recently v0.3.1

recently

Helper to get the last time something happened

Initialization

var Recently = require('recently');
var cache = new Recently();

Add some items:

cache.add('a');
cache.add('b');
cache.add('b');
cache.add('c');

We can also initialize as follows:

var Recently = require('recently');
var cache = new Recently(['a','b','b','c']);

last(value, number)

Retrieves the last items that were inserted into the cache.

Arguments

1. value. Optional value which, when present, is used to compare to each item in the cache. If present then last() returns a count.
2. number. The number of items to extract from the cache.

Returns

If value is present, a bool is returned (true if the item was found). If value is not present, then an array is returned

Example

// get the last two items in the cache
cache.last(2); // returns ['b','c']

// count the number of times that 'b' occurs in the last 3 items
cache.last('b', 3); // returns 2

lastTime(value)

Retrieves the last time a given value was added to the cache.

Arguments

1. value. The value to retrieve from the cache

Returns

A date in ISO format if the item is found (or null if not)

Example

var cache = new Recently();
cache.add('a');
cache.add('b');
cache.add('b');

// get the last time the item 'b' was entered 
cache.lastTime('b'); // returns a date in ISO format (e.g. 2016-07-13T19:12:07.602Z)

ago(value, seconds)

Retrieves the items in the cache since a certain duration from insertion.

Arguments

1. value. Optional value which, when present, is used to compare to each item in the cache. If present then ago() returns a count.
2. seconds. The number of seconds back we want to check the cache.

Return

If value is present, a bool is returned (true if the item was found). If value is not present, then an array is returned

Example

Imagine we enter some value over time:

// add one item
cache.add(true);
// wait 1s and add another 
setTimeout(() => {
    cache.add(true);
    // add 1.5s more and add a final one
    setTimeout(() => {
        cache.add(false);
    }, 1500);
}, 1000);

Now if were to immediately query the cache with the .ago() method, we would see the following:

// get the items from the cache based on # of seconds
cache.ago(1); // returns [false]
cache.ago(2); // returns [true,false]
cache.ago(3); // returns [true,true,false]

As with, the last() method, an optional value can also be provided:

// count the number of items in the cache that match 'true'
cache.ago(true, 2); // returns 1

// count the number of items in the cache that match 'false'
cache.ago(true, 3); // returns 2

// count the number of items in the cache that match 'false'
cache.ago(false, 2); // returns 1