Markdown in Gatsby

Gatsby allows you to build sites from many different data sources. Currently Tina has plugins for editing content in Markdown & JSON files, with plans to support many more data sources.

Have an idea for a Tina content editing plugin? Consider contributing! Check out how to create your own form or field plugin.

Editing Markdown in Gatsby

The gatsby-transformer-remark plugin lets us use Markdown in our Gatsby sites. Two other plugins let us edit Markdown with Tina:

  • gatsby-tinacms-remark: Provides hooks and components for creating Remark forms.
  • gatsby-tinacms-git: Extends the gatsby development server to write changes to the local filesystem.

This guide assumes your Gatsby site is already setup to use Markdown. Check out the Gatsby Docs to learn how to use Markdown in your site.

Install the Git & Markdown Packages

npm install --save gatsby-tinacms-remark gatsby-tinacms-git

or

yarn add gatsby-tinacms-remark gatsby-tinacms-git

Adding the Git Plugin

Open the gatsby-config.js file and add both plugins:

module.exports = {
  // ...
  plugins: [
    {
      resolve: 'gatsby-plugin-tinacms',
      options: {
        plugins: [
          "gatsby-tinacms-git",
          "gatsby-tinacms-remark",
        ],
      },
    },
    // ...
  ],
}

Creating Remark Forms

There are three ways to register remark forms with the CMS, depending on the component:

All of these options can only take data (transformed by gatsby-transformer-remark) from a markdownRemark query. If you need more information on using Markdown in Gatsby, refer to this documentation.

If you're adding Tina to a page component in Gatsby, skip to remarkForm.

1. The Hook: useRemarkForm

This hook connects the markdownRemark data with Tina to be made editable. It is useful in situations where you need to edit on non-page components, or just prefer working with hooks or static queries. You can also use this hook with functional page components.

Usage:

useRemarkForm(remark, options): [values, form]

Arguments:

  • remark: The data returned from a Gatsby markdownRemark query.
  • options: A configuration object that can include form options or form actions (such as the DeleteAction)— optional.

Return:

  • [values, form]
    • values: The current values to render in the template. This has the same shape as the markdownRemark data.
    • form: A reference to the Form. Most of the time you won't need to directly work with the Form.
/*
 ** example component --> src/components/Title.js
 */

// 1. import useRemarkForm and usePlugin
import { useRemarkForm } from 'gatsby-tinacms-remark'
import { usePlugin } from 'tinacms'
import { useStaticQuery } from 'gatsby'

const Title = data => {
  // 2. Add required GraphQL fragment
  const data = useStaticQuery(graphql`
    query TitleQuery {
      markdownRemark(fields: { slug: { eq: "song-of-myself" } }) {
        ...TinaRemark
        frontmatter {
          title
        }
      }
    }
  `)

  // 3. Call the hook and pass in the data
  const [markdownRemark, form] = useRemarkForm(data.markdownRemark)

  // 4. Register the form plugin
  usePlugin(form)

  return <h1>{markdownRemark.frontmatter.title}</h1>
}

export default Title

To use this hook, you'll first need to import it from gatsby-tinacms-remark. Then you'll need to add the GraphQL fragment ...TinaRemark to your query. The fragment adds these parameters: id, fileRelativePath, rawFrontmatter, and rawMarkdownBody. Finally you'll call the hook and pass in the markdownRemark data.

The form will populate with default text fields. To customize it, you can pass in a config options object as the second parameter. Jump ahead to learn more on customizing the form.

2. The Render Props Component: RemarkForm

RemarkForm is a thin wrapper around useRemarkForm and usePlugin. Since React Hooks are only available within function components you will need to use RemarkForm instead of calling those hooks directly working with a class component.

Props:

  • remark: the data returned from a Gatsby markdownRemark query.
  • render(renderProps): JSX.Element: A function that returns JSX elements
    • renderProps.markdownRemark: The current values to be displayed. This has the same shape as the markdownRemark data that was passed in.
    • renderProps.form: A reference to the Form.

You can use this with both page and non-page components in Gatsby. Below is an example of using RemarkForm in a non-page component using StaticQuery.

/*
 ** example component --> src/components/Title.js
 */
import { StaticQuery, graphql } from 'gatsby'

// 1. import RemarkFrom
import { RemarkForm } from 'gatsby-tinacms-remark'

class Title extends React.Component {
  render() {
    return (
      <StaticQuery
        // 2. add ...TinaRemark fragment to query
        query={graphql`
          query TitleQuery {
            markdownRemark(fields: { slug: { eq: "song-of-myself" } }) {
              ...TinaRemark
              frontmatter {
                title
              }
            }
          }
        `}
        render={data => (
          /*
           ** 3. Return RemarkForm, pass in the props
           **    and then return the JSX this component
           **    should render
           */
          <RemarkForm
            remark={data.markdownRemark}
            render={({ markdownRemark }) => {
              return <h1>{markdownRemark.frontmatter.title}</h1>
            }}
          />
        )}
      />
    )
  }
}

export default Title

Here is another example using RemarkForm with a page component:

/*
 ** src/templates/blog-post.js
 */

// 1. import RemarkForm
import { RemarkForm } from '@tinacms/gatsby-tinacms-remark'

class BlogPostTemplate extends React.Component {
  render() {
    /*
     ** 2. Return RemarkForm, pass in markdownRemark
     **    as props and return the jsx this component
     **    should render
     */
    return (
      <RemarkForm
        remark={this.props.data.markdownRemark}
        render={({ markdownRemark }) => {
          return <h1>{markdownRemark.frontmatter.title}</h1>
        }}
      />
    )
  }
}

export default BlogPostTemplate

// 3. Add ...TinaRemark fragment to query
export const pageQuery = graphql`
  query {
    markdownRemark(fields: { slug: { eq: $slug } }) {
      ...TinaRemark
      frontmatter {
        title
      }
    }
  }
`

Learn how to customize the fields displayed in the form below.

3. The Higher-Order Component: remarkForm

The remarkForm higher-order component (HOC) let's us register forms with Tina on Gatsby page components.

There are 3 steps to making a Markdown file editable with remarkForm:

  1. Import the remarkForm HOC
  2. Wrap your template with remarkForm
  3. Add ...TinaRemark to the GraphQL query

Required fields used to be queried individually: id, fileRelativePath, rawFrontmatter, & rawMarkdownBody. The same fields are now being queried via ...TinaRemark

Example: src/templates/blog-post.js

// 1. Import the `remarkForm` HOC
import { remarkForm } from 'gatsby-tinacms-remark'

function BlogPostTemplate(props) {
  return <h1>{props.data.markdownRemark.frontmatter.title}</h1>
}

// 2. Wrap your template with `remarkForm`
export default remarkForm(BlogPostTemplate)

// 3. Add the required fields to the GraphQL query
export const pageQuery = graphql`
  query BlogPostBySlug($slug: String!) {
    markdownRemark(fields: { slug: { eq: $slug } }) {
      id
      html
      frontmatter {
        title
        date
        description
      }
      ...TinaRemark
    }
  }
`

You should now see text inputs for each of your front matter fields and for the Markdown body. Try changing the title and see what happens!

Queries aliasing 'markdownRemark'

NOTE: If your query uses an alias for 'markdownRemark', then you will have to use the 'queryName' option to specify the alias name.

Example: src/templates/blog-post.js

/// ...

// Use 'queryName' to specify where markdownRemark is found.
export default remarkForm(BlogPostTemplate, { queryName: 'myContent' })

// Aliasing markdownRemark as 'myContent'
export const pageQuery = graphql`
  query BlogPostBySlug($slug: String!) {
    myContent: markdownRemark(fields: { slug: { eq: $slug } }) {
      // ...
    }
  }
`

Editing Markdown Content

With the Remark Form created, you can now edit your Markdown file in the Tina sidebar. The markdown component is CommonMark compatible. Content changes are written to the Markdown files in real time. Hitting Save will commit those changes to your repository.

Why write to disk "on change"?

This allows any gatsby-remark-* plugins to properly transform the data in to a remark node and provide a true-fidelity preview of the changes.

Customizing Remark Forms

Tina's remark hook or components create the form based on the shape of the data. This is convenient for getting started but you will want to customize the form eventually to make it more user friendly.

Why customize the form?

  1. The default label for a field is it's name.
  2. Every field is made a text component.
  3. The order of fields might not be consistent.

How to customize the form

You can pass additional configuration options to customize the form. The following properties are accepted:

  • label: A label for the form that will render in a list if there are multiple forms. This will default to the name of the component.
  • actions: A list of form actions, such as DeleteAction.
  • fields: A list of field definitions
    • name: The path to some value in the data being edited. (e.g. frontmatter.title)
    • component: The name of the React component that should be used to edit this field. The default options are: "text", "textarea", "color".
    • label: A human readable label for the field.
    • description: An optional description that expands on the purpose of the field or prompts a specific action.

remarkForm HOC Example

The remarkForm HOC and useRemarkForm hook both accept an optional config object as the second argument.

/*
 ** src/templates/blog-post.js
 */

import { remarkForm } from 'gatsby-tinacms-remark'

function BlogPostTemplate(props) {
  return (
    <>
      <h1>{props.markdownRemark.frontmatter.title}</h1>
      <p>{props.markdownRemark.frontmatter.description}</p>
    </>
  )
}

// 1. Define the form config
const BlogPostForm = {
  label: 'Blog Post',
  fields: [
    {
      label: 'Title',
      name: 'frontmatter.title',
      description: 'Enter the title of the post here',
      component: 'text',
    },
    {
      label: 'Description',
      name: 'frontmatter.description',
      description: 'Enter the post description',
      component: 'textarea',
    },
  ],
}

// 2. Pass it as a the second argument to `remarkForm`
export default remarkForm(BlogPostTemplate, BlogPostForm)

useRemarkForm Hook Example

import { useRemarkForm } from 'gatsby-tinacms-remark'

function BlogPostTemplate(props) {
  // 1. Define the form
  const BlogPostForm = {
    label: 'Blog Post',
    fields: [
      {
        label: 'Title',
        name: 'frontmatter.title',
        description: 'Enter the title of the post here',
        component: 'text',
      },
      {
        label: 'Description',
        name: 'frontmatter.description',
        description: 'Enter the post description',
        component: 'textarea',
      },
    ],
  }

  // 2. Pass the form as the second argument
  const [markdownRemark, form] = useRemarkForm(
    props.markdownRemark,
    BlogPostForm
  )

  // 3. Register the form as a plugin
  usePlugin(form)

  return (
    <>
      <h1>{markdownRemark.frontmatter.title}</h1>
      <p>{markdownRemark.frontmatter.description}</p>
    </>
  )
}

export default BlogPostTemplate

RemarkForm Render Props Example

For the RemarkFormcomponent, you pass in the config options individually as props to the render function.

import { RemarkForm } from 'gatsby-tinacms-remark'

class BlogPostTemplate extends React.Component {
  render() {
    return (
      <RemarkForm
        remark={this.props.data.markdownRemark}
        render={({ markdownRemark }) => {
          return (
            <>
              <h1>{markdownRemark.frontmatter.title}</h1>
              <p>{markdownRemark.frontmatter.description}</p>
            </>
          )
        }}
        label="Blog Post"
        fields={[
          {
            label: 'Title',
            name: 'frontmatter.title',
            description: 'Enter the title of the post here',
            component: 'text',
          },
          {
            label: 'Description',
            name: 'frontmatter.description',
            description: 'Enter the post description',
            component: 'textarea',
          },
        ]}
      />
    )
  }
}

export default BlogPostTemplate

Avoiding Errors Caused by Empty Fields

If a value is empty from a source file, for example an empty string, Tina will delete the entire key-value pair from the file. This will cause Gatsby to throw a GraphQL error, since it's trying to query a field that doesn't exist. If you're editing in Tina and you completely delete the text from a field, you may see this error.

This may not be a problem if you have a query that is running over numerous files with a similar data shape. Let's say you have a collection of recipes, and they all have the same frontmatter data. The recipe pages are generated from a template where this query lives. If a key-value pair gets deleted from one recipe file, the query will still run since there are other files that still have the populated value.

However, if you have a single source file for a page, you will run into issues because this is the only instance of the data shape. If the value is deleted, then GraphQL doesn't know what field it's querying.

To work around this, we need to create either a dummy file or manually override the parse value in the field object by passing in an empty string.

Option 1: Override the parse value

/*
** Override the parse value
** in the field definition object
*/

fields: [
  {
    label: "Favorite Food",
    name: "frontmatter.fav_food",
    component: "text",
    // If there's no value, return empty string
    parse(value) {
      return value || ""
    },
  },...
]

This option will provide an empty string if no value exists, so the frontmatter key/value pair will not get fully deleted from the source file.

Option 2: Creating a Dummy File

This second option involves creating a dummy source file with the same shape of data in your real source files, but filled with dummy values. This works best when you're using a template to generate numerous pages.

Check-out this approach implemented in Tina Grande: the dummy file, the other content files files, and the query.

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