salesforce-development

What this skill does

# Salesforce Development

Expert patterns for Salesforce platform development including Lightning Web
Components (LWC), Apex triggers and classes, REST/Bulk APIs, Connected Apps,
and Salesforce DX with scratch orgs and 2nd generation packages (2GP).

## Patterns

### Lightning Web Component with Wire Service

Use @wire decorator for reactive data binding with Lightning Data Service
or Apex methods. @wire fits LWC's reactive architecture and enables
Salesforce performance optimizations.

// myComponent.js
import { LightningElement, wire, api } from 'lwc';
import { getRecord, getFieldValue } from 'lightning/uiRecordApi';
import getRelatedRecords from '@salesforce/apex/MyController.getRelatedRecords';
import ACCOUNT_NAME from '@salesforce/schema/Account.Name';
import ACCOUNT_INDUSTRY from '@salesforce/schema/Account.Industry';

const FIELDS = [ACCOUNT_NAME, ACCOUNT_INDUSTRY];

export default class MyComponent extends LightningElement {
  @api recordId;  // Passed from parent or record page

  // Wire to Lightning Data Service (preferred for single records)
  @wire(getRecord, { recordId: '$recordId', fields: FIELDS })
  account;

  // Wire to Apex method (for complex queries)
  @wire(getRelatedRecords, { accountId: '$recordId' })
  wiredRecords({ error, data }) {
    if (data) {
      this.relatedRecords = data;
      this.error = undefined;
    } else if (error) {
      this.error = error;
      this.relatedRecords = undefined;
    }
  }

  get accountName() {
    return getFieldValue(this.account.data, ACCOUNT_NAME);
  }

  get isLoading() {
    return !this.account.data && !this.account.error;
  }

  // Reactive: changing recordId automatically re-fetches
}

// myComponent.html
<template>
  <lightning-card title={accountName}>
    <template if:true={isLoading}>
      <lightning-spinner alternative-text="Loading"></lightning-spinner>
    </template>

    <template if:true={account.data}>
      <p>Industry: {industry}</p>
    </template>

    <template if:true={error}>
      <p class="slds-text-color_error">{error.body.message}</p>
    </template>
  </lightning-card>
</template>

// MyController.cls
public with sharing class MyController {
  @AuraEnabled(cacheable=true)
  public static List<Contact> getRelatedRecords(Id accountId) {
    return [
      SELECT Id, Name, Email, Phone
      FROM Contact
      WHERE AccountId = :accountId
      WITH SECURITY_ENFORCED
      LIMIT 100
    ];
  }
}

### Context

- building LWC components
- fetching Salesforce data
- reactive UI

### Bulkified Apex Trigger with Handler Pattern

Apex triggers must be bulkified to handle 200+ records per transaction.
Use handler pattern for separation of concerns, testability, and
recursion prevention.

// AccountTrigger.trigger
trigger AccountTrigger on Account (
  before insert, before update, before delete,
  after insert, after update, after delete, after undelete
) {
  new AccountTriggerHandler().run();
}

// TriggerHandler.cls (base class)
public virtual class TriggerHandler {
  // Recursion prevention
  private static Set<String> executedHandlers = new Set<String>();

  public void run() {
    String handlerName = String.valueOf(this).split(':')[0];

    // Prevent recursion
    String contextKey = handlerName + '_' + Trigger.operationType;
    if (executedHandlers.contains(contextKey)) {
      return;
    }
    executedHandlers.add(contextKey);

    switch on Trigger.operationType {
      when BEFORE_INSERT { this.beforeInsert(); }
      when BEFORE_UPDATE { this.beforeUpdate(); }
      when BEFORE_DELETE { this.beforeDelete(); }
      when AFTER_INSERT { this.afterInsert(); }
      when AFTER_UPDATE { this.afterUpdate(); }
      when AFTER_DELETE { this.afterDelete(); }
      when AFTER_UNDELETE { this.afterUndelete(); }
    }
  }

  // Override in child classes
  protected virtual void beforeInsert() {}
  protected virtual void beforeUpdate() {}
  protected virtual void beforeDelete() {}
  protected virtual void afterInsert() {}
  protected virtual void afterUpdate() {}
  protected virtual void afterDelete() {}
  protected virtual void afterUndelete() {}
}

// AccountTriggerHandler.cls
public class AccountTriggerHandler extends TriggerHandler {
  private List<Account> newAccounts;
  private List<Account> oldAccounts;
  private Map<Id, Account> newMap;
  private Map<Id, Account> oldMap;

  public AccountTriggerHandler() {
    this.newAccounts = (List<Account>) Trigger.new;
    this.oldAccounts = (List<Account>) Trigger.old;
    this.newMap = (Map<Id, Account>) Trigger.newMap;
    this.oldMap = (Map<Id, Account>) Trigger.oldMap;
  }

  protected override void afterInsert() {
    createDefaultContacts();
    notifySlack();
  }

  protected override void afterUpdate() {
    handleIndustryChange();
  }

  // BULKIFIED: Query once, update once
  private void createDefaultContacts() {
    List<Contact> contactsToInsert = new List<Contact>();

    for (Account acc : newAccounts) {
      if (acc.Type == 'Prospect') {
        contactsToInsert.add(new Contact(
          AccountId = acc.Id,
          LastName = 'Primary Contact',
          Email = 'contact@' + acc.Website
        ));
      }
    }

    if (!contactsToInsert.isEmpty()) {
      insert contactsToInsert;  // Single DML for all
    }
  }

  private void handleIndustryChange() {
    Set<Id> changedAccountIds = new Set<Id>();

    for (Account acc : newAccounts) {
      Account oldAcc = oldMap.get(acc.Id);
      if (acc.Industry != oldAcc.Industry) {
        changedAccountIds.add(acc.Id);
      }
    }

    if (!changedAccountIds.isEmpty()) {
      // Queue async processing for heavy work
      System.enqueueJob(new IndustryChangeQueueable(changedAccountIds));
    }
  }

  private void notifySlack() {
    // Offload callouts to async
    List<Id> accountIds = new List<Id>(newMap.keySet());
    System.enqueueJob(new SlackNotificationQueueable(accountIds));
  }
}

### Context

- apex triggers
- data operations
- automation

### Queueable Apex for Async Processing

Use Queueable Apex for async processing with support for non-primitive
types, monitoring via AsyncApexJob, and job chaining. Limit: 50 jobs
per transaction, 1 child job when chaining.

// IndustryChangeQueueable.cls
public class IndustryChangeQueueable implements Queueable, Database.AllowsCallouts {
  private Set<Id> accountIds;
  private Integer retryCount;

  public IndustryChangeQueueable(Set<Id> accountIds) {
    this(accountIds, 0);
  }

  public IndustryChangeQueueable(Set<Id> accountIds, Integer retryCount) {
    this.accountIds = accountIds;
    this.retryCount = retryCount;
  }

  public void execute(QueueableContext context) {
    try {
      // Query with fresh data
      List<Account> accounts = [
        SELECT Id, Name, Industry, OwnerId
        FROM Account
        WHERE Id IN :accountIds
        WITH SECURITY_ENFORCED
      ];

      // Process and make callout
      for (Account acc : accounts) {
        syncToExternalSystem(acc);
      }

      // Update records
      updateRelatedOpportunities(accountIds);

    } catch (Exception e) {
      handleError(e);
    }
  }

  private void syncToExternalSystem(Account acc) {
    HttpRequest req = new HttpRequest();
    req.setEndpoint('callout:ExternalCRM/accounts');
    req.setMethod('POST');
    req.setHeader('Content-Type', 'application/json');
    req.setBody(JSON.serialize(new Map<String, Object>{
      'salesforceId' => acc.Id,
      'name' => acc.Name,
      'industry' => acc.Industry
    }));

    Http http = new Http();
    HttpResponse res = http.send(req);

    if (res.getStatusCode() != 200 && res.getStatusCode() != 201) {
      throw new CalloutException('Sync failed: ' + res.getBody());
    }
  }

  private void updateRelatedOpportunities(Set<Id> accIds) {
    List<Opportunity> oppsToUpdate = [
      SELECT Id, Industry__c, AccountId
      FROM Opportunity
      WHERE AccountId IN :accIds
      WITH SECURITY_ENFORCED
    ];

    Map<Id, Account> accountMap = new Map<Id, Account>([