Show Confirmation Banners in View Mode from Server-Side Scripts

/**
 * @NApiVersion 2.1
 * @NScriptType UserEventScript
 * @description Show an info banner on View if the URL has &updated=T
 */
define(['N/ui/serverWidget', 'N/ui/message', 'N/url'], (serverWidget, message, url) => {

  function beforeLoad(ctx) {
    if (ctx.type !== ctx.UserEventType.VIEW) return;

    // Read the URL for a simple boolean flag ?updated=T
    const req = ctx.request; // available in beforeLoad only
    const updated = (req && String(req.parameters.updated || '').toUpperCase() === 'T');

    // Add a custom button that calls a Suitelet to perform the action
    ctx.form.addButton({
      id: 'custpage_refresh_prices',
      label: 'Refresh Prices',
      functionName: `window.location='${makeSuiteletUrl(ctx.newRecord.id)}'`
    });

    // If the Suitelet redirected back with updated=T, show the banner
    if (updated) {
      ctx.form.addPageInitMessage({
        type: message.Type.INFORMATION,           // INFORMATION | WARNING | ERROR | CONFIRMATION
        title: 'Success',
        message: 'Prices were refreshed successfully.',
        duration: 7000                            // ms; optional, auto-dismiss
      });
    }
  }

  function makeSuiteletUrl(internalId) {
    // Build a relative Suitelet URL with the record id as a param
    // Replace script/deploy with your IDs
    const scriptId = 'customscript_sl_refresh_prices';
    const deployId = 'customdeploy_sl_refresh_prices';
    // For simplicity use net-new path; feel free to use N/url.resolveScript if preferred
    return `/app/site/hosting/scriptlet.nl?script=${scriptId}&deploy=${deployId}&id=${encodeURIComponent(internalId)}`;
  }

  return { beforeLoad };
});

/**
 * @NApiVersion 2.1
 * @NScriptType Suitelet
 * @description Loads record, performs updates, then redirects back with &updated=T
 */
define(['N/record', 'N/redirect'], (record, redirect) => {

  function onRequest(ctx) {
    const recId = ctx.request.parameters.id;
    if (!recId) return redirect.toTaskLink({ id: 'LIST_PURCHASE_ORDERS' }); // fallback

    // Example: perform your backend work here
    // const rec = record.load({ type: record.Type.ESTIMATE, id: recId, isDynamic: true });
    // ... compute new rates ...
    // rec.save({ enableSourcing: true, ignoreMandatoryFields: true });

    // Redirect back to the record in View mode and set the flag
    redirect.toRecord({
      type: record.Type.ESTIMATE,  // change to your record type
      id: recId,
      parameters: { updated: 'T' }
    });
  }

  return { onRequest };
});