j01.daterangepicker

    DateRange picker widget for `z3c.form`. Wraps Air Datepicker v3.6.0
    (MIT, Timur Borodin).
    
    Two normal `zope.schema.Date` fields are paired into a single
    range-picker UI through the `setUpDateRangePickerWidget` factory.
    Standard `z3c.form` data managers handle the write-back -- no
    custom data manager required.
    
    ## Usage
    
    ```python
    from j01.daterangepicker import setUpDateRangePickerWidget
    
    class MyForm(form.Form):
        fields = field.Fields(IMySchema).select(
            'startDate', 'endDate')
    
        widgetFactories = {
            'startDate': setUpDateRangePickerWidget(
                'startDate', 'endDate'),
            'endDate':   setUpDateRangePickerWidget(
                'startDate', 'endDate'),
        }
    ```
    
    Both factory calls use the same `fromName`/`toName` arguments;
    the widget detects on its own which side it is (primary or
    secondary) by comparing `field.__name__` to `fromName`.
    
    Optional min/max constraints and custom validator:
    
    ```python
    setUpDateRangePickerWidget(
        'startDate', 'endDate',
        minDate=datetime.date.today(),
        maxDate=datetime.date(2030, 12, 31),
        validator=myCustomValidator)
    ```
    
    The widget exposes `validateRange(fromValue, toValue)` with an
    in-built `fromValue <= toValue` check; a custom `validator` callable
    is called in addition. Wire the check into the consumer's action
    handler after `extractData()`.
    
    ## Vendor library
    
    Air Datepicker v3.6.0 files are vendored under `cdn/js/` and
    `cdn/css/`. See `LICENSE.txt` for the upstream MIT licence text.
    The locale files in `cdn/js/air-datepicker.locale.<lang>.js` are
    hand-rewrapped from the upstream CJS modules into browser-IIFE form
    so they can be loaded via a regular `<script>` tag without a
    bundler; the locale data itself is verbatim from upstream.
    
    
    =======
    CHANGES
    =======
    
    0.5.1 (2026-05-20)
    ------------------
    
    - Fix: Inline init script bailed out on initial page parse because
      the secondary widget's hidden `_to` input was rendered *after*
      the primary widget's `<script>` block in document order, so
      `document.getElementById(toInputId)` returned null and the
      `if (!toEl) return;` guard tripped -- Air Datepicker was never
      attached. Init now waits for `DOMContentLoaded` when the document
      is still loading, falls back to `setTimeout(init, 0)` otherwise.
    
    
    0.5.0 (2026-05-20)
    ------------------
    
    - Initial release. DateRange picker widget for z3c.form wrapping
      Air Datepicker v3.6.0 (MIT, Timur Borodin).
    - Pair-mode wiring through `setUpDateRangePickerWidget`: two
      `zope.schema.Date` fields share one picker UI, standard
      z3c.form data managers write back.
    - ISO-8601 (`YYYY-MM-DD`) on the wire; locale-formatted display
      string driven by the standard `z3c.form` `IDate` converter.
    - Vendored Air Datepicker library files in `cdn/{js,css}/` for
      consumer-side resource registration. Locale files (de/en/fr/it)
      rewrapped as browser IIFEs that attach to
      `window.AirDatepickerLocales[lang]`.
    - Optional `m01.mongo` IMongoDate adapter (zcml:condition).