development server and build the site:

npm run build

The build output will confirm that the /pres route is static:

Output from GatsbyJS build process
Pages

┌ src/pages/404.js
│ ├   /404/
│ └   /404.html
├ src/pages/index.js
│ └   /
└ src/pages/pres.js
  └   /pres/

  ╭────────────────────────────────────────────────────────────────╮
  │                                                                │
  │   (SSG) Generated at build time                                │
  │ D (DSG) Deferred static generation - page generated at runtime │
  │ ∞ (SSR) Server-side renders at runtime (uses getServerData)    │
  │ λ (Function) Gatsby function                                   │
  │                                                                │
  ╰────────────────────────────────────────────────────────────────╯

The generated page will be placed in public/pres/index.html.

12) Open public/pres/index.html with a text editor and search for "SheetJS". There will be a HTML row:

public/pres/index.html (Expected contents)
<tr><td>SheetJS Dev</td><td>47</td></tr>
  1. The package is available as gatsby-transformer-excel on the public NPM registry. It is also listed on the GatsbyJS plugin library.↩
  2. See the gatsby-source-filesystem plugin in the GatsbyJS documentation↩
  3. See read in "Reading Files"↩
  4. See "Workbook Object" for more details on the SheetJS workbook object.↩
  5. See sheet_to_json in "Utilities"↩