CSSPropertyOperations.js

/**
 * Copyright 2013-2015, 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 CSSPropertyOperations
 * @typechecks static-only
 */

'use strict';

var CSSProperty = require("./CSSProperty");
var ExecutionEnvironment = require("./ExecutionEnvironment");

var camelizeStyleName = require("./camelizeStyleName");
var dangerousStyleValue = require("./dangerousStyleValue");
var hyphenateStyleName = require("./hyphenateStyleName");
var memoizeStringOnly = require("./memoizeStringOnly");
var warning = require("./warning");

var processStyleName = memoizeStringOnly(function(styleName) {
  return hyphenateStyleName(styleName);
});

var styleFloatAccessor = 'cssFloat';
if (ExecutionEnvironment.canUseDOM) {
  // IE8 only supports accessing cssFloat (standard) as styleFloat
  if (document.documentElement.style.cssFloat === undefined) {
    styleFloatAccessor = 'styleFloat';
  }
}

if ("production" !== process.env.NODE_ENV) {
  // '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 warnHyphenatedStyleName = function(name) {
    if (warnedStyleNames.hasOwnProperty(name) && warnedStyleNames[name]) {
      return;
    }

    warnedStyleNames[name] = true;
    ("production" !== process.env.NODE_ENV ? warning(
      false,
      'Unsupported style property %s. Did you mean %s?',
      name,
      camelizeStyleName(name)
    ) : null);
  };

  var warnBadVendoredStyleName = function(name) {
    if (warnedStyleNames.hasOwnProperty(name) && warnedStyleNames[name]) {
      return;
    }

    warnedStyleNames[name] = true;
    ("production" !== process.env.NODE_ENV ? warning(
      false,
      'Unsupported vendor-prefixed style property %s. Did you mean %s?',
      name,
      name.charAt(0).toUpperCase() + name.slice(1)
    ) : null);
  };

  var warnStyleValueWithSemicolon = function(name, value) {
    if (warnedStyleValues.hasOwnProperty(value) && warnedStyleValues[value]) {
      return;
    }

    warnedStyleValues[value] = true;
    ("production" !== process.env.NODE_ENV ? warning(
      false,
      'Style property values shouldn\'t contain a semicolon. ' +
      'Try "%s: %s" instead.',
      name,
      value.replace(badStyleValueWithSemicolonPattern, '')
    ) : null);
  };

  /**
   * @param {string} name
   * @param {*} value
   */
  var warnValidStyle = function(name, value) {
    if (name.indexOf('-') > -1) {
      warnHyphenatedStyleName(name);
    } else if (badVendoredStyleNamePattern.test(name)) {
      warnBadVendoredStyleName(name);
    } else if (badStyleValueWithSemicolonPattern.test(value)) {
      warnStyleValueWithSemicolon(name, value);
    }
  };
}

/**
 * Operations for dealing with CSS properties.
 */
var CSSPropertyOperations = {

  /**
   * Serializes a mapping of style properties for use as inline styles:
   *
   *   > createMarkupForStyles({width: '200px', height: 0})
   *   "width:200px;height:0;"
   *
   * Undefined values are ignored so that declarative programming is easier.
   * The result should be HTML-escaped before insertion into the DOM.
   *
   * @param {object} styles
   * @return {?string}
   */
  createMarkupForStyles: function(styles) {
    var serialized = '';
    for (var styleName in styles) {
      if (!styles.hasOwnProperty(styleName)) {
        continue;
      }
      var styleValue = styles[styleName];
      if ("production" !== process.env.NODE_ENV) {
        warnValidStyle(styleName, styleValue);
      }
      if (styleValue != null) {
        serialized += processStyleName(styleName) + ':';
        serialized += dangerousStyleValue(styleName, styleValue) + ';';
      }
    }
    return serialized || null;
  },

  /**
   * Sets the value for multiple styles on a node.  If a value is specified as
   * '' (empty string), the corresponding style property will be unset.
   *
   * @param {DOMElement} node
   * @param {object} styles
   */
  setValueForStyles: function(node, styles) {
    var style = node.style;
    for (var styleName in styles) {
      if (!styles.hasOwnProperty(styleName)) {
        continue;
      }
      if ("production" !== process.env.NODE_ENV) {
        warnValidStyle(styleName, styles[styleName]);
      }
      var styleValue = dangerousStyleValue(styleName, styles[styleName]);
      if (styleName === 'float') {
        styleName = styleFloatAccessor;
      }
      if (styleValue) {
        style[styleName] = styleValue;
      } else {
        var expansion = CSSProperty.shorthandPropertyExpansions[styleName];
        if (expansion) {
          // Shorthand property that IE8 won't like unsetting, so unset each
          // component to placate it
          for (var individualStyleName in expansion) {
            style[individualStyleName] = '';
          }
        } else {
          style[styleName] = '';
        }
      }
    }
  }

};

module.exports = CSSPropertyOperations;