I. Data Update Event - Function Template:

1. On New/Edit Page, Trigger Custom Function When a Field is Modified (Value Changed and Lost Focus) to Update Master or Detail Object Data

// Get current page identifier: Add for new page, Edit for edit page  
context.actionPage  
// Create UIEvent  
UIEvent event = UIEvent.build(context) {  
    // Set field as read-only, hidden, or required  
    editMasterFields "field_I18ri__c" readOnly(true) hidden(true) required(true)  

    // Set reminder message  
    remind Remind.Text("Warning reminder")  

    // Set alert message  
    remind Remind.Alert("Popup alert")  

    // Modify master object data  
    editMaster("name": "test", "b": 2)  

    // Whether to automatically calculate computed fields and default values for master and detail objects  
    doCalculate(true)  

    // Add a detail object (must specify business type matching current layout)  
    addDetail "detailApiName" set("record_type": "default__c", "name": "demo001")  

    // Delete detail objects where condition returns true  
    removeDetail "detailApiName" where { x -> (x["a"] as Integer) > 0 }  

    // Edit detail objects where condition returns true  
    editDetail "detailApiName" set("a": 1, "b": 2) where { x -> (x["a"] as Integer) > 0 }  

    // removeDetail and editDetail can work on all data without where condition  
    removeDetail "detailApiName"  
    editDetail "detailApiName" set("a": 1, "b": 2)  

    // Hide detail object with apiName object_0uyAd__c (Note: Hidden detail data will be cleared on save by default)  
    editObject 'object_0uyAd__c' hidden(true) keepData(true) // keepData defaults to false  

    // Hide detail record type  
    editDetailRecordType "object_qep6N__c" recordType("defaultA__c") hidden(true)  

    // Hide option value  
    editOption "object_qep6N__c" fieldApiName("field_y210t__c") option("wwxJqgnO4") hidden(true)  

    // Hide batch edit button  
    editDetailButton "object_qep6N__c" recordType("defaultA__c") hiddenButton(ButtonAction.BATCH_UPDATE, true)  
    // Hide batch delete button  
    editDetailButton "object_qep6N__c" recordType("defaultA__c") hiddenButton(ButtonAction.BATCH_DELETE, true)  
    // Hide batch clone button  
    editDetailButton "object_qep6N__c" recordType("defaultA__c") hiddenButton(ButtonAction.BATCH_CLONE, true)  
    // Hide single add row button  
    editDetailButton "object_qep6N__c" recordType("defaultA__c") hiddenButton(ButtonAction.SINGLE_ADD_ONE, true)  

    // Hide lookup create button  
    editDetailButton "object_qep6N__c" recordType("defaultA__c") lookupFieldApiName("field_y1XV1__c") hiddenButton(ButtonAction.BATCH_LOOKUP_CREATE, true)  

    // Hide single delete operation with condition  
    editDetailButton "object_qep6N__c" recordType("defaultA__c") hiddenButton(ButtonAction.SINGLE_DELETE, true) where { x -> (x["a"] as Integer) > 0 }  
    // Hide single clone operation with condition  
    editDetailButton "object_qep6N__c" recordType("defaultA__c") hiddenButton(ButtonAction.SINGLE_CLONE, true) where { x -> (x["a"] as Integer) > 0 }  

    // Detail field visibility/read-only/required with condition  
    editDetailFields "object_qep6N__c" fieldApiName("field_jt9F4__c") hidden(true) readOnly(true) required(true) where { x -> (x["a"] as Integer) > 0 }  
    editDetailFields "object_qep6N__c" fieldApiName("field_y220t__c") hidden(true) readOnly(true) required(true) where { x -> (x["a"] as Integer) > 0 }  

    // Method 1 to get deleted details  
    if (context.arg != null) {  
        def deletedDetails = (context.arg as Map)["deletedDetails"] as Map  
    }  

    // Method 2 to get deleted details  
    Map currentDeletedDetail = event.getCurrentDeletedDetail()  
}  
return event

2. On Master-Detail New/Edit Page, Trigger Custom Function When Adding/Editing/Deleting Detail Objects to Update Master/Detail Data

UIEvent event = UIEvent.build(context) {  
// Master/detail data modifications (same as above)  
}  
// Get currently operated detail data  
Map currentData = event.getCurrentDetail()  
// Modify current detail data (mainly for add/edit scenarios)  
currentData.put("detailFieldApiName", "newValue")  
currentData.put("detailField1ApiName", "newValue1")  

// Get newly added detail data  
List currentData = event.getCurrentAddDetail()  

// Get batch operated detail data (supports single operation)  
Map currentBatchDetails = event.getCurrentBatchDetails();  

return event  

 (3) Return error message example:  
Fx.message.throwErrorMessage("Error message");  
return null;

II. Page Load Event - Function Template:

Refer to Data Update Event

III. Validation Event - Function Template:

// Text reminder  
Remind remind = Remind.Text("Text");  
// Alert reminder  
Remind remind = Remind.Alert("Text");  

// Set reminder messages  
remind Remind.builder()  
    .remindText("name", "Duplicate master attribute name")  
    .remindText("field_y2k46__c", "Field cannot contain 'test'")  
    .build()  

// Clear reminder messages  
remind Remind.builder()  
    .remindText("name", "")  
    .remindText("field_y2k46__c", "")  
    .build()  

return remind;