Hooks

You can extend datasette-ui-extras by writing small Python functions that implement one of these hooks.

edit_control

This hook determines which UI control is shown to edit a value.

def edit_control(
  datasette, # An instance of the Datasette class
  database,  # The database name, e.g. "cooking"
  table,     # The table name, e.g. "posts"
  column,    # The column name, e.g. "tags"
  row,       # A sqlite3.Row with the other values for columns of the row
  value,     # The value being rendered
  metadata   # Stats about the column being rendered
)

We ship several UI controls for editing fields.

By default, we choose which control to show based on your database's schema. Sometimes that choice is ambiguous. For example, if the existing rows are all ones and zeroes, we might show a checkbox control. But perhaps we really ought to have shown a free-form number input.

You can override our choice by implementing this hook.

from datasette_ui_extras import hookimpl

@hookimpl
def edit_control(table, column):
  if table == 'my_table' and column == 'not_a_checkbox':
    return 'NumberControl'

Your function can return:

• None - to use the default behaviour
• a string, like NumberControl - to use the specified JavaScript class to render the control. This can be one of our built-in controls or a custom control that you implement
• a tuple of (string, dict) - to use the specified JavaScript class to render the control, and pass the dict of parameters to it as configuration
• an awaitable function that returns one of the above values

redirect_after_edit

This hook determines where a user is sent after creating, updating or deleting a row.

def redirect_after_edit(
  datasette, # An instance of the Datasette class.
  database,  # The database name, e.g. "cooking"
  table,     # The table name, e.g. "posts"
  action,    # "insert-row", "update-row" or "delete-row"
  pk         # The key of the modified row, eg `1` or `compound,key`
)

The pk value is tilde-encoded.

By default:

• for inserted or updated rows, the user is redirected to the row page
• for deleted rows, the user is redirected to the table page

You can customize this to create purpose-built workflows for editing:

from datasette_ui_extras import hookimpl
from datasette.database import MultipleValues

@hookimpl
def redirect_after_edit(datasette, database, table):
  async def inner():
    next_row = await datasette.databases[database].execute(
      'SELECT id FROM turker_queue LIMIT 1'
    )

    try:
      return '{}/{}'.format(
        datasette.urls.table(database, table),
        next_row.single_value()
      )
    except MultipleValues:
      return '/congratulations-no-more-work'

  if table == 'turker_queue':
    return inner