Gatsby: [gatsby-transformer-javascript-frontmatter] Improve README and add peer dependencies

[jlengstorf]

Currently, gatsby-transformer-javascript-frontmatter doesn’t warn when gatsby-source-filesystem isn’t configured; instead, it just fails silently.

To fix this, we need to:

• [ ] Improve the README by including the filesystem plugin in the install step
• [ ] Add the filesystem config to the plugin config example
• [ ] Add gatsby-source-filesystem to peerDependencies in gatsby-transformer-javascript-frontmatter to warn developers if they’ve left it out

Plugin config example:

module.exports = {
  plugins: [
    {
      resolve: `gatsby-source-filesystem`,
      options: {
        name: `pages`,
        path: `${__dirname}/src/pages/`
      }
    },
    'gatsby-transformer-javascript-frontmatter'
  ]
}

This would make a great first issue for someone!

[TylerBarnes]

@jlengstorf thanks for being so on top of things! I was actually aware of the gatsby-source-filesystem requirement and I'm able to query the frontmatter using the plugin. It's definitely a good idea to add what you've listed though.

The problem I'm having is that I can't figure out how to connect the queried data to pages that are using the javascript files that have frontmatter. I have pages that are generated by other source plugins and they're using a javascript template that has frontmatter. I can't figure out for the life of me how to actually use the frontmatter in a page though. I'm wanting to pass the frontmatter to page context in gatsby node but following the tutorials and reading the guides doesn't help me unfortunately.

[rfbotto]

I would like to tackle this one, if that's okay @jlengstorf :)

[TylerBarnes]

This issue was opened based on my comment in another issue but this issue doesn't actually solve the problem I was having there. Should this be closed? Should I open a different issue?

[jlengstorf]

@TylerBarnes I think it might be worth opening a new issue or asking @DSchau on Discord. This issue isn't really scoped for the problem you're describing, so we should get something open to capture it directly.

[TylerBarnes]

@jlengstorf thanks again for all the awesome support you guys are doing! I ended up learning how to use the context api and realized it makes much more sense for what I'm trying to do.

A Gatsby example of using javascript frontmatter in combination with another source plugin still might be helpful for someone in the future though.

[jlengstorf]

@TylerBarnes could you share your final code with me? I'd love to see how you're using the Context API for page transitions.

[TylerBarnes]

@jlengstorf I spent a bunch of time on it over the weekend and I'm packaging up a demonstration plugin as a kind of working proof of concept. I'll post it up for you once I get something worth looking at.