lino.core.actors

This defines Actor and related classes.

See Introduction to actors.

(This module's source code is available here.)

Functions

discover()
field_getter(name)
register_actor(a)	Internally called during startup process to insert a actor class in the global actors_list and actors_dict.
resolve_action(spec[, action])	Return the BoundAction object corresponding to the given specifier spec.

Classes

Actor(*args, **kw)	The base class for all actors.
ActorMetaClass(classname, bases, classDict)

lino.core.actors.register_actor(a)

Internally called during startup process to insert a actor class in the global actors_list and actors_dict.

Special attention is given to the case when a plugin extends another plugin and redefines an actor of same name. In that case we want the ordering to remain as it was from the beginning. Actor overrides are not appended to the end but replaced, in order to not disturb the finding of _lino_default_table.

class lino.core.actors.Actor(*args, **kw)

Bases: lino.core.actors.NewBase

The base class for all actors. Subclassed by AbstractTable, Table, ChoiceList and Frame.

label

The text to appear e.g. on a button that will call the default action of an actor. This attribute is not inherited to subclasses. For Actor subclasses that don't have a label, Lino will call get_actor_label().

known_values

A dict of fieldname -> value pairs that specify "known values".

Requests will automatically be filtered to show only existing records with those values. This is like filter, but new instances created in this Table will automatically have these values set.

welcome_message_when_count

Set this to an integer (e.g. 0) to tell Lino to make a generic welcome message "You have X items in Y" when the number of rows in this table is greater than the given integer.

The following class methods are None in the default implementation. Subclass can define them.

classmethod get_handle_name(self, ar)

Most actors use the same UI handle for each request. But e.g. lino_welfare.modlib.debts.models.PrintEntriesByBudget and lino_xl.lib.events.EventsByType override this to implement dynamic columns depending on it's master_instance.

classmethod get_row_classes(self, ar)

If a method of this name is defined on an actor, then it must be a class method which takes an ar as single argument and returns either None or a string "red", "green" or "blue" (todo: add more colors and styles). Example:

@classmethod
def get_row_classes(cls,obj,ar):
    if obj.client_state == ClientStates.newcomer:
        return 'green'

Defining this method will cause an additional special RowClassStoreField field in the lino.core.Store objects of this actor.

classmethod get_welcome_messages(self, ar)

If a method of this name is defined on an actor, then it must be a class method which takes an ar as single argument and returns or yields a list of welcome messages (messages to be displayed in the welcome block of admin_main.html).

Note that this handler will be called independently of whether the user has permission to view the actor or not.

required_roles = {<class 'lino.core.roles.SiteUser'>}

See lino.core.permissions.Permittable.required_roles

model = None

The model on which this table iterates.

The application programmer can specify either the model class itself or a string of type 'app.Model'.

This should be None on all tables which are not subclass of lino.core.dbtables.Table.

actions = None

An AttrDict containing the actions available on this actor.

app_label = 'core'

Specify this if you want to "override" an existing actor.

The default value is deduced from the module where the subclass is defined.

Note that this attribute is not inherited from base classes.

lino.core.table.table_factory() also uses this.

master = None

The class of the "master" for this actor.

Application code usually doesn't need to specify this because it is automatically set on actors whose master_key is specified.

Setting this to something else than None will turn the table into a slave table.

If the master is something else than a database model (e.g. a ChoiceList), then the actor must also define a get_master_instance() method.

master_key = None

The name of a field of this table's model that points to its master.

The field named by master_key should usually be a ForeignKey field.

Special cases: lino_xl.lib.cal.EntriesByGuest shows the entries having a presence pointing to this guest.

Note that the master_key is automatically added to hidden_columns.

parameters = None

See lino.core.utils.Parametrizable.parameters.

ignore_required_states = False

Whether to ignore the required states of workflow actions.

Set this to True on a workflow if you want to disable workflow control based on the state of the object.

Note that you must set this to True before importing any library workflows because permission handlers are defined when a workflow is imported.

sort_index = 60

The sort_index to be used when this table is being used by a ShowSlaveTable.

icon_name = None

The lino.core.actions.Action.icon_name to be used for a lino.core.actions.ShowSlaveTable action on this actor.

simple_parameters = None

A tuple of names of filter parameters which are handled automatically.

Application developers should not set this attribute directly, they should rather define a get_simple_parameters() on the model.

hidden_elements = frozenset({})

A set of names of layout elements which are hidden by default.

The default is an empty set except for lino.core.dbtables.Table where this will be populated from hidden_elements of the lino.core.model.Model.

Note that these names are not being verified to be names of existing fields. This fact is being used by UNION tables like lino_xl.lib.vat.IntracomInvoices

detail_html_template = 'bootstrap3/detail.html'

The template to be used for rendering a row of this actor as a detail html page.

list_html_template = 'bootstrap3/table.html'

The template to be used for rendering a collection of rows of this actor as a table html page.

window_size = None

Set this to a tuple of (height, width) to have this actor display in a modal non-maximized window.

• height must be either an integer expressing a number of rows or the string "auto". If it is auto, then the window should not contain any v-flexible component.

• width must be either an integer expressing a number of rows or a string of style "90%".

  Note that a relative width will be converted to a number of pixels when the window is rendered for the first time. That is, if you close the window, resize your browser window and reopen the same window, you will get the old size.

editable = None

Set this explicitly to True or False to make the whole table editable or not. Otherwise Lino will guess what you want during startup and set it to False if the actor is a Table and has a get_data_rows method (which usually means that it is a virtual table), otherwise to True.

Non-editable actors won't even call get_view_permission() for actions whose readonly is False.

The changes.Changes table is an example where this is being used: nobody should ever edit something in the table of Changes. The user interface uses this to generate optimized JS code for this case.

auto_apply_params = True

Whether the parameter values of the parameter panel should be applied automatically when some value has been changed.

insert_layout_width = 60

When specifying an insert_layout using a simple a multline string, then Lino will instantiate a FormPanel with this width.

hide_window_title = False

This is set to True e.h. in home pages (e.g. lino_welfare.modlib.pcsw.models.Home).

allow_create = True

If this is False, the table won't have any insert_action.

hide_headers = False

Set this to True in order to hide the column headers.

This is ignored when the table is rendered in an ExtJS grid.

hide_top_toolbar = False

Whether a Detail Window should have navigation buttons, a "New" and a "Delete" buttons. In ExtJS UI also influences the title of a Detail Window to specify only the current element without prefixing the Tables's title.

If used in a grid view in React will remove the top toolbar and selection tools.

This option is True in lino.models.SiteConfigs, lino_welfare.pcsw.models.Home, lino.modlib.users.desktop.MySettings, lino_xl.cal.CalenderView.

simple_slavegrid_header = False

If True the slave grid in a detail will be simplified

paginator_template = None

Paginator elements can be customized using the template property using the predefined keys, default value is "FirstPageLink PrevPageLink PageLinks NextPageLink LastPageLink RowsPerPageDropdown". Here are the available elements that can be placed inside a paginator.

FirstPageLink PrevPageLink PageLinks NextPageLink LastPageLink RowsPerPageDropdown CurrentPageReport

title = None

The text to appear e.g. as window title when the actor's default action has been called. If this is not set, Lino will use the label as title.

button_text = None

The text to appear on buttons of a ShowSlaveTable action for this actor.

detail_layout = None

Define the layout to use for the detail window. Actors with detail_layout will get a show_detail action.

When you define a detail_layout, you will probably also want to define a insert_layout.

The detail_layout is normally an instance of DetailLayout or a subclass thereof. For example:

class FooDetail(dd.DetailLayout):
    ...

class Foos(dd.Table):
    ...
    detail_layout = FooDetail()

It is possible and recommended to specify detail_layout as a string, in which case it will be resolved at startup as follows:

If the string contains at least one newline (or no newline and also no dot) then it is taken as the main of a DetailLayout. For example:

class Foos(dd.Table):
    ...
    detail_layout = """
    id name
    description
    """

If the string contains a dot ('.') and does not contain any newlines, then Lino takes this as the name of the class to be instantiated and used.

For example:

class Courses(dd.Table):
    ...
    detail_layout = 'courses.CourseDetail'

This feature makes it possible to override the detail layout in an extended plugin. Before this you had to define a new class and to assign an instance of that class to every actor which uses it. But e.g. in lino_xl.lib.courses we have a lot of subclasses of the Courses actor.

insert_layout = None

Define the form layout to use for the insert window.

If there's a detail_layout but no insert_layout, the table won't have any (+) button to create a new row via a dialog window, but users can still create rows by writing into the phantom row. Example of this is lino_xl.lib.courses.Topics which has a detail layout with slave tables, but the model itself has only two fields (id and name) and it makes no sense to have an insert window.

card_layout = None

Define a layout for a card view of the table.

help_text = None

A help text that shortly explains what the default action of this actor does. In a graphical user interface this will be rendered as a tooltip text.

If this is not given by the code, Lino will potentially set it at startup when loading the help_texts.py files.

abstract = True

Set this to True to prevent Lino from generating useless JavaScript if this is just an abstract base class to be inherited by other actors.

Note that this class attribute is not inherited to subclasses.

sum_text_column = 0

The index of the column which should hold the text to display on the totals row (returned by get_sum_text()).

preview_limit = None

For non-table actors this is always None, otherwise see lino.core.tables.AbstractTable.preview_limit.

handle_uploaded_files = None

Handler for uploaded files. Same remarks as for lino.core.actors.Actor.disabled_fields.

classmethod apply_cell_format(ar, row, col, recno, td)

Actor-level hook for overriding the formating when rendering this table as plain html.

For example ml.cal.Events overrides this.

classmethod get_pk_field()

Return the Django field used to represent the primary key when filling selected_pks.

classmethod get_actions_hotkeys()

Return or yield a list of hotkeys to be linked to named actions.

[{'key': key, 'ctrl': Bool, 'shift': Bool, 'ba': action_name}]

classmethod get_row_by_pk(ar, pk)

Return the data row identified by the given primary key.

classmethod get_master_instance(ar, model, pk)

Return the master_instance corresponding to the specified primary key.

You need to override this on slave actors whose master is not a database model, e.g. the ProblemsByChecker table.

ar is the action request on this actor. model is the master, except if master is ContentType (in which case model is the requested master).

classmethod get_disabled_fields(obj, ar)

Return the cached set of disabled fields for this obj and ar.

classmethod make_disabled_fields(obj, ar)

Return a set of disabled fields for the specified object and request.

See Disabling individual fields.

classmethod get_request_handle(ar)

Return the dynamic (per-request) handle for this actor for the renderer used by specified action request.

classmethod get_navinfo(ar, obj)

Return navigation info for the given obj in the given ar.

The default implementation assumes that you navigate on the data_iterator.

lino_xl.lib.cal.CalendarView overrides this.

classmethod clear_handle()

When an actor has dynamic columns which depend on database content, then its layout handle may not persist between different Django test cases because a handle from a first test case may refer to elements which no longer exist in a second test case.

classmethod summary_row(ar, obj, **kw)

Return a HTML representation of the given data row obj for usage in a summary panel.

The default implementation calls lino.core.model.Model.summary_row().

classmethod get_handle()

Return a static handle for this actor.

classmethod class_init()

Called internally at site startup.

classmethod collect_virtual_fields()

Collect virtual fields from class attributes and register them as virtual fields.

classmethod get_view_permission(user_type)

Return True if this actor as a whole is visible for users with the given user_type.

classmethod get_create_permission(ar)

Dynamic test per request. This is being called only when allow_create is True.

classmethod get_row_permission(obj, ar, state, ba)

Returns True or False whether the given action request ActionRequest ar is allowed on the given row instance row.

classmethod get_request_detail_action(ar)

Return the detail action of this actor, respecting the user's view permissions.

This is equivalent to the actors's detail_action, except when the model's get_detail_action() method returns a table for which the user has no view permission. In that case we don't want Lino to give up too quickly because there is still a possibility that the same layout is used on other tables, to which the user does have permission.

An example is described in Who can see the detail of an activity?

classmethod get_actor_label()

Compute the label of this actor.

classmethod get_detail_title(ar, obj)

Return the string to use when building the title of a detail window on a given row of this actor.

classmethod get_choices_text(obj, request, field)

Return the text to be displayed in a combo box for the field field of this actor to represent the choice obj. Override this if you want a customized representation. For example lino_voga.models.InvoiceItems

classmethod get_title(ar)

Return the title of this actor for the given action request ar.

The default implementation calls get_title_base() and get_title_tags() and returns a string of type BASE [ (TAG, TAG...)].

Override this if your table's title should mention for example filter conditions. See also Table.get_title.

classmethod get_title_base(ar)

Return the base part of the title. This should be a translatable string. This is called by get_title() to construct the actual title.

It is also called by lino.core.dashboard.DashboardItem.render_request()

classmethod get_title_tags(ar)

Yield a list of translatable strings to be added to the base part of the title. This is called by get_title() to construct the actual title.

classmethod setup_request(ar)

Customized versions may e.g. set master_instance before calling super().

Used e.g. by lino_xl.lib.outbox.models.MyOutbox or lino.modlib.users.ByUser.

Other usages are more hackerish:

• lino_xl.lib.households.models.SiblingsByPerson

• lino_welfare.modlib.cal.EntriesByClient

• lino_welfare.pcsw.models.Home,

• lino.modlib.users.MySettings.

classmethod setup_parameters(params)

Inheritable hook for defining parameters. Called once per actor at site startup. The default implementation just calls setup_parameters of the model (if a model is set).

classmethod get_simple_parameters()

Inheritable hook for defining which parameters are simple. Expected to return a list of names of parameter fields.

classmethod override_column_headers(ar, **kwargs)

A hook to dynamically override the column headers. This has no effect on a GridPanel, only in printed documents or plain html.

classmethod get_sum_text(ar, sums)

Return the text to display on the totals row. The default implementation returns "Total (N rows)".

classmethod get_layout_aliases()

Yield a series of (ALIAS, repl) tuples that cause a name ALIAS in a layout based on this actor to be replaced by its replacement repl.

classmethod set_detail_layout(*args, **kw)

Update the detail_layout of this actor, or create a new layout if there wasn't one before.

This is maybe deprecated. See #526.

The first argument can be either a string or a FormLayout instance. If it is a string, it will replace the currently defined 'main' panel. With the special case that if the current main panel is horizontal (i.e. the layout has tabs), it replaces the 'general' tab.

Typical usage example:

@dd.receiver(dd.post_analyze)
def my_details(sender, **kw):
    contacts = sender.modules.contacts
    contacts.Partners.set_detail_layout(PartnerDetail())

classmethod set_insert_layout(*args, **kw)

Update the insert_layout of this actor, or create a new layout if there wasn't one before.

Otherwise same usage as set_detail_layout().

classmethod add_detail_panel(*args, **kw)

Adds a panel to the Detail of this actor. Arguments: see lino.core.layouts.BaseLayout.add_panel()

This is deprecated. Use mixins instead.

classmethod add_detail_tab(*args, **kw)

Adds a tab panel to the Detail of this actor. See lino.core.layouts.BaseLayout.add_tabpanel()

This is deprecated. Use mixins instead.

classmethod get_toolbar_actions(parent)

Return a list of actions for which a button should exist in the toolbar of the specified "parent" action.

classmethod get_button_actions(parent)

Return a sorted list of actions that should be available as buttons in the specified parent (a window action).

This is used (1) by get_toolbar_actions() and (2) to reduce the list of disabled actions in disabled_fields to those which make sense. dbtables.make_disabled_fields

classmethod get_actions()

Return a sorted list of all bound actions offered by this actor.

classmethod get_detail_elems(*args)

An optional first argument is the front end plugin, a Plugin instance. If this is None, use settings.SITE.kernel.default_ui.

Returns a list of the widgets (layout elements) that make up the detail layout.

classmethod get_data_elem(name)

Find data element in this actor by name.

classmethod param_defaults(ar, **kw)

Return a dict with default values for the parameters. This will be called per request.

Usage example. The Clients table has a parameter coached_since whose default value is empty:

class Clients(dd.Table):
    parameters = dd.ParameterPanel(
      ...
      coached_since=models.DateField(blank=True))

But NewClients is a subclass of Clients with the only difference that the default value is amonthago:

class NewClients(Clients):
    @classmethod
    def param_defaults(self,ar,**kw):
        kw = super(NewClients,self).param_defaults(ar,**kw)
        kw.update(coached_since=amonthago())
        return kw

classmethod request(*args, **kw)

Return an action request on this actor.

classmethod request_from(ar, *args, **kwargs)

Return an action request on this actor which inherits from the given parent request.

Deprecated. Rather call cls.request(parent=ar)

classmethod to_html(**kw)

classmethod get_screenshot_requests(language)

Return or yield a list of screenshots to generate for this actor. Not yet stable. Don't override this. Don't worry if you don't understand.

classmethod slave_as_html(master, ar)

Creates and returns the method to be used when display_mode is html.

summary_sep = functools.partial(<lxml.builder.ElementMaker object>, 'br')

classmethod get_table_summary(obj, ar)

Return the HTML <div> to be displayed by lino.core.elems.TableSummaryPanel. That is (1) in a detail form when display_mode is summary or (2) in a grid.

Lino internally creates a virtualfield slave_summary on each table that invokes this method.

lino.core.actors.resolve_action(spec, action=None)

Return the BoundAction object corresponding to the given specifier spec. The specifier can be:

• a model or a table

• a bound action

• an action instance

• a string of the form myapp.MyModel (i.e. resolving to a model)

• a string of the form myapp.MyModels (i.e. resolving to a table)

If it is an action instance, Lino will use the definiing_actor of that action.