使用GatsbyJS在GraphQL查询中确定文件夹结构

时间:2019-03-04 10:25:46

标签: javascript typescript filesystems graphql gatsby

我确实有类别,作品和图片。它们全都处于层叠状态;典型的儿童与父母的关系。文件夹结构已经代表了该层次结构。最后,我将详细解释我的主要问题。

文件夹结构:

work
├── drawing
│   ├── drawing-1
│   │   ├── image.1.jpg
│   │   ├── image.2.jpg
│   │   ├── image.3.jpg
│   │   ├── image.jpg
│   │   └── index.md
│   └── index.md
├── sculpture
│   ├── gaehnschreier
│   │   ├── image.1.JPG
│   │   ├── image.2.jpg
│   │   ├── image.3.JPEG
│   │   ├── image.4.png
│   │   ├── image.PNG
│   │   └── index.md
│   └── index.md
└── watercolor
    ├── index.md
    ├── portrait-1
    │   ├── image.jpg
    │   └── index.md
    └── portrait-2
        ├── image.jpg
        └── index.md

这是投资组合的简单层次结构。 work是根文件夹,具有不同的类别,例如drawing。在内部,您将找到代表特定作品的文件夹。每个作品都有一个index.md,其中包含有关该作品的详细信息和多个图像(jpeg,png等)。


gatsby-config.js:

// ...
{
  resolve: 'gatsby-source-filesystem',
  options: {
    name: 'work',
    path: `${__dirname}/work/`,
  },
},
// ...

为了解析文件,我使用了gatsby-source-filesystem插件。因此,我可以通过sourceInstanceName: { eq: "work" }查询该文件夹。


gatsby-node.js:

exports.onCreateNode = ({ node, getNode, actions }) => {

  const { createNodeField } = actions

  if (node.internal.type === `Directory`) {

    if (node.sourceInstanceName === `work`) {

      if (!node.relativeDirectory) {
        createNodeField({
          node,   
          name: `workCategory`,
          value: true,  
        })
      }
    }
  }
}

此代码可帮助我标记类别以供以后使用,例如在概览页面上显示类别列表。


示例查询

{
  allDirectory(
    filter: {
      sourceInstanceName: { eq: "work" }
      relativeDirectory: { eq: "" }
    }
  ) {
    edges {
      node {
        dir
        name
        extension
        relativeDirectory
        relativePath
      }
    }
  }
}

查询所有类别。


{
  allDirectory(
    filter: {
      sourceInstanceName: { eq: "work" }
      relativeDirectory: { eq: "drawing" }
    }
  ) {
    edges {
      node {
        dir
        name
        extension
        relativeDirectory
        relativePath
      }
    }
  }
}

查询类别drawing的所有片段。


{
  allFile(
    filter: {
      sourceInstanceName: { eq: "work" }
      extension: { in: ["jpg", "jpeg", "png"] }
        relativeDirectory: { eq: "drawing/drawing-1" }
    }
  ) {
    edges {
      node {
        dir
        name
        extension
        relativeDirectory
        relativePath
      }
    }
  }
}

查询类别drawing-1中的一块drawing的所有图片。


问题:

在最佳情况下,我想遍历每个类别并显示来自index.md的带有图片和描述的工件。但是,如何才能分别提取类别以查询片段呢?我应该如何将这些实体与盖茨比一起映射?我的概念误导了吗?如果您有什么好的建议,为实现自己的目标我应该怎么想,我会很高兴的。

编辑:

现在,我正在摆弄sourceNodes(),并从文件夹结构创建抽象节点。所需的JSON可能看起来像这样:

{
  "data": {
    "allWorkCategory": {
      "edges": [
        {
          "node": {
            "path": "work/scuplture",
            "children": [
              {
                "node": {
                  "internal": {
                    "type": "WorkItem",
                    "name": "Drawing 1",
                    "pictures": {
                       // ...
                    }
                  }
                }
              }
            ],
            "internal": {
              "type": "WorkCategory"
            }
          }
        },
        {
          "node": {
            "path": "work/drawing",
            "children": [],
            "internal": {
              "type": "WorkCategory"
            }
          }
        },
        {
          "node": {
            "path": "work/watercolor",
            "children": [],
            "internal": {
              "type": "WorkCategory"
            }
          }
        }
      ]
    }
  }
}

1 个答案:

答案 0 :(得分:1)

您可以使用createParentChildLink method在gatsby节点之间创建父/子关系,为了找到父节点,可以使用getNodesByType undocumented method

const path = require('path')
exports.onCreateNode = ({
    node,
    getNodesByType,
    actions
}) => {
    const {
        createParentChildLink
    } = actions

    if (node.internal.type === 'Directory') {
        if (node.sourceInstanceName === 'work') {
            // in some case the trailing slash is missing.
            // Always add it and normalize the path to remove duplication
            const parentDirectory = path.normalize(node.dir + '/')
            const parent = getNodesByType('Directory').find(
                n => path.normalize(n.absolutePath + '/') === parentDirectory
            )
            if (parent) {
                node.parent = parent.id
                createParentChildLink({
                    child: node,
                    parent: parent
                })
            }
        }
    }
}

相应的查询可能如下所示:

    {
      allDirectory(
        filter: {
          sourceInstanceName: { eq: "work" }
            relativeDirectory: { eq: "" }
        }
      ) {
        edges {
          node {
            name
            relativePath
            children {
              __typename ... on Directory {
                name
                relativePath
              }
            }
          }
        }
      }
    }

输出结果如下:

    {
      "data": {
        "allDirectory": {
          "edges": [
            {
              "node": {
                "name": "drawing",
                "relativePath": "drawing",
                "children": [
                  {
                    "__typename": "Directory",
                    "name": "drawing-1",
                    "relativePath": "drawing/drawing-1"
                  }
                ]
              }
            },
            {
              "node": {
                "name": "sculpture",
                "relativePath": "sculpture",
                "children": [
                  {
                    "__typename": "Directory",
                    "name": "gaehnschreier",
                    "relativePath": "sculpture/gaehnschreier"
                  }
                ]
              }
            },
            {
              "node": {
                "name": "watercolor",
                "relativePath": "watercolor",
                "children": [
                  {
                    "__typename": "Directory",
                    "name": "portrait-1",
                    "relativePath": "watercolor/portrait-1"
                  },
                  {
                    "__typename": "Directory",
                    "name": "portrait-2",
                    "relativePath": "watercolor/portrait-2"
                  }
                ]
              }
            }
          ]
        }
      }
    }

为便于解释,__typename ... on Directory使您有机会查询整个相应的节点。否则,您将仅获得子节点的ID。为了更好地理解,请访问:https://graphql.org/learn/schema/#union-types