Awesome Pagination for Gatsby

A sensible approach to pagination for Gatsby sites.

Please post questions on StackOverflow, only bug reports are accepted via GitHub.

Contents

• QuickStart
• Introduction
• Philosophy
• Notes

Quick start

Open gatsby-node.js and import:

import { paginate } from 'gatsby-awesome-pagination';

Then, use paginate() like so:

exports.createPages = ({ actions, graphql }) => {
  const { createPage } = actions;

  // Fetch your items (blog posts, categories, etc).
  const blogPosts = doSomeMagic();

  // Create your paginated pages
  paginate({
    createPage, // The Gatsby `createPage` function
    items: blogPosts, // An array of objects
    itemsPerPage: 10, // How many items you want per page
    pathPrefix: '/blog', // Creates pages like `/blog`, `/blog/2`, etc
    component: path.resolve('...'), // Just like `createPage()`
  })
}

Now in your page query you can use the pagination context like so:

export const pageQuery = graphql`
  query ($skip: Int!, $limit: Int!) {
    allMarkdownRemark(
      sort: { fields: [frontmatter___date], order: DESC }
      skip: $skip // This was added by the plugin
      limit: $limit // This was added by the plugin
    ) {
      ...
    }
  }
`

Then inside your component, you can link to next / previous pages, and so on:

const BlogIndex = (props) => {
  return (
    <div>
      {data.allMarkdownRemark.edges.map(edge => <PostItem item={edge.node}/>)}
      <div>
        {/* previousPageLink and nextPageLink were added by the plugin */ }
        <Link to={props.pageContext.previousPagePath}>Previous</Link>
        <Link to={props.pageContext.nextPagePath}>Next</Link>
      </div>
    </div>
  )
}

For a more detailed example, see docs/examples.md

Introduction

Love Gatsby, wanna paginate. Sweet, that's exactly what this package is for.

We differ from other pagination options as follows:

• Don't abuse context to pass data into components
• Pass only pagination context via context
• Provide helpers for next / previous links

There are 2 types of pagination. You have 80 blog posts and you want to show them 15 at a time on pages like /blog, /blog/2, /blog/3, etc. You do this with paginate(). Then on each blog post, you want to link to the previous and next blog posts. You do this with createPagePerItem().

Philosophy

Why did we create this plugin? We felt that the other Gatsby pagination plugins were using an approach that goes against the principles of GraphQL. One of the advantages of GraphQL is to be able to decide what data you need right where you use that data. That's how Gatsby works with page queries.

By putting all the data into context, the other pagination plugins break this. Now you need to decide what data you require for each page inside gatsby-node.js and not inside your page query.

We also felt that there were some helpers missing. Generating links to the next and previous pages.

This plugin aims to make it easy to paginate in Gatsby properly. No compromises.

API

Both paginate() and createPagePerItem() take a single argument, an object. They share the following keys (* = required):

• createPage* - The createPage function from exports.createPages
• component* - The value you would pass to createPage() as component Gatsby docs here
• items* - An array of objects, the items you want to paginate over

paginate()

In addition to the arguments above, paginate() also supports:

• itemsPerPage* - An integer, how many items should be displayed on each page
• itemsPerFirstPage - An integer, how many items should be displayed on the first page
• pathPrefix* - A (nonempty) string or string returning function, the path (eg /blog) to which /2, /3, etc will be added
• context - A base context object which is extended with the pagination context values
• trailingSlash - A boolean, indicating the setting of canonical URLs with trailing slashes

Example:

paginate({
  createPage: boundActionCreators.createPage,
  component: path.resolve('./src/templates/blog-index.js'),
  items: blogPosts,
  itemsPerPage: 15,
  itemsPerFirstPage: 3,
  pathPrefix: '/blog',
  trailingSlash: true
})

Each page's context automatically receives the following values:

• pageNumber - The page number (starting from 0)
• humanPageNumber - The page number (starting from 1) for human consumption
• skip - The $skip you can use in a GraphQL query
• limit - The $limit you can use in a GraphQL query
• numberOfPages - The total number of pages
• previousPagePath - The path to the previous page or undefined
• nextPagePath - The path to the next page or undefined

pathPrefix()

For more advanced use cases, you can supply a function to pathPrefix. This function will receive a single object as its only argument, that object will contain pageNumber and numberOfPages, both integers.

A simple example implementation could be:

const pathPrefix = ({ pageNumber, numberOfPages }) =>
  pageNumber === 0 ? '/blog' : '/blog/page'

This example produces pages like /blog, /blog/page/2, /blog/page/3, etc.

createPagePerItem()

WARNING: This API is under active development and will probably change. USE WITH CAUTION.

In addition to the arguments above, createPagePerItem() also accepts:

• itemToPath* - A function that takes one object from items and returns the path for this item
• itemToId* - A function that takes one object from items and returns the item's ID

NOTE: Both itemToPath and itemToId also accept a string with the path to the value, for example node.frontmatter.permalink or node.id.

NOTE: If an individual item has a property called context, and that property is an object, then it's own properties will be added to the page's context for that item.

Example:

createPagePerItem({
  createPage: boundActionCreators.createPage,
  component: path.resolve('./src/templates/blog-post.js'),
  items: blogPosts,
  itemToPath: 'node.frontmatter.permalink',
  itemToId: 'node.id'
})

Each page's context automatically receives the following values:

• previousPagePath - The path to the previous page or undefined
• previousItem - A copy of the previous element from items
• previousPageId - The ID of the previous page
• nextPagePath - The path to the next page or undefined
• nextItem - A copy of the next element from items
• nextPageId - The ID of the next page

Notes

Flow

This plugin is written using flow. There are some limitations when using flow and lodash. Specifically this issue. In many cases we use $FlowExpectError and explicitly define the type of something to workaround. A more elegant solution does not currently seem to exist. Any input on improving the typing is greatly appreciated in the plugin's issues.

Contributors

Thanks to the following for their contributions:

• https://github.com/Pyrax
• https://github.com/JesseSingleton
• https://github.com/silvenon