README

data-crisper

Refresh cached data on a decaying interval. Getter is synchronous and non-blocking for client performance. For use when your app is ok with stale data when requests are infrequent.

Usage

var crisper = require('data-crisper')

var footerDataCache = crisper(60000, function(cb){
    api.fetch('get/my/data',function(err,data){
        cb(err,data)
    })
})

require('http').createServer(function(req, res){
    var footerHtml = renderView('footer', footerDataCache.get())
    res.end('<html><body>'
        + '<header>My website</header><main>is awesome.</main>'
        + 'heres some less important info in the footer:<footer>'+footerHtml+'</footer>'
    + '</body></html>')
}).listen(3000)

// optional: set default value - will be returned if no data in cache
footerDataCache.setDefault({});

Api

crisper( [ttl,] fetchData [, defaultValue] )

Returns a Crisper that will fetchData() and update cache every ttl ms behind the scenes

ttl will increase over time if data is not being accessed

ttl will reset if fetchData() calls back with an error

fetchData is the only required field; ttl defaults to 30000 (30 sec)

Crisper.get()

Returns last successfully stored value

Otherwise returns getDefault()

Crisper.getSilently()

Same as get() but will not affect ttl

Crisper.setDefault( value )

Set the value returned if data has never been set

Crisper.getDefault()

Return the current default

Crisper.pause()

Stop fetching

The value returned from get() will not change while paused. i.e. values in the process of being fetched will be trashed.

Crisper.resume()

Resume fetching

Crisper.destroy()

You never want to use this data again

To Do

Use global timer if # timeouts reach a threshold

Usage no npm install needed!