forked from zhurui/management
127 lines
3.5 KiB
Markdown
127 lines
3.5 KiB
Markdown
# clone
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[](http://travis-ci.org/pvorb/node-clone)
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[](http://npm-stat.com/charts.html?package=clone)
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offers foolproof _deep cloning_ of objects, arrays, numbers, strings etc. in JavaScript.
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## Installation
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npm install clone
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(It also works with browserify, ender or standalone.)
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## Example
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~~~ javascript
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var clone = require('clone');
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var a, b;
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a = { foo: { bar: 'baz' } }; // initial value of a
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b = clone(a); // clone a -> b
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a.foo.bar = 'foo'; // change a
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console.log(a); // show a
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console.log(b); // show b
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~~~
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This will print:
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~~~ javascript
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{ foo: { bar: 'foo' } }
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{ foo: { bar: 'baz' } }
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~~~
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**clone** masters cloning simple objects (even with custom prototype), arrays,
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Date objects, and RegExp objects. Everything is cloned recursively, so that you
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can clone dates in arrays in objects, for example.
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## API
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`clone(val, circular, depth)`
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* `val` -- the value that you want to clone, any type allowed
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* `circular` -- boolean
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Call `clone` with `circular` set to `false` if you are certain that `obj`
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contains no circular references. This will give better performance if needed.
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There is no error if `undefined` or `null` is passed as `obj`.
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* `depth` -- depth to which the object is to be cloned (optional,
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defaults to infinity)
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`clone.clonePrototype(obj)`
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* `obj` -- the object that you want to clone
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Does a prototype clone as
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[described by Oran Looney](http://oranlooney.com/functional-javascript/).
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## Circular References
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~~~ javascript
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var a, b;
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a = { hello: 'world' };
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a.myself = a;
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b = clone(a);
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console.log(b);
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~~~
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This will print:
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~~~ javascript
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{ hello: "world", myself: [Circular] }
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~~~
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So, `b.myself` points to `b`, not `a`. Neat!
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## Test
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npm test
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## Caveat
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Some special objects like a socket or `process.stdout`/`stderr` are known to not
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be cloneable. If you find other objects that cannot be cloned, please [open an
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issue](https://github.com/pvorb/node-clone/issues/new).
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## Bugs and Issues
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If you encounter any bugs or issues, feel free to [open an issue at
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github](https://github.com/pvorb/node-clone/issues) or send me an email to
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<paul@vorba.ch>. I also always like to hear from you, if you’re using my code.
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## License
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Copyright © 2011-2015 [Paul Vorbach](http://paul.vorba.ch/) and
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[contributors](https://github.com/pvorb/node-clone/graphs/contributors).
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Permission is hereby granted, free of charge, to any person obtaining a copy of
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this software and associated documentation files (the “Software”), to deal in
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the Software without restriction, including without limitation the rights to
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use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
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the Software, and to permit persons to whom the Software is furnished to do so,
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subject to the following conditions:
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The above copyright notice and this permission notice shall be included in all
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copies or substantial portions of the Software.
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THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
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FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
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COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
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IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, OUT OF OR IN CONNECTION WITH THE
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SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
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