squirrels.parameters or the squirrels module.
Factory methods
Factory methods are class methods that create and configure parameter instances. These methods are typically used in thepyconfigs/parameters.py file to create the parameter configurations (which describes the “shape” of the parameter but does not include the realtime user selections).
create_simple()
Decorator for creating a simple parameter from a function that returns select options. The decorated function must return a list of SelectParameterOption objects.create_with_options()
Decorator for creating a parameter with options that can vary based on user attributes or parent parameter selections. The decorated function must return a list of SelectParameterOption objects. This is functionally equivalent tocreate_simple but with additional arguments available for user_attribute and parent_name.
create_from_source()
Decorator for creating a parameter populated from a database table or query using a SelectDataSource. The decorated function must return a SelectDataSource object.Instance methods
Instance methods are available on parameter instances at query time (incontext.py or data models) to retrieve selected values.
get_selected_list() -> Sequence[SelectParameterOption]
Gets the sequence of selected SelectParameterOption objects.Sequence[SelectParameterOption]
A sequence of selected SelectParameterOption objects.
get_selected_list() -> Sequence[Any]
Gets the sequence of selected custom fields.Sequence[Any]
A sequence of custom field values, or an empty sequence if no options are selected (unless
none_is_all is True, in which case all options are returned).get_selected_ids_as_list()
Gets the sequence of ID(s) of the selected option(s).Sequence[str]
A sequence of ID strings of the selected options.
has_non_empty_selection()
Returns True if more than zero options were selected. False otherwise. Note that even when this returns False, all methods starting with “get_selected” would return the full list of options ifnone_is_all is set to True.
bool
True if at least one option is selected, False otherwise.
is_enabled()
Returns whether the parameter is enabled. A parameter is enabled if it has at least one selectable option.bool
True if the parameter has at least one selectable option, False otherwise.
Examples for factory methods
All examples below are defined in thepyconfigs/parameters.py file.
Using create_simple for basic multi-select
For parameters that don’t need user-specific or parent-dependent options, you can usecreate_simple.
Cascading multi-select with parent dependency
This example shows how multi-select options can change based on a parent parameter selection.User-specific multi-select options
This example shows different options based on user access levels.pyconfigs/user.py, then they can be used to restrict visibility of parameter options as well. To do so, the user_attribute argument must be prefixed with custom_fields..
Multi-select from database source
This example populates multi-select options from a database table.Cascading multi-select from database
This example shows a multi-select that depends on a parent parameter, both populated from database sources.Examples for instance methods
Once parameters are configured, you can use instance methods in your models to access the selected values. The parameter instances are available through the context object (e.g.,sqrl.prms).
Basic usage in context.py
Basic usage in Jinja SQL models
The following example works but is not recommended. See tip below for why.Accessing custom fields
Suppose you define a multi-select parameter with custom fields as such:context.py as follows: