问在/second%20post还没有一页

EN

const path = require(`path`)


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

// Define a template for blog post
 const blogPost = path.resolve(`./src/templates/blog-post-contentful.js`)

// Get all markdown blog posts sorted by date
const result = await graphql(
`
 {
  allContentfulBlockchainlearning{
    edges{
      node{
        slug
        title
        subtitle
        
       
      }
    }
  }
}
`
)

if (result.errors) {
 reporter.panicOnBuild(
  `There was an error loading your blog posts`,
  result.errors
  )
  return
}

 const posts = result.data.allContentfulBlockchainlearning.edges

  // Create blog posts pages
  // But only if there's at least one markdown file found at "content/blog" (defined in gatsby- 
config.js)
  // `context` is available in the template as a prop and as a variable in GraphQL

 if (posts.length > 0) {
  posts.forEach((post, index) => {
  const previousPostSlug = index === 0 ? null : posts[index - 1].id
  const $nextPostSlug = index === posts.length - 1 ? null : posts[index + 1].id

  createPage({
    path: post.node.slug,
    component: blogPost,
    context: {
      slug: post.node.slug,
      previousPostSlug,
      $nextPostSlug,
    },
  })
})
}
}

import React from "react"
import { Link, graphql } from "gatsby"

import Bio from "../components/bio"
import Layout from "../components/layout"
import SEO from "../components/seo"

const BlogPostTemplate = ({ data, location }) => {
const post = data.contentfulBlockchainlearning
const siteTitle = data.site.siteMetadata?.title || `Title`
const { previous, next } = data

return (
<Layout location={location} title={siteTitle}>
  <SEO
    title={post.title}
    description={post.subtitle}
  />
  <article
    className="blog-post"
    itemScope
    itemType="http://schema.org/Article"
  >
    <header>
      <h1 itemProp="headline">{post.title}</h1>
      <p>{post.date}</p>
    </header>
    <section
      dangerouslySetInnerHTML={{ __html: post.content.raw }}
      itemProp="articleBody"
    />
    <hr />
    <footer>
      <Bio />
    </footer>
  </article>
  <nav className="blog-post-nav">
    <ul
      style={{
        display: `flex`,
        flexWrap: `wrap`,
        justifyContent: `space-between`,
        listStyle: `none`,
        padding: 0,
      }}
    >
      <li>
        {previous && (
          <Link to={previous.slug} rel="prev">Hey There
            ← {previous.title}
          </Link>
        )}
      </li>
      <li>
        {next && (
          <Link to={next.slug} rel="next">
            {next.title} →
          </Link>
        )}
      </li>
    </ul>
    </nav>
  </Layout>
 )
 }

  export default BlogPostTemplate

export const pageQuery = graphql`
query BlogPostBySlug(
$slug: String!
$previousPostSlug: String
$nextPostSlug: String

) {
site {
  siteMetadata {
    title
    
    
  }
}
contentfulBlockchainlearning(slug: {eq: $slug}){
  title
  subtitle
  content{
    raw
  }

}
previous: contentfulBlockchainlearning(slug: { eq: $previousPostSlug}) {
  title 
}

    


next:  contentfulBlockchainlearning(slug: { eq: $nextPostSlug }) {
     title     
    
 
      
  
 }
 }
 `