How To Apply Multiple MAT_DATE_FORMATS On Same Component

2 min read 06-10-2024

How To Apply Multiple MAT_DATE_FORMATS On Same Component

Mastering Multiple Date Formats in Angular Material: A Comprehensive Guide

Angular Material's MAT_DATE_FORMATS is a powerful tool for controlling how dates are displayed and formatted within your application. However, situations arise where you might need to apply multiple date formats within the same component. This article will guide you through the process, equipping you with the knowledge to effectively handle date formatting complexities.

The Problem: A Single Format Doesn't Fit All

Imagine you're building a user interface that displays dates in two distinct formats:

Short Format (e.g., "12/25/2023") for quick visual reference
Long Format (e.g., "December 25, 2023") for detailed information

Using a single MAT_DATE_FORMATS provider would force you to choose one format, sacrificing the flexibility required for your application.

Solution: Harnessing the Power of Injection and Overrides

The key lies in harnessing the power of Angular's dependency injection and provider overriding. Instead of relying on a global MAT_DATE_FORMATS definition, we can create separate instances for each format and selectively inject them where needed.

Here's how it works:

Create a custom date format provider:

import { MAT_DATE_FORMATS, DateAdapter } from '@angular/material/core';

export const CUSTOM_DATE_FORMATS = {
    parse: {
        dateInput: 'YYYY-MM-DD' 
    },
    display: {
        dateInput: 'YYYY-MM-DD',
        monthYearLabel: 'MMMM YYYY',
        dateA11yLabel: 'LL',
        monthYearA11yLabel: 'MMMM YYYY',
    }
};

// Example: 
//  - Inject the custom provider into a component using the 'providers' array
//  - Use the `DateAdapter` to format dates within the component
@Component({
    selector: 'app-my-component',
    template: `
        <mat-form-field>
            <input matInput [matDatepicker]="picker" placeholder="Enter Date">
            <mat-datepicker-toggle matSuffix [for]="picker"></mat-datepicker-toggle>
            <mat-datepicker #picker></mat-datepicker>
        </mat-form-field>
    `,
    providers: [
        { provide: MAT_DATE_FORMATS, useValue: CUSTOM_DATE_FORMATS },
        { provide: DateAdapter, useClass: yourCustomDateAdapter },
    ]
})
export class MyComponent {
    // ... component logic
}

// Custom Date Adapter (if needed)
@Injectable()
export class yourCustomDateAdapter extends DateAdapter<Date> {
    // ... custom logic to format dates
}

Utilize separate date adapters:

// Short Format Adapter
@Injectable()
export class ShortDateAdapter extends DateAdapter<Date> {
    format(date: Date, displayFormat: string): string {
        return this.dateFns.format(date, 'MM/dd/yyyy');
    }
}

// Long Format Adapter
@Injectable()
export class LongDateAdapter extends DateAdapter<Date> {
    format(date: Date, displayFormat: string): string {
        return this.dateFns.format(date, 'MMMM dd, yyyy');
    }
}

Apply the appropriate provider based on context:

@Component({
    selector: 'app-my-component',
    template: `
        <div>
            <span>Short Format: {{ date | date:'MM/dd/yyyy' }}</span>
            <span>Long Format: {{ date | date:'MMMM dd, yyyy' }}</span>
        </div>
    `,
    providers: [
        // Short format provider
        { provide: MAT_DATE_FORMATS, useValue: CUSTOM_DATE_FORMATS },
        { provide: DateAdapter, useClass: ShortDateAdapter },
        // Long format provider
        { provide: MAT_DATE_FORMATS, useValue: CUSTOM_DATE_FORMATS },
        { provide: DateAdapter, useClass: LongDateAdapter },
    ]
})
export class MyComponent {
    // ... component logic
}

Advantages of This Approach

Flexibility: Easily switch between different formats based on the context.
Modularity: Keep your date formatting logic organized and reusable.
Efficiency: Avoid unnecessary re-rendering of your component when only the date format changes.

Best Practices

Use date libraries: Utilize libraries like date-fns for robust and efficient date formatting.
Consider your user experience: Choose formats that are intuitive and culturally appropriate.
Document your date formatting logic: Ensure clarity and maintainability within your codebase.

Conclusion

By implementing these techniques, you gain the flexibility to apply multiple date formats within the same Angular Material component. Remember to carefully consider your application's requirements and user needs when choosing the right format for each context. With a little creativity, you can enhance your application's usability and provide a smoother user experience.