ELEMENTS-1450: compute validity based on the current value

[mnixo]

Context

• On an auto search, the results are updated as the user tweaks the values of the widgets in the search form layout.
• When value is changed, the form is validated and, if successful, the appropriate results are shown.
• When using a <nuxeo-date-picker> the user is able to set a date and the results are updated automatically.
• However, when changing the date to another value, the elements shows itself as invalid and therefore the results are not updated.
• This seems to be caused to the way <vaadin-date-picker> checks the validity of its value:
  • As the user picks a second date, the change is picked up by the form layout and Web UI automatically tries to validate the form to present the new results.
  • While validating the form, <vaadin-date-picker> does its own validation but doesn't seem to be ready, as at this moment there's still a difference between value (same as this._inputValue, still the first date the user picked) and this._selectedDate (which is already the second date picked).

Proposed Solution

• By passing this.value in this.$.date.validate() it ensures that the comparison is done with the most up to date value, instead of relying on the outdated this._inputValue.
• Since the comparison is done with formatted date values and to ensure a smooth outcome, we should be using the same formatting that <vaadin-date-picker> uses (relies on locales), but since <nuxeo-date-picker> has no access to the Vaadin global variable and its helpers, I propose using the moment formatting (also based on locales) that is already used throughout <nuxeo-date-picker> we should just use this.$.date.i18n.formatDate().

[nuxeojenkins]

View issue in JIRA: ELEMENTS-1450: Fix auto-search when changing the select in nuxeo-date-picker

[Gabez0r]

LGTM.

[mnixo]

At last, 🔵 pipeline run.

[Gabez0r]

Cross-repo check 🔵 : https://github.com/nuxeo/nuxeo-web-ui/actions/runs/1824512436