perfectkb-yate/lib/deparam.js

Yet Another Turtle Editor, forked from YASQE

"use strict";
/*
  jQuery deparam is an extraction of the deparam method from Ben Alman's jQuery BBQ
  http://benalman.com/projects/jquery-bbq-plugin/
*/
var $ = require("jquery");
$.deparam = function(params, coerce) {
  var obj = {}, coerce_types = { true: !0, false: !1, null: null };

  // Iterate over all name=value pairs.
  $.each(params.replace(/\+/g, " ").split("&"), function(j, v) {
    var param = v.split("="),
      key = decodeURIComponent(param[0]),
      val,
      cur = obj,
      i = 0,
      // If key is more complex than 'foo', like 'a[]' or 'a[b][c]', split it
      // into its component parts.
      keys = key.split("]["),
      keys_last = keys.length - 1;

    // If the first keys part contains [ and the last ends with ], then []
    // are correctly balanced.
    if (/\[/.test(keys[0]) && /\]$/.test(keys[keys_last])) {
      // Remove the trailing ] from the last keys part.
      keys[keys_last] = keys[keys_last].replace(/\]$/, "");

      // Split first keys part into two parts on the [ and add them back onto
      // the beginning of the keys array.
      keys = keys.shift().split("[").concat(keys);

      keys_last = keys.length - 1;
    } else {
      // Basic 'foo' style key.
      keys_last = 0;
    }

    // Are we dealing with a name=value pair, or just a name?
    if (param.length === 2) {
      val = decodeURIComponent(param[1]);

      // Coerce values.
      if (coerce) {
        val = val && !isNaN(val)
          ? +val // number
          : val === "undefined"
              ? undefined // undefined
              : coerce_types[val] !== undefined
                  ? coerce_types[val] // true, false, null
                  : val; // string
      }

      if (keys_last) {
        // Complex key, build deep object structure based on a few rules:
        // * The 'cur' pointer starts at the object top-level.
        // * [] = array push (n is set to array length), [n] = array if n is
        //   numeric, otherwise object.
        // * If at the last keys part, set the value.
        // * For each keys part, if the current level is undefined create an
        //   object or array based on the type of the next keys part.
        // * Move the 'cur' pointer to the next level.
        // * Rinse & repeat.
        for (; i <= keys_last; i++) {
          key = keys[i] === "" ? cur.length : keys[i];
          cur = cur[key] = i < keys_last ? cur[key] || (keys[i + 1] && isNaN(keys[i + 1]) ? {} : []) : val;
        }
      } else {
        // Simple key, even simpler rules, since only scalars and shallow
        // arrays are allowed.

        if ($.isArray(obj[key])) {
          // val is already an array, so push on the next value.
          obj[key].push(val);
        } else if (obj[key] !== undefined) {
          // val isn't an array, but since a second value has been specified,
          // convert val into an array.
          obj[key] = [obj[key], val];
        } else {
          // val is a scalar.
          obj[key] = val;
        }
      }
    } else if (key) {
      // No value was defined, so set something meaningful.
      obj[key] = coerce ? undefined : "";
    }
  });

  return obj;
};