Bubble chart
Updated 2 days ago to v4.2.1 by Flourish team
How to use this template
How to get started
Your data must be in a wide format with one row for each bubble, the only required column being Label. Here's what your data might look like.
App | Download (millions) | Type | Image |
TikTok | 656 | Social Network | Image URL |
545 | Social Network | Image URL | |
416 | Social Network | Image URL | |
395 | Messenger | Image URL |
You can add extra columns to customize the color, size, axis values and images of your bubbles, and bind any extra information under Info for popups. Learn more about uploading images to Flourish here.
How to use numeric data in this template
There are two ways you can use numeric data in a bubble chart: either sizing bubbles by their values or positioning them on an X or Y axis. If you have numeric values, you can choose to use one or both of the Size by and Axis values column bindings.
Position your bubbles on an axis
If you have bound a column under Axis values, first set the alignment of your bubbles under Bubble styles. The Center option clusters bubbles together, while the other two options position them on an X or Y axis.
When positioned on an axis, you also have the option to adjust the bubbles' maximum radius if they look too small. In addition, you can set a fixed space between each bubble.
Currently, this template doesn't support date formats. To learn how you can position bubbles based on a date, read this help doc.
Style your labels
Under Labels, style the text labels for your bubbles adjusting text weight, style, case, color and shadow. If you have images, you can also adjust their border and opacity under the Images settings.
Style your legends
Depending on your data, you might have up to three different legends for color, size and position. Under the Legend settings, customize options like orientation, alignment, ordering and add custom legend titles.
API information
This section documents API usage specific to this template, so for an introduction we suggest you refer to the generic API documentation instead.
template: @flourish/bubble-chart
version: 4
Template data
There are three different formats in which you can supply data to this template. The most convenient for you to use likely depends on the source of your data, as described below.
1. Array of arrays, and a bindings object
You can supply arrays of arrays to opts.data
, which might look
like:
{ data: { data: [ [ "DataColumn1Value1", "DataColumn2Value1", [ "DataColumn1Value2", "DataColumn2Value2", [ "DataColumn1Value3", "DataColumn2Value3", ... ] } }
where each array of arrays represents the rows in a data sheet.
To tell the API how the values from each column should be
associated with the keys that the template is expecting, you must also supply
an object attached to opts.bindings
. (The meanings of the
keys in the bindings object are documented
below.) The minimal bindings you can
supply for this template are as shown in this example:
{ template: "@flourish/bubble-chart", version: "4", bindings: { data: { label: 0, // index of a column in your data } }, data: { data: [ [ "DataColumn1Value1", "DataColumn2Value1", [ "DataColumn1Value2", "DataColumn2Value2", [ "DataColumn1Value3", "DataColumn2Value3", ... ] } }
All possible bindings that you can supply are shown in this example:
{ template: "@flourish/bubble-chart", version: "4", bindings: { data: { label: 0, // index of a column in your data color: 1, // index of a column in your data size: 2, // index of a column in your data axis_values: 3, // index of a column in your data image: 4, // index of a column in your data metadata: [5, 6, ...], // index(es) of column(s) in your data } }, data: { data: [ [ "DataColumn1Value1", "DataColumn2Value1", [ "DataColumn1Value2", "DataColumn2Value2", [ "DataColumn1Value3", "DataColumn2Value3", ... ] } }
2. Array of objects with arbitrary keys, and a bindings object
This format is most likely useful when you have data from an external source,
such as CSV data loaded from d3-dsv.
You should supply this attached to the opts.data
, which might look
like:
{ data: [ { "DataHeader1": ..., "DataHeader2": ..., ... }, { "DataHeader1": ..., "DataHeader2": ..., ... }, { "DataHeader1": ..., "DataHeader2": ..., ... }, ... ] }
... but with the keys being the column headers from your
source data instead. You must also supply an object attached to
opts.bindings
. The minimal bindings you can
supply for this template are as shown in this example:
{ template: "@flourish/bubble-chart", version: "4", bindings: { data: { label: "DataHeader1", } }, data: { data: [ { "DataHeader1": ..., "DataHeader2": ..., ... }, { "DataHeader1": ..., "DataHeader2": ..., ... }, { "DataHeader1": ..., "DataHeader2": ..., ... }, ... ] } }
All possible bindings that you can supply are shown in this example:
{ template: "@flourish/bubble-chart", version: "4", bindings: { data: { label: "DataHeader1", color: "DataHeader2", size: "DataHeader3", axis_values: "DataHeader4", image: "DataHeader5", metadata: ["DataHeader6", "DataHeader7", ...], } }, data: { data: [ { "DataHeader1": ..., "DataHeader2": ..., ... }, { "DataHeader1": ..., "DataHeader2": ..., ... }, { "DataHeader1": ..., "DataHeader2": ..., ... }, ... ] } }
(As before, the keys containing "Header" would be replaced by column names from your data source.)
3. Array of objects with template-defined keys
There is an alternative format you can use, which is likely to be easier to
use if your data is not from a spreadsheet source. With this alternative format
you supply your data to the template as
an array of objects, attached to opts.data
, where the keys must
be those used by the template, as documented below. In this case
there is no need to supply a bindings object, since the key names are already
those expected by the template. The required properties in the data
object are as follows (scroll down for a
description of what each property is):
{ template: "@flourish/bubble-chart", version: "4", data: { data: [ { label: ..., metadata: [...] }, ... ] }, ... }
And the full list of all possible properties is as follows:
{ template: "@flourish/bubble-chart", version: "4", data: { data: [ { label: ..., color: ..., size: ..., axis_values: ..., image: ..., metadata: [...] }, ... ] }, ... }
Meanings of the template data keys:
- data.label: label
- data.color: Used to color the bubbles
- data.size: Value for bubble size
- data.axis_values: Values used to plot the bubbles when the bubbles are aligned on an axis
- data.image: <a href="https://helpcenter.flourish.studio/hc/en-us/articles/8827970581391-How-to-add-images-to-your-visualization">Images</a> for bubbles. Add an image URL or right-click on a cell to upload an image.
- data.metadata: One or more columns of information (text, <a href="https://help.flourish.studio/article/46-how-to-add-images-to-your-visualization">image URLs</a>, <a href="https://help.flourish.studio/article/259-how-to-embed-charts-in-your-popups-or-panels">embedded charts</a> etc) to include in custom <a href="https://help.flourish.studio/article/69-how-to-add-custom-content-to-your-popups">popups and panels</a>
Template settings
Options for opts.state
.
Bubble styles
bubble_alignment string
Alignment of bubbles. Allowed values:
margin_bubbles number
Space between bubbles. Max: 3
animation_duration number
Animation duration. in seconds Max: 10
Chart setup
height_mode string
Height mode. Fill space: the graphic will fill the container (which by default will be the the standard Flourish responsive chart size) Allowed values:
Aspect ratio: sets the aspect of the chart.
This setting is ignored when embedded in a fixed-height context, such as a simple iframe embed.
aspect_ratio number
Aspect (desktop). Height of the plot as a proportion of its width, between 0 and 1 Max: 1
aspect_ratio_mobile number
Aspect (mobile). Height of the plot as a proportion of its width, between 0 and 1 Max: 1
aspect_ratio_breakpoint number
Breakpoint. The width at which mobile mode ends and desktop begins
Colors
circle_background_color color
Color. Default color
color.categorical_palette colors
Palette.
color.categorical_extend boolean
Extend. Automatically generate additional colours when needed to avoid the palette colours being used more than once
color.categorical_custom_palette text
Custom overrides. Enter the label name for which you wish to set the color, followed by a colon and the desired color value.
Colors can be set using Hex, RGB, color names or RGBA, if you want to set the opacity. Multiple colors can be set using multiple lines. For example:
Party 1: red
Party 2: #4455AA
Party 3: rgb(30,168,26)
color.numeric_type string
Scale type. Allowed values:
color.binning boolean
In linear mode, the color scale will run as a smooth gradient between 2 colors. In binned mode, the gradient will be divided in smaller blocks. Allowed values:
color.bin_mode string
Binning mode. Allowed values:
color.bin_count number
Number of bins.
color.bin_thresholds string
Custom thresholds. Enter your desired thresholds, separating them with a ";". For instance, "5;10;15".
Bins form as follows:
For "5;10;15", you'll get four bins based on your data's range.
color.sequential_palette string
Palette. Allowed values:
color.sequential_reverse boolean
Reverse.
color.sequential_custom_min color
Minimum color.
color.sequential_custom_max color
Maximum color.
color.sequential_color_space string
Color space. Allowed values:
color.sequential_custom_domain boolean
Domain. Allowed values:
color.sequential_domain_min number
Min.
color.sequential_domain_max number
Max.
color.diverging_palette string
Palette. Allowed values:
color.diverging_reverse boolean
Reverse.
color.diverging_custom_min color
Minimum color.
color.diverging_custom_mid color
Midpoint color.
color.diverging_custom_max color
Maximum color.
color.diverging_color_space string
Color space. Allowed values:
color.diverging_custom_domain boolean
Domain. Allowed values:
color.diverging_domain_min number
Min.
color.diverging_domain_mid number
Mid.
color.diverging_domain_max number
Max.
Images
circle_background_border number
Border.
image_opacity number
Opacity. Max: 1
Labels
label_font_weight string
Weight. Allowed values:
label_font_style string
Style. Allowed values:
label_font_case string
Case. Allowed values:
label_font_color color
Color. Defaults to contrast coloring when no image is set
label_shadow boolean
Text shadow.
Highlights
enable_highlighting boolean
Enable highlighting.
selected_bubbles text
Highlight bubbles. To highlight bubbles, write the name of each bubble on a new line. You can also create a story and highlight/unhighlight by clicking.
opacity_highlighted number
Opacity of highlighted bubble. Max: 1
opacity_not_highlighted number
Opacity of all other bubbles. Max: 1
highlight_pictures boolean
Show pictures only on highlighted bubbles.
Legends
legend_container.alignment string
Alignment. Allowed values:
legend_container.orientation string
Orientation. Allowed values:
legend_container.title_weight string
Title weight. Allowed values:
legend_container.text_weight string
Text weight. Allowed values:
legend_container.text_color color
Color.
legend_container.text_size number
Size. Max: 10
show_legend_axis boolean
Allowed values:
- true (Enabled)
- false (Disabled)
axis_legend_title_mode string
Title mode. Allowed values:
axis_legend_title string
Title.
legend_categorical.show_legend boolean
Legend mode. A legend will not show with a single entry Allowed values:
legend_categorical.title_mode string
Title mode. Allowed values:
legend_categorical.title string
Title.
legend_categorical.swatch_width number
Width.
legend_categorical.swatch_height number
Height.
legend_categorical.swatch_radius number
Roundness. The radius of the corners of the swatch (in pixels)
legend_categorical.legend_items_padding number
Padding. Padding between legend items (in rems)
legend_categorical.swatch_outline boolean
Outline. An optional outline for the swatch in the legend
legend_categorical.swatch_outline_color color
Color.
legend_categorical.order_override text
Custom order override. Manually specify the order of legend entries (one entry per line)
legend_categorical.icon_height number
Height. Height of icon (in rems)
legend_categorical.icon_color color
Color. Fallback color (icon color if not determined by template)
legend_categorical.max_width number
Max width.
legend_categorical.orientation string
Orientation. Allowed values:
legend_size.show_legend boolean
Allowed values:
- true (Enabled)
- false (Disabled)
legend_size.title_mode string
Title mode. Allowed values:
legend_size.title string
Title.
legend_size.shape_fill color
Shape fill.
legend_size.shape_stroke color
Shape stroke. Hint: set to same value as fill for no stroke
legend_size.clip_height number
Max height. Maximum height of shape (relative to root font size)
legend_size.small_symbol_size number
Small/large proportion. Proportion of the smallest symbol's value compared to the biggest symbol's value. 0.5 means it's half the value of the big symbol. Max: 1
Popups and panels
popup.mode string
Allowed values:
- none (None)
- popup (Popup)
- panel (Panel)
- both (Both)
popup.popup_is_custom boolean
Popup content. Allowed values:
popup.show_popup_styles boolean
Show popup styles.
popup.popup_custom_header html
Popup custom header. Use {{column_name}} to add a value from your data. Ensure the column is selected, or add it to Info for popups for popup use.
Advanced users can add HTML styling or add category colors to popup headers.
To hide parts of the popup when a column is empty using {{#if column_name}}Content for non-empty column_name{{/if}}.
For example: {{#if Capital name}}Capital:{{/if}} {{Capital name}}.
Here, the word "Capital:" will only show if the corresponding cell in the "Capital name" column is not empty.
popup.popup_custom_main html
Popup custom main content. Use {{column_name}} to add a value from your data. Ensure the column is selected, or add it to Info for popups for popup use.
Advanced users can add HTML for designs, styles, and images.
To hide parts of the popup when a column is empty use the syntax {{#if column_name}}Content for non-empty column_name{{/if}}.
For example: {{#if Capital name}}Capital:{{/if}} {{Capital name}}.
Here, the word "Capital:" will only show if the corresponding cell in the "Capital name" column is not empty.
popup.popup_custom_accessible text
Popup custom accessible content. A text alternative to visual custom popup content that will be read out by screenreaders. This content is added as an aria-label
attribute to data point elements. You can still use {{column_name}} to add values from your data, but do not use HTML. For example: {Name}}, Population: {{Population}}, GDP: {{GDP}}
If left empty, accessible content will fallback to the default popup content.
popup.popup_width number
Max width. In rems, multiples of base font size. Leave blank to let the width adjust based on the contents.
popup.popup_font_size number
Text size.
popup.popup_text_color color
Text color.
popup.popup_align string
Align. Allowed values:
popup.popup_background color
Fill color.
popup.popup_background_opacity number
Fill opacity. Max: 1
popup.popup_padding number
Padding.
popup.popup_radius number
Radius. Corner radius of popup
popup.popup_header_type string
Header style. Allowed values:
popup.popup_header_background color
Background.
popup.popup_header_text_color color
Text.
popup.popup_list_type string
List type. Allowed values:
popup.popup_list_label_weight string
Label weight. Allowed values:
popup.popup_list_separator string
List separator. Predefined values:
popup.popup_shadow boolean
Shadow.
popup.popup_pointer boolean
Pointer.
popup.panel_position string
Allowed values:
- overlay (Overlay)
- left (Left)
- right (Right)
- top (Top)
- bottom (Bottom)
popup.panel_open_duration number
Open duration. Max: 2000
popup.panel_side_fixed boolean
Always show.
popup.panel_side_default_content text
Placeholder content.
popup.panel_is_custom boolean
Panel content. Allowed values:
popup.show_panel_styles boolean
Show panel styles.
popup.panel_custom_header html
Panel custom header. Use {{column_name}} to add a value from your data. Ensure the column is selected, or add it to Info for popups for panel use.
Advanced users can add HTML for styling or add category colors to panel headers.
To hide parts of the panel when a column is empty using {{#if column_name}}Content for non-empty column_name{{/if}}.
For example: {{#if Capital name}}Capital:{{/if}} {{Capital name}}.
Here, the word "Capital:" will only show if the corresponding cell in the "Capital name" column is not empty.
popup.panel_custom_main html
Panel custom main content. Use {{column_name}} to add a value from your data. Ensure the column is selected, or add it to Info for popups for panel use.
Advanced users can add HTML for designs, styles, images, videos and embedded Flourish charts,
To hide parts of the panel when a column is empty using {{#if column_name}}Content for non-empty column_name{{/if}}.
For example: {{#if Capital name}}Capital:{{/if}} {{Capital name}}.
Here, the word "Capital:" will only show if the corresponding cell in the "Capital name" column is not empty.
popup.panel_width_overlay number
Width (%).
popup.panel_height_overlay number
Height (%).
popup.panel_width_side number
Width (%).
popup.panel_height_side number
Height (%).
popup.panel_max_width number
Max width (px).
popup.panel_max_height number
Max height (px).
popup.panel_vertical_position string
Vertical position. Choosing Click position is especially useful when your visualization is really tall, this will make sure the panel content is always on top of the element you've clicked on Allowed values:
popup.panel_text_color color
Text color.
popup.panel_font_size number
Text size.
popup.panel_align string
Alignment. Allowed values:
popup.panel_background color
Fill color.
popup.panel_background_opacity number
Fill opacity. Max: 1
popup.panel_padding number
Padding.
popup.panel_radius number
Radius. Corner radius of panel
popup.panel_list_type string
List type. Allowed values:
popup.panel_list_label_weight string
Label weight. Allowed values:
popup.panel_list_separator string
List separator. Predefined values:
popup.panel_shadow boolean
Shadow.
Number formatting
localization.input_decimal_separator string
Decimal separator in data sheet. Used for interpreting your data. Only change if data is not displaying on the chart as expected. Allowed values:
localization.output_separators string
Number format to display. How the numbers should appear on chart labels Allowed values:
size_by_format.prefix string
Prefix. Text to place in front of number
size_by_format.suffix string
Suffix. Text to place after number
size_by_format.n_dec number
Decimal places. Enter a negative integer to round to a whole number with that many zeros. For example, -2 will round to the nearest hundred. Min: -10 Max: 10
size_by_format.advanced boolean
Advanced.
size_by_format.negative_sign string
Styling of negative numbers. Allowed values:
size_by_format.strip_zeros boolean
Remove trailing zeros.
size_by_format.strip_separator boolean
Hide thousands separator below 10,000. Turn off if you want four-digit numbers to include a separator, e.g. “1,234” rather than “1234”.
size_by_format.transform_labels boolean
Multiply/divide values.
size_by_format.transform string
Allowed values:
- multiply (Multiply by)
- divide (Divide by)
- exponentiate (×10 to the power of)
size_by_format.multiply_divide_constant number
size_by_format.exponentiate_constant number
Layout
Layout
layout.body_font font
Main font. This font will apply to the whole graphic by default. You can optionally change the font for the title, subtitle, footer, etc in the Header and Footer settings panels.
layout.font_color color
Text color. This color will apply to the whole graphic by default, You can optionally change the color for individual text elements, in other settings panels.
layout.background_color_enabled boolean
Color. Allowed values:
layout.background_image_enabled boolean
Image. Allowed values:
layout.background_color color
Background color.
layout.background_image_src url
Image URL.
layout.background_image_size string
Size. Allowed values:
layout.background_image_position string
Position. Allowed values:
layout.max_width_target string
Maximum width. Apply a maximum width to just the main graphic or everything (main graphic plus header, footer, etc). Allowed values:
layout.max_width number
Maximum width. Leave blank to stretch to container width Min: 50
layout.max_width_align string
Align. Allowed values:
layout.layout_order string
Layout order. Allowed values:
layout.space_between_sections string
Space between sections. Allowed values:
layout.space_between_sections_custom number
Custom. Max: 100
layout.margin_top number
Top.
layout.margin_right number
Right.
layout.margin_bottom number
Bottom.
layout.margin_left number
Left.
layout.border.enabled boolean
Show borders around visualisation.
layout.border.top.width number
Top.
layout.border.top.style string
Style. Allowed values:
layout.border.top.color color
Color.
layout.border.right.width number
Right.
layout.border.right.style string
Style. Allowed values:
layout.border.right.color color
Color.
layout.border.bottom.width number
Bottom.
layout.border.bottom.style string
Style. Allowed values:
layout.border.bottom.color color
Color.
layout.border.left.width number
Left.
layout.border.left.style string
Style. Allowed values:
layout.border.left.color color
Color.
layout.read_direction string
Read direction. This will change the reading direction of the main text elements on the page. It's not possible to adjust this on all elements, such as axes. Allowed values:
Note that when direction is set to right to left any alignment icons will be reversed.
layout.font_size_mobile_small number
layout.font_size_mobile_big number
layout.font_size_tablet number
layout.font_size_desktop number
layout.font_size_big_screen number
layout.breakpoint_mobile_small number
layout.breakpoint_mobile_big number
layout.breakpoint_tablet number
layout.breakpoint_desktop number
layout.breakpoint_big_screen number
Header
layout.header_align string
Alignment. Allowed values:
layout.title html
layout.title_styling boolean
Styling.
layout.title_font font
Title Font.
layout.title_size string
Size. Allowed values:
layout.title_size_custom number
Custom. Specify a custom responsive font size in rems. The best results will be with values between 1.2 and 3
layout.title_weight string
Weight. Allowed values:
layout.title_color color
Color.
layout.title_line_height number
Line height. Max: 3
layout.title_space_above string
Space above. Allowed values:
layout.title_space_above_custom number
Custom. Max: 100
layout.subtitle html
layout.subtitle_styling boolean
Styling.
layout.subtitle_font font
Subtitle Font.
layout.subtitle_size string
Size. Allowed values:
layout.subtitle_size_custom number
Custom. Specify a custom responsive font size in rems. The best results will be with values between 1.2 and 3
layout.subtitle_weight string
Weight. Allowed values:
layout.subtitle_color color
Color.
layout.subtitle_line_height number
Line height. Max: 3
layout.subtitle_space_above string
Space above. Allowed values:
layout.subtitle_space_above_custom number
Custom. Max: 100
layout.header_text html
layout.header_text_styling boolean
Styling.
layout.header_text_size string
Size. Allowed values:
layout.header_text_size_custom number
Custom. Specify a custom responsive font size in rems. The best results will be with values between 1.2 and 3
layout.header_text_weight string
Weight. Allowed values:
layout.header_text_color color
Color.
layout.header_text_line_height number
Line height. Max: 3
layout.header_text_space_above string
Space above. Allowed values:
layout.header_text_space_above_custom number
Custom. Max: 100
layout.header_border string
Allowed values:
- top (Top)
- bottom (Bottom)
- top_and_bottom (Top & bottom)
- none (None)
layout.header_border_width number
Width.
layout.header_border_color color
Color.
layout.header_border_style string
Style. Allowed values:
layout.header_border_space number
Space. Space between border and header text
layout.header_logo_enabled boolean
Allowed values:
- true (Enabled)
- false (Disabled)
layout.header_logo_src url
Image.
layout.header_logo_alt string
Alt text.
layout.header_logo_link_url string
Link.
layout.header_logo_height number
Height.
layout.header_logo_align string
Align. Align logo inside either the header or the main visualization container Allowed values:
layout.header_logo_position_inside string
Position. Allowed values:
layout.header_logo_position_outside string
Position. Allowed values:
layout.header_logo_margin_top number
Top.
layout.header_logo_margin_right number
Right.
layout.header_logo_margin_bottom number
Bottom.
layout.header_logo_margin_left number
Left.
Footer
layout.footer_align string
Alignment. Allowed values:
layout.footer_text_size number
Size.
layout.footer_text_color color
Color.
layout.footer_styling boolean
Advanced footer styles.
layout.footer_font font
Font.
layout.footer_text_weight string
Weight. Allowed values:
layout.source_name string
Source name.
layout.source_url string
Source url.
layout.multiple_sources boolean
Multiple sources.
layout.source_name_2 string
Source name.
layout.source_url_2 string
Source url.
layout.source_name_3 string
Source name.
layout.source_url_3 string
Source url.
layout.source_label string
Source label.
layout.footer_note html
Note. To add the time/date stamp of when the data was last updated add {{data_last_updated}}. For example, "Last updated at {{data_last_updated}}". To customize the format, use the advanced options below.
layout.footer_note_secondary html
Note (secondary). The secondary note is placed below the source and primary note. To add the time/date stamp of when the data was last updated add {{data_last_updated}}. For example, "Last updated at {{data_last_updated}}". To customize the format, use the advanced options below.
layout.advanced_note_styling boolean
Advanced.
layout.footer_timestamp_format string
Time/date stamp formatting. To change the date/time format of your timestamp, choose from the below options or provide a custom date format in d3-time-format syntax Predefined values:
layout.footer_logo_enabled boolean
Image. Allowed values:
layout.footer_logo_src url
Image.
layout.footer_logo_src_light hidden
Image (light version). If provided this version will be used whenever the background color is dark
layout.footer_logo_alt string
Alt text.
layout.footer_logo_link_url string
Link.
layout.footer_logo_height number
Height.
layout.footer_logo_margin number
Margin.
layout.footer_logo_order string
Position. Allowed values:
layout.footer_align_vertical string
V. align. Allowed values:
layout.footer_border string
Allowed values:
- top (Top)
- bottom (Bottom)
- top_and_bottom (Top & bottom)
- none (None)
layout.footer_border_width number
Width.
layout.footer_border_color color
Color.
layout.footer_border_style string
Style. Allowed values:
layout.footer_border_space number
Space. Space between border and footer text
Accessibility
layout.screenreader_text_primary text
Screenreader description. A text alternative to the visual content that will only be visible to screenreaders, e.g. “The line chart shows China consistently higher than the other countries since 1990”.
Do not replicate your title, since that will also be read by screenreaders.
layout.screenreader_label string
Screenreader label. A short text label given to the main Flourish embed wrapper to provide an accessible name that is only visible to screenreaders. Added in the form of an "aria-label".
layout.screenreader_hide_primary boolean
Screenreader mode for main visual container. Whether the main visual container is visible to screenreaders. (Text in the header and footer are always available to screenreaders.) Allowed values: