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1 # This Source Code Form is subject to the terms of the Mozilla Public |
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2 # License, v. 2.0. If a copy of the MPL was not distributed with this |
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3 # file, You can obtain one at http://mozilla.org/MPL/2.0/. |
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4 |
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5 |
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6 /** |
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7 * lang.js - Some missing JavaScript language features |
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8 */ |
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9 |
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10 /** |
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11 * Partially applies a function to a particular "this object" and zero or |
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12 * more arguments. The result is a new function with some arguments of the first |
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13 * function pre-filled and the value of |this| "pre-specified". |
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14 * |
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15 * Remaining arguments specified at call-time are appended to the pre- |
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16 * specified ones. |
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17 * |
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18 * Usage: |
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19 * var barMethBound = BindToObject(myFunction, myObj, "arg1", "arg2"); |
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20 * barMethBound("arg3", "arg4"); |
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21 * |
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22 * @param fn {string} Reference to the function to be bound |
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23 * |
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24 * @param self {object} Specifies the object which |this| should point to |
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25 * when the function is run. If the value is null or undefined, it will default |
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26 * to the global object. |
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27 * |
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28 * @returns {function} A partially-applied form of the speficied function. |
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29 */ |
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30 function BindToObject(fn, self, opt_args) { |
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31 var boundargs = fn.boundArgs_ || []; |
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32 boundargs = boundargs.concat(Array.slice(arguments, 2, arguments.length)); |
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33 |
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34 if (fn.boundSelf_) |
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35 self = fn.boundSelf_; |
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36 if (fn.boundFn_) |
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37 fn = fn.boundFn_; |
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38 |
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39 var newfn = function() { |
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40 // Combine the static args and the new args into one big array |
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41 var args = boundargs.concat(Array.slice(arguments)); |
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42 return fn.apply(self, args); |
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43 } |
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44 |
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45 newfn.boundArgs_ = boundargs; |
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46 newfn.boundSelf_ = self; |
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47 newfn.boundFn_ = fn; |
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48 |
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49 return newfn; |
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50 } |
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51 |
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52 /** |
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53 * Inherit the prototype methods from one constructor into another. |
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54 * |
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55 * Usage: |
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56 * |
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57 * function ParentClass(a, b) { } |
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58 * ParentClass.prototype.foo = function(a) { } |
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59 * |
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60 * function ChildClass(a, b, c) { |
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61 * ParentClass.call(this, a, b); |
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62 * } |
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63 * |
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64 * ChildClass.inherits(ParentClass); |
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65 * |
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66 * var child = new ChildClass("a", "b", "see"); |
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67 * child.foo(); // works |
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68 * |
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69 * In addition, a superclass' implementation of a method can be invoked |
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70 * as follows: |
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71 * |
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72 * ChildClass.prototype.foo = function(a) { |
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73 * ChildClass.superClass_.foo.call(this, a); |
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74 * // other code |
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75 * }; |
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76 */ |
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77 Function.prototype.inherits = function(parentCtor) { |
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78 var tempCtor = function(){}; |
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79 tempCtor.prototype = parentCtor.prototype; |
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80 this.superClass_ = parentCtor.prototype; |
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81 this.prototype = new tempCtor(); |
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82 } |