How to implement MD_DATE_FORMATS for datepicker?

问题

I'm trying to implement my own date format for shiny new datepicker from material2. According to documentation i have to provide my version of MD_DATE_FORMATS:

providers: [
  {provide: DateAdapter, useValue: NativeDateAdapter },
  {provide: MD_DATE_FORMATS, useValue: MY_DATE_FORMATS },
],

When I use default implementation:

export const MD_NATIVE_DATE_FORMATS: MdDateFormats = {
  parse: {
    dateInput: null,
  },
  display: {
    dateInput: {year: 'numeric', month: 'numeric', day: 'numeric'},
    monthYearLabel: {year: 'numeric', month: 'short'},
    dateA11yLabel: {year: 'numeric', month: 'long', day: 'numeric'},
    monthYearA11yLabel: {year: 'numeric', month: 'long'},
  }
};

I get an error that date input is null. But what type it really is? Documentation says any.

If i try to put some dummy function there i get error: _dateAdapter.parse is not a function.

function dateInput() {
    return 'ddd';
}
const MY_DATE_FORMATS: MdDateFormats = Object.assign({}, MD_NATIVE_DATE_FORMATS, {parse: dateInput });

How to make it work?

回答1:

Many thanks to @MariusR who pushed the solution. As stated you need to provide your own date adapter. From the plunkr, this is as simple as follows:

export class OurDateAdapter extends NativeDateAdapter {
  parse(value: any): Date | null {
    if ((typeof value === 'string') && (value.indexOf('/') > -1)) {
      const str = value.split('/');
      return new Date(Number(str[2]), Number(str[1])-1, Number(str[0]), 12);
    }
    const timestamp = typeof value === 'number' ? value : Date.parse(value);
    return isNaN(timestamp) ? null : new Date(timestamp);
  }
}

This can be any of your TS files and just needs to be provided in the module of your component with the date picker:

  providers: [
    {provide: DateAdapter, useClass: OurDateAdapter}
  ]

In your component you need to use it in the constructor:

  constructor(private dateAdapter: DateAdapter<Date>) {
    this.dateAdapter.setLocale('en-GB');
  }

The list of locales can be gathered here, the plunkr example uses Portuguese, mine is UK English.

http://www.i18nguy.com/unicode/language-identifiers.html

MariusR, take a bow, why can't the official docs have this?

回答2:

In your code you should replace the

{provide: DateAdapter, useValue: NativeDateAdapter },

with

{provide: DateAdapter, useClass: NativeDateAdapter },

as the NativeDateAdapter is a class and not a constant.

This should resolve your problem with the .parse is not a function error.

I couldn't replicate the date input is null error though. Could be due to the same useClass problem but if you still encounter an error you could define the dateInput like

parse: {
  dateInput: {year: 'numeric', month: 'numeric', day: 'numeric'},
},

or a variation of

parse: {
  dateInput: 'YYYY-MM-DD',
},

回答3:

Angular implementation uses Javascript date implementation by default, which means that you probably would like to create your own MdDateFormats and DateAdapter implementation in order to get a custom representation of the date. As @MariusR said:

In your code you should replace the

{provide: DateAdapter, useValue: NativeDateAdapter }, with

{provide: DateAdapter, useClass: NativeDateAdapter },

I've made a project showing how to implement custom MdDateFormats and DateAdapter (implementing dates to fit 'es-UY' locale). It uses Moment.js to represent other date formats, and the implementation it's fully customizable to fit your needs. Custom locale files are here.

来源：https://stackoverflow.com/questions/44201050/how-to-implement-md-date-formats-for-datepicker

标签

angular

angular-material