react-dom-core/lib/dangerousStyleValue.js

/**
 * Copyright (c) 2013-present, Facebook, Inc.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 *
 */

'use strict';

var CSSProperty = require('./CSSProperty');
var warning = require('fbjs/lib/warning');

var isUnitlessNumber = CSSProperty.isUnitlessNumber;
var styleWarnings = {};

/**
 * 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`.
 * @param {ReactDOMComponent} component
 * @return {string} Normalized style value with dimensions applied.
 */
function dangerousStyleValue(name, value, component, 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 '';
  }

  var isNonNumeric = isNaN(value);
  if (isCustomProperty || isNonNumeric || value === 0 || isUnitlessNumber.hasOwnProperty(name) && isUnitlessNumber[name]) {
    return '' + value; // cast to string
  }

  if (typeof value === 'string') {
    if (process.env.NODE_ENV !== 'production') {
      // 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';
}

module.exports = dangerousStyleValue;