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 --save 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.
// 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,
// The redux store which is passed to all Node APIs.
store,
// Gatsby's cache which the helper uses to check if the file has been downloaded already. It's passed to all Node APIs.
cache,
// 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,
store,
cache,
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,
store,
cache,
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,
store,
cache,
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, store, cache },
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,
store,
cache,
})
)
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,
store: ctx.store,
cache: ctx.cache,
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
Edit this page on GitHub