[SalesForce] Conditional disabled fields in visualforce

Updated 2017-05-24

Visualforce respects Field Level Security when using apex:inputText. It will appear editable if the user has Edit permission on the field, Read-Only if the user has Read permission on the field, and will not be rendered at all if no access is granted to the field. When writing Visualforce, it helps to remember that System Administrators have Edit Read-Only Fields, which overrides the Edit permission on a field (but they won't have any access without Read access to the field). Always make sure you're testing with a profile that does not have the Edit Read-Only Fields permission.

Original Answer

apex:inputText does not honor Field Level Security. Use apex:inputField instead. See Enforcing CRUD and FLS for more details.

This might be useful for you.

VF Page

<apex:page controller="accountSearcher" docType="html-5.0">
<center><h1>Account Search Page</h1></center>
<apex:form>
   Start Date: <apex:input type="date" value="{!startDate}" required="true" />
   End Date: <apex:input type="date" value="{!endDate}" required="true" />
   <apex:commandButton action="{!searchAccount}" value="Search" reRender="dataWrapperPanel" lang="End Date"/>

   <apex:outputPanel id="dataWrapperPanel">
      <apex:pageBlock title="Account List" id="dataBlock" rendered="{! showResult }">
          <apex:pageBlockSection >
              <apex:pageBlockTable value="{!accList}" var="acc" >
                  <apex:column value="{!acc.Name}"/>
              </apex:pageBlockTable>
          </apex:pageBlockSection> 
      </apex:pageBlock>
      <apex:outputLabel id="noRecFound" rendered="{! blnNoResultFound }">No Record Found !!!</apex:outputLabel>
   </apex:outputPanel>
 </apex:form>
 </apex:page>

Controller

public class accountSearcher{

public static Date startDate{get;set;}
public static Date endDate{get;set;}
public static List<Account> accList{get;set;}
public boolean showResult{get;set;}
public boolean blnNoResultFound{get;set;}

public accountSearcher(){
    showResult = false;
    blnNoResultFound = false;
    accList = new List<Account>();
}
public PageReference searchAccount(){
    if(startDate != NULL && endDate != NULL){
        accList = [SELECT Id,Name FROM Account WHERE createdDate >= : startDate AND createdDate <: endDate];
    } 
    if(accList.size() > 0){
         showResult = true;
         blnNoResultFound = false;
    }
    else{
         blnNoResultFound = true;
         showResult = false;
    }
    return null;        
      }
   }