graphql - 如何向 graphQL 查询添加变量？

Question

我正在使用 Gatsby。我需要将每个 onCLick 的限制增加 3。我试着关注 this post , 但没有成功，所以我删除了编辑，这是原始代码...

这将帮助我加载更多帖子。

export const LatestNews = ({data}) => {
console.log(data);

  return (
    <section id="news_posts_section">
<p>some data</p>
    </section>
  );
};

export const latestNewsQuery = graphql`
query myquery{
  allMarkdownRemark(
    filter: { frontmatter: { layout: { eq: "news" } } }
    sort: { fields: frontmatter___date, order: DESC }
    limit: 2
  ) {
    nodes {
      frontmatter {
        layout
        title
        path
        date
        featuredImage
        thumbnail
      }
      excerpt(pruneLength: 325)
    }
  }
}
`;

这是我的 gatsby 节点:

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

  const blogPostTemplate = path.resolve('src/templates/blog-post/BlogPost.js');
  const newsTemplate = path.resolve('src/templates/news-single/NewsSingle.js');
  const latestNewsPage = path.resolve(
    'src/components/pages-implementation/news/sections/LatestNews.js',
  );

  const blog = graphql(`
    {
      blog: allMarkdownRemark(
        filter: { frontmatter: { layout: { eq: "blog" } } }
      ) {
        edges {
          node {
            frontmatter {
              path
            }
          }
        }
      }
    }
  `).then((result) => {
    if (result.errors) {
      result.errors.forEach((e) => console.error(e.toString()));
      return Promise.reject(result.errors);
    }
    const posts = result.data.blog.edges;

    posts.forEach((edge) => {
      const { path } = edge.node.frontmatter;
      createPage({
        path: path,
        component: blogPostTemplate,
        context: {},
      });
    });
  });

  const news = graphql(`
    {
      news: allMarkdownRemark(
        filter: { frontmatter: { layout: { eq: "news" } } }
      ) {
        edges {
          node {
            frontmatter {
              path
            }
          }
        }
      }
    }
  `).then((result) => {
    if (result.errors) {
      result.errors.forEach((e) => console.error(e.toString()));
      return Promise.reject(result.errors);
    }
    const news = result.data.news.edges;

    news.forEach((edge) => {
      const { path } = edge.node.frontmatter;
      createPage({
        path: path,
        component: newsTemplate,
        context: {},
      });
    });

    
    news.forEach(edge => {
      createPage({
        path: `/news/`,
        component: latestNewsPage,
        context: {
          // This time the entire product is passed down as context
          product: edge
        }
      });
    });


  });

  return Promise.all([blog, news]);
};

编辑 11 月 21 日:

• 我尝试使用非静态查询替换了上面的代码
• 我添加了 gatsby-node 配置
• 我在这里给出一点解释:BlogPost.js 和 NewsSingle.js 是为每个帖子或新闻帖子创建新页面的模板(来自 Netlify CMS)
• LatestNews.js 是页面中的一个组件。这是新闻的主页。所有新闻都在哪里显示？对于静态查询，它工作正常，但是，我需要将“限制”设置为一个变量，以便应用加载更多按钮，onClick 将增加限制，从而在循环中显示更多新闻帖子。

通过上面的配置，它说:

warning The GraphQL query in the non-page component "/home/user/projectname/src/components/pages-implementation/news/sections/LatestNews.js" will not be run.
Exported queries are only executed for Page components. It's possible you're
trying to create pages in your gatsby-node.js and that's failing for some
reason.

Answer 1

useStaticQuery(因此得名)不允许接收变量。如果你看看at the docs :

useStaticQuery does not accept variables (hence the name “static”),but can be used in any component, including pages

在 GraphQL 查询中传递变量的唯一方法是使用 gatsby-node.js 中的上下文 API。例如:

  queryResults.data.allProducts.nodes.forEach(node => {
    createPage({
      path: `/products/${node.id}`,
      component: productTemplate,
      context: {
        // This time the entire product is passed down as context
        product: node
      }
    });
  });
};

在上面的代码片段中，将是整个节点上下文中的 product 变量。它可以通过目标模板中的 pageContext prop 访问或用作查询参数。