🧩 Introduction

If <apex:repeat> feels like a narrow bridge that allows only 1000 records to cross… then readOnly="true" is like opening an express highway. 🛣️

By default, Visualforce pages store view state (page memory).
This memory tracks:

Field values
Component states
Form changes

And because view state must stay lightweight, Salesforce restricts list rendering to 1000 records.

But when you mark the page as read-only, Salesforce stops tracking changes… and the limit expands dramatically.

⚠️ When to Use `readOnly="true"`

Use it when:

✅ You only display data
✅ No inline editing required
✅ No heavy form submission
✅ Reporting / dashboards / exports

Avoid it when:

❌ You need DML on the same page
❌ You use input fields heavily
❌ You rely on view state values

🛠️ Solution: Enable ReadOnly Mode

🔹 Visualforce Page Code

<apex:page controller="AccountReadOnlyCtrl"
           readOnly="true">

    <h2>Account List</h2>

    <apex:repeat value="{!accounts}" var="acc">
        <p>
            {!acc.Name} — {!acc.Industry}
        </p>
    </apex:repeat>

</apex:page>

🔹 Apex Controller

public with sharing class AccountReadOnlyCtrl {

    public List<Account> accounts { get; set; }

    public AccountReadOnlyCtrl() {

        accounts = [
            SELECT Id, Name, Industry
            FROM Account
            LIMIT 50000
        ];
    }
}

🎯 What Changed?

Without readOnly:

Limit → 1000 records
View State → Enabled

With readOnly:

Limit → Up to 50,000 records
View State → Disabled

It’s like switching from carrying luggage 🎒 to traveling weightless.

📊 Performance Comparison

Feature	Normal Page	ReadOnly Page
Record limit	1000	Up to 50,000
View state	Enabled	Disabled
Page speed	Slower	Faster
Editable fields	Supported	Limited
DML operations	Allowed	Not allowed directly

🧠 Important Considerations

1️⃣ No Standard Form Processing

If you use:

<apex:form>
<apex:inputText>
<apex:commandButton>

They won’t behave normally because view state is off.

2️⃣ DML Not Allowed in Same Context

You cannot directly perform insert/update/delete inside read-only request flow.

Workaround:

Call another action method
Redirect to editable page
Use JavaScript remoting / API

3️⃣ Best Use Cases

ReadOnly pages shine in:

Reports
Data exports
Audit logs
Dashboards
Public data pages

Anywhere data is displayed, not edited.

🥇 Example: Large Data Table

<apex:page controller="AccountReadOnlyCtrl"
           readOnly="true">

    <apex:pageBlock title="All Accounts">

        <apex:pageBlockTable value="{!accounts}" var="acc">

            <apex:column value="{!acc.Name}"/>
            <apex:column value="{!acc.Industry}"/>

        </apex:pageBlockTable>

    </apex:pageBlock>

</apex:page>

This can render tens of thousands of rows without hitting the repeat limit.

⚡ Pro Performance Tips

Combine readOnly with:

SOQL selective fields
Indexed filters
Pagination (for UX)
CSV export buttons

Even though 50k is allowed, rendering that many rows in a browser can feel like pouring a swimming pool into a teacup. ☕

So optimize UI wisely.

🏁 Conclusion

The <apex:repeat> 1000 limit exists because Visualforce tries to remember everything.

By enabling:

readOnly="true"

You politely tell Salesforce:

“Relax. Just display the data. No need to remember it.”

And just like that, the gates open from 1000 → 50,000 records. 🚪✨

Please Wait

Comments (0)