[WIP] Webview

[kellrott]

This will create a web based UI to view and edit sifter transform files. The web UI is a next.js app written in the sifter-view folder. It will be compiled is a static distribution ( using npm run build ) and then the resulting dist directory will be added to the build using the Go Embed system ( https://gobyexample.com/embed-directive ).

The UI can serve all of the transform files in a directory with the command:

sifter web ./examples/

To have it use a custom website, add the --site-dir ./sifter-view/dist/ argument

Todos:

• Connect viewer to actual listing of playbooks (current version has hard coded demo pipeline)
• Enhance editor nodes so they have fields that represent the inputs for the various step types
• Editor panels for the input and output nodes
• Ensure that each pipeline starts with a from statement and given them a dropdown box of possible inputs
  • Disable default react-flow edge drawing (or figure out how to connect it to the from nodes, and limit to single inputs)
• Add 'sample' method to sifter runtime. This would record the values passed between pipelines and each of the steps. Intended to be like the 'debug' steps, but everywhere automatically. A pipeline would be run, and the first N records (ie 10 or maybe all..) would be recorded. They would then be available to integration into the UI. Users would be able to edit a transform pipeline, have it run, and then see what the data looked like at each step of the transform.
• Create a add new pipeline button
• Mechanism to save playbook back to disk (figure out backup strategy?)