Gatsbyjs Page generation | Best practices

Question

I'm working on Gatsbyjs web with headless WordPress as data source. I don't want to generate all pages statically in /pages, but instead in im gatsby-node.js mapping through allPages / allPosts queries and sending data to page/post template using createPage API.

But my pages are kinda complex, they seem to need very different queries ( acf.. )

What would be the best practice here? Should I create a template for each and every page and map data directly into those?

Answer 1

Yes, you hit the nail. You have to generate templates/pages for each type of page you want to generate.

TL;DR

You only need to create different createPage actions and point them in different templates/pages. For example:

createPage({
      path: node.fields.slug,
      component: path.resolve(`./src/templates/blog-post.js`),
      context: {
        slug: node.fields.slug,
      },
    })

and

 createPage({
      path: node.fields.slug,
      component: path.resolve(`./src/templates/tags.js`),
      context: {
        slug: node.fields.slug,
      },
    })

Long version

Standard use-case

exports.createPages = async ({ graphql, actions }) => {
  const { createPage } = actions
  const result = await graphql(`
    query {
      allMarkdownRemark {
        edges {
          node {
            fields {
              slug
            }
          }
        }
      }
    }
  `)
  result.data.allMarkdownRemark.edges.forEach(({ node }) => {
    createPage({
      path: node.fields.slug,
      component: path.resolve(`./src/templates/blog-post.js`),
      context: {
        slug: node.fields.slug,
      },
    })
  })
}

component will define where the data will be available to use and which template/page/component will use.

If you want to use a different template rather than /blog-post you need to create another createPage action. Something like this:

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

  return graphql(`
    {
      allMarkdownRemark(limit: 1000) {
        edges {
          node {
            id
            fields {
              slug
            }
            frontmatter {
              tags
              templateKey
            }
          }
        }
      }
    }
  `).then(result => {
    if (result.errors) {
      result.errors.forEach(e => console.error(e.toString()))
      return Promise.reject(result.errors)
    }

    const posts = result.data.allMarkdownRemark.edges

    posts.forEach(edge => {
      const id = edge.node.id
      createPage({
        path: edge.node.fields.slug,
        tags: edge.node.frontmatter.tags,
        component: path.resolve(
          `src/templates/blog-post.js`
        ),
        // additional data can be passed via context
        context: {
          id,
        },
      })
    })

    // Tag pages:
    let tags = []
    // Iterate through each post, putting all found tags into `tags`
    posts.forEach(edge => {
      if (_.get(edge, `node.frontmatter.tags`)) {
        tags = tags.concat(edge.node.frontmatter.tags)
      }
    })
    // Eliminate duplicate tags
    tags = _.uniq(tags)

    // Make tag pages
    tags.forEach(tag => {
      const tagPath = `/tags/${_.kebabCase(tag)}/`

      createPage({
        path: tagPath,
        component: path.resolve(`src/templates/tags.js`),
        context: {
          tag,
        },
      })
    })
  })
}

Without going into details of what it does or how (if you need I can detail the answer), the important thing is that you can use createPage action to define how many pages, data, and components you need. In this case, blog-post.js and tags.js which will be found under /blog-post/postSlug and in /tag/tagPath.

Promise use-case

If you have a small website or project, the previous case may work, but if your project grows, it becomes hell to find information among so many lines. So I use to create promises to store that information. In my gatsby-node:

const postsBuilder = require("./src/build/postsBuilder");
const tagsBuilder = require("./src/build/tagsBuilder");

exports.createPages = async ({graphql, actions}) => {
  await Promise.all(
    [
      postBuilder(graphql, actions),
      tagsBuilder(graphql, actions)
    ]
  );
};

Then, in one of those builders:

const path = require('path')

async function postsBuilder(graphql, actions) {
  const {createPage} = actions;

  const postsQuery= await graphql(`
     {
      allMarkdownRemark(limit: 1000) {
        edges {
          node {
            id
            fields {
              slug
            }
            frontmatter {
              tags
              templateKey
            }
          }
        }
      }
    }`);

  const resultForms = postsQuery.data.allMarkdownRemark.edges;

  resultForms.map(node => {
      createPage({
        path: node.node.url + '/',
        component: whateverYouNeed,
        context: {
          name: node.node.name,
          url: node.node.url
        },
      })
  });
}

module.exports = postsBuilder;

Note that code could be refactored in many ways, is just to show another approach of what you are able to do.

I think the promise way is much more semantic and clean but it's up to you to use whatever you need in each case.

References:

1. First query
2. Second query