NAME
    jQuery Extensions - RSpade framework extensions and overrides to jQuery

SYNOPSIS
    // Standard click handler with automatic preventDefault
    $('.btn').click(function(e) {
        console.log('Button clicked');
    });

    // Escape hatch for native behavior (rare)
    $('.nav-link').click_allow_default(function(e) {
        analytics.track('click');
        // Link navigation happens
    });

    // Other jQuery helpers
    if ($('.element').exists()) { ... }
    if ($('.element').is_in_viewport()) { ... }
    $('.form').checkValidity();

DESCRIPTION
    RSpade extends jQuery with utility methods and overrides default behaviors
    to provide sensible defaults for modern web applications. The most significant
    change is the .click() override that automatically calls e.preventDefault()
    to prevent accidental page navigation and form submission.

    Unlike vanilla jQuery where developers must remember to call preventDefault
    in nearly every click handler, RSpade makes the correct behavior automatic.
    This eliminates a common source of bugs where forgotten preventDefault calls
    cause unwanted page reloads or navigation.

    Philosophy:
    - Prevent default is correct 95% of the time
    - Escape hatch available for the 5% case
    - Fail toward the safe behavior (no navigation)
    - Make the common case trivial

CLICK OVERRIDE

    .click(handler)
        Attach click handler that automatically calls e.preventDefault()

        This prevents:
        - Link navigation (<a href>)
        - Form submission (<button type="submit">)
        - Default button actions

        Usage:
            $('.delete-btn').click(function(e) {
                delete_record($(this).data('id'));
                // No need for e.preventDefault() - automatic
            });

            $('a.modal-trigger').click(function(e) {
                open_modal();
                // Link won't navigate - preventDefault called
            });

    .click() (no handler)
        Trigger click event - native behavior unchanged

        Usage:
            $('.hidden-button').click(); // Triggers click

    .click_allow_default(handler)
        Escape hatch for native click behavior without preventDefault

        Use this ONLY when you explicitly need default browser behavior.
        Examples: analytics tracking before navigation, conditional preventDefault

        Usage:
            $('.external-link').click_allow_default(function(e) {
                analytics.track('external_click', this.href);
                // Navigation happens after handler
            });

            $('button[type=submit]').click_allow_default(function(e) {
                if (!validate_form()) {
                    e.preventDefault(); // Conditionally prevent
                }
                // Otherwise allows form submission
            });

JQUERY HELPERS

    Element Existence and State

        .exists()
            Returns true if jQuery selector matched any elements

            if ($('.error-message').exists()) {
                console.log('Error message present');
            }

        .is_visible()
            Returns true if element is visible (not display:none or hidden)

            if ($('.modal').is_visible()) {
                $('.modal').fadeOut();
            }

        .is_in_dom()
            Returns true if element exists in and is attached to the DOM

            if ($('.dynamic-element').is_in_dom()) {
                // Element is live in the page
            }

        .is_in_viewport()
            Returns true if element is currently visible in the viewport

            $('.lazy-image').each(function() {
                if ($(this).is_in_viewport()) {
                    load_image($(this));
                }
            });

    Scrolling

        .scroll_up_to(speed = 0)
            Scrolls page up to bring element into view if it's above viewport

            $('.error-field').scroll_up_to(300);

    Element Information

        .tagname()
            Returns lowercase tag name of element

            if ($element.tagname() === 'a') {
                // It's a link
            }

        .is_external()
            Returns true if link href is external to current domain
            Only works on <a> elements

            if ($('a').is_external()) {
                $(this).attr('target', '_blank');
            }

    Component-Aware DOM Traversal

        .shallowFind(selector)
            Finds child elements matching the selector that don't have another
            element of the same class as a parent between them and the component.

            Useful for finding direct widget children in nested component trees
            without accidentally selecting widgets from nested child components.

            Example:
                Component_A
                └── div
                    └── Widget (found)
                        └── span
                            └── Widget (not found - has Widget parent)

            $('.Component_A').shallowFind('.Widget')
            // Returns only the first Widget

            Use case - Finding form widgets without selecting nested widgets:
                this.$.shallowFind('.Form_Field').each(function() {
                    // Only processes fields directly in this form,
                    // not fields in nested sub-forms
                });

        .closest_sibling(selector)
            Searches for elements within progressively higher ancestor containers.
            Similar to .closest() but searches within ancestors instead of
            matching the ancestors themselves. Stops searching at <body> tag.

            Useful for component-to-component communication when components need
            to find related sibling or cousin components without knowing the
            exact DOM structure.

            Algorithm:
            1. Get current element's parent
            2. Search within parent using parent.find(selector)
            3. If found, return results
            4. If not found, move to parent's parent and repeat
            5. Stop when reaching <body> (searches body but not beyond)
            6. Return empty jQuery object if nothing found

            Example DOM structure:
                <body>
                  <div class="form-section">
                    <div class="row">
                      <div class="Country_Select_Input"></div>
                    </div>
                    <div class="another-row">
                      <div class="State_Select_Input"></div>
                    </div>
                  </div>
                </body>

            $('.Country_Select_Input').closest_sibling('.State_Select_Input')
            // Finds State_Select_Input by searching up to form-section

            Use case - Country selector updating state selector:
                on_ready() {
                    if (this.tom_select) {
                        this.tom_select.on('change', () => {
                            const state_input = this.$el.closest_sibling('.State_Select_Input');
                            if (state_input.exists()) {
                                const widget = state_input.component();
                                widget.set_country_code(this.val());
                            }
                        });
                    }
                }

    Form Validation

        .checkValidity()
            Returns true if form/field passes HTML5 validation

            if ($('form').checkValidity()) {
                submit_form();
            }

        .reportValidity()
            Triggers browser's native validation UI, returns validity

            if (!$('form').reportValidity()) {
                return; // Browser shows validation errors
            }

        .requestSubmit()
            Programmatically submit form (triggers validation)

            $('form').requestSubmit();

    Focus Selector

        :focus pseudo-selector
            Select element that currently has focus

            if ($('input').is(':focus')) {
                // Input is focused
            }

            $('input:focus').addClass('active');

RSPADE VS VANILLA JQUERY

    Click Handlers

        Vanilla jQuery:
            $('.btn').click(function(e) {
                e.preventDefault(); // Must remember this
                do_something();
            });

        RSpade:
            $('.btn').click(function(e) {
                do_something(); // preventDefault automatic
            });

    Existence Checks

        Vanilla jQuery:
            if ($('.element').length > 0) { ... }

        RSpade:
            if ($('.element').exists()) { ... }

    Form Validation

        Vanilla jQuery:
            if ($('form')[0].checkValidity()) { ... }

        RSpade:
            if ($('form').checkValidity()) { ... }

WHEN TO USE .click_allow_default()

    Valid use cases (rare):

    1. Analytics tracking before navigation
        $('a.external').click_allow_default(function(e) {
            analytics.track('external_link');
            // Let navigation happen
        });

    2. Conditional preventDefault
        $('button[type=submit]').click_allow_default(function(e) {
            if (!validate_form()) {
                e.preventDefault();
            }
        });

    3. Progressive enhancement fallbacks
        $('a[href="/fallback"]').click_allow_default(function(e) {
            if (ajax_available()) {
                e.preventDefault();
                load_via_ajax();
            }
            // Otherwise let href work
        });

    Invalid use cases (use standard .click() instead):

    - Opening modals (don't need navigation)
    - Triggering actions (don't need navigation)
    - Ajax requests (don't need navigation)
    - Any case where you don't want the browser's default behavior

MIGRATION FROM VANILLA JQUERY

    When porting jQuery code to RSpade:

    1. Remove explicit preventDefault calls in click handlers
        Before:
            $('.btn').click(function(e) {
                e.preventDefault();
                do_action();
            });

        After:
            $('.btn').click(function(e) {
                do_action();
            });

    2. Identify legitimate native behavior needs
        If you have click handlers that SHOULD allow navigation/submission,
        switch to .click_allow_default()

    3. Replace existence checks
        Before: if ($('.el').length > 0)
        After:  if ($('.el').exists())

    4. Replace form validation
        Before: $('form')[0].checkValidity()
        After:  $('form').checkValidity()

EXAMPLES

    Modal Trigger
        // Opens modal without navigating
        $('a.open-modal').click(function(e) {
            const modal_id = $(this).data('modal');
            $(`#${modal_id}`).fadeIn();
        });

    Delete Button
        // Deletes record without form submission
        $('.delete-btn').click(function(e) {
            const id = $(this).data('id');
            if (confirm('Delete this record?')) {
                delete_record(id);
            }
        });

    External Link with Tracking
        // Tracks click then allows navigation
        $('a.external').click_allow_default(function(e) {
            analytics.track('external_link', {
                url: this.href,
                text: $(this).text()
            });
        });

    Conditional Form Submit
        // Only prevents submit if validation fails
        $('form button[type=submit]').click_allow_default(function(e) {
            if (!validate_custom_rules()) {
                e.preventDefault();
                show_errors();
            }
        });

    Lazy Loading on Scroll
        $(window).on('scroll', function() {
            $('.lazy-image').each(function() {
                if ($(this).is_in_viewport() && !$(this).data('loaded')) {
                    const src = $(this).data('src');
                    $(this).attr('src', src).data('loaded', true);
                }
            });
        });

TROUBLESHOOTING

    Problem: Links not navigating when they should
    Solution: Use .click_allow_default() instead of .click()

    Problem: Form submitting unexpectedly
    Solution: This shouldn't happen - .click() prevents submission by default
              If using .click_allow_default(), add explicit e.preventDefault()

    Problem: .exists() not working
    Solution: Ensure Rsx_Jq_Helpers is loaded - check browser console for errors

    Problem: Want to use .on('click') to avoid preventDefault
    Solution: Don't do this - it defeats the framework's safety. If you need
              native behavior, use .click_allow_default() to make intent explicit

IMPLEMENTATION NOTES

    The click override is implemented in:
        /app/RSpade/Core/Js/Rsx_Jq_Helpers.js

    Native jQuery .click() is preserved as:
        $.fn._click_native()

    The override applies to all elements, not just links and buttons. This is
    intentional - preventDefault is harmless on elements without default actions
    and ensures consistency across the codebase.

SEE ALSO
    jqhtml.txt - JQHTML component system
    controller.txt - Controller click handlers
    error_handling.txt - JavaScript error patterns