gatsby-node.js

// Create pages for docs
exports.createPages = ({ actions, graphql }) => {
  const path = require(`path`);
  const { createPage } = actions;
  const projects = path.resolve("src/templates/projects.js");
  const defaultPage = path.resolve("src/templates/defaultPage.js");
  const projectsSubPages = path.resolve("src/templates/projectsSubPages.js");

  return graphql(`
    {
      allSanityDefaultPage {
        edges {
          node {
            slug
          }
        }
      }
      allSanityProjects {
        edges {
          node {
            slug
            childPages {
              slug
              childPages {
                slug
                childPages {
                  slug
                  childPages {
                    slug
                  }
                }
              }
            }
          }
        }
      }
    }
  `).then((result) => {
    if (result.errors) {
      reporter.panic("failed to create pages ", result.errors);
    }

    result.data.allSanityDefaultPage.edges.forEach(({ node }) => {
      createPage({
        path: node.slug,
        component: defaultPage,
        context: {
          slug: node.slug,
        },
      });
    });
    result.data.allSanityProjects.edges.forEach(({ node }) => {
      createPage({
        path: node.slug,
        component: projects,
        context: {
          slug: node.slug,
        },
      });
    });
    result.data.allSanityProjects.edges.forEach(({ node }) => {
      console.log(node);
      if (node && node.childPages.length > 0) {
        node.childPages.map((childPage) => {
          createPage({
            path: node.slug + "/" + childPage.slug,
            component: projectsSubPages,
            context: {
              slug: childPage.slug,
              parentSlug: node.slug,
            },
          });
          // TODO:  Can be optimized by moving this snippet into the node.childPages.map above, so that it does not run twice
          if (childPage.childPages.length > 0) {
            node.childPages.map((childPage) => {
              childPage.childPages.map((subChildPage) => {
                createPage({
                  path: node.slug + "/" + subChildPage.slug,
                  component: projectsSubPages,
                  context: {
                    slug: subChildPage.slug,
                    parentSlug: node.slug,
                  },
                });
                if (subChildPage.childPages.length > 0) {
                  createPage({
                    path: node.slug + "/" + subChildPage.childPages.slug,
                    component: projectsSubPages,
                    context: {
                      slug: subChildPage.childPages.slug,
                      parentSlug: node.slug,
                    },
                  });
                }
              });
            });
          }
        });
      }
    });
  });
};

Return from GraphQL query.js

{
  "data": {
    "allSanityProjects": {
      "edges": [
        {
          "node": {
            "childPages": [],
            "_key": null
          }
        },
        {
          "node": {
            "childPages": [
              {
                "_rawBlockContent": [
                  {
                    "_key": "198132f6c5fc",
                    "_type": "block",
                    "children": [
                      {
                        "_key": "198132f6c5fc0",
                        "_type": "span",
                        "marks": [],
                        "text": "Project 1 level 1, number 1"
                      }
                    ],
                    "markDefs": [],
                    "style": "normal"
                  }
                ],
                "title": "Melk",
                "slug": "melk",
                "childPages": [
                  {
                    "slug": "akjdslfkajsdf",
                    "title": "camambert",
                    "childPages": [
                      {
                        "title": "corn flakes",
                        "slug": "faasdfasdf",
                        "childPages": [],
                        "_key": "bdaa7339fdc0"
                      }
                    ],
                    "_key": "f98b0182d3e3"
                  },
                  {
                    "slug": "briouch",
                    "title": "briouch",
                    "childPages": [],
                    "_key": "ddd596843b79"
                  }
                ],
                "_key": "314959ade166"
              },
              {
                "_rawBlockContent": [
                  {
                    "_key": "5a5d97c7fdcf",
                    "_type": "block",
                    "children": [
                      {
                        "_key": "5a5d97c7fdcf0",
                        "_type": "span",
                        "marks": [],
                        "text": "asdfasdfasdfasdf"
                      }
                    ],
                    "markDefs": [],
                    "style": "normal"
                  }
                ],
                "title": "Brød",
                "slug": "bread",
                "childPages": [
                  {
                    "slug": "asdfasdf",
                    "title": "asdfasdf",
                    "childPages": [],
                    "_key": "22ec6cd560ad"
                  }
                ],
                "_key": "36a6d3a14071"
              },
              {
                "_rawBlockContent": null,
                "title": "Sodastream Trademark ",
                "slug": "sodastream",
                "childPages": [],
                "_key": "e7deb1870019"
              }
            ],
            "_key": null
          }
        },
        {
          "node": {
            "childPages": [
              {
                "_rawBlockContent": null,
                "title": "Lik",
                "slug": "lik",
                "childPages": [],
                "_key": "3643126ff628"
              },
              {
                "_rawBlockContent": null,
                "title": "Fryser",
                "slug": "fryser",
                "childPages": [],
                "_key": "85197ee7d8a2"
              },
              {
                "_rawBlockContent": null,
                "title": "Tesla model S",
                "slug": "wannebe",
                "childPages": [],
                "_key": "4b6f03429a69"
              }
            ],
            "_key": null
          }
        }
      ]
    }
  }
}