The purpose of this Issue is just to give an example use case.

[adpatter]

Our telemetry project, ETC JupyterLab Telemetry Extension, captures user interactions and logs these messages to a specified handler. The ETC JupyterLab Telemetry Example repo gives an example of the service provided by the extension being consumed and the events being logged to console.log.

Presently, we are capturing several user interactions with the Notebook:

• Active Cell Changed
• Cell Added
• Cell Executed
• Cell Removed
• Notebook Opened
• Notebook Saved
• Notebook Scrolled

For each event, a list of cells relevant to the event are captured as well. This is described here. The messages include a list of relevant cells and the present state of the Notebook. Cell contents that have been seen before get replaced with a cell 'ID' in order to save storage space, which allows for the state of the Notebook to be reconstructed at a later time. The reason I point that out is that there might be use cases where multiple schemas could be registered for a single event.

This JSON schema matches the event messages:

{
  "$schema": "http://json-schema.org/draft-04/schema#",
  "type": "object",
  "properties": {
    "event_name": {
      "type": "string"
    },
    "cells": {
      "type": "array",
      "items": [
        {
          "type": "object",
          "properties": {
            "id": {
              "type": "string"
            },
            "index": {
              "type": "integer"
            }
          },
          "required": [
            "id",
            "index"
          ]
        }
      ]
    },
    "notebook": {
      "type": "object",
      "properties": {
        "metadata": {
          "type": "object",
          "properties": {
            "kernelspec": {
              "type": "object",
              "properties": {
                "display_name": {
                  "type": "string"
                },
                "language": {
                  "type": "string"
                },
                "name": {
                  "type": "string"
                }
              },
              "required": [
                "display_name",
                "language",
                "name"
              ]
            },
            "language_info": {
              "type": "object",
              "properties": {
                "codemirror_mode": {
                  "type": "object",
                  "properties": {
                    "name": {
                      "type": "string"
                    },
                    "version": {
                      "type": "integer"
                    }
                  },
                  "required": [
                    "name",
                    "version"
                  ]
                },
                "file_extension": {
                  "type": "string"
                },
                "mimetype": {
                  "type": "string"
                },
                "name": {
                  "type": "string"
                },
                "nbconvert_exporter": {
                  "type": "string"
                },
                "pygments_lexer": {
                  "type": "string"
                },
                "version": {
                  "type": "string"
                }
              },
              "required": [
                "codemirror_mode",
                "file_extension",
                "mimetype",
                "name",
                "nbconvert_exporter",
                "pygments_lexer",
                "version"
              ]
            }
          },
          "required": [
            "kernelspec",
            "language_info"
          ]
        },
        "nbformat_minor": {
          "type": "integer"
        },
        "nbformat": {
          "type": "integer"
        },
        "cells": {
          "type": "array",
          "items": {
            "type": "object",
            "properties": {
              "cell_type": {
                "type": "string"
              },
              "source": {
                "type": "string"
              },
              "metadata": {
                "type": "object",
                "properties": {
                  "trusted": {
                    "type": "boolean"
                  }
                },
                "required": [
                  "trusted"
                ]
              },
              "execution_count": {
                "type": "null"
              },
              "outputs": {
                "type": "array",
                "items": {}
              },
              "id": {
                "type": "string"
              }
            },
            "required": [

              "id"
            ]
          }
        }
      },
      "required": [
        "metadata",
        "nbformat_minor",
        "nbformat",
        "cells"
      ]
    },
    "seq": {
      "type": "integer"
    },
    "notebook_path": {
      "type": "string"
    },
    "user_id": {
      "type": "string"
    }
  },
  "required": [
    "event_name",
    "cells",
    "notebook",
    "seq",
    "notebook_path",
    "user_id"
  ]
}

Please let me know if anyone has any questions regarding our use case.

[adpatter]

I posted this to the wrong repo. I moved it here: jupyter/enhancement-proposals#41