Snowplow Documentation Website

This is the source for https://docs.snowplow.io/docs.

• Contributing
• How to preview locally
• Organizing content
• Formatting content

Contributing

All contributions are welcome, from reporting issues to correcting typos and formatting to full-blown how-tos and guides.

If you are new to Github, the easiest way to propose changes is via the UI.

For more substantial contributions, below you can find tips on how to preview your changes, as well as how to organize and format your content.

How to preview locally

Step 1. Clone this repository.

Step 2 (one-time setup). Install some tools:

brew install node
brew install yarn
# On Linux, use your favorite package manager

Step 3. Install dependencies and start the preview:

yarn
yarn start

(Hitting an error with yarn start? brew upgrade yarn and try again. Yarn might also suggest further commands to update docusaurus.)

Step 4. Go to localhost:3000 in your browser and enjoy!

Organizing content

In this section you’ll find some general tips on how the docs are structured.

Sidebar

The sidebar on the left follows file structure (all docs are in the /docs folder). So when you add new pages, create folders as you see fit.

To control the position of a section in the sidebar, go to the index.md file for that section and adjust the sidebar_position attribute at the top (see this example). Sidebar positions are just numbers, and you can use any number as long as the order is correct.

Offerings

Some documentation is only relevant to a particular offering. You can indicate it like this:

---
title: ...
...
sidebar_custom_props:
  offerings:
    - bdp
...
---

This will result in an icon appearing in the sidebar, as well as an automatic banner on the page, specifying that the docs only apply to a given offering.

The available values are: bdp and community. Do not specify both values at once — if a piece of documentation is relevant to all offerings, there should be no offerings property as that’s the default.

Whenever the same functionality can be achieved in multiple offerings but in a different way (e.g. managing schemas), create a parent folder (“Managing schemas”) that’s offering-neutral, and then add offering-specific pages inside it. This way, other pages can link to the generic page without having to specify different methods for different offerings.

Links

For links within this documentation, please end the link with /index.md. This way all links will be checked, and you’ll get an error if a link is broken at any point.

If you forgot to do this, you can quickly fix a bunch of links by running ./make-links-validatable.sh. (You might need to install the moreutils package via brew install moreutils to get the sponge command.)

Concepts

There are several key concepts in Snowplow: events (self-describing, structured), entities, schemas. We must ensure that we use and explain them consistently.

Please, use up-to-date terms:

• Self-describing event, not unstructured event
• Entities, not contexts (it’s ok-ish to refer to a set of entities as “context”, but only in a casual sense, as in “these provide some context to the event”)
• Failed events and not bad rows, unless specifically referring to the legacy bad row JSON format and associated tooling
• If you are writing about schemas, pick “schema” or “data structure” and stick with it

Please, do not over-explain these in any of your writing. Instead, just link to one of the existing concept pages:

• Events in general: /docs/understanding-your-pipeline/events/index.md
• Custom events: /docs/understanding-your-pipeline/events/index.md#self-describing-events
• Self-describing events: /docs/understanding-your-pipeline/events/index.md#self-describing-events
• Structured events: /docs/understanding-your-pipeline/events/index.md#structured-events
• Entities in general: /docs/understanding-your-pipeline/entities/index.md
• Custom entities: /docs/understanding-your-pipeline/events/index.md#custom-entities
• Schemas: /docs/understanding-your-pipeline/schemas/index.md
• Iglu resolvers/registries: /docs/understanding-your-pipeline/schemas/index.md#iglu
• Failed events: /docs/understanding-your-pipeline/failed-events/index.md

Reusable fragments

You can create reusable fragments and include them in multiple files (see this example).

Versioned modules

Some of our modules are versioned (e.g. trackers, loaders). Here are a few simple rules to follow.

• Within pages for versioned modules, use relative links (e.g. ../setup/index.md) when pointing to pages for the same version. This helps moving directories around without breaking the links.
• For the latest docs, don’t include the version number in the URL. Otherwise we’d need to update internal links to it with every version change (also, it would get indexed and we’ll need to add a redirect later to avoid breaking external links). For example, see the Scala tracker docs — the path ends with scala-tracker rather than scala-tracker-2-0.
• Put older versions in a single folder, e.g. previous-versions/. In the index.md for that folder, add the following:

  sidebar_custom_props:
    outdated: true
  

  This automatically enables the “you are looking at an old version” warning. See the Scala tracker docs for an example of how to add the previous-versions directory and what to put there.
• When a new version is released, you can either update the latest version pages, or move them to previous-versions and replace with the new content. If there are not too many breaking changes, you might want to do the former to avoid having too many previous version directories.
• Put the latest bugfix version for each component into componentVersions.js. This way you only need to update it in one place when a new bugfix release comes out. See the Scala tracker docs for how to then use this on the page. If you need to use them in a markdown table you will have to render it in a particular way for it to work, see the dbt package docs for an example.

Moving pages around

When you move pages around, make sure to add a redirect in static/_redirects. This ensures that any external links pointing to the old URL still work.

To easily accomplish this, you can use ./move.sh. (You might need to install the moreutils package via brew install moreutils to get the sponge command.)

./move.sh docs/old/page/location docs/new/page/location

This command will automatically move the pages, create redirect rules, and add all changes to git.

Note: the script is somewhat brittle, and you need to follow these rules:

• Only run it from the root of the repo
• Use relative paths, starting with docs/ (like above)
• End the path on a directory, rather than an index.md
• Do not include trailing slashes

Formatting content

In this section you’ll find some general tips on how to write the pages.

The documentation is written in Markdown. In addition, since we are using Docusaurus, more features are available. Here are a few of our favorites:

• Use “admonitions” (e.g. :::note) to draw attention to a certain paragraph.
• Use collapsible blocks for information that most readers will want to skip.
• Use code blocks for code, and don’t forget to specify the languange.
• Use tabs for content where multiple alternatives are possible (e.g. iOS code vs Android code). Inside the tabs, try to only put the content that differs.

Formatting your work using prettier

To ensure consistency of our codebase we also utilize prettier to format our source files and enforce correctness in a CI step.

For the best experience set up your IDE to automatically format files on save. Here's a guide for VSCode.

You can also run the formatter command before committing changes manually:

yarn format

Images

We need to ensure that all images are visible in both light and dark themes, if your image does not have a background this can be achieved in a few ways:

• Where possible for diagrams prefer the use of mermaid diagrams as these adjust automatically
• If you are using drawio diagrams, ensure that either the diagram has a non-transparent background, or provide a dark and light mode version using Themed images. If possible also include a copy of your diagram in the image as part of the export to allow easy editing in the future.
• If you are editing a page with an existing diagram you cannot recreate, you can replace the existing image link with the below, which will add the light background even in dark mode. If you do this please also comment on the issue here to let us know so we can try and re-make the diagram in the future.

  <div style={{"background-color": '#F2F4F7'}}>
  <img src={require("./images/IMAGE_NAME.png").default}/>
  </div>

VSCode Snippets

We have created a selection of VSCode Snippets that cover some of the common, but fiddly, blocks of code you may require when writing docs. You can trigger these by starting to type their name and then pressing tab or use Insert Snippet in the Command Palette. All snippets we have created can be found here and we currently have ones for:

• Admonitions
• Collapsible blocks
• Tabs
• Themed images
• DocCards
• Mdx blocks for enabling tabs and themed images
• Front matter