@mariusandra/simmerjs/lib/simmer.js

A pure Javascript reverse CSS selector engine which calculates a DOM element's unique CSS selector on the current page.

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.default = createSimmer;

var _queryEngine = _interopRequireWildcard(require("./queryEngine"));

var _methods = _interopRequireDefault(require("./methods"));

var _validateSelector = _interopRequireDefault(require("./validateSelector"));

var _convertSelectorStateIntoCSSSelector = _interopRequireDefault(require("./convertSelectorStateIntoCSSSelector"));

var _parser = _interopRequireDefault(require("./parser"));

var _stackHierarchy = _interopRequireDefault(require("./stackHierarchy"));

var _configuration = require("./configuration");

function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }

function _getRequireWildcardCache() { if (typeof WeakMap !== "function") return null; var cache = new WeakMap(); _getRequireWildcardCache = function () { return cache; }; return cache; }

function _interopRequireWildcard(obj) { if (obj && obj.__esModule) { return obj; } if (obj === null || typeof obj !== "object" && typeof obj !== "function") { return { default: obj }; } var cache = _getRequireWildcardCache(); if (cache && cache.has(obj)) { return cache.get(obj); } var newObj = {}; var hasPropertyDescriptor = Object.defineProperty && Object.getOwnPropertyDescriptor; for (var key in obj) { if (Object.prototype.hasOwnProperty.call(obj, key)) { var desc = hasPropertyDescriptor ? Object.getOwnPropertyDescriptor(obj, key) : null; if (desc && (desc.get || desc.set)) { Object.defineProperty(newObj, key, desc); } else { newObj[key] = obj[key]; } } } newObj.default = obj; if (cache) { cache.set(obj, newObj); } return newObj; }

function createSimmer() {
  let windowScope = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : window;
  let customConfig = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : {};
  let customQuery = arguments.length > 2 && arguments[2] !== undefined ? arguments[2] : false;
  const config = (0, _configuration.configure)(customConfig);
  const query = customQuery || (0, _queryEngine.default)(windowScope, config.queryEngine);
  /**
     * Handle errors in accordance with what is specified in the configuration
     * @param {object/string} ex. The exception object or message
     * @param {object} element. The element Simmer was asked to process
     */

  function onError(ex, element) {
    // handle error
    if (config.errorHandling === true) {
      throw ex;
    }

    if (typeof config.errorHandling === 'function') {
      config.errorHandling(ex, element);
    }
  } // Initialize the Simmer object and set it over the reference on the window

  /**
   * The main Simmer action - parses an element on the page to produce a CSS selector for it.
   * This function will be returned into the global Simmer object.
   * @param {object} element. A DOM element you wish to create a selector for.
   * @example
   <code><pre>
   var cssSelectorForDonJulio = Simmer(document.getElementByID('DonJulio'));
   </pre></code>
   */


  const simmer = function (element) {
    if (!element) {
      // handle error
      onError.call(simmer, new Error('Simmer: No element was specified for parsing.'), element);
      return null;
    } // The parser cycles through a set of parsing methods specified in an order optimal
    // for creating as specific as possible a selector


    const parser = new _parser.default(_methods.default); // get the element's ancestors

    const hierarchy = (0, _stackHierarchy.default)((0, _queryEngine.wrap)(element), config.depth); // initialize the state of the selector

    let selectorState = {
      // the stack is used to build a layer of selectors, each layer coresponding to a specific element in the heirarchy
      // for each level we create a private stack of properties, so that we can then merge them
      // comfortably and allow all methods to see the level at which existing properties have been set
      stack: Array(hierarchy.length).fill().map(() => []),
      // follow the current specificity level of the selector - the higher the better
      specificity: 0
    };
    const validator = (0, _validateSelector.default)(element, config, query, onError); // cycle through the available parsing methods and while we still have yet to find the requested element's one-to-one selector
    // we keep calling the methods until we are either satisfied or run out of methods

    while (!parser.finished() && !selectorState.verified) {
      try {
        selectorState = parser.next(hierarchy, selectorState, validator, config, query); // if we have reached a satisfactory level of specificity, try the selector, perhaps we have found our selector?

        if (selectorState.specificity >= config.specificityThreshold && !selectorState.verified) {
          selectorState.verified = validator(selectorState);
        }
      } catch (ex) {
        // handle error
        onError.call(simmer, ex, element);
      }
    } // if we were not able to produce a one-to-one selector, return false


    if (selectorState.verified === undefined || selectorState.specificity < config.specificityThreshold) {
      // if it is undefined then verfication has never been run!
      // try and verify, and if verification fails - return false
      // if it is false and the specificity is too low to actually try and find the element in the first place, then we may simply have not run
      // an up to date verification - try again
      selectorState.verified = validator(selectorState);
    }

    if (!selectorState.verified) {
      return null;
    }

    if (selectorState.verificationDepth) {
      return (0, _convertSelectorStateIntoCSSSelector.default)(selectorState, selectorState.verificationDepth);
    }

    return (0, _convertSelectorStateIntoCSSSelector.default)(selectorState);
  };
  /**
   * Get/Set the configuration for the Simmer object
   * @param config (Object) A configuration object with any of the properties tweeked (none/depth/minimumSpecificity)
   * @example
   <code><pre>
   configuration({
            depth: 3
         });
   </pre></code>
   */


  simmer.configure = function () {
    let configValues = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : {};
    let scope = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : windowScope;
    const newConfig = (0, _configuration.configure)({ ...config,
      ...configValues
    });
    return createSimmer(scope, newConfig, (0, _queryEngine.default)(scope, newConfig.queryEngine));
  };

  return simmer;
}