107 lines
11 KiB
JSON
107 lines
11 KiB
JSON
{
|
|
"_args": [
|
|
[
|
|
{
|
|
"raw": "private@^0.1.6",
|
|
"scope": null,
|
|
"escapedName": "private",
|
|
"name": "private",
|
|
"rawSpec": "^0.1.6",
|
|
"spec": ">=0.1.6 <0.2.0",
|
|
"type": "range"
|
|
},
|
|
"/Volumes/2009-SSD/GT2/GT2-iOS/node_modules/regenerator-transform"
|
|
]
|
|
],
|
|
"_from": "private@>=0.1.6 <0.2.0",
|
|
"_id": "private@0.1.8",
|
|
"_inCache": true,
|
|
"_location": "/private",
|
|
"_nodeVersion": "8.7.0",
|
|
"_npmOperationalInternal": {
|
|
"host": "s3://npm-registry-packages",
|
|
"tmp": "tmp/private-0.1.8.tgz_1507855679328_0.11361804232001305"
|
|
},
|
|
"_npmUser": {
|
|
"name": "benjamn",
|
|
"email": "ben@benjamn.com"
|
|
},
|
|
"_npmVersion": "5.4.2",
|
|
"_phantomChildren": {},
|
|
"_requested": {
|
|
"raw": "private@^0.1.6",
|
|
"scope": null,
|
|
"escapedName": "private",
|
|
"name": "private",
|
|
"rawSpec": "^0.1.6",
|
|
"spec": ">=0.1.6 <0.2.0",
|
|
"type": "range"
|
|
},
|
|
"_requiredBy": [
|
|
"/babel-core",
|
|
"/regenerator-transform"
|
|
],
|
|
"_resolved": "https://registry.npmjs.org/private/-/private-0.1.8.tgz",
|
|
"_shasum": "2381edb3689f7a53d653190060fcf822d2f368ff",
|
|
"_shrinkwrap": null,
|
|
"_spec": "private@^0.1.6",
|
|
"_where": "/Volumes/2009-SSD/GT2/GT2-iOS/node_modules/regenerator-transform",
|
|
"author": {
|
|
"name": "Ben Newman",
|
|
"email": "bn@cs.stanford.edu"
|
|
},
|
|
"bugs": {
|
|
"url": "https://github.com/benjamn/private/issues"
|
|
},
|
|
"dependencies": {},
|
|
"description": "Utility for associating truly private state with any JavaScript object",
|
|
"devDependencies": {
|
|
"mocha": "^4.0.1"
|
|
},
|
|
"directories": {},
|
|
"dist": {
|
|
"integrity": "sha512-VvivMrbvd2nKkiG38qjULzlc+4Vx4wm/whI9pQD35YrARNnhxeiRktSOhSukRLFNlzg6Br/cJPet5J/u19r/mg==",
|
|
"shasum": "2381edb3689f7a53d653190060fcf822d2f368ff",
|
|
"tarball": "https://registry.npmjs.org/private/-/private-0.1.8.tgz"
|
|
},
|
|
"engines": {
|
|
"node": ">= 0.6"
|
|
},
|
|
"files": [
|
|
"private.js"
|
|
],
|
|
"gitHead": "8fde2c4c9f760c0ae17f3ff375c02d6498472fbc",
|
|
"homepage": "http://github.com/benjamn/private",
|
|
"keywords": [
|
|
"private",
|
|
"access control",
|
|
"access modifiers",
|
|
"encapsulation",
|
|
"secret",
|
|
"state",
|
|
"privilege",
|
|
"scope",
|
|
"es5"
|
|
],
|
|
"license": "MIT",
|
|
"main": "private.js",
|
|
"maintainers": [
|
|
{
|
|
"name": "benjamn",
|
|
"email": "bn@cs.stanford.edu"
|
|
}
|
|
],
|
|
"name": "private",
|
|
"optionalDependencies": {},
|
|
"readme": "# private [](https://travis-ci.org/benjamn/private) [](https://greenkeeper.io/)\n\nA general-purpose utility for associating truly private state with any JavaScript object.\n\nInstallation\n---\n\nFrom NPM:\n\n npm install private\n\nFrom GitHub:\n\n cd path/to/node_modules\n git clone git://github.com/benjamn/private.git\n cd private\n npm install .\n\nUsage\n---\n**Get or create a secret object associated with any (non-frozen) object:**\n```js\nvar getSecret = require(\"private\").makeAccessor();\nvar obj = Object.create(null); // any kind of object works\ngetSecret(obj).totallySafeProperty = \"p455w0rd\";\n\nconsole.log(Object.keys(obj)); // []\nconsole.log(Object.getOwnPropertyNames(obj)); // []\nconsole.log(getSecret(obj)); // { totallySafeProperty: \"p455w0rd\" }\n```\nNow, only code that has a reference to both `getSecret` and `obj` can possibly access `.totallySafeProperty`.\n\n*Importantly, no global references to the secret object are retained by the `private` package, so as soon as `obj` gets garbage collected, the secret will be reclaimed as well. In other words, you don't have to worry about memory leaks.*\n\n**Create a unique property name that cannot be enumerated or guessed:**\n```js\nvar secretKey = require(\"private\").makeUniqueKey();\nvar obj = Object.create(null); // any kind of object works\n\nObject.defineProperty(obj, secretKey, {\n value: { totallySafeProperty: \"p455w0rd\" },\n enumerable: false // optional; non-enumerability is the default\n});\n\nObject.defineProperty(obj, \"nonEnumerableProperty\", {\n value: \"anyone can guess my name\",\n enumerable: false\n});\n\nconsole.log(obj[secretKey].totallySafeProperty); // p455w0rd\nconsole.log(obj.nonEnumerableProperty); // \"anyone can guess my name\"\nconsole.log(Object.keys(obj)); // []\nconsole.log(Object.getOwnPropertyNames(obj)); // [\"nonEnumerableProperty\"]\n\nfor (var key in obj) {\n console.log(key); // never called\n}\n```\nBecause these keys are non-enumerable, you can't discover them using a `for`-`in` loop. Because `secretKey` is a long string of random characters, you would have a lot of trouble guessing it. And because the `private` module wraps `Object.getOwnPropertyNames` to exclude the keys it generates, you can't even use that interface to discover it.\n\nUnless you have access to the value of the `secretKey` property name, there is no way to access the value associated with it. So your only responsibility as secret-keeper is to avoid handing out the value of `secretKey` to untrusted code.\n\nThink of this style as a home-grown version of the first style. Note, however, that it requires a full implementation of ES5's `Object.defineProperty` method in order to make any safety guarantees, whereas the first example will provide safety even in environments that do not support `Object.defineProperty`.\n\nRationale\n---\n\nIn JavaScript, the only data that are truly private are local variables\nwhose values do not *leak* from the scope in which they were defined.\n\nThis notion of *closure privacy* is powerful, and it readily provides some\nof the benefits of traditional data privacy, a la Java or C++:\n```js\nfunction MyClass(secret) {\n this.increment = function() {\n return ++secret;\n };\n}\n\nvar mc = new MyClass(3);\nconsole.log(mc.increment()); // 4\n```\nYou can learn something about `secret` by calling `.increment()`, and you\ncan increase its value by one as many times as you like, but you can never\ndecrease its value, because it is completely inaccessible except through\nthe `.increment` method. And if the `.increment` method were not\navailable, it would be as if no `secret` variable had ever been declared,\nas far as you could tell.\n\nThis style breaks down as soon as you want to inherit methods from the\nprototype of a class:\n```js\nfunction MyClass(secret) {\n this.secret = secret;\n}\n\nMyClass.prototype.increment = function() {\n return ++this.secret;\n};\n```\nThe only way to communicate between the `MyClass` constructor and the\n`.increment` method in this example is to manipulate shared properties of\n`this`. Unfortunately `this.secret` is now exposed to unlicensed\nmodification:\n```js\nvar mc = new MyClass(6);\nconsole.log(mc.increment()); // 7\nmc.secret -= Infinity;\nconsole.log(mc.increment()); // -Infinity\nmc.secret = \"Go home JavaScript, you're drunk.\";\nmc.increment(); // NaN\n```\nAnother problem with closure privacy is that it only lends itself to\nper-instance privacy, whereas the `private` keyword in most\nobject-oriented languages indicates that the data member in question is\nvisible to all instances of the same class.\n\nSuppose you have a `Node` class with a notion of parents and children:\n```js\nfunction Node() {\n var parent;\n var children = [];\n\n this.getParent = function() {\n return parent;\n };\n\n this.appendChild = function(child) {\n children.push(child);\n child.parent = this; // Can this be made to work?\n };\n}\n```\nThe desire here is to allow other `Node` objects to manipulate the value\nreturned by `.getParent()`, but otherwise disallow any modification of the\n`parent` variable. You could expose a `.setParent` function, but then\nanyone could call it, and you might as well give up on the getter/setter\npattern.\n\nThis module solves both of these problems.\n\nUsage\n---\n\nLet's revisit the `Node` example from above:\n```js\nvar p = require(\"private\").makeAccessor();\n\nfunction Node() {\n var privates = p(this);\n var children = [];\n\n this.getParent = function() {\n return privates.parent;\n };\n\n this.appendChild = function(child) {\n children.push(child);\n var cp = p(child);\n if (cp.parent)\n cp.parent.removeChild(child);\n cp.parent = this;\n return child;\n };\n}\n```\nNow, in order to access the private data of a `Node` object, you need to\nhave access to the unique `p` function that is being used here. This is\nalready an improvement over the previous example, because it allows\nrestricted access by other `Node` instances, but can it help with the\n`Node.prototype` problem too?\n\nYes it can!\n```js\nvar p = require(\"private\").makeAccessor();\n\nfunction Node() {\n p(this).children = [];\n}\n\nvar Np = Node.prototype;\n\nNp.getParent = function() {\n return p(this).parent;\n};\n\nNp.appendChild = function(child) {\n p(this).children.push(child);\n var cp = p(child);\n if (cp.parent)\n cp.parent.removeChild(child);\n cp.parent = this;\n return child;\n};\n```\nBecause `p` is in scope not only within the `Node` constructor but also\nwithin `Node` methods, we can finally avoid redefining methods every time\nthe `Node` constructor is called.\n\nNow, you might be wondering how you can restrict access to `p` so that no\nuntrusted code is able to call it. The answer is to use your favorite\nmodule pattern, be it CommonJS, AMD `define`, or even the old\nImmediately-Invoked Function Expression:\n```js\nvar Node = (function() {\n var p = require(\"private\").makeAccessor();\n\n function Node() {\n p(this).children = [];\n }\n\n var Np = Node.prototype;\n\n Np.getParent = function() {\n return p(this).parent;\n };\n\n Np.appendChild = function(child) {\n p(this).children.push(child);\n var cp = p(child);\n if (cp.parent)\n cp.parent.removeChild(child);\n cp.parent = this;\n return child;\n };\n\n return Node;\n}());\n\nvar parent = new Node;\nvar child = new Node;\nparent.appendChild(child);\nassert.strictEqual(child.getParent(), parent);\n```\nBecause this version of `p` never leaks from the enclosing function scope,\nonly `Node` objects have access to it.\n\nSo, you see, the claim I made at the beginning of this README remains\ntrue:\n\n> In JavaScript, the only data that are truly private are local variables\n> whose values do not *leak* from the scope in which they were defined.\n\nIt just so happens that closure privacy is sufficient to implement a\nprivacy model similar to that provided by other languages.\n",
|
|
"readmeFilename": "README.md",
|
|
"repository": {
|
|
"type": "git",
|
|
"url": "git://github.com/benjamn/private.git"
|
|
},
|
|
"scripts": {
|
|
"test": "mocha --reporter spec --full-trace test/run.js"
|
|
},
|
|
"version": "0.1.8"
|
|
}
|