Chrono Node - lmucs/grapevine GitHub Wiki

This page has information on how to use Chrono-Node.

chrono-node

Chrono is a natural language date parser in Javascript, designed for extracting date information from any given test. Source Code

###Setup Node.js

npm install chrono-node

Bower

npm install bower
bower install chrono

###Usage Simply pass a string to funciton chrono.parseDate or chrono.parse

> var chrono = require('chrono-node')
 
> chrono.parseDate('An appointment on Sep 12-13') 
Fri Sep 12 2014 12:00:00 GMT-0500 (CDT)
    
> chrono.parse('An appointment on Sep 12-13');
[ { index: 18,
    text: 'Sep 12-13',
    tags: { ENMonthNameMiddleEndianParser: true },
    start: 
     { knownValues: [Object],
       impliedValues: [Object] },
    end: 
     { knownValues: [Object],
       impliedValues: [Object] } } ]

parse() returns an array of ParsedResults. Since most posts will have zero or one events, the array that is returned will be empty or have a single element in most cases.

> myDate = chrono.parse('We will have pizza from 3-6pm tomorrow afternoon!');
[ { ref: Tue Sep 22 2015 10:21:39 GMT-0700 (PDT),
    index: 19,
    text: 'from 3-6pm tomorrow',
    tags: 
     { ENCasualDateParser: true,
       ENTimeExpressionParser: true,
       ENMergeDateAndTimeRefiner: true },
    start: { knownValues: [Object], impliedValues: [Object] },
    end: { knownValues: [Object], impliedValues: [Object] } } ]

###Examples

>var results = chrono.parse('ServeLA is Sept. 19 from 7:30 am-2:00 pm! Sign up for the free event here: http://bit.ly/1JXtzu7 @csa_lmu #ServeLA')
> results
[ { ref: Tue Sep 15 2015 16:48:06 GMT-0700 (PDT),
    index: 11,
    text: 'Sept. 19 from 7:30 am-2:00 pm',
    tags:
     { ENMonthNameMiddleEndianParser: true,
       ENTimeExpressionParser: true,
       ENMergeDateAndTimeRefiner: true },
    start: { knownValues: [Object], impliedValues: [Object] },
    end: { knownValues: [Object], impliedValues: [Object] } } ]
> results[0].start.date()
Sat Sep 19 2015 07:30:00 GMT-0700 (PDT)
> results[0].end.date()
Sat Sep 19 2015 14:00:00 GMT-0700 (PDT)

> var results = chrono.parse('Not sure what is open today? The Lair is open 9am-7pm, Iggys from 11am-1am, C-Lion Levy 11am-2am, and C-Lion Del Rey 10am- 1:30am!')
> results
[ { ref: Tue Sep 15 2015 17:01:01 GMT-0700 (PDT),
    index: 22,
    text: 'today',
    tags: { ENCasualDateParser: true },
    start: { knownValues: [Object], impliedValues: [Object] } },
  { ref: Tue Sep 15 2015 17:01:01 GMT-0700 (PDT),
    index: 46,
    text: '9am-7pm',
    tags: { ENTimeExpressionParser: true },
    start: { knownValues: [Object], impliedValues: [Object] },
    end: { knownValues: [Object], impliedValues: [Object] } },
  { ref: Tue Sep 15 2015 17:01:01 GMT-0700 (PDT),
    index: 61,
    text: 'from 11am-1am',
    tags: { ENTimeExpressionParser: true },
    start: { knownValues: [Object], impliedValues: [Object] },
    end: { knownValues: [Object], impliedValues: [Object] } },
  { ref: Tue Sep 15 2015 17:01:01 GMT-0700 (PDT),
    index: 88,
    text: '11am-2am',
    tags: { ENTimeExpressionParser: true },
    start: { knownValues: [Object], impliedValues: [Object] },
    end: { knownValues: [Object], impliedValues: [Object] } },
  { ref: Tue Sep 15 2015 17:01:01 GMT-0700 (PDT),
    index: 117,
    text: '10am- 1:30am',
    tags: { ENTimeExpressionParser: true },
    start: { knownValues: [Object], impliedValues: [Object] },
    end: { knownValues: [Object], impliedValues: [Object] } } ]
> results[2].start.date()
Tue Sep 15 2015 11:00:00 GMT-0700 (PDT)
> results[2].end.date()
Tue Sep 15 2015 01:00:00 GMT-0700 (PDT)

Pros:

  • Can recognize multiple events in one string
  • Can be customized to recognize specific events (example can be found in the project's wiki)
  • Output can be refined too

Cons:

  • Takes the word 'today' by itself as an event in itself (can easily be ignored)
  • Doesn't recognize an end time that goes to the next day as belonging to the next day. For example, The C-Lion event goes from 11am-1am, but chrono interprets the end date as being the same day than the start date

Issues With Chrono

  1. In the following example, Chrono will parse the single event into two separate events because of the period.
> myDate = chrono.parse("Next Sat. from 11:30-1:30, join LMU\'s second annual Community Open House! RSVPs are encouraged at [email protected] http://t.co/JIZwsotDVZ")
[ { ref: Tue Sep 22 2015 10:58:04 GMT-0700 (PDT),
    index: 0,
    text: 'Next Sat',
    tags: {},
    start: { knownValues: [Object], impliedValues: [Object] } },
  { ref: Tue Sep 22 2015 10:58:04 GMT-0700 (PDT),
    index: 10,
    text: 'from 11:30-1:30',
    tags: { ENTimeExpressionParser: true },
    start: { knownValues: [Object], impliedValues: [Object] },
    end: { knownValues: [Object], impliedValues: [Object] } } ]

However, if we remove the period from Sat., we get the single event we desire.

> myDate = chrono.parse("Next Sat from 11:30-1:30, join LMU\'s second annual Community Open House! RSVPs are encouraged at [email protected] http://t.co/JIZwsotDVZ")
[ { ref: Tue Sep 22 2015 11:03:06 GMT-0700 (PDT),
    index: 0,
    text: 'Next Sat from 11:30-1:30',
    tags: 
     { ENTimeExpressionParser: true,
       ENMergeDateAndTimeRefiner: true },
    start: { knownValues: [Object], impliedValues: [Object] },
    end: { knownValues: [Object], impliedValues: [Object] } } ]

We could process the string before passing it to Chrono, removing . from abbreviations.