id,page,ref,title,content,breadcrumbs,references
plugin_hooks:plugin-hook-startup,plugin_hooks,plugin-hook-startup,startup(datasette),"This hook fires when the Datasette application server first starts up. You can implement a regular function, for example to validate required plugin configuration: 
             @hookimpl
def startup(datasette):
    config = datasette.plugin_config(""my-plugin"") or {}
    assert (
        ""required-setting"" in config
    ), ""my-plugin requires setting required-setting"" 
             Or you can return an async function which will be awaited on startup. Use this option if you need to make any database queries: 
             @hookimpl
def startup(datasette):
    async def inner():
        db = datasette.get_database()
        if ""my_table"" not in await db.table_names():
            await db.execute_write(
                """"""
                create table my_table (mycol text)
            """"""
            )

    return inner 
             Potential use-cases: 
             
                 
                     Run some initialization code for the plugin 
                 
                 
                     Create database tables that a plugin needs on startup 
                 
                 
                     Validate the metadata configuration for a plugin on startup, and raise an error if it is invalid 
                 
             
             
                 If you are writing  unit tests  for a plugin that uses this hook and doesn't exercise Datasette by sending
                    any simulated requests through it you will need to explicitly call  await ds.invoke_startup()  in your tests. An example: 
                 @pytest.mark.asyncio
async def test_my_plugin():
    ds = Datasette()
    await ds.invoke_startup()
    # Rest of test goes here 
             
             Examples:  datasette-saved-queries ,  datasette-init","[""Plugin hooks""]","[{""href"": ""https://datasette.io/plugins/datasette-saved-queries"", ""label"": ""datasette-saved-queries""}, {""href"": ""https://datasette.io/plugins/datasette-init"", ""label"": ""datasette-init""}]"