Argument Collection

Index of All Documentation » Wing Pro Reference Manual » Scripting and Extending Wing » Script Syntax »

Commands that are defined in scripts can take arguments, optionally with a default value. Wing can collect any missing arguments for a command invocation by interacting with the user in a dialog or, in some keyboard personalities, in the status area at the bottom of the IDE window.

By default, Wing derives the labels to use for arguments from the argument name and assumes that the argument being collected is a string. When this is not the case, argument type can be specified by setting the arginfo function attribute on the script function that defines the command. This uses the CArgInfo from and the datatype and formbuilder modules from Wing's internals, as documented below.


The following sets up two arguments, one that is a filename, and another that allows selecting from a popup menu:

import wingapi
from wingutils import datatype
from guiutils import formbuilder

def test_arg_entry(filename, word):
  wingapi.gApplication.ShowMessageDialog('Choice {}'.format(word), "You chose: {}".format(filename))

_choices = [
  ("Default", None),
  ("One", 1),
  ("Two", 2),
  ("Three", 3)

test_arg_entry.arginfo = {
  'filename': wingapi.CArgInfo(
    "The filename to enter",               # The tooltip shown to use over this field
    datatype.CType(''),                    # The data type is string
    formbuilder.CFileSelectorGui(),        # Use a file selection field to collect the value
    "Filename:"                            # The field label
  'word': wingapi.CArgInfo(
    "The word to enter",
    formbuilder.CPopupChoiceGui(_choices), # Use a popup menu to collect this value


The arguments used to instantiate a CArgInfo instance for the arginfo function attribute are:

doc sets the documentation string for the argument.

type sets the data type, using one of the classes descended from wingutils.datatype.CTypeDef. See below for the most commonly used ones.

formlet sets the type of GUI formlet to use to collect the argument from the user. This is one of the classes descended from wingutils.formbuilder.CDataGui See below for the most commonly used ones.

label sets the label to use for the argument when collected from the user. When this argument is omitted, the label is built from the function name with cmdname.replace('_', ' ').title().

Commonly Used Types

The following classes in wingutils.datatype cover most cases needed for scripting:

CBoolean specifies a boolean. The constructor takes no arguments.

CType specifies the type matching one of the parameters sent to the constructor. For example, CType("") is a string, CType(1) is an integer, and CType(1.0, 1) is a float or an integer.

CValue restricts a value to one of those passed to the constructor. For example CValue("one", "two", "three") allows a value to be either "one", "two", or "three".

CRange specifies a numeric range between the first and second argument passed to the constructor. For example, CRange(1, 10) allows a value between 1 and 10, inclusive.

Additional types are defined in src/wingutils/ in the Wing source code, but these are not usually needed in describing scripting arguments.

Commonly Used Interface

The following classes in guiutils.formbuilder cover most of the data collection fields needed for scripting:

CSmallTextGui collects a short text string, with history, auto-completion, and other options. The constructor takes the following keyword arguments, all of which are optional:

max_chars sets the maximum allowed text length. Set this to -1 to allow any length. Default: 80

history is a list of strings for the history, most recent first, that is accessed with the up and down arrow keys. This may be the list or a callable that returns the list. Default: None

choices is a list of strings with all valid choices, to use in the auto-completer that is shown as the user types. This may be a list or a callable that takes a fragment and returns all possible matches. Default: None

partial_complete is set to True to only complete as far as the unique match when the Tab``key is pressed for auto-completion.  When set to ``False, all of the currently selected auto-completion match will be entered instead. Default: True

stopchars is a string of characters that always stop partial completion. For example, '/' might be used to prevent completion of an entire url. Default=``''``

allow_only is a list of characters allowed for input. All others are not processed. When this is set to None, it allows all characters to be input. Default: None

auto_select_choice is set to True to automatically select all of the entry text when browsing on the auto-completer. This is used so that the entry will be erased if any subsequent typing occurs. Default: False

default is the default value to auto-enter initially. Default: ''

select_on_focus can be set to True to select any existing text when focus enters the field. Default: False

editable can be set to False to display the field but to prevent editing it. Default: True

selection can be set to a (start, end) tuple to select a range of text in the auto-entered default value. If omitted, nothing is selected. Default: None

CLargeTextGui is an multi-line entry area for longer text strings. The constructor takes no arguments.

CBooleanGui is a single checkbox for collecting a boolean value. The constructor takes no arguments.

CFileSelectorGui is a keyboard-driven file selector with auto-completion, history, and ability to browse using a standard file dialog. The constructor takes the following optional keyword arguments:

name_type specifies what type of file or directory is being selected: 'existing-file', 'existing-dir', 'existing-executable-file', 'new-dir', 'new-file', or 'save-as-file'

default is the default value to pre-fill into the field. Default: ''

default_ext specifies the default file extension to use. Default: None

filters is a list of valid file name extensions. For example ['py', 'pyi'] to select either a *.py or *.pyi file. Default: None

history can be set to a list of past choices, most recent first, to traverse with the up and down arrow keys. Default: ()

tab_shows_completer indicates that pressing the Tab key should show the auto-completer. Default: False

hostname (Wing Pro only) specifies the name of a remote host from which the file or directory should be selected. Default: '', which indicates the local host.

CPopupChoiceGui is a popup menu to select from a range of values. The constructor takes a list of items for the popup. Each item may be one of:

None to insert a divider into the menu

A string to insert that value into the menu. The label used in the menu is derived from the value: label = str(value).replace('_', ' ').title()

(value, label) inserts the value into the menu using the given label.

(value, label, tooltip) inserts the value into the menu using the given label and displays the given tooltip when the mouse hovers over the item in the menu.

CNumberGui is a small entry area for collecting a number. The constructor takes the following required arguments:

min_value is the minimum allowable value.

max_value is the maximum allowable value.

page_size is the increment to use when the when scroller is used.

num_decimals is the number of decimal places to show. This is set to 0 to collect an integer.

Additional fields for collecting data are defined in src/guiutils/ in the Wing source code, but these are not usually needed for scripting.