APL Text


The Text component displays text in either a single line or multiple lines.

Properties

The Text component has the following properties in addition to the base component properties. See the meaning of the columns.

Property Type Default Styled Dynamic Description

color

Color

depends on the theme

Yes

Yes

The color of the text.

fontFamily

String

sans-serif

Yes

Yes

Font family (such as "Amazon Ember Display").

fontSize

Non-negative absolute Dimension

40dp

Yes

Yes

The size of the text.

fontStyle

normal, italic

normal

Yes

Yes

The font style to display.

fontWeight

normal, bold, 100, 200, 300, 400, 500, 600, 700, 800, 900

normal

Yes

Yes

The font weight to display.

lang

String

""

Yes

Yes

The language of the text. When set, APL attempts to find a language-specific version of the fontFamily for displaying the text.

letterSpacing

Absolute Dimension

0

Yes

No

Additional space to add between letters.

lineHeight

Number (percentage)

125%

Yes

No

Line-height multiplier.

maxLines

Non-negative integer

0

Yes

No

The maximum number of lines of text to display. The text will be truncated with an ellipsis if not all text is visible.

text

String

""

No

Yes

The markup to display in this text box. If this value is set to null or an empty string "", no content appears.

textAlign

auto, left, right, center, start, end

auto

Yes

No

Alignment of text within a paragraph.

textAlignVertical

auto, top, bottom, center

auto

Yes

No

Vertical alignment of text.

Most of these properties have default values specified by the current text style. Refer to Resources for a discussion of styles.

A Text component doesn't scroll unless it's within a ScrollView.

When the Text is the source or target of an event, the following values are reported in event.source or event.target:

{
  // Text-specific values
  "type": "Text",
  "text": String,      // Displayed text
  "color": Color,      // The text color

  // General component values
  "bind": Map,         // Access to component data-binding context
  "checked": Boolean,  // Checked state
  "disabled": Boolean, // Disabled state
  "focused": Boolean,  // Focused state
  "height": Number,    // Height of the component, in dp (includes the padding)
  "id": ID,            // ID of the component
  "opacity": Number,   // Opacity of the component [0-1]
  "pressed": Boolean,  // Pressed state
  "uid": UID,          // Runtime-generated unique ID of the component
  "width": Number      // Width of the component, in dp (includes the padding)
}

layoutDirection component property

The component layoutDirection property determines how the Text component interprets the textAlign property for aligning text.

height and width component properties

The component properties for height and width control the size of the bounding box for a Text component. When the bounding box is too small for the text to display, the device truncates the text and displays an ellipsis to indicate that not all text is displayed.

For details about the component height and width properties, see APL Base Component Properties.

For details and examples of the text bounding box, see Understand the bounding box for the Text component.

color

The color of the text. If the theme is light, the default is #1E2222. If the theme is dark, the default is #FAFAFA.

fontFamily

Specifies the font for the displayed text. The fontFamily property takes a single font name or a string containing a comma-separated list of font names. The APL runtime searches the list for the first named font installed on the device. If no valid font is found, the runtime defaults to the sans-serif font.

Font names can contain spaces. APL supports two types of font names:

  • The specific name of an installed font such as "amazon-ember", "times", "times new roman".
  • A generic name - either "serif" or "sans-serif".

Alexa devices don't guarantee a specific set of fonts. End your fontFamily list with either "serif" or "sans-serif" to make sure that a valid font is available.

{
"type": "Text",
"fontFamily", "times new roman, times, georgia, serif"
}

On many Alexa devices, "sans-serif" defaults to "Amazon Ember Display" and "serif" defaults to "Bookerly". In some Asian markets they default to "Noto Sans CJK".

For details about font styles available in the alexa-styles package, see Font family.

fontSize

The size of the font, normally expressed in dp. The default is 40dp.

fontStyle

The style of the font, either normal or italic. Defaults to normal.

fontWeight

The font weight for the displayed text. Defaults to normal. The normal and bold values are assigned at runtime. The integer values 100 through 900 correspond to progressively darker variations of the font. Most fonts don't support this many variations. For example, Amazon Ember Display has five weights (Thin, Light, Regular, Medium, Bold) which are assigned 100, 300, 500, 700, and 900 respectively.

Note that fontWeight represents an enumerated set, not integers or strings. For example, the value 750 is invalid and doesn't set the font to a weight between 700 and 800.

When you create a resource for a fontWeight, use a string resource. The following example resource block creates two resources for fontWeight called myMidFontWeight and myLightFontWeight.

{
  "resources": [
    {
      "strings": {
        "myMidFontWeight": "500",
        "myLightFontWeight": "100"
      }
    }
  ]
}

lang

The language of the text. When set, APL attempts to find a language-specific version of the fontFamily for displaying the text.

If no valid font is found, APL ignores this property and uses the specified fontFamily.

Set the lang property to a BCP-47 string (for example, "en-US").

The following example displays a Text component with a Japanese-style version of the NotoSans-CJK font:

{
    "type": "APL",
    "version": "2024.1",
    "mainTemplate": {
        "item": {
            "type": "Text",
            "lang": "ja-JP",
            "fontFamily": "Noto Sans CJK"
        }
    }
}

Note: Alexa devices might not have the font in specific language installed. Test the experience on the device or devices to confirm that it works.

letterSpacing

Additional space to add between letters. Defaults to 0.

lineHeight

Line-height multiplier. Defaults to 125%.

The leading of the font is the fontSize multiplied by the lineHeight. For example, on a 320 dpi display with 100dp fontSize and 120% lineHeight, the font size is 200 pixels and the leading is 240 pixels. Setting the lineHeight to less than 100% can cause characters to overlap.

maxLines

The maximum number of lines of text to display. Defaults to 0, which indicates no maximum. Set to a positive integer to clip the text to the specified number of lines and insert an ellipsis to show that the text is truncated.

text

Text string to display in the text block. If set to an empty string, no text displays. Setting to null is equivalent to an empty string ("").

Text blocks support simple markup. Supported tags include:

Tag Description Example Display

<br>

Insert a line break. Line breaks may be repeated.

Line 1<br>Line 2

Line 1
Line 2

<strong>, <b>

Bold a span of text. (font weight 700).

<b>Large</b> dogs are friendly.

Large dogs are friendly.

<em>, <i>

Italic a span of text.

Read <em>Emma</em> for homework.

Read Emma for homework.

<strike>

Strikethrough a span of text

The document is <strike>fine</strike> pretty good.

The document is fine pretty good.

<u>

Underline a span of text

I just <u>loved</u> the chocolate!

I just loved the chocolate!

<tt>, <code>

Monospace a span of text.

The <code>main</code> function is the entry point.

The main function is the entry point.

<sup>, <sub>

Superscript and subscript a span of text.

See Gibson<sup>1</sup> for the H<sub>2</sub>O formula.

See Gibson1 for the H2O formula.

<nobr>

Prevent text from automatically wrapping across multiple lines

Avoid breaking <nobr>Dr. A. Ramaswamy</nobr> and treat it as one whole word.

Avoid breaking
Dr. A. Ramaswamy and treat it as one whole word.

<span>

Define a span to apply inline formatting. See Supported span attributes.

This is <span color="red">RED</span>

This is RED

You can nest markup elements. Improperly nested markup gives undefined behavior. For example, the following code might not render correctly because the <b> and <u> elements aren't nested correctly.

<b>Once upon a time, <u>a small dog</b> ate a grasshopper and felt ill.</u>.

The following example shows the use of text markup.


Markup characters in text must be replaced with character entity references.

Entity Character Description

&amp;

&

Ampersand

&lt;

<

Less-than

&gt;

>

Greater-than

&#nn;

Any Decimal Unicode code-point.

"nn" is a valid integer.

&#xnn;

Hexadecimal Unicode code-point.

"nn" is a valid hexadecimal number

Numeric entity references can be in decimal or hexadecimal. For example, © can be written &#169; or &#xa9;.

Supported span attributes

The <span> tag supports the named attributes shown in the following table.

Attribute Description Example Display

color

Color of the text span.

Can be any color. You can specify the color using a resource.

Set to inherit to set the span color to the color property of the text.

This is <span color="red">RED</span>

This is RED

fontSize

Font size for the text span. Must be a non-negative absolute dimension. You can set the dimension using a resource.

Set to inherit to set the font size of the span to the fontSize of the text.

This is <span fontSize="48dp"\>BIG</span\>

This is BIG

textAlign

Controls the horizontal alignment for lines of text. Set to one of the following:

  • auto (default)
  • left
  • center
  • right
  • start
  • end

The auto, start, and end properties all align the text based on the specified layoutDirection for the component:

Property Left-to-right ("LTR") Right-to-left ("RTL")

auto

Left-aligns text

Right-aligns text

start

Left-aligns text

Right-aligns text

end

Right-aligns text

Left-aligns text

textAlignVertical

Positions the text within the text box. Only used if the text box is taller than the text content. Defaults to top.

Sample text

The following example shows a Text component that displays the provided text in green. The example uses a conditional statement for the maxLines property to truncate the text on small, round hubs, but show the full text on larger devices.



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Last updated: Jan 08, 2024