md-datepicker: support string representation of date as a model

[lwj5]

The datepicker currently throws error if model given is not a date instance.
With parseDate function available, it would be helpful check if valid dateString is given before throwing an error.

Possible replacement of line 256-259 ref: pull #5503 of src/components/datepicker/datePicker.js:

  if (value && !(value instanceof Date)) {
    var parseValue = self.dateLocale.parseDate(value);
    if (isNaN(parseValue)) {
        throw Error('The ng-model for md-datepicker must be a Date instance. ' +
        'Currently the model is a: ' + (typeof value));
    } else {
        value = parseValue;
    }
  }

Up for discussion

[cecilia-sanare]

+1
I'm currently getting around this by parsing my responses for dates in order to keep the functionality centralized, but this isn't a very efficient solution. I'd like to see this functionality offloaded to the datepicker.

[tolemac]

+1
https://groups.google.com/forum/?utm_medium=email&utm_source=footer#!msg/ngmaterial/gq3v5MBw8Pg/ylmHSDJYDAAJ

[tolemac]

I copy here my temporal solution, it works fine:

      if (value && !(value instanceof Date)) {
        if (typeof value === "string")
            value = new Date(value);
        if (Object.prototype.toString.call(value) !== "[object Date]")
            throw Error('The ng-model for md-datepicker must be a Date instance. ' +
                'Currently the model is a: ' + (typeof value));
      }

[molehillrocker]

As a general workaround when interacting with JSON data, one could write a custom Date reviver and pass it to JSON#parse() as second parameter (see https://developer.mozilla.org/de/docs/Web/JavaScript/Reference/Global_Objects/JSON/parse).

From my point of view, this is something that should have been implemented directly into JSON#parse(), but fore sure the devs had their reasons why they did not when initially implementing it. flies away

[d668]

seems like this hack works http://jsfiddle.net/kQZw8/6/ http://jsfiddle.net/katfby9L/1/

[tolemac]

Yep @super-coder, I think this is the best solution.

Thanks for share.

[d668]

but the regex is not perfect, i tried another one and here is the updated version http://jsfiddle.net/katfby9L/1/

[tolemac]

@super-coder be careful with complex regex.

We have to look for the best option, run a regex or parse date with new Date(value);

Do you know some way to compare two javascript codes/functions and determine what is more efficient?

[d668]

@tolemac i changed the regex because it wasn't working with past dates from Web API. The new one seems to be working. Would be good to have a confirmed perfect regex...

[marcomafessolli]

+1

@super-coder your solution will convert every integer value as a date object, don't?