How to make a field editable only if a checkbox is checked

Question

I have a text field that is set to un-editable for all profiles. However if another field (checkbox) is checked, then this text field should become editable and required. I have created a validation rule for the required part. however I need this field remain un-editable when the checkbox is unchecked. Thanks for any input.

Answer 1

You cannot allow them to edit this text field if you make it unallowed by removing access to profiles.

What you can do though, is allow them to edit by profile, but use a VF page in order to display this field. You can then put this VF page on the page Layout for the object. Use the VF page and/or Controller in order to control access to that variable.

<apex:page standardController="Account">
  <apex:inputField value="{!Account.MyTextVal__c}" rendered="{!Account.IsEditable__c}" />
  <apex:outputField value="{!Account.MyTextVal__c}" rendered="{!!Account.IsEditable__c}" />
</apex:page>

Answer 2

You will want to make the field editable by all profiles that will need to edit it. Then you could use a similar validation rule to make sure that the text field remains null if the checkbox equals 0. I would try the following:

AND(Checkbox__c = 0, (NOT(ISNULL(Text_Field__c)))

Per metadaddy's comment, you could combined this with the other answer to dynamically show/hide the field. You could always consider using record types with page layouts that make the field visible & required, and create a workflow rule that updates the Record Type field to switch when the checkbox gets checked.