blog/src/templates/Post.jsx

import React, { Fragment } from 'react'
import PropTypes from 'prop-types'
import Helmet from 'react-helmet'
import { graphql } from 'gatsby'
import Layout from '../components/Layout'
import PostImage from '../components/Post/PostImage'
import PostTitle from '../components/Post/PostTitle'
import PostLead from '../components/Post/PostLead'
import PostContent from '../components/Post/PostContent'
import PostActions from '../components/Post/PostActions'
import PostLinkActions from '../components/Post/PostLinkActions'
import SEO from '../components/atoms/SEO'
import PostMeta from '../components/Post/PostMeta'
import Exif from '../components/atoms/Exif'
import RelatedPosts from '../components/molecules/RelatedPosts'
import styles from './Post.module.scss'

const Post = ({ data, location }) => {
  const { markdownRemark: post } = data
  const meta = data.site.siteMetadata
  const { title, image, type, linkurl, style, tags } = post.frontmatter
  const { slug, githubLink } = post.fields

  return (
    <Fragment>
      <Helmet title={title}>
        {style && <link rel="stylesheet" href={style.publicURL} />}
      </Helmet>

      <SEO slug={slug} post={post} postSEO />

      <Layout location={location}>
        <article className={styles.hentry}>
          <PostTitle type={type} linkurl={linkurl} title={title} />
          {type === 'post' && <PostLead post={post} />}
          {type === 'photo' && <PostContent post={post} />}
          {image && (
            <PostImage fluid={image.childImageSharp.fluid} alt={title} />
          )}
          {image && image.fields && <Exif exif={image.fields.exif} />}

          {type !== 'photo' && <PostContent post={post} />}

          {type === 'link' && <PostLinkActions slug={slug} linkurl={linkurl} />}
          <PostActions slug={slug} url={meta.siteUrl} githubLink={githubLink} />
          <PostMeta post={post} meta={meta} />
        </article>

        {type === 'post' && <RelatedPosts tags={tags} />}
      </Layout>
    </Fragment>
  )
}

PostLead.propTypes = {
  post: PropTypes.object.isRequired
}

PostContent.propTypes = {
  post: PropTypes.object.isRequired
}

Post.propTypes = {
  data: PropTypes.object.isRequired,
  location: PropTypes.object.isRequired
}

export default Post

export const pageQuery = graphql`
  query BlogPostBySlug($slug: String!) {
    markdownRemark(fields: { slug: { eq: $slug } }) {
      html
      excerpt
      frontmatter {
        type
        title
        image {
          childImageSharp {
            ...ImageFluid
          }
          fields {
            exif {
              iso
              model
              fstop
              shutterspeed
              focalLength
              exposure
              gps {
                latitude
                longitude
              }
            }
          }
        }
        author
        updated
        tags
        linkurl
        style {
          publicURL
        }
        changelog
      }
      fields {
        slug
        date
        githubLink
      }
      rawMarkdownBody
    }

    site {
      siteMetadata {
        siteUrl
        author {
          name
          uri
        }
      }
    }
  }
`