Dynamics 365/CRM | Use the value of an Option Set to set up a custom form layout

gistfile1.js

// Use the value of an Option Set to set up a custom form layout

// This example assumes a company uses the same Opportunity form, 
// but shows/hides sections and makes fields required/optional based
// on the value of a new_division field

// Consider using Business Rules before using this code

function opportunity_onLoad () {
  // hook this up to the onLoad event and the onChange event of the new_division field

  // Create variables for the form sections
  var tab=Xrm.Page.ui.tabs.get("tab_division");
  var sectionComputers = tab.sections.get("section_computers");
  var sectionMonitors = tab.sections.get("section_monitors");
  var sectionPeripherals = tab.sections.get("section_peripherals");
  
  // Set all sections as hidden
  sectionComputers.setVisible(false);
  sectionMonitors.setVisible(false);
  sectionPeripherals.setVisible(false);
  
  // Set all required fields as not required
  Xrm.Page.getAttribute("new_computerField").setRequiredLevel("none");
  Xrm.Page.getAttribute("new_monitorField").setRequiredLevel("none");
  Xrm.Page.getAttribute("new_peripheralField").setRequiredLevel("none");
  
  // Get the text of the Division field 
  var division = Xrm.Page.data.entity.attributes.get("new_division").getText();
  
  // Make sure Division is populated
  if (division != null) {
    
    // Use a switch statement to set up the form for each division
    switch(division) {
      
      // Computer division
      case "Computers":
      sectionComputers.setVisible(true);
      Xrm.Page.getAttribute("new_computerField").setRequiredLevel("required");
      break;
      
      // Monitor division
      case "Monitors":
      sectionMonitors.setVisible(true);
      Xrm.Page.getAttribute("new_monitorField").setRequiredLevel("required");
      break;
      
      // Peripherals division
      case "Peripherals":
      sectionPeripherals.setVisible(true);
      Xrm.Page.getAttribute("new_peripheralField").setRequiredLevel("required");
      break;
    }
  }
}