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    expired
    DefinitelyTyped icon, indicating that this package has TypeScript declarations provided by the separate @types/expired package

    1.3.12 • Public • Published

    expired

    Calculate when HTTP responses expire from the cache headers

    Build Status Coverage Status npm

    expired accepts HTTP headers as an argument and will return information on when the resource will expire. Cache-Control and Expires headers are supported, if both exist Cache-Control takes priority (Why?).

    Install

    npm install --save expired

    Usage

    const expired = require('expired');
     
    const headers = `
    Age: 0
    Cache-Control: public, max-age=300
    Content-Encoding: gzip
    Content-Type: application/json;charset=utf-8
    Date: Fri, 23 Dec 2016 05:50:31 GMT
    Last-Modified: Fri, 23 Dec 2016 05:23:23 GMT`;
     
    expired(headers);
    // false
     
    expired.in(headers);
    // 500000
     
    expired.on(headers);
    // Date('2016-12-23T05:55:31.000Z')
     
    delay(600000).then(() => {
     
      expired(headers);
      // true
     
      expired.in(headers);
      // -100000
     
      expired.on(headers);
      // Date('2016-12-23T05:55:31.000Z')
     
    });

    Many HTTP modules will parse response headers into an object for you. expired will also accept headers in this format:

    const expired = require('expired');
     
    const headers = {
      'age': '0',
      'cache-control': 'public, max-age=300',
      'content-encoding': 'gzip',
      'content-type': 'application/json;charset=utf-8',
      'date': 'Fri, 23 Dec 2016 05:50:31 GMT',
      'last-modified': 'Fri, 23 Dec 2016 05:23:23 GMT'
    };
     
    expired(headers);
    // false

    Pure Usage

    You can make the functions pure by passing in a JavaScript Date object to compare to instead of depending on new Date(). This isn't necessary for expired.on as it doesn't compare dates and is already pure.

    The following are all pure functions:

    const headers = `...`;
    const date = new Date();
     
    expired(headers, date);
    expired.in(headers, date);
    expired.on(headers);

    API

    expired(headers, [date])

    Returns a boolean relating to whether the resource has expired or not. true means it's expired, false means it's fresh.

    expired.in(headers, [date])

    Returns the amount of milliseconds from the current date until the resource will expire. If the resource has already expired it will return a negative integer.

    expired.on(headers)

    Returns a JavaScript Date object for the date the resource will expire.

    License

    MIT © Luke Childs

    Install

    npm i expired

    DownloadsWeekly Downloads

    97

    Version

    1.3.12

    License

    MIT

    Last publish

    Collaborators

    • lukechilds