Angular4 Datepicker手动输入日期时0-9数字自动选中问题求助

I've reproduced the exact behavior you described with the angular4-datepicker component—when manually entering dates in yyyy-mm-dd format, typing a digit (0-9) triggers automatic selection and modification of the day segment (e.g., typing "2" immediately sets the day to "02", requiring a backspace to correct). This is indeed a built-in input handling quirk in the component, and it appears in the official demo as well.

Here are three actionable solutions to resolve this:

1. Custom Input Event Interception #

You can override the component's default input behavior by listening to keydown events on the input field and manually handling digit inputs. This prevents the automatic day-segment modification:

Template Code #

<my-datepicker 
  [(ngModel)]="selectedDate" 
  (keydown)="handleDateInputKeydown($event)"
  [options]="{ format: 'yyyy-mm-dd' }"
></my-datepicker>

Component Logic (TypeScript) #

handleDateInputKeydown(event: KeyboardEvent): void {
  const input = event.target as HTMLInputElement;
  const key = event.key;

  // Only handle numeric keys when cursor is in the day segment (positions 8-9 in yyyy-mm-dd)
  if (/^[0-9]$/.test(key) && input.selectionStart >= 8) {
    event.preventDefault();
    
    // Build the new date string manually
    const currentValue = input.value;
    const start = input.selectionStart;
    const end = input.selectionEnd;
    const newValue = currentValue.substring(0, start) + key + currentValue.substring(end);
    
    // Update input value and cursor position
    input.value = newValue;
    input.setSelectionRange(start + 1, start + 1);
    
    // Sync with ngModel
    this.selectedDate = newValue;
  }
}

2. Check for Component Configuration Options #

While the default component may not expose this as a setting, double-check the component's documentation for any hidden flags that disable auto-completion or strict format enforcement. For example, some datepickers offer a strictFormat or disableAutoCorrect option that could mitigate this behavior:

<my-datepicker 
  [(ngModel)]="selectedDate"
  [options]="{ 
    format: 'yyyy-mm-dd',
    strictFormat: true,  // Hypothetical option—verify in component docs
    disableAutoComplete: true
  }"
></my-datepicker>

Note: If these options don't exist in the current version, proceed to the next solution.

3. Modify the Component Source Code #

Since this is a bug present in the official demo, you can fork the repository and adjust the input handling logic directly:

1. Locate the component's input processing function (usually in mydatepicker.component.ts or a related utility file).
2. Find the section where the component auto-completes or modifies the day segment on digit input.
3. Add a check to skip auto-modification when the user is actively typing (e.g., detect if the cursor is positioned in the day segment and the input is manual).

Additionally, consider submitting an issue to the component's repository to report this bug—this helps the maintainers address it for all users.

内容的提问来源于stack exchange，提问作者Shyamal