Expo

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Text

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

export default class TextInANest extends Component {
  constructor(props) {
    super(props);
    this.state = {
      titleText: "Bird's Nest",
      bodyText: 'This is not really a bird nest.'
    };
  }

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

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

// skip this line if using Create React Native App
AppRegistry.registerComponent('TextInANest', () => TextInANest);

Both iOS and Android allow you to display formatted text by annotating ranges of a string with specific formatting like bold or colored text (NSAttributedString on iOS, SpannableString on Android). In practice, this is very tedious. For React Native, we decided to use web paradigm for this where you can nest text to achieve the same effect.
import React, { Component } from 'react';
import { AppRegistry, Text } from 'react-native';

export default class BoldAndBeautiful extends Component {
  render() {
    return (
      <Text style={{fontWeight: 'bold'}}>
        I am bold
        <Text style={{color: 'red'}}>
          and red
        </Text>
      </Text>
    );
  }
}

// skip this line if using Create React Native App
AppRegistry.registerComponent('AwesomeProject', () => 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

The <Text> element is special relative to layout: everything inside is no longer using the flexbox layout but using text layout. This means that elements inside of a <Text> are no longer rectangles, but wrap when they see the end of the line.
<Text>
  <Text>First part and </Text>
  <Text>second part</Text>
</Text>
// Text container: the text will be inline if the space allowed it
// |First part and second part|

// otherwise, the text will flow as if it was one
// |First part |
// |and second |
// |part       |

<View>
  <Text>First part and </Text>
  <Text>second part</Text>
</View>
// View container: each text is its own block
// |First part and|
// |second part   |

// otherwise, the text will flow in its own block
// |First part |
// |and        |
// |second part|

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 <Text> component. You cannot have a text node directly under a <View>.
// 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 simply renders out its children into a Text component with styling, then MyAppHeaderText can be defined as follows:
class MyAppHeaderText extends Component {
  render() {
    return (
      <MyAppText>
        <Text style={{fontSize: 20}}>{this.props.children}</Text>
      </MyAppText>
    );
  }
}
Composing MyAppText in this way ensures that we get the styles from a top-level component, but leaves us the ability to add / 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

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

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.
TypeRequired
stringNo

Tells the screen reader to treat the currently focused on element as having a specific role.
Possible values for AccessibilityRole is one of:
  • 'none' - The element has no role.
  • 'button' - The element should be treated as a button.
  • 'link' - The element should be treated as a link.
  • 'header' - The element is a header that divides content into sections.
  • 'search' - The element should be treated as a search field.
  • 'image' - The element should be treated as an image.
  • 'key' - The element should be treated like a keyboard key.
  • 'text' - The element should be treated as text.
  • 'summary' - The element provides app summary information.
  • 'imagebutton' - The element has the role of both an image and also a button.
  • 'adjustable' - The element allows adjustment over a range of values.
On iOS, these roles map to corresponding Accessibility Traits. Image button has the same functionality as if the trait was set to both 'image' and 'button'. See the Accessibility guide for more information.
On Android, these roles have similar functionality on TalkBack as adding Accessibility Traits does on Voiceover in iOS
TypeRequired
AccessibilityRoleNo

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. Ex: {selected: true, disabled: true}.
Possible values for AccessibilityState are:
  • 'selected' - The element is in a selected state.
  • 'disabled' - The element is in a disabled state.
TypeRequired
objectNo

When set to true, indicates that the view is an accessibility element. The default value for a Text element is true.
See the Accessibility guide for more information.
TypeRequired
boolNo

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

Specifies whether fonts should scale to respect Text Size accessibility settings. The default is true.
TypeRequired
boolNo

Determines the types of data converted to clickable URLs in the text element. By default no data types are detected.
You can provide only one type.
Possible values for dataDetectorType are:
  • 'phoneNumber'
  • 'link'
  • 'email'
  • 'none'
  • 'all'
TypeRequiredPlatform
enum('phoneNumber', 'link', 'email', 'none', 'all')NoAndroid

Specifies the disabled state of the text view for testing purposes
TypeRequiredPlatform
boolNoAndroid

When numberOfLines is set, this prop defines how 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.
The default is tail.
TypeRequired
enum('head', 'middle', 'tail', 'clip')No

Specifies largest possible scale a font can reach when allowFontScaling is enabled. Possible values:
  • null/undefined (default): inherit from the parent node or the global default (0)
  • 0: no max, ignore parent/global default
  • >= 1: sets the maxFontSizeMultiplier of this node to this value
TypeRequired
numberNo

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

Used to locate this view from native code.
TypeRequired
stringNo

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.
This prop is commonly used with ellipsizeMode.
TypeRequired
numberNo

Invoked on mount and layout changes with
{nativeEvent: {layout: {x, y, width, height}}}
TypeRequired
functionNo

This function is called on long press.
e.g., onLongPress={this.increaseSize}>
TypeRequired
functionNo

Does this view want to "claim" touch responsiveness? This is called for every touch move on the View when it is not the responder.
View.props.onMoveShouldSetResponder: (event) => [true | false], where event is a synthetic touch event as described above.
TypeRequired
functionNo

This function is called on press.
e.g., onPress={() => console.log('1st')}
TypeRequired
functionNo

The View is now responding for touch events. This is the time to highlight and show the user what is happening.
View.props.onResponderGrant: (event) => {}, where event is a synthetic touch event as described above.
TypeRequired
functionNo

The user is moving their finger.
View.props.onResponderMove: (event) => {}, where event is a synthetic touch event as described above.
TypeRequired
functionNo

Fired at the end of the touch.
View.props.onResponderRelease: (event) => {}, where event is a synthetic touch event as described above.
TypeRequired
functionNo

The responder has been taken from the View. Might be taken by other views after a call to onResponderTerminationRequest, or might be taken by the OS without asking (e.g., happens with control center/ notification center on iOS)
View.props.onResponderTerminate: (event) => {}, where event is a synthetic touch event as described above.
TypeRequired
functionNo

Some other View wants to become responder and is asking this View to release its responder. Returning true allows its release.
View.props.onResponderTerminationRequest: (event) => {}, where event is a synthetic touch event as described above.
TypeRequired
functionNo

If a parent View wants to prevent a child View from becoming responder on a touch start, it should have this handler which returns true.
View.props.onStartShouldSetResponderCapture: (event) => [true | false], where event is a synthetic touch event as described above.
TypeRequired
functionNo

TODO.

When the scroll view is disabled, this defines how far your touch may move off of the button, before deactivating the button. Once deactivated, try moving it back and you'll see that the button is once again reactivated! Move it back and forth several times while the scroll view is disabled. Ensure you pass in a constant to reduce memory allocations.
TypeRequired
object: {top: number, left: number, bottom: number, right: number}No

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

The highlight color of the text.
TypeRequiredPlatform
colorNoAndroid

TypeRequired
styleNo
  • textShadowOffset: object: {width: number,height: number}
  • color: color
  • fontSize: number
  • fontStyle: enum('normal', 'italic')
  • fontWeight: enum('normal', 'bold', '100', '200', '300', '400', '500', '600', '700', '800', '900')
    Specifies font weight. The values 'normal' and 'bold' are supported for most fonts. Not all fonts have a variant for each of the numeric values, in that case the closest one is chosen.
  • lineHeight: number
  • textAlign: enum('auto', 'left', 'right', 'center', 'justify')
    Specifies text alignment. The value 'justify' is only supported on iOS and Android Oreo (8.0) or above (API level >= 26). For lower android version it will fallback to left.
  • textDecorationLine: enum('none', 'underline', 'line-through', 'underline line-through')
  • textShadowColor: color
  • fontFamily: string
  • textShadowRadius: number
  • includeFontPadding: bool (Android)
    Set to false to remove extra font padding intended to make space for certain ascenders / descenders. With some fonts, this padding can make text look slightly misaligned when centered vertically. For best results also set textAlignVertical to center. Default is true.
  • textAlignVertical: enum('auto', 'top', 'bottom', 'center') (Android)
  • fontVariant: array of enum('small-caps', 'oldstyle-nums', 'lining-nums', 'tabular-nums', 'proportional-nums') (iOS)
  • letterSpacing: number
    Increase or decrease the spacing between characters. The default is 0, for no extra letter spacing.
    iOS: The additional space will be rendered after each glyph.
    Android: Only supported since Android 5.0 - older versions will ignore this attribute. Please note that additional space will be added around the glyphs (half on each side), which differs from the iOS rendering. It is possible to emulate the iOS rendering by using layout attributes, e.g. negative margins, as appropriate for your situation.
  • textDecorationColor: color (iOS)
  • textDecorationStyle: enum('solid', 'double', 'dotted', 'dashed') (iOS)
  • textTransform: enum('none', 'uppercase', 'lowercase', 'capitalize')
  • writingDirection: enum('auto', 'ltr', 'rtl') (iOS)

When true, no visual change is made when text is pressed down. By default, a gray oval highlights the text on press down.
TypeRequiredPlatform
boolNoiOS

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

Set text break strategy on Android API Level 23+, possible values are simple, highQuality, balanced The default value is highQuality.
TypeRequiredPlatform
enum('simple', 'highQuality', 'balanced')NoAndroid

Known issues