SingleChoice#

class alfred3.element.input.SingleChoice(*choice_labels: Union[str, alfred3.element.core.Element], vertical: bool = False, align: str = 'center', **kwargs)[source]#

Bases: alfred3.element.core.ChoiceElement

Radio buttons for choosing a single option.

Parameters

*choice_labels – Variable numbers of choice labels. See ChoiceElement for details.
default – The default argument of single choice elements is an integer, indicating which choice should be selected by default. Counting of choices starts at 1.

**kwargs –

Inherited keyword arguments

align	Horizontal alignment of text in the element. Does not usually apply to labels. Think of it as an alignment that applies to the innermost layer of an element (while labels are generally located at outer layers). See `LabelledElement` for more on labelled elements. Can be left (default), center, right, or justify.
debug_value	Value to be used in debug mode. If None (default), alfred will first try to use the elements ordinary default value. If there is no default value, alfred will read the debug value from the config.conf.
description	An additional description of the element. This will show up in the alfred-generated codebook. It has no effect on the display of the experiment, as it only serves as a descriptor for humans.
font_size	Font size for text in the element. You can use a keyword or an exact specification. The available keywords are tiny, small, normal, big, and huge. The exact specification shoul ideally include a unit, such as 1rem, or 12pt. If you supply an integer without a unit, a unit of pt will be assumed. Defaults to normal.
force_input	If True, users can only progress to the next page if they enter data into this field. Note that a `NoValidationSection` or similar sections might overrule this setting. A general, experiment-wide setting for force_input can be placed in the config.conf (section general). That setting is used by default and can be overruled here for individual elements. Defaults to False. The experiment-wide default can be changed in config.conf.
height	Vertical height of the elements display area. Supply a string with a unit, e.g. 80px. Usually, the default is fine. For adding vertical space to a page, you should prefer the `VerticalSpace` element, as it is sematically more clear.
instance_log	If True, the element will use an instance-specific logger, thereby allowing detailed fine- tuning of its logging behavior.
layout	Can be one of the following: 1) An instance of `RowLayout`, or 2) a tuple of integers, specifying the allocation of horizontal space between leftlab, main element widget and rightlab on small screens upwards. Option 1) offers fine-tuned flexibility, 2) uses a default RowLayout and changes the `RowLayout.width_sm` attribute. By default, the layout is set automatically depending on the specification of the left and right labels.
name	Name of the element. This should be a unique identifier. It will be used to identify the corresponding data in the final data set.
no_input_hint	Hint to be displayed if force_input set to True and no user input registered. Defaults to the experiment-wide default value specified in config.conf.
position	Horizontal position of the full element on the page. Values can be left, center (default), end, or any valid value for the justify-content flexbox utility. Takes effect only, when the element is not full-width.
prefix	Prefix for the input field.
save_data (bool)	If False, this element will not save any data to the experiment data and will not appear in the codebook.
showif	A dictionary, defining conditions that must be met for the element to be shown. The conditions take the form of key-value pairs, where each key is an element name and the value is the required input. See `showif` for details.
suffix	Suffix for the input field.
toplab, bottomlab, leftlab, rightlab	Labels above, below, left and right of the element.
vertical	Boolean switch, indicating whether the choices should be listed vertically. Defaults to False, i.e. horizontal display.
width	Defines the horizontal width of the element from small screens upwards. It is always full-width on extra small screens. Possible values are narrow, medium, wide, and full. For more detailed control, you can define the `element_width` attribute.

Notes

This element saves answers in the form of integers, counting up from 1. Take a look at the examples to see how to work with user input to a SingleChoice element.

See also

SingleChoiceButtons and SingleChoiceBar are nicer displays of SingleChoice elements. Those are also more suitable for responsive displays.
The class SubmittingButtons is a version of SingleChoiceButtons that automatically moves the experiment to the next page, once the participant clicks on an answer.
SingleChoiceList is a dropdown list of single choices. The SingleChoiceList saves its data as strings (instead of integers) and is a good option if you have ten or more choices.
MultipleChoiceButtons can be used to allow multiple answers.

Examples

A simple SingleChoice element:

import alfred3 as al
exp = al.Experiment()

@exp.member
class Demo(al.Page):
    name = "demo_page"

    def on_exp_access(self):
        self += al.SingleChoice("Yes", "No", name="c1")

Accessing the input to a SingleChoice element:

import alfred3 as al
exp = al.Experiment()

@exp.member
class Demo(al.Page):
    name = "demo_page"

    def on_exp_access(self):
        self += al.SingleChoice("Yes", "No", toplab="Choose one", name="c1")


@exp.member
class Show(al.Page):

    def on_first_show(self):
        c1_answer = self.exp.values["c1"] # access value
        self += al.Text(f"Your answer was: {c1_answer}")

Methods

`add_css`	Adds CSS to the element.
`add_js`	Adds Javascript to the element.
`added_to_experiment`	Tells the element that it was added to an experiment.
`added_to_page`	If choice labels are element instances, they are added to the page to enable their full functionality.
`define_choices`	Abstract method for the definition of the individual choices belonging to this element.
`prepare_web_widget`	Hook for computations for preparing an element's web widget.
`render_inner_html`	Renders the element template `element_template`.
`set_data`	Sets the `input` data.
`validate_data`	Method for validation of input to the element.

Attributes

`base_template`	Base template for the element, which will be used to hold the rendered element template.
`bottomlab`	Label below of the main element widget.
`choice_labels`	Stored list of choice labels.
`codebook_data`	Information about the element in dictionary form.
`converted_width`	List of bootstrap column widths at different screen sizes.
`corrective_hints`	Shortcut for accessing the element's corrective hints.
`css_class_container`	Returns the name the element container's CSS class.
`css_class_element`	Returns the name of the element's CSS class.
`css_code`	A list of tuples, which contain a priority and CSS code.
`css_urls`	A list of tuples, which contain a priority and an url pointing to CSS code.
`data`	Dictionary of element data.
`debug_enabled`	Boolean flag, indicating whether debug mode is enabled and default values should be set.
`debug_value`	Value to be used as a default in debug mode.
`default`	Default value of this element.
`default_no_input_hint`	Default hint if subject input is missing in force_entry elements.
`description`	Detailed description of this element to be added to the automatically generated codebook
`disabled`	A boolean flag, indicating whether the element is disabled A disabled input element is shown and displays its input value, but subjects cannot enter any data.
`display_standalone`	If True (default), the element will be displayed as usual on its own.
`element_template`	The element's specific, inner template.
`element_width`	Returns a string of column width definitions.
`emojize`	Switch for turning the interpretation of emoji shortcodes in the choice labels off, if necessary.
`exp`	The experiment session to which this element belongs.
`experiment`	Alias for `exp`
`font_size`	Font size
`force_input`	If True, subjects must fill this element to proceed.
`hint_manager`	A `MessageManager`, handling the corrective hints for this element.
`input`	Index of selected choice (starting at 1).
`js_code`	A list of tuples, which contain a priority and Javascript.
`js_urls`	A list of tuples, which contain a priority and an url pointing to JavaScript.
`labels`	Returns the labels in a single, nicely formatted string.
`layout`	Controls the allocation of horizontal space between the left and right label, as well as the main element.
`leftlab`	Label to the left of the main element widget.
`name`	Unique identifier for the element.
`no_input_hint`	Hint for subjects, if they left a force_input field empty.
`page`	The page to which this element belongs.
`position`	Position of the whole element on the page.
`prefix`	A string or element, serving as prefix.
`rightlab`	Label to the right of the main element widget.
`section`	The direct parent section of this element's page.
`short_tree`	String, giving the exact position in the experiment.
`should_be_shown`	Boolean, indicating whether the element is meant to be shown.
`show_hints`	Flag, indicating whether corrective hints regarding this element should be shown.
`showif`	Conditions that have to be met for the element to be shown.
`suffix`	A string or element, serving as suffix.
`template_data`	Dictionary of data to be passed on to jinja templates.
`toplab`	Label above of the main element widget.
`tree`	String, giving the exact position in the experiment.
`type`	Choice type (e.g.
`vertical`	Attribute defining, whether the element is displayed vertically.
`web_widget`	The element's rendered html code for display on a page.
`width`	Element width