Added programmatic user author detection

gatsby-node.js

@@ -1,9 +1,52 @@
 const path = require(`path`)
-const fs = require('fs')
+const fs = require("fs")
 const { createFilePath } = require(`gatsby-source-filesystem`)
 
+exports.onCreateNode = ({ node, actions, getNode }) => {
+  const { createNodeField } = actions
+
+  if (node.internal.type === `MarkdownRemark`) {
+    const value = createFilePath({
+      node,
+      getNode,
+    })
+    createNodeField({
+      name: `slug`,
+      node,
+      value,
+    })
+  }
+
+  if (node.internal.type === `UsersJson`) {
+    const value = createFilePath({
+      node,
+      getNode,
+    })
+    createNodeField({
+      name: `slug`,
+      node,
+      value,
+    })
+  }
+}
+
+exports.sourceNodes = ({ getNodesByType, actions: { createNodeField } }) => {
+  const postNodes = getNodesByType(`MarkdownRemark`)
+  const userNodes = getNodesByType(`UsersJson`)
+
+  userNodes.forEach(userNode => {
+    const isAuthor = postNodes.some(post => post.frontmatter.author === userNode.id)
+
+    createNodeField({
+      name: `isAuthor`,
+      node: userNode,
+      value: isAuthor,
+    })
+  })
+}
+
 exports.createPages = ({ graphql, actions }) => {
-  const { createPage } = actions
+  const { createPage, createNodeField } = actions
 
   const blogPost = path.resolve(`./src/templates/blog-post.js`)
   const blogAuthor = path.resolve(`./src/templates/blog-author.js`)
@@ -22,6 +65,9 @@ exports.createPages = ({ graphql, actions }) => {
             }
             frontmatter {
               title
+              author {
+                id
+              }
             }
           }
         }
@@ -34,7 +80,7 @@ exports.createPages = ({ graphql, actions }) => {
         }
       }
     }
-    `
+    `,
   ).then(result => {
     if (result.errors) {
       throw result.errors
@@ -50,16 +96,16 @@ exports.createPages = ({ graphql, actions }) => {
 
       const postInfo = post.node.frontmatter
       if (postInfo.attached && postInfo.attached.length > 0) {
-        postInfo.attached.forEach(({file: fileStr}) => {
+        postInfo.attached.forEach(({ file: fileStr }) => {
           const postPath = post.node.fields.slug
-          const relFilePath = path.join(__dirname, 'static', 'posts', postPath, fileStr)
+          const relFilePath = path.join(__dirname, "static", "posts", postPath, fileStr)
           const fileExists = fs.existsSync(path.resolve(relFilePath))
           if (!fileExists) {
             console.error(`Could not find file to attach in the static folder: ${postPath}${fileStr}`)
             console.error(`To fix this problem, attach the file to the static folder's expected path above, or remove it from the post frontmatter definition`)
             process.exit(1)
           }
-        });
+        })
       }
 
       createPage({
@@ -78,7 +124,7 @@ exports.createPages = ({ graphql, actions }) => {
         path: `authors/${author.node.id}`,
         component: blogAuthor,
         context: {
-          slug: author.node.id
+          slug: author.node.id,
         },
       })
     })
@@ -86,16 +132,3 @@ exports.createPages = ({ graphql, actions }) => {
     return null
   })
 }
-
-exports.onCreateNode = ({ node, actions, getNode }) => {
-  const { createNodeField } = actions
-
-  if (node.internal.type === `MarkdownRemark`) {
-    const value = createFilePath({ node, getNode })
-    createNodeField({
-      name: `slug`,
-      node,
-      value,
-    })
-  }
-}