Introduction

In Visualforce, displaying data and capturing user input are two different actions. While data can be displayed without a form, any user input or action that sends data to Salesforce must be placed inside an <apex:form>.

The <apex:form> component acts as a bridge between the Visualforce page and Salesforce when data needs to be submitted or updated.

What is `<apex:form>`?

<apex:form> is a Visualforce component used to submit data from a page to Salesforce. It is similar to the HTML <form> tag but is tightly integrated with Salesforce security, validation, and controllers.

All input components and action components must be placed inside <apex:form> to work correctly.

Why `<apex:form>` is Required

The <apex:form> component is required because it:

● Sends user input to Salesforce
● Allows execution of controller methods
● Enables record creation and updates
● Handles validation rules automatically
● Enforces Salesforce security

Without <apex:form>, input fields and buttons cannot submit data.

Basic Syntax of `<apex:form>`

<apex:form>
    <!-- Input and action components -->
</apex:form>

This is the basic structure used in all data-entry Visualforce pages.

Example: Simple Form with Input and Save

<apex:page standardController="Contact">
    <apex:form>
        <apex:pageBlock title="Edit Contact">
            <apex:pageBlockSection>
                <apex:inputField value="{!Contact.FirstName}" />
                <apex:inputField value="{!Contact.LastName}" />
                <apex:inputField value="{!Contact.Email}" />
            </apex:pageBlockSection>
            <apex:commandButton value="Save" action="{!save}" />
        </apex:pageBlock>
    </apex:form>
</apex:page>

Explanation of the Example

●  <apex:form> wraps all input components
●  <apex:inputField> captures user input
●  save method is called on button click
● Salesforce validates and saves the record

Components That Must Be Inside `<apex:form>`

The following components must be inside <apex:form>:

●  <apex:inputText>
●  <apex:inputField>
●  <apex:commandButton>
●  <apex:commandLink>
●  <apex:selectList>

Without <apex:form>, these components will not work correctly.

Multiple `<apex:form>` in a Page

A Visualforce page can have multiple <apex:form> components, but each form submits independently.

Important points:

● Each form submits only its own data
● Avoid nesting forms (not allowed)
● Use multiple forms only when necessary

`<apex:form>` and Validation

When a form is submitted:

● Required fields are checked
● Validation rules are enforced
● Data types are validated
● Errors are displayed automatically

This reduces the need for manual validation.

`<apex:form>` with Custom Controllers

<apex:form> also works with custom Apex controllers.

In this case:

● Input fields bind to Apex variables
● Buttons call custom controller methods
● Business logic runs in Apex

This provides flexibility for advanced scenarios.

Common Mistakes Beginners Make

● Forgetting to use <apex:form>
● Placing input components outside the form
● Using multiple forms unnecessarily
● Expecting output components to submit data

Understanding the role of <apex:form> helps avoid these issues.

Best Practices for Using `<apex:form>`

● Use <apex:form> only when data submission is required
● Keep forms simple and focused
● Avoid unnecessary multiple forms
● Use standard controllers when possible
● Test form behavior with different users

Conclusion

The <apex:form> component is essential for capturing and submitting user input in Visualforce pages. It enables data updates, controller actions, and validation while ensuring Salesforce security and consistency. Understanding <apex:form> is a key step toward building functional and interactive Visualforce applications.

VF Page Beginner to Advance

<apex:form> Component in VF Page