[change] support CSS custom properties

Update 'setValueForStyles' and style validation to support defining and
using custom properties.

Fix #516

docs/storybook/1-components/View/ViewScreen.js

@@ -14,6 +14,7 @@ import UIExplorer, {
   Code,
   Description,
   DocItem,
+  ExternalLink,
   Section,
   StyleList
 } from '../../ui-explorer';
@@ -291,6 +292,12 @@ const ViewScreen = () =>
   </UIExplorer>;
 
 const stylePropTypes = [
+  {
+    label: 'web',
+    name: (
+      <ExternalLink href="https://drafts.csswg.org/css-variables/">Custom properties</ExternalLink>
+    )
+  },
   {
     name: 'alignContent',
     typeInfo: 'string'

docs/storybook/ui-explorer/ExternalLink.js

@@ -0,0 +1,12 @@
+/* eslint-disable react/prop-types */
+
+/**
+ * @flow
+ */
+
+import AppText from './AppText';
+import React from 'react';
+
+const ExternalLink = props => <AppText {...props} accessibilityRole="link" target="_blank" />;
+
+export default ExternalLink;

docs/storybook/ui-explorer/StyleList.js

@@ -16,10 +16,12 @@ const StyleList = ({ stylePropTypes }) =>
         <Text style={styles.name}>
           {name}
         </Text>
-        {': '}
+        {typeInfo ? ': ' : null}
-        <Text style={styles.code}>
+        {typeInfo
-          {typeInfo}
+          ? <Text style={styles.code}>
-        </Text>
+              {typeInfo}
+            </Text>
+          : null}
       </AppText>
     )}
   </View>;

docs/storybook/ui-explorer/UIExplorer.js

@@ -5,6 +5,7 @@
  */
 
 import AppText from './AppText';
+import ExternalLink from './ExternalLink';
 import insertBetween from './insertBetween';
 import React from 'react';
 import { StyleSheet, View } from 'react-native';
@@ -22,14 +23,12 @@ export const Description = ({ children }) =>
 const Divider = () => <View style={styles.divider} />;
 
 const SourceLink = ({ uri }) =>
-  <AppText
+  <ExternalLink
-    accessibilityRole="link"
     href={`https://github.com/necolas/react-native-web/tree/master/docs/storybook/${uri}`}
     style={styles.link}
-    target="_blank"
   >
     View source code on GitHub
-  </AppText>;
+  </ExternalLink>;
 
 const UIExplorer = ({ children, description, sections, title, url }) =>
   <View style={styles.root}>

docs/storybook/ui-explorer/index.js

@@ -5,10 +5,11 @@
 import AppText from './AppText';
 import Code from './Code';
 import DocItem from './DocItem';
+import ExternalLink from './ExternalLink';
 import Section from './Section';
 import StyleList from './StyleList';
 import TextList from './TextList';
 import UIExplorer, { Description } from './UIExplorer';
 
 export default UIExplorer;
-export { AppText, Code, Description, DocItem, Section, StyleList, TextList };
+export { AppText, Code, Description, DocItem, ExternalLink, Section, StyleList, TextList };

src/apis/AppState/index.js

@@ -15,7 +15,8 @@ import findIndex from 'array-find-index';
 import invariant from 'fbjs/lib/invariant';
 
 // Android 4.4 browser
-const isPrefixed = canUseDOM && !document.hasOwnProperty('hidden') && document.hasOwnProperty('webkitHidden');
+const isPrefixed =
+  canUseDOM && !document.hasOwnProperty('hidden') && document.hasOwnProperty('webkitHidden');
 
 const EVENT_TYPES = ['change'];
 const VISIBILITY_CHANGE_EVENT = isPrefixed ? 'webkitvisibilitychange' : 'visibilitychange';

src/apis/StyleSheet/StyleSheetValidation.js

@@ -26,23 +26,27 @@ const ReactPropTypesSecret = 'SECRET_DO_NOT_PASS_THIS_OR_YOU_WILL_BE_FIRED';
 export default class StyleSheetValidation {
   static validateStyleProp(prop, style, caller) {
     if (process.env.NODE_ENV !== 'production') {
+      const isCustomProperty = prop.indexOf('--') === 0;
+      if (isCustomProperty) return;
+
       if (allStylePropTypes[prop] === undefined) {
         const message1 = '"' + prop + '" is not a valid style property.';
         const message2 =
           '\nValid style props: ' +
           JSON.stringify(Object.keys(allStylePropTypes).sort(), null, '  ');
         styleError(message1, style, caller, message2);
-      }
+      } else {
-      const error = allStylePropTypes[prop](
+        const error = allStylePropTypes[prop](
-        style,
+          style,
-        prop,
+          prop,
-        caller,
+          caller,
-        'prop',
+          'prop',
-        null,
+          null,
-        ReactPropTypesSecret
+          ReactPropTypesSecret
-      );
+        );
-      if (error) {
+        if (error) {
-        styleError(error.message, style, caller);
+          styleError(error.message, style, caller);
+        }
       }
     }
   }

src/propTypes/ColorPropType.js

@@ -35,7 +35,8 @@ const colorPropType = function(isRequired, props, propName, componentName, locat
     return;
   }
 
-  if (color === 'currentcolor' || color === 'inherit') {
+  // Web supports additional color keywords and custom property values
+  if (color === 'currentcolor' || color === 'inherit' || color.indexOf('var(') === 0) {
     return;
   }
 

src/propTypes/StyleSheetPropType.js

@@ -19,7 +19,15 @@ function StyleSheetPropType(shape: { [key: string]: ReactPropsCheckType }): Reac
     if (props[propName]) {
       // Just make a dummy prop object with only the flattened style
       newProps = {};
-      newProps[propName] = StyleSheet.flatten(props[propName]);
+      const flatStyle = StyleSheet.flatten(props[propName]);
+      // Remove custom properties from check
+      const nextStyle = Object.keys(flatStyle).reduce((acc, curr) => {
+        if (curr.indexOf('--') !== 0) {
+          acc[curr] = flatStyle[curr];
+        }
+        return acc;
+      }, {});
+      newProps[propName] = nextStyle;
     }
     return shapePropType(newProps, propName, componentName, location, ...rest);
   };

src/vendor/dangerousStyleValue/index.js

@@ -0,0 +1,53 @@
+/* eslint-disable */
+
+/**
+ * Copyright 2013-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ *
+ * @providesModule dangerousStyleValue
+ */
+
+import isUnitlessNumber from '../../modules/unitlessNumbers';
+
+/**
+ * Convert a value into the proper css writable value. The style name `name`
+ * should be logical (no hyphens), as specified
+ * in `CSSProperty.isUnitlessNumber`.
+ *
+ * @param {string} name CSS property name such as `topMargin`.
+ * @param {*} value CSS property value such as `10px`.
+ * @return {string} Normalized style value with dimensions applied.
+ */
+function dangerousStyleValue(name, value, isCustomProperty) {
+  // Note that we've removed escapeTextForBrowser() calls here since the
+  // whole string will be escaped when the attribute is injected into
+  // the markup. If you provide unsafe user data here they can inject
+  // arbitrary CSS which may be problematic (I couldn't repro this):
+  // https://www.owasp.org/index.php/XSS_Filter_Evasion_Cheat_Sheet
+  // http://www.thespanner.co.uk/2007/11/26/ultimate-xss-css-injection/
+  // This is not an XSS hole but instead a potential CSS injection issue
+  // which has lead to a greater discussion about how we're going to
+  // trust URLs moving forward. See #2115901
+
+  var isEmpty = value == null || typeof value === 'boolean' || value === '';
+  if (isEmpty) {
+    return '';
+  }
+
+  if (
+    !isCustomProperty &&
+    typeof value === 'number' &&
+    value !== 0 &&
+    !(isUnitlessNumber.hasOwnProperty(name) && isUnitlessNumber[name])
+  ) {
+    return value + 'px'; // Presumes implicit 'px' suffix for unitless numbers
+  }
+
+  return ('' + value).trim();
+}
+
+export default dangerousStyleValue;

src/vendor/setValueForStyles/index.js

@@ -10,199 +10,8 @@
  *
  */
 
-import unitlessNumbers from '../../modules/unitlessNumbers';
+import dangerousStyleValue from '../dangerousStyleValue';
-
+import warnValidStyle from '../warnValidStyle';
-if (process.env.NODE_ENV !== 'production') {
-  var camelizeStyleName = require('fbjs/lib/camelizeStyleName');
-  var warning = require('fbjs/lib/warning');
-
-  // 'msTransform' is correct, but the other prefixes should be capitalized
-  var badVendoredStyleNamePattern = /^(?:webkit|moz|o)[A-Z]/;
-
-  // style values shouldn't contain a semicolon
-  var badStyleValueWithSemicolonPattern = /;\s*$/;
-
-  var warnedStyleNames = {};
-  var warnedStyleValues = {};
-  var warnedForNaNValue = false;
-
-  var warnHyphenatedStyleName = function(name, owner) {
-    if (warnedStyleNames.hasOwnProperty(name) && warnedStyleNames[name]) {
-      return;
-    }
-
-    warnedStyleNames[name] = true;
-    process.env.NODE_ENV !== 'production'
-      ? warning(
-          false,
-          'Unsupported style property %s. Did you mean %s?%s',
-          name,
-          camelizeStyleName(name),
-          checkRenderMessage(owner)
-        )
-      : void 0;
-  };
-
-  var warnBadVendoredStyleName = function(name, owner) {
-    if (warnedStyleNames.hasOwnProperty(name) && warnedStyleNames[name]) {
-      return;
-    }
-
-    warnedStyleNames[name] = true;
-    process.env.NODE_ENV !== 'production'
-      ? warning(
-          false,
-          'Unsupported vendor-prefixed style property %s. Did you mean %s?%s',
-          name,
-          name.charAt(0).toUpperCase() + name.slice(1),
-          checkRenderMessage(owner)
-        )
-      : void 0;
-  };
-
-  var warnStyleValueWithSemicolon = function(name, value, owner) {
-    if (warnedStyleValues.hasOwnProperty(value) && warnedStyleValues[value]) {
-      return;
-    }
-
-    warnedStyleValues[value] = true;
-    process.env.NODE_ENV !== 'production'
-      ? warning(
-          false,
-          "Style property values shouldn't contain a semicolon.%s " + 'Try "%s: %s" instead.',
-          checkRenderMessage(owner),
-          name,
-          value.replace(badStyleValueWithSemicolonPattern, '')
-        )
-      : void 0;
-  };
-
-  var warnStyleValueIsNaN = function(name, value, owner) {
-    if (warnedForNaNValue) {
-      return;
-    }
-
-    warnedForNaNValue = true;
-    process.env.NODE_ENV !== 'production'
-      ? warning(
-          false,
-          '`NaN` is an invalid value for the `%s` css style property.%s',
-          name,
-          checkRenderMessage(owner)
-        )
-      : void 0;
-  };
-
-  var checkRenderMessage = function(owner) {
-    if (owner) {
-      var name = owner.getName();
-      if (name) {
-        return ' Check the render method of `' + name + '`.';
-      }
-    }
-    return '';
-  };
-
-  /**
-   * @param {string} name
-   * @param {*} value
-   * @param {ReactDOMComponent} component
-   */
-  var warnValidStyle = function(name, value, component) {
-    var owner;
-    if (component) {
-      owner = component._currentElement._owner;
-    }
-    if (name.indexOf('-') > -1) {
-      warnHyphenatedStyleName(name, owner);
-    } else if (badVendoredStyleNamePattern.test(name)) {
-      warnBadVendoredStyleName(name, owner);
-    } else if (badStyleValueWithSemicolonPattern.test(value)) {
-      warnStyleValueWithSemicolon(name, value, owner);
-    }
-
-    if (typeof value === 'number' && isNaN(value)) {
-      warnStyleValueIsNaN(name, value, owner);
-    }
-  };
-}
-
-var styleWarnings = {};
-
-/**
- * Convert a value into the proper css writable value. The style name `name`
- * should be logical (no hyphens)
- *
- * @param {string} name CSS property name such as `topMargin`.
- * @param {*} value CSS property value such as `10px`.
- * @param {ReactDOMComponent} component
- * @return {string} Normalized style value with dimensions applied.
- */
-function dangerousStyleValue(name, value, component) {
-  // Note that we've removed escapeTextForBrowser() calls here since the
-  // whole string will be escaped when the attribute is injected into
-  // the markup. If you provide unsafe user data here they can inject
-  // arbitrary CSS which may be problematic (I couldn't repro this):
-  // https://www.owasp.org/index.php/XSS_Filter_Evasion_Cheat_Sheet
-  // http://www.thespanner.co.uk/2007/11/26/ultimate-xss-css-injection/
-  // This is not an XSS hole but instead a potential CSS injection issue
-  // which has lead to a greater discussion about how we're going to
-  // trust URLs moving forward. See #2115901
-
-  var isEmpty = value == null || typeof value === 'boolean' || value === '';
-  if (isEmpty) {
-    return '';
-  }
-
-  var isNonNumeric = isNaN(value);
-  if (
-    isNonNumeric ||
-    value === 0 ||
-    (unitlessNumbers.hasOwnProperty(name) && unitlessNumbers[name])
-  ) {
-    return '' + value; // cast to string
-  }
-
-  if (typeof value === 'string') {
-    if (process.env.NODE_ENV !== 'production') {
-      var warning = require('fbjs/lib/warning');
-
-      // Allow '0' to pass through without warning. 0 is already special and
-      // doesn't require units, so we don't need to warn about it.
-      if (component && value !== '0') {
-        var owner = component._currentElement._owner;
-        var ownerName = owner ? owner.getName() : null;
-        if (ownerName && !styleWarnings[ownerName]) {
-          styleWarnings[ownerName] = {};
-        }
-        var warned = false;
-        if (ownerName) {
-          var warnings = styleWarnings[ownerName];
-          warned = warnings[name];
-          if (!warned) {
-            warnings[name] = true;
-          }
-        }
-        if (!warned) {
-          process.env.NODE_ENV !== 'production'
-            ? warning(
-                false,
-                'a `%s` tag (owner: `%s`) was passed a numeric string value ' +
-                  'for CSS property `%s` (value: `%s`) which will be treated ' +
-                  'as a unitless number in a future version of React.',
-                component._currentElement.type,
-                ownerName || 'unknown',
-                name,
-                value
-              )
-            : void 0;
-        }
-      }
-    }
-    value = value.trim();
-  }
-  return value + 'px';
-}
 
 /**
    * Sets the value for multiple styles on a node.  If a value is specified as
@@ -218,14 +27,19 @@ const setValueForStyles = function(node, styles, component) {
     if (!styles.hasOwnProperty(styleName)) {
       continue;
     }
+    var isCustomProperty = styleName.indexOf('--') === 0;
     if (process.env.NODE_ENV !== 'production') {
-      warnValidStyle(styleName, styles[styleName], component);
+      if (!isCustomProperty) {
+        warnValidStyle(styleName, styles[styleName], component);
+      }
     }
-    var styleValue = dangerousStyleValue(styleName, styles[styleName], component);
+    var styleValue = dangerousStyleValue(styleName, styles[styleName], isCustomProperty);
-    if (styleName === 'float' || styleName === 'cssFloat') {
+    if (styleName === 'float') {
       styleName = 'cssFloat';
     }
-    if (styleValue) {
+    if (isCustomProperty) {
+      style.setProperty(styleName, styleValue);
+    } else if (styleValue) {
       style[styleName] = styleValue;
     } else {
       style[styleName] = '';

src/vendor/warnValidStyle/index.js

@@ -0,0 +1,170 @@
+/* eslint-disable */
+
+/**
+ * Copyright 2013-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ *
+ * @providesModule warnValidStyle
+ */
+
+'use strict';
+
+var emptyFunction = require('fbjs/lib/emptyFunction');
+
+var warnValidStyle = emptyFunction;
+
+if (process.env.NODE_ENV !== 'production') {
+  var camelizeStyleName = require('fbjs/lib/camelizeStyleName');
+  var warning = require('fbjs/lib/warning');
+
+  function getComponentName(instanceOrFiber) {
+    if (typeof instanceOrFiber.getName === 'function') {
+      // Stack reconciler
+      const instance = ((instanceOrFiber: any): ReactInstance);
+      return instance.getName();
+    }
+    if (typeof instanceOrFiber.tag === 'number') {
+      // Fiber reconciler
+      const fiber = ((instanceOrFiber: any): Fiber);
+      const { type } = fiber;
+      if (typeof type === 'string') {
+        return type;
+      }
+      if (typeof type === 'function') {
+        return type.displayName || type.name;
+      }
+    }
+    return null;
+  }
+
+  // 'msTransform' is correct, but the other prefixes should be capitalized
+  var badVendoredStyleNamePattern = /^(?:webkit|moz|o)[A-Z]/;
+
+  // style values shouldn't contain a semicolon
+  var badStyleValueWithSemicolonPattern = /;\s*$/;
+
+  var warnedStyleNames = {};
+  var warnedStyleValues = {};
+  var warnedForNaNValue = false;
+  var warnedForInfinityValue = false;
+
+  var warnHyphenatedStyleName = function(name, owner) {
+    if (warnedStyleNames.hasOwnProperty(name) && warnedStyleNames[name]) {
+      return;
+    }
+
+    warnedStyleNames[name] = true;
+    warning(
+      false,
+      'Unsupported style property %s. Did you mean %s?%s',
+      name,
+      camelizeStyleName(name),
+      checkRenderMessage(owner)
+    );
+  };
+
+  var warnBadVendoredStyleName = function(name, owner) {
+    if (warnedStyleNames.hasOwnProperty(name) && warnedStyleNames[name]) {
+      return;
+    }
+
+    warnedStyleNames[name] = true;
+    warning(
+      false,
+      'Unsupported vendor-prefixed style property %s. Did you mean %s?%s',
+      name,
+      name.charAt(0).toUpperCase() + name.slice(1),
+      checkRenderMessage(owner)
+    );
+  };
+
+  var warnStyleValueWithSemicolon = function(name, value, owner) {
+    if (warnedStyleValues.hasOwnProperty(value) && warnedStyleValues[value]) {
+      return;
+    }
+
+    warnedStyleValues[value] = true;
+    warning(
+      false,
+      "Style property values shouldn't contain a semicolon.%s " + 'Try "%s: %s" instead.',
+      checkRenderMessage(owner),
+      name,
+      value.replace(badStyleValueWithSemicolonPattern, '')
+    );
+  };
+
+  var warnStyleValueIsNaN = function(name, value, owner) {
+    if (warnedForNaNValue) {
+      return;
+    }
+
+    warnedForNaNValue = true;
+    warning(
+      false,
+      '`NaN` is an invalid value for the `%s` css style property.%s',
+      name,
+      checkRenderMessage(owner)
+    );
+  };
+
+  var warnStyleValueIsInfinity = function(name, value, owner) {
+    if (warnedForInfinityValue) {
+      return;
+    }
+
+    warnedForInfinityValue = true;
+    warning(
+      false,
+      '`Infinity` is an invalid value for the `%s` css style property.%s',
+      name,
+      checkRenderMessage(owner)
+    );
+  };
+
+  var checkRenderMessage = function(owner) {
+    var ownerName;
+    if (owner != null) {
+      // Stack passes the owner manually all the way to CSSPropertyOperations.
+      ownerName = getComponentName(owner);
+    } else {
+      // Fiber doesn't pass it but uses ReactDebugCurrentFiber to track it.
+      // It is only enabled in development and tracks host components too.
+      // var {getCurrentFiberOwnerName} = require('ReactDebugCurrentFiber');
+      //  ownerName = getCurrentFiberOwnerName();
+      // TODO: also report the stack.
+    }
+    if (ownerName) {
+      return '\n\nCheck the render method of `' + ownerName + '`.';
+    }
+    return '';
+  };
+
+  warnValidStyle = function(name, value, component) {
+    var owner;
+    if (component) {
+      // TODO: this only works with Stack. Seems like we need to add unit tests?
+      // owner = component._currentElement._owner;
+    }
+    if (name.indexOf('-') > -1) {
+      warnHyphenatedStyleName(name, owner);
+    } else if (badVendoredStyleNamePattern.test(name)) {
+      warnBadVendoredStyleName(name, owner);
+    } else if (badStyleValueWithSemicolonPattern.test(value)) {
+      warnStyleValueWithSemicolon(name, value, owner);
+    }
+
+    if (typeof value === 'number') {
+      if (isNaN(value)) {
+        warnStyleValueIsNaN(name, value, owner);
+      } else if (!isFinite(value)) {
+        warnStyleValueIsInfinity(name, value, owner);
+      }
+    }
+  };
+}
+
+export default warnValidStyle;