jiten-singh-shahi/sf-visualforce-development

Visualforce Development

Visualforce is Salesforce's server-side rendering framework. While LWC is the modern standard, Visualforce remains heavily used for PDF generation, email templates, custom overrides, and legacy applications.

When to Use

• When maintaining or extending existing Visualforce pages in production
• When building PDF renderable pages (renderAs="pdf") — LWC cannot do this
• When creating custom email templates with complex formatting
• When overriding standard buttons (New, Edit, View) with custom UIs
• When planning and executing migration from Visualforce to LWC
• When debugging ViewState issues or page performance problems

@../_reference/VISUALFORCE_PATTERNS.md

---

Page Creation Procedure

Step 1 — Choose Controller Type

| Type | When to Use | |------|------------| | Standard Controller | Single-record CRUD without custom logic | | Standard List Controller | List views with built-in pagination | | Custom Controller | Full control over logic, data, navigation | | Controller Extension | Add functionality to standard/custom controllers |

Step 2 — Create the Page

<apex:page standardController="Account"
           extensions="AccountOverviewExtension"
           lightningStylesheets="true"
           docType="html-5.0"
           title="Account Overview">
    <apex:pageBlock title="Account Details">
        <apex:pageBlockSection columns="2">
            <apex:outputField value="{!Account.Name}" />
            <apex:outputField value="{!Account.Industry}" />
        </apex:pageBlockSection>
    </apex:pageBlock>
</apex:page>

Step 3 — Custom Controller (if needed)

public with sharing class InvoiceController {
    public List<Invoice__c> invoices { get; private set; }
    public String searchTerm { get; set; }

    public InvoiceController() {
        searchTerm = '';
        loadInvoices();
    }

    public PageReference search() {
        loadInvoices();
        return null; // Stay on same page
    }

    private void loadInvoices() {
        String likeSearch = '%' + String.escapeSingleQuotes(searchTerm) + '%';
        invoices = [
            SELECT Id, Name, Amount__c, Status__c, CreatedDate
            FROM Invoice__c WHERE Name LIKE :likeSearch
            WITH USER_MODE ORDER BY CreatedDate DESC LIMIT 100
        ];
    }
}

Step 4 — Controller Extension (if needed)

public with sharing class AccountOverviewExtension {
    private final Account account;

    // Required constructor signature
    public AccountOverviewExtension(ApexPages.StandardController stdController) {
        if (!Test.isRunningTest()) {
            stdController.addFields(new List<String>{ 'OwnerId', 'AnnualRevenue' });
        }
        this.account = (Account) stdController.getRecord();
    }

    public List<Contact> relatedContacts {
        get {
            if (relatedContacts == null) {
                relatedContacts = [
                    SELECT Id, Name, Email, Phone
                    FROM Contact WHERE AccountId = :account.Id
                    WITH USER_MODE ORDER BY Name LIMIT 50
                ];
            }
            return relatedContacts;
        }
        private set;
    }
}

---

ViewState Management

ViewState is a hidden, encrypted form field that maintains page state across postbacks. 170KB limit — exceeding it causes a runtime error.

The transient Keyword

Mark variables that do not need to survive postbacks as transient:

public with sharing class ReportController {
    // IN ViewState — needed across postbacks
    public String selectedFilter { get; set; }
    public Integer currentPage { get; set; }

    // NOT in ViewState — recomputed on each request
    transient public List<AggregateResult> reportData { get; private set; }
    transient public Blob chartImage { get; private set; }
}

Reduction Strategies

| Strategy | Impact | |----------|--------| | transient keyword on large/recomputable variables | High | | apex:outputPanel + reRender (partial refresh) | Medium | | Paginate large data sets | High | | Use JavaScript Remoting (stateless) | High | | Move read-only data outside apex:form | Medium |

---

JavaScript Remoting

Stateless, high-performance Apex calls that bypass ViewState entirely.

Apex Method

@RemoteAction
public static List<Account> findAccounts(String searchTerm) {
    String safeTerm = '%' + String.escapeSingleQuotes(searchTerm) + '%';
    return [
        SELECT Id, Name, Industry FROM Account
        WHERE Name LIKE :safeTerm WITH USER_MODE LIMIT 25
    ];
}

JavaScript Invocation

Visualforce.remoting.Manager.invokeAction(
    '{!$RemoteAction.AccountSearchController.findAccounts}',
    term,
    function(result, event) {
        if (event.status) {
            renderResults(result);
        } else {
            console.error(event.message);
        }
    },
    { escape: true, timeout: 30000 }
);

Use {!$RemoteAction.ClassName.methodName} (namespace-safe). Set escape: true to prevent XSS.

---

Partial Page Refresh

<apex:actionFunction name="refreshDashboard" action="{!refresh}"
                     reRender="dashPanel" status="loadingStatus" />

<apex:selectList value="{!selectedRegion}" size="1">
    <apex:selectOptions value="{!regionOptions}" />
    <apex:actionSupport event="onchange" action="{!filterByRegion}"
                        reRender="dashPanel" status="loadingStatus" />
</apex:selectList>

<apex:actionStatus id="loadingStatus">
    <apex:facet name="start"><img src="/img/loading.gif" alt="Loading..." /></apex:facet>
</apex:actionStatus>

---

Migration to LWC

Decision Matrix

| Keep Visualforce | Migrate to LWC | |-----------------|----------------| | PDF generation (renderAs="pdf") | High-traffic pages needing performance | | Email templates | New feature development | | Complex server-state wizards | Pages using Apex controller only |

Key VF-to-LWC Mappings

| Visualforce | LWC | |------------|-----| | apex:pageBlockTable | lightning-datatable | | apex:commandButton action="{!save}" | lightning-button onclick={handleSave} + imperative Apex | | apex:inputField | lightning-input-field (in lightning-record-edit-form) | | JavaScript Remoting | @wire or imperative Apex import | | apex:actionSupport | Standard DOM event handlers | | {!property} merge fields | {property} template expressions |

Embedding LWC in Visualforce (Lightning Out)

For incremental migration, embed LWC inside existing VF pages:

<apex:includeLightning />
<div id="lwc-container"></div>
<script>
$Lightning.use("c:lwcOutApp", function() {
    $Lightning.createComponent("c:accountDashboard",
        { recordId: "{!Account.Id}" }, "lwc-container");
});
</script>

Migration Checklist

1. Inventory — list all VF pages, controllers, usage frequency
2. Categorize — mark each page as Keep VF / Migrate / Retire
3. Dependencies — map controller extensions, custom components, static resources
4. Security audit — review XSS/injection issues before or during migration
5. Feature parity — replicate all VF functionality in LWC
6. Test coverage — write LWC Jest tests to match existing Apex test coverage
7. Incremental rollout — use Lightning Out to embed LWC in VF during transition
8. Redirect — update links, overrides, navigation to new LWC pages
9. Deprecate — mark old VF pages as inactive, remove after validation

---

Related

Guardrails

• sf-security-constraints — Enforced rules for XSS prevention, SOQL injection, CRUD/FLS enforcement

Agents

• sf-visualforce-reviewer — For interactive, in-depth Visualforce review guidance