Advanced AEM dialog validation Example - includes RegEx field check and complicated logic

dialog.xml

<?xml version="1.0" encoding="UTF-8"?>
<jcr:root xmlns:cq="http://www.day.com/jcr/cq/1.0" xmlns:jcr="http://www.jcp.org/jcr/1.0"
    jcr:primaryType="cq:Dialog"
    title="My Dialog"
    xtype="dialog">
    <items
        jcr:primaryType="cq:Widget"
        xtype="tabpanel">
        <items jcr:primaryType="cq:WidgetCollection">
            <tab1
                jcr:primaryType="cq:Panel"
                title="tab 1">
                <items jcr:primaryType="cq:WidgetCollection">
                    <link
                        jcr:primaryType="cq:Widget"
                        fieldLabel="Link"
                        name="./link"
                        xtype="pathfield"/>
                    <enable
                        jcr:primaryType="cq:Widget"
                        defaultValue="{Boolean}false"
                        fieldLabel="Enable"
                        name="./enable"
                        type="checkbox"
                        xtype="selection"/>
                </items>
            </tab1>
        </items>
    </items>
    <listeners
        jcr:primaryType="nt:unstructured"
        beforesubmit="
        function(dialog) {
            var linkField = dialog.find('name', './link')[0];
            var enableField = dialog.find('name', './enable')[0];
            var linkVal = linkField.getValue().trim();
            var enableVal = enableField.getValue();
            /* matches NOT starting with '/content/' or ending with '.html' or '/' */
            var reFail = new RegExp('(^(?!\/content\/)(.*))|(\.htm.?$)|(\/$)', 'i');
            
            if(reFail.test(linkVal) &amp;&amp; enableVal == 'true') {
                CQ.Ext.Msg.alert('Validation', 'Link should not be an external path or include a .html or / at the end.');
                return false;
            }
            
            return true;
        }"/>
</jcr:root>