cache-base

Basic object cache with get, set, del, and has methods for node.js/javascript projects.

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• Install
• Quickstart
• API
• Usage examples
• About

(TOC generated by verb using markdown-toc)

Install

Install with npm:

$ npm install --save cache-base

Quickstart

const CacheBase = require('cache-base');
const app = new CacheBase();

app.set('a.b', 'c');

console.log(app.cache.a);    //=> { b: 'c' }
console.log(app.cache.a.b);  //=> 'c'

console.log(app.get('a'));   //=> { b: 'c' }
console.log(app.get('a.b')); //=> 'c'

More usage examples below.

API

Params

• prop {String|Object}: (optional) Property name to use for the cache, or the object to initialize with.
• cache {Object}: (optional) An object to initialize with.

Example

const app = new CacheBase();

.set

Assign value to key. Also emits set with the key and value.

Params

• key {String|Array}: The name of the property to set. Dot-notation may be used to set nested properties.
• value {any}
• returns {Object}: Returns the instance for chaining.

Events

• emits: set with key and value as arguments.

Example

app.on('set', function(key, val) {
  // do something when `set` is emitted
});

app.set('admin', true);

// also takes an object or an array of objects
app.set({ name: 'Brian' });
app.set([{ foo: 'bar' }, { baz: 'quux' }]);
console.log(app);
//=> { name: 'Brian', foo: 'bar', baz: 'quux' }

.get

Return the value of key.

Params

• key {String|Array}: The name of the property to get. Dot-notation may be used to set nested properties.
• returns {any}: Returns the value of key

Events

• emits: get with key and value as arguments.

Example

app.set('a.b.c', 'd');
app.get('a.b');
//=> { c: 'd' }

.prime

Create a property on the cache with the given value only if it doesn't already exist.

Params

• key {String}: Property name or object path notation.
• val {any}
• returns {Object}: Returns the instance for chaining.

Example

console.log(app.cache); //=> {}
app.set('one', { foo: 'bar' });
app.prime('one', { a: 'b' });
app.prime('two', { c: 'd' });
console.log(app.cache.one); //=> { foo: 'bar' }
console.log(app.cache.two); //=> { c: 'd' }

.default

Set a default value to be used when .get() is called and the value is not defined on the cache. Returns a value from the defaults when only a key is passed.

Params

• key {String|Array}: The name of the property to set. Dot-notation may be used to set nested properties.
• value {any}: (optional) The value to set on the defaults object.
• returns {Object}: Returns the instance for chaining.

Example

app.set('foo', 'xxx');
app.default('foo', 'one');
app.default('bar', 'two');
app.default('baz', 'three');
app.set('baz', 'zzz');

console.log(app.get('foo'));
//=> 'xxx'

console.log(app.get('bar'));
//=> 'two'

console.log(app.get('baz'));
//=> 'zzz'

console.log(app);
// CacheBase {
//   cache: { foo: 'xxx', bar: 'two', baz: 'zzz' },
//   defaults: { foo: 'one', bar: 'two', baz: 'three' } }

.union

Set an array of unique values on cache key.

Params

• key {String|Array}: The name of the property to union. Dot-notation may be used to set nested properties.
• value {any}
• returns {Object}: Returns the instance for chaining.

Example

app.union('a.b.c', 'foo');
app.union('a.b.c', 'bar');
app.union('a.b.c', ['bar', 'baz']);
console.log(app.get('a'));
//=> { b: { c: ['foo', 'bar', 'baz'] } }

.has

Return true if the value of property key is not undefined.

Params

• key {String|Array}: The name of the property to check. Dot-notation may be used to set nested properties.
• returns {Boolean}

Example

app.set('foo', true);
app.set('baz', null);
app.set('bar', undefined);

app.has('foo'); //=> true
app.has('bar'); //=> true
app.has('baz'); //=> false

.hasOwn

Returns true if the specified property is an own (not inherited) property. Similar to .has(), but returns true if the key exists, even if the value is undefined.

Params

• key {String}
• returns {Boolean}: Returns true if object key exists. Dot-notation may be used to set nested properties.

Example

app.set('a.b.c', 'd');
app.set('x', false);
app.set('y', null);
app.set('z', undefined);

app.hasOwn('a');      //=> true
app.hasOwn('b');      //=> true
app.hasOwn('c');      //=> true
app.hasOwn('a.b.c');  //=> true
app.hasOwn('x');      //=> true
app.hasOwn('y');      //=> true
app.hasOwn('z');      //=> true
app.hasOwn('lslsls'); //=> false

.del

Delete one or more properties from the instance.

Params

• key {String|Array}: The name of the property to delete. Dot-notation may be used to set nested properties.
• returns {Object}: Returns the instance for chaining.

Events

• emits: del with the key as the only argument.

Example

// setup a listener to update a property with a default
// value when it's deleted by the user
app.on('del', key => app.set(key, app.default(key)));

app.del(); // delete all properties on the cache
// or
app.del('foo');
// or an array of keys
app.del(['foo', 'bar']);

.clear

Reset the entire cache to an empty object. Note that this does not also clear the defaults object, since you can manually do cache.defaults = {} if you want to reset that object as well.

Example

// clear "defaults" whenever the cache is cleared
app.on('clear', key => (app.defaults = {}));
app.clear();

.visit

Visit (or map visit) the specified method (key) over the properties in the given object or array.

Params

• key {String|Array}: The name of the method to visit.
• val {Object|Array}: The object or array to iterate over.
• returns {Object}: Returns the instance for chaining.

.keys

Gets an array of names of all enumerable properties on the cache.

Example

const app = new CacheBase();
app.set('user', true);
app.set('admin', false);

console.log(app.keys);
//=> ['user', 'admin']

.size

Gets the length of keys.

Example

const app = new CacheBase();
app.set('user', true);
app.set('admin', false);

console.log(app.size);
//=> 2

Usage examples

Create an instance of cache-base

const app = new CacheBase();

app.set('a', 'b');
app.set('c.d', 'e');

console.log(app.get('a'));
//=> 'b'
console.log(app.get('c'));
//=> { d: 'e' }
console.log(app);
//=> CacheBase { a: 'b' }

Initialize with an object

const app = new CacheBase({ a: 'b', c: { d: 'e' } });

console.log(app.get('a'));
//=> 'b'
console.log(app.get('c'));
//=> { d: 'e' }
console.log(app.get('c.d'));
//=> 'e'
console.log(app);
//=> CacheBase { cache: { a: 'b' } }

Inherit

class MyApp extends CacheBase {}

const app = new MyApp();
app.set('a', 'b');
app.set('c', 'd');

console.log(app.get('a'));
//=> 'b'

console.log(app);
//=> MyApp { cache: { a: 'b', c: 'd' } }

Custom namespace

Pass a string as the first value to the contructor to define a custom property name to use for the cache. By default values are stored on the cache property.

const CacheBase = require('cache-base');
const app = new CacheBase('data', { a: 'b' });
app.set('c.d', 'e');

// get values
console.log(app.get('a'));
//=> 'b'
console.log(app.get('c'));
//=> { d: 'e' }
console.log(app.data);
//=> { a: 'b', c: { d: 'e' } }
console.log(app);
//=> CacheBase { data: { a: 'b', c: { d: 'e' } } }

About

Related projects

You might also be interested in these projects:

• base-methods: base-methods is the foundation for creating modular, unit testable and highly pluggable node.js applications, starting… more | homepage
• get-value: Use property paths like 'a.b.c' to get a nested value from an object. Even works… more | homepage
• has-value: Returns true if a value exists, false if empty. Works with deeply nested values using… more | homepage
• option-cache: Simple API for managing options in JavaScript applications. | homepage
• set-value: Create nested values and any intermediaries using dot notation ('a.b.c') paths. | homepage
• unset-value: Delete nested properties from an object using dot notation. | homepage

Contributors

Author

Jon Schlinkert

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License

Copyright © 2018, Jon Schlinkert. Released under the MIT License.

This file was generated by verb-generate-readme, v0.6.0, on March 23, 2018.