React Native Style Tachyons
Overview
React Native Style Tachyons brings functional styling to react-native. It is inspired by Tachyons and uses it's scales and naming convention. More about the advantages of this approach.
Let's see how tachyons compares to traditional styling:
1. Traditional react-native style:
import {StyleSheet} from "react-native";
const s = StyleSheet.create({
view: {
borderWidth: 1,
justifyContent: "flex-start",
padding: MAGIC_PIXEL_VALUE
},
text: {
color: "white",
textAlign: "center"
}
})
<View style={[s.view]}
<Text style={[s.text]}>Something</Text>
</View>2. Improved with react-native-style-tachyons:
import {styles as s} from "react-native-style-tachyons";
<View style={[s.ba, s.jcfs, s.pa2]}> /* 'ba' means border-all */
<Text style={[s.white, s.tc]}>
Something
</Text>
</View>3. or even simpler:
<View cls="ba jcfs pa2"> /* string is checked for validity */
<Text cls="white tc">
Something
</Text>
</View>Of course you can use your old styles along tachyons' classes.
Advantages
- Less code
- No need to maintain a separate stylesheet
- No need to find a proper name for every component you want to style
- Looking at a component tells you exactly how it looks, it's all in one place.
Tachyons' scale
-
Dimensions and typography build on a proven scale, which is relative to
rem, the root font-size. Instead of having to find proper values for padding (or margin, width or height), you use a simple 7-step scale.pa2gets youpaddingof0.5rem. -
The scale progresses with powers of two, so each step is twice as big as the last. This means everything will always line up, no more "off-by-one-pixel"-problems.
-
You can scale the entire design just by setting a different
rem. This is a great advantage when building a responsive app. -
The optional
fontRemparameter scales the font sizes independently of other styles.
Usage
react-native-style-tachyons needs to know your rem upon start:
-
In the entry point of your app include:
import NativeTachyons from 'react-native-style-tachyons'; import { StyleSheet } from 'react-native'; NativeTachyons.build({ /* REM parameter is optional, default is 16 */ rem: screenWidth > 340 ? 18 : 16, /* fontRem parameter is optional to allow adjustment in font-scaling. default falls back to rem */ fontRem: 20 }, StyleSheet);
Sensible rem/fontRem values
Experience with variously sized iPhone and Android phones from 4" to 6" displays showed, that for tablets, rem values in the range of 12 - 18, depending on device resolution, work well. For phones, the same rem can be used, but fontRem should be floored at 14, to keep everything readable.
-
To use the styles
import { styles as s } from "react-native-style-tachyons";
To support javascript property syntax, all style names with hyphens have an equivalent with an underscore, e.g.
s.bg_blackinstead ofs["bg-black"]. -
To use the
cls=''syntax, you have to wrap your component:import NativeTachyons from "react-native-style-tachyons"; NativeTachyons.wrap( class MyComponent extends React.Component { ... }) /* or if you use simple functions */ NativeTachyons.wrap(() => <Text cls="b">Hi there!</Text>)
If you prefer to use a different propName instead of
cls, specify the name in the options:NativeTachyons.build({ clsPropName: "cls" }, StyleSheet);
Reference / Supported Properties
FlexBox
absolute position: "absolute" /* default: "relative" */
flx-i flex: 1
flx-row flexDirection: "row" /* default: "column" */
flx-row-reverse flexDirection: "row-reverse"
flx-col-reverse flexDirection: "column-reverse"
flx-wrap flexWrap: "wrap" /* default: "nowrap" */
aifs alignItems: "flex-start" /* default: "stretch" */
aic alignItems: "center"
aife alignItems: "flex-end"
jcc justifyContent: "center" /* default: "flex-start" */
jcfe justifyContent: "flex-end"
jcsb justifyContent: "space-between"
jcsa justifyContent: "space-around"
asfs alignSelf: "flex-start"
asfe alignSelf: "flex-end"
asc alignSelf: "center"
ass alignSelf: "stretch"Margins & Paddings (Scale)
ma0 ... ma8 margin: 0|0.25|0.5|1|2|4|8|16|32 rem
ml|mr|mb|mt [0-8] marginLeft, marginRight, marginBottom, marginTop
mh [0-8] marginHorizontal
mv [0-8] marginVertical
/* Same with p for padding */Heights & Widths
h1 ... h6 height: 1|2|4|8|16|32 rem
w1 ... w6 width: 1|2|4|8|16|32 rem
min-h1 ... min-h6 minHeight: 1|2|4|8|16|32 rem
max-h1 ... max-h6 maxHeight: 1|2|4|8|16|32 remAbsolute
absolute position: absolute
top|right|bottom|left-0 top|right|bottom|left: 0 rem
... 1 ... 1 rem
... 2 ... 2 rem
absolute-fill position: absolute, top/left/right/bottom: 0Borders
ba borderWidth: 1
bl|br|bt|bb borderLeftWidth: 1 | borderRightWidth: 1...
br0 ... br5 borderRadius: 0|0.125|0.25|0.5|1]2 rem
br--bottom bottom radius only
br--top top radius only
br--right right radius only
br--left left radius onlyText & Fonts (Scale)
f5 fontSize: 1 rem
f1 ... f6 fontSize: 3|2.25|1.5|1.25|1|0.875 rem
f-headline fontSize: 6 rem
f-subheadline fontSize: 5 rem
normal fontWeight: normal
b fontWeight: bold
fw1 ... fw9 fontWeight: 100 ... fontWeight: 900
i fontStyle: italic
tl|tc|tr|tj textAlign: left|center|right|justify
lh-solid lineHeight: 1 rem
lh-title lineHeight: 1.25 rem
lh-copy lineHeight: 1.5 rem
/* Letter-spacing is only supported on iOS */
tracked letterSpacing: 0.1 rem
tracked-tight letterSpacing: -0.05 rem
tracked-mega letterSpacing: 0.25 rem
no-underline textDecorationLine: "none"
strike textDecorationLine: "line-through"
underline textDecorationLine: "underline"
strike-underline textDecorationLine: "underline line-through"Font-Families
Specify the font-families you need in the configuration to use them:
ff-iowan fontFamily: "Iowan Old Style"
/* setup: */
NativeTachyons.build({
fonts: {
iowan: 'Iowan Old Style'
}
}, StyleSheet);Note for Android: For weights on custom fonts to work correctly you have to name them like this (reference):
{fontFamilyName}.(ttf|otf)
{fontFamilyName}_bold.(ttf|otf)
{fontFamilyName}_italic.(ttf|otf)
{fontFamilyName}_bold_italic.(ttf|otf)
Images
rm-contain resizeMode: "contain"
rm-cover resizeMode: "cover"
rm-stretch resizeMode: "stretch"
tint-$color tintColor: $color, see Colors sectionOpacity
o-10|20|...|100 opacity: 0.1|0.2|...|1
o-05 opacity: 0.05
o-025 opacity: 0.025Colors
-
When using the
cls=''syntax, colors can be specified directly in the string. Every Color supported by react-native works. If the color is prefixed withbg-thebackgroundColorwill be set. A prefix ofb--sets theborderColor.bg-green green background #232323 text color of #232323 b--rgba(255,255,255,0.5) border set to rgba(255,255,255,0.5) tint-blue tint-color set to blue
-
You can also specify a palette in the options and Tachyons will generate styles for you. It will also generate variants with different opacities.
NativeTachyons.build({ colors: { palette: { green: "#00FF00", } } }, StyleSheet);
The same syntax with
bg-for background andb--for borderColor applies.bg-green green background b--green green border // Note: double hyphens signify a class that needs green green text // another class to work in this case a border-setting /* alpha variants (same for bg- and b--) */ green-10, green-20 ... green-90 green text with 10%, 20%, ... , 90% alpha
TypeScale
- You can specify the typescale in the options and Tachyons will generate the font sizes for you.
NativeTachyons.build({
typeScale: {
f1: '1.625',
f2: '1.375',
f3: '1.125',
f4: '0.9375',
f5: '0.8125',
f6: '0.75',
f7: '0.625',
},
rem: 16,
}, StyleSheet);This will result in font sizes of:
{
f1: 26,
f2: 22,
f3: 18,
f4: 15,
f5: 13,
f6: 12,
f7: 10,
}Custom Styles
You can add custom styles you may need to the configuration at startup.
/* setup: */
NativeTachyons.build({
customStyles: {
myCustomBW: {
borderWidth: 2
}
}
}, StyleSheet);Raw Values
To access the actual computed sizes:
import { sizes } from "react-native-style-tachyons"
const s = sizes.ma2 /* sizes.w4, ... */Changes
See the ChangeLog