A React component for displaying text. Text supports nesting, styling, and touch handling. In the following example, the nested title and body text will inherit the fontFamily from styles.baseText, but the title provides its own additional styles. The title and body will stack on top of each other on account of the literal newlines:

import React, {useState} from 'react';
import {Text, StyleSheet} from 'react-native';

const TextInANest = () => {
  const [titleText, setTitleText] = useState("Bird's Nest");
  const bodyText = 'This is not really a bird nest.';

  const onPressTitle = () => {
    setTitleText("Bird's Nest [pressed]");
  };

  return (
    <Text style={styles.baseText}>
      <Text style={styles.titleText} onPress={onPressTitle}>
        {titleText}
        {'\n'}
        {'\n'}
      </Text>
      <Text numberOfLines={5}>{bodyText}</Text>
    </Text>
  );
};

const styles = StyleSheet.create({
  container: {
    flex: 1,
  },
  baseText: {
    fontFamily: 'Cochin',
  },
  titleText: {
    fontSize: 20,
    fontWeight: 'bold',
  },
});

export default TextInANest;

Nested text

Vega allows you to display formatted text by annotating ranges of a string with specific formatting like bold or colored text. In practice, this is very tedious. For React Native, we decided to use tge web paradigm for this where you can nest text to achieve the same effect.

import React from 'react';
import {Text, StyleSheet} from 'react-native';

const BoldAndBeautiful = () => (
    <Text style={styles.baseText}>
      I am bold
      <Text style={styles.innerText}> and red</Text>
    </Text>
);

const styles = StyleSheet.create({
  container: {
    flex: 1,
  },
  baseText: {
    fontWeight: 'bold',
  },
  innerText: {
    color: 'red',
  },
});

export default BoldAndBeautiful;

Behind the scenes, React Native converts this to a flat NSAttributedString or SpannableString that contains the following information:

"I am bold and red"
0-9: bold
9-17: bold, red

Limited style inheritance

On the web, the usual way to set a font family and size for the entire document is to take advantage of inherited CSS properties like so:

html {
  font-family: 'lucida grande', tahoma, verdana, arial, sans-serif;
  font-size: 11px;
  color: #141823;
}

All elements in the document will inherit this font unless they or one of their parents specifies a new rule. In React Native, we are more strict about it: you must wrap all the text nodes inside of a component. You cannot have a text node directly under a .

// BAD: will raise exception, can't have a text node as child of a <View>
<View>
  Some text
</View>

// GOOD
<View>
  <Text>
    Some text
  </Text>
</View>

You also lose the ability to set up a default font for an entire subtree. Meanwhile, fontFamily only accepts a single font name, which is different from font-family in CSS. The recommended way to use consistent fonts and sizes across your application is to create a component MyAppText that includes them and use this component across your app. You can also use this component to make more specific components like MyAppHeaderText for other kinds of text.

<View>
  <MyAppText>
    Text styled with the default font for the entire application
  </MyAppText>
  <MyAppHeaderText>Text styled as a header</MyAppHeaderText>
</View>

Assuming that MyAppText is a component that only renders out its children into a Text component with styling, then MyAppHeaderText can be defined as follows:

const MyAppHeaderText = ({children}) => {
  return (
    <MyAppText>
      <Text style={{fontSize: 20}}>{children}</Text>
    </MyAppText>
  );
};

Composing MyAppText in this way makes sure that we get the styles from a top-level component, but leaves us the ability to add or override them in specific use cases. React Native still has the concept of style inheritance, but limited to text subtrees. In this case, the second part will be both bold and red.

<Text style={{fontWeight: 'bold'}}>
  I am bold
  <Text style={{color: 'red'}}>and red</Text>
</Text>

We believe that this more constrained way to style text will yield better apps:

(Developer) React components are designed with strong isolation in mind: You should be able to drop a component anywhere in your application, trusting that as long as the props are the same, it will look and behave the same way. Text properties that could inherit from outside of the props would break this isolation.
(Implementor) The implementation of React Native is also simplified. We do not need to have a fontFamily field on every single element, and we do not need to potentially traverse the tree up to the root every time we display a text node. The style inheritance is only encoded inside of the native Text component and doesn’t leak to other components or the system itself.

Reference

Props

accessibilityHint

An accessibility hint helps users understand what will happen when they perform an action on the accessibility element when that result is not clear from the accessibility label.

Type
string

accessibilityLabel

Overrides the text that’s read by the screen reader when the user interacts with the element. By default, the label is constructed by traversing all the children and accumulating all the Text nodes separated by space.

Type
string

accessibilityRole

Tells the screen reader to treat the currently focused on element as having a specific role.

Type
AccessibilityRole

accessibilityState

Tells the screen reader to treat the currently focused on element as being in a specific state. You can provide one state, no state, or multiple states. The states must be passed in through an object. For exmaple, {selected: true, disabled: true}.

Type
AccessibilityState

accessibilityActions

Accessibility actions allow an assistive technology to programmatically invoke the actions of a component. The accessibilityActions property should contain a list of action objects. Each action object should contain the field name and label. See the Accessibility guide for more information.

Type	Required
array	No

onAccessibilityAction

Invoked when the user performs the accessibility actions. The only argument to this function is an event containing the name of the action to perform. See the Accessibility guide for more information.

Type	Required
function	No

accessible

When set to true, indicates that the view is an accessibility element.

Type	Default
boolean	`true`

adjustsFontSizeToFit

Specifies whether fonts should be scaled down automatically to fit given style constraints.

Type	Default
boolean	`false`

aria-disabled

Indicates that the element is perceivable but disabled, so it is not editable or otherwise operable.

Type	Default
boolean	false

aria-expanded

Indicates whether an expandable element is currently expanded or collapsed.

Type	Default
boolean	false

ariaLabel

Deprecated. Use aria-label instead. The value for ariaLabel refers to the name of the item, such as “Alexa, select Prime Video”. This prop is required you want your app to allow The user to perform voice selection based on the name. Providing the prop with a value does not result in the value being render as the title of the component, app needs to explicted render the same text value for the item.

Type
string

aria-label

Defines a string value that labels an interactive element, that you can use to specify the name of the item in voice selection, such as “Alexa, select Prime Video”. This prop is required if the app wants to allow the user to perform voice selection based on the name. Note that providing the prop with a value does not result in the value being render as the title of the component. The app needs to explictly render the same text value for the item.

Type
string

aria-live

Indicates that an element will be updated, and describes the types of updates the user agents, assistive technologies, and user can expect from the live region.

off Accessibility services should not announce changes to this view.
polite Accessibility services should announce changes to this view.
assertive Accessibility services should interrupt ongoing speech to immediately announce changes to this view.

Type	Default
enum(`'assertive'`, `'off'`, `'polite'`)	`'off'`

Type
string

aria-selected

Indicates whether a selectable element is currently selected or not.

Type
boolean

disabled

Specifies the disabled state of the text view for testing purposes.

Type	Default
boolean	`false`

ellipsizeMode

When numberOfLines is set, this prop defines how the text will be truncated. numberOfLines must be set in conjunction with this prop. This can be one of the following values:

head - The line is displayed so that the end fits in the container and the missing text at the beginning of the line is indicated by an ellipsis glyph. e.g., “…wxyz”
middle - The line is displayed so that the beginning and end fit in the container and the missing text in the middle is indicated by an ellipsis glyph. “ab…yz”
tail - The line is displayed so that the beginning fits in the container and the missing text at the end of the line is indicated by an ellipsis glyph. e.g., “abcd…”
clip - Lines are not drawn past the edge of the text container.
marquee - If the text content exceeds the width of the text container, the text scrolls horizontally in a “marquee” effect to display the hidden content.
- Requirements for this effect to take place:
  - The <Text> component must be focusable. The marquee effect is applied whenever the focus enters or leaves the <Text> component.

When numberOfLines is set to a value higher than 1, only tail value will work correctly.

Type	Default
enum(`'head'`, `'middle'`, `'tail'`, `'clip'`,`'marquee'` )	`tail`

minimumFontScale

Specifies the smallest possible scale a font can reach when adjustsFontSizeToFit is enabled. (values 0.01-1.0).

Type
number

nativeID

Used to locate this view from native code.

Type
string

selected

Specifies that the view is explicitly marked as chosen or active, regardless of user interaction or focus. When set to true, it may trigger associated styling or behavioral changes. For example, if ellipsizeMode is set to marquee, selected=true starts the marquee animation.

Type	Default
boolean	`false`

numberOfLines

Used to truncate the text with an ellipsis after computing the text layout, including line wrapping, such that the total number of lines does not exceed this number. Setting this property to 0 will result in unsetting this value, which means that no lines restriction will be applied. This prop is commonly used with ellipsizeMode.

Type	Default
number	`0`

onLayout

Invoked on mount and on layout changes.

Type
`({nativeEvent: [LayoutEvent](layoutevent)}) => void`

onPress

Function called on user press, triggered after onPressOut.

Type
`({nativeEvent: [PressEvent](pressevent)}) => void`

onTextLayout

Invoked on Text layout change.

Type
(`TextLayoutEvent`) => mixed

role

role communicates the purpose of a component to the user of an assistive technology. Has precedence over the accessibilityRole prop.

Type
Role

selectable

Lets the user select text, to use the native copy and paste functionality.

Type	Default
boolean	`false`

style

Type
Text Style, View Style Props

testID

Used to locate this view in end-to-end tests.

Type
string

alexaEntityType - Vega Only

Represents the value for the type of object to pass to the Alexa UIController Interface. This is an optional prop and specific to Alexa UIController Interface support, it maps to the entity.type field from the Alexa UIController Interface. For additional information, see Alexa UIController API doc.

Type
enum(‘Thing’, ‘VideoObject’, ‘ItemList’, ‘SoftwareApplication’)

alexaExternalIds - Vega Only

This is an optional prop and specific to Alexa UIController Interface support, it maps to the entity.ExternalIds field from the Alexa UIController Interface. For additiona information, see Alexa UIController API doc. The entity.ExternalIds are the identifiers for this entity unique within the scope of this endpoint. The entity.externalIds field is opaque to Alexa and is only used to include in directives from Alexa. The identifiers reported in entity.externalIds are required to be understood by the endpoint on all directive commands that accept an entity structure.

Type
`object: {key: "string", value: "string"}`

keplerAtlLabels - Vega Only

The value for keplerAltLabels refers to the list of alternate names for the item. Note: This property replaces keplerAtlLabels. keplerAtlLabels is deprecated and will be removed in a future release. This prop is required if the app wants to allow user to perform voice selection on the same item with different names.

Type
Array of string

Type definitions

TextLayout

TextLayout object is a part of TextLayoutEvent callback and contains the measurement data for Text line.

Example

{
    capHeight: 10.496,
    ascender: 14.624,
    descender: 4,
    width: 28.224,
    height: 18.624,
    xHeight: 6.048,
    x: 0,
    y: 0
}

Properties

Name	Type	Optional	Description
ascender	number	No	The line ascender height after the text layout changes.
capHeight	number	No	Height of capital letter above the baseline.
descender	number	No	The line descender height after the text layout changes.
height	number	No	Height of the line after the text layout changes.
width	number	No	Width of the line after the text layout changes.
x	number	No	Line X coordinate inside the Text component.
xHeight	number	No	Distance between the baseline and median of the line (corpus size).
y	number	No	Line Y coordinate inside the Text component.

TextLayoutEvent

TextLayoutEvent object is returned in the callback as a result of a component layout change. It contains a key called lines with a value which is an array containing TextLayout object corresponded to every rendered text line.

Example

{
  lines: [
    TextLayout,
    TextLayout,
    // ...
  ];
  target: 1127;
}

Properties

Name	Type	Optional	Description
lines	array of TextLayout	No	Provides the TextLayout data for every rendered line.
target	number	No	The node id of the element.

id

Used to locate this view from native code. Has precedence over nativeID prop.

Type
string

keplerAltLabels - Vega Only

Type
Array of string

​Nested text

​Limited style inheritance

​Reference

​Props

​accessibilityHint

​accessibilityLabel

​accessibilityRole

​accessibilityState

​accessibilityActions

​onAccessibilityAction

​accessible

​adjustsFontSizeToFit

​aria-disabled

​aria-expanded

​ariaLabel

​aria-label

​aria-live

​aria-selected

​disabled

​ellipsizeMode

​minimumFontScale

​nativeID

​selected

​numberOfLines

​onLayout

​onPress

​onTextLayout

​role

​selectable

​style

​testID

​alexaEntityType - Vega Only

​alexaExternalIds - Vega Only

​keplerAtlLabels - Vega Only

​Type definitions

​TextLayout

​Example

​Properties

​TextLayoutEvent

​Example

​Properties

​id

​keplerAltLabels - Vega Only

Nested text

Limited style inheritance

Reference

Props

accessibilityHint

accessibilityLabel

accessibilityRole

accessibilityState

accessibilityActions

onAccessibilityAction

accessible

adjustsFontSizeToFit

aria-disabled

aria-expanded

ariaLabel

aria-label

aria-live

aria-selected

disabled

ellipsizeMode

minimumFontScale

nativeID

selected

numberOfLines

onLayout

onPress

onTextLayout

role

selectable

style

testID

alexaEntityType - Vega Only

alexaExternalIds - Vega Only

keplerAtlLabels - Vega Only

Type definitions

TextLayout

Example

Properties

TextLayoutEvent

Example

Properties

id

keplerAltLabels - Vega Only