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    gatsby-source-filesystem
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    4.0.0 • Public • Published

    gatsby-source-filesystem

    A Gatsby source plugin for sourcing data into your Gatsby application from your local filesystem.

    The plugin creates File nodes from files. The various "transformer" plugins can transform File nodes into various other types of data e.g. gatsby-transformer-json transforms JSON files into JSON data nodes and gatsby-transformer-remark transforms markdown files into MarkdownRemark nodes from which you can query an HTML representation of the markdown.

    Install

    npm install gatsby-source-filesystem

    How to use

    // In your gatsby-config.js
    module.exports = {
      plugins: [
        // You can have multiple instances of this plugin
        // to read source nodes from different locations on your
        // filesystem.
        //
        // The following sets up the Jekyll pattern of having a
        // "pages" directory for Markdown files and a "data" directory
        // for `.json`, `.yaml`, `.csv`.
        {
          resolve: `gatsby-source-filesystem`,
          options: {
            name: `pages`,
            path: `${__dirname}/src/pages/`,
          },
        },
        {
          resolve: `gatsby-source-filesystem`,
          options: {
            name: `data`,
            path: `${__dirname}/src/data/`,
            ignore: [`**/\.*`], // ignore files starting with a dot
          },
        },
      ],
    }

    Options

    In addition to the name and path parameters you may pass an optional ignore array of file globs to ignore.

    They will be added to the following default list:

    **/*.un~
    **/.DS_Store
    **/.gitignore
    **/.npmignore
    **/.babelrc
    **/yarn.lock
    **/node_modules
    ../**/dist/**
    

    To prevent concurrent requests overload of processRemoteNode, you can adjust the 200 default concurrent downloads, with GATSBY_CONCURRENT_DOWNLOAD environment variable.

    How to query

    You can query file nodes like the following:

    {
      allFile {
        edges {
          node {
            extension
            dir
            modifiedTime
          }
        }
      }
    }

    To filter by the name you specified in the config, use sourceInstanceName:

    {
      allFile(filter: { sourceInstanceName: { eq: "data" } }) {
        edges {
          node {
            extension
            dir
            modifiedTime
          }
        }
      }
    }

    Helper functions

    gatsby-source-filesystem exports three helper functions:

    • createFilePath
    • createRemoteFileNode
    • createFileNodeFromBuffer

    createFilePath

    When building pages from files, you often want to create a URL from a file's path on the file system. E.g. if you have a markdown file at src/content/2018-01-23-an-exploration-of-the-nature-of-reality/index.md, you might want to turn that into a page on your site at example.com/2018-01-23-an-exploration-of-the-nature-of-reality/. createFilePath is a helper function to make this task easier.

    createFilePath({
      // The node you'd like to convert to a path
      // e.g. from a markdown, JSON, YAML file, etc
      node,
      // Method used to get a node
      // The parameter from `onCreateNode` should be passed in here
      getNode,
      // The base path for your files.
      // It is relative to the `options.path` setting in the `gatsby-source-filesystem` entries of your `gatsby-config.js`.
      // Defaults to `src/pages`. For the example above, you'd use `src/content`.
      basePath,
      // Whether you want your file paths to contain a trailing `/` slash
      // Defaults to true
      trailingSlash,
    })

    Example usage

    The following is taken from Gatsby Tutorial, Part Seven and is used to create URL slugs for markdown pages.

    const { createFilePath } = require(`gatsby-source-filesystem`)
    
    exports.onCreateNode = ({ node, getNode, actions }) => {
      const { createNodeField } = actions
      // Ensures we are processing only markdown files
      if (node.internal.type === "MarkdownRemark") {
        // Use `createFilePath` to turn markdown files in our `data/faqs` directory into `/faqs/slug`
        const relativeFilePath = createFilePath({
          node,
          getNode,
          basePath: "data/faqs/",
        })
    
        // Creates new query'able field with name of 'slug'
        createNodeField({
          node,
          name: "slug",
          value: `/faqs${relativeFilePath}`,
        })
      }
    }

    createRemoteFileNode

    When building source plugins for remote data sources such as headless CMSs, their data will often link to files stored remotely that are often convenient to download so you can work with them locally.

    The createRemoteFileNode helper makes it easy to download remote files and add them to your site's GraphQL schema.

    createRemoteFileNode({
      // The source url of the remote file
      url: `https://example.com/a-file.jpg`,
    
      // The id of the parent node (i.e. the node to which the new remote File node will be linked to.
      parentNodeId,
    
      // Gatsby's cache which the helper uses to check if the file has been downloaded already. It's passed to all Node APIs.
      getCache,
    
      // The action used to create nodes
      createNode,
    
      // A helper function for creating node Ids
      createNodeId,
    
      // OPTIONAL
      // Adds htaccess authentication to the download request if passed in.
      auth: { htaccess_user: `USER`, htaccess_pass: `PASSWORD` },
    
      // OPTIONAL
      // Adds extra http headers to download request if passed in.
      httpHeaders: { Authorization: `Bearer someAccessToken` },
    
      // OPTIONAL
      // Sets the file extension
      ext: ".jpg",
    })

    Example usage

    The following example is pulled from gatsby-source-wordpress. Downloaded files are created as File nodes and then linked to the WordPress Media node, so it can be queried both as a regular File node and from the localFile field in the Media node.

    const { createRemoteFileNode } = require(`gatsby-source-filesystem`)
    
    exports.downloadMediaFiles = ({
      nodes,
      getCache,
      createNode,
      createNodeId,
      _auth,
    }) => {
      nodes.map(async node => {
        let fileNode
        // Ensures we are only processing Media Files
        // `wordpress__wp_media` is the media file type name for WordPress
        if (node.__type === `wordpress__wp_media`) {
          try {
            fileNode = await createRemoteFileNode({
              url: node.source_url,
              parentNodeId: node.id,
              getCache,
              createNode,
              createNodeId,
              auth: _auth,
            })
          } catch (e) {
            // Ignore
          }
        }
    
        // Adds a field `localFile` to the node
        // ___NODE appendix tells Gatsby that this field will link to another node
        if (fileNode) {
          node.localFile___NODE = fileNode.id
        }
      })
    }

    The file node can then be queried using GraphQL. See an example of this in the gatsby-source-wordpress README where downloaded images are queried using gatsby-transformer-sharp to use in the component gatsby-image.

    Retrieving the remote file name and extension

    The helper tries first to retrieve the file name and extension by parsing the url and the path provided (e.g. if the url is https://example.com/image.jpg, the extension will be inferred as .jpg and the name as image). If the url does not contain an extension, we use the file-type package to infer the file type. Finally, the name and the extension can be explicitly passed, like so:

    createRemoteFileNode({
      // The source url of the remote file
      url: `https://example.com/a-file-without-an-extension`,
      parentNodeId: node.id,
      getCache,
      createNode,
      createNodeId,
      // if necessary!
      ext: ".jpg",
      name: "image",
    })

    createFileNodeFromBuffer

    When working with data that isn't already stored in a file, such as when querying binary/blob fields from a database, it's helpful to cache that data to the filesystem in order to use it with other transformers that accept files as input.

    The createFileNodeFromBuffer helper accepts a Buffer, caches its contents to disk, and creates a file node that points to it.

    Example usage

    The following example is adapted from the source of gatsby-source-mysql:

    // gatsby-node.js
    const createMySqlNodes = require(`./create-nodes`)
    
    exports.sourceNodes = async ({ actions, createNodeId, getCache }, config) => {
      const { createNode } = actions
      const { conn, queries } = config
      const { db, results } = await query(conn, queries)
    
      try {
        queries
          .map((query, i) => ({ ...query, ___sql: results[i] }))
          .forEach(result =>
            createMySqlNodes(result, results, createNode, {
              createNode,
              createNodeId,
              getCache,
            })
          )
        db.end()
      } catch (e) {
        console.error(e)
        db.end()
      }
    }
    
    // create-nodes.js
    const { createFileNodeFromBuffer } = require(`gatsby-source-filesystem`)
    const createNodeHelpers = require(`gatsby-node-helpers`).default
    
    const { createNodeFactory } = createNodeHelpers({ typePrefix: `mysql` })
    
    function attach(node, key, value, ctx) {
      if (Buffer.isBuffer(value)) {
        ctx.linkChildren.push(parentNodeId =>
          createFileNodeFromBuffer({
            buffer: value,
            getCache: ctx.getCache,
            createNode: ctx.createNode,
            createNodeId: ctx.createNodeId,
          })
        )
        value = `Buffer`
      }
    
      node[key] = value
    }
    
    function createMySqlNodes({ name, __sql, idField, keys }, results, ctx) {
      const MySqlNode = createNodeFactory(name)
      ctx.linkChildren = []
    
      return __sql.forEach(row => {
        if (!keys) keys = Object.keys(row)
    
        const node = { id: row[idField] }
    
        for (const key of keys) {
          attach(node, key, row[key], ctx)
        }
    
        node = ctx.createNode(node)
    
        for (const link of ctx.linkChildren) {
          link(node.id)
        }
      })
    }
    
    module.exports = createMySqlNodes

    Troubleshooting

    In case that due to spotty network, or slow connection, some remote files fail to download. Even after multiple retries and adjusting concurrent downloads, you can adjust timeout and retry settings with these environment variables:

    • GATSBY_STALL_RETRY_LIMIT, default: 3
    • GATSBY_STALL_TIMEOUT, default: 30000
    • GATSBY_CONNECTION_TIMEOUT, default: 30000

    Install

    npm i gatsby-source-filesystem

    DownloadsWeekly Downloads

    353,148

    Version

    4.0.0

    License

    MIT

    Unpacked Size

    98.6 kB

    Total Files

    15

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