Salesforce (VisualForce): How to test for no records returned in 'apex:repeat' statement?

Question

I am trying to figure out how to test fields (included within a apex:repeat) to see if they are blank, or null, and if so display some alternate text (Ex: No records to display) in the table instead of a blank table. Existing code snippet below:

<apex:repeat var="auditList" value="{!relatedTo.Site_Audit__r}">
   <tr>
    <td>
    <apex:outputField value="{!auditList.Audit_Type__c}" />
    </td>
    <td>
        <apex:outputField value="{!auditList.Delivery_Date__c}" />
    </td>
    <td>
    <apex:outputField value="{!auditList.Review_Date__c}" />
    </td>
   </tr>
</apex:repeat>

So in pseudo code I am looking for a test such as:

IF RELATED RECORDS FOUND FOR APEX:REPEAT PERFORM FOLLOWING:

<apex:repeat var="auditList" value="{!relatedTo.Site_Audit__r}">
   <tr>
    <td>
    <apex:outputField value="{!auditList.Audit_Type__c}" />
    </td>
    <td>
        <apex:outputField value="{!auditList.Delivery_Date__c}" />
    </td>
    <td>
    <apex:outputField value="{!auditList.Review_Date__c}" />
    </td>
   </tr>
</apex:repeat>

ELSE IF NO RELATED RECORDS PERFORM FOLLOWING:

<tr>
    <td>
    No records to display.

    </td>
</tr>

Thanks in advance for the help!

---

Update in response to first answer from 'eyescream'

---

Gave the apex:pageBlock method a shot, but ran into the following error when trying to save/deploy:

Result: FAILED Problem: <messaging:emailTemplate> cannot contain <apex:pageBlock>.

Now this is a email template that produces an attached PDF (see general outline of the code below). So is that the case...pageBlock is not allowed within a email template? Thanks for the help!

<messaging:emailTemplate subject="Your requested quote #{!relatedTo.Name}" 
recipientType="Contact"
relatedToType="X360_Contract_Cycle__c">

<messaging:plainTextEmailBody >
.
.
.
</messaging:plainTextEmailBody>

<messaging:attachment renderAs="pdf" filename="{!relatedTo.name}">
.
.
.
<apex:pageBlock rendered="{!AND(NOT(ISNULL(auditList)),auditList.size>0)}">

    <apex:repeat var="auditList" value="{!relatedTo.Site_Audit__r}">
       <tr>
        <td>
            <apex:outputField value="{!auditList.Audit_Type__c}" />
        </td>
        <td>
            <apex:outputField value="{!auditList.Delivery_Date__c}" />
        </td>
        <td>
            <apex:outputField value="{!auditList.Review_Date__c}" />
        </td>
       </tr>
   </apex:repeat>

</apex:pageBlock>

<apex:pageBlock rendered="{!OR(ISNULL(auditList),auditList.size=0)}">
    <i>No records to display.</i>
</apex:pageBlock>
.
.
.
</messaging:attachment>
</messaging:emailTemplate>

Answer 1

Generally speaking - wrap your code in higher page element (like <apex:pageBlock>) and then use the attribute rendered. It's optional and available on most of the page elements, the component reference should give you complete list of attributes supported for each tag.

In your case I suppose something like that should do the trick:

<apex:pageBlock rendered="{!AND(NOT(ISNULL(auditList)),auditList.size>0)}">
    Stuff is in, put "repeat" tag here.
</apex:pageBlock>
<apex:pageBlock rendered="{!OR(ISNULL(auditList),auditList.size=0)}">
    No records to display.
</apex:pageBlock>

Feel free to experiment with the syntax. I've used the function names as in the formula editor (for formula fields, validation rules etc.) but normal logic operators like &&, || should be available too.

Answer 2

Stick with the wrapper (use apex:outputPanel or apex:variable) and create a method that returns the list size i.e.

public Integer listSize{get {
 if(auditList != null)
  return auditList.size();
else
  return 0;}}

Use this in the conditional that determines visibility.

Answer 3

Use a wrapper ( is my personal favorite), and use a formula that checks the size of the list for the rendered attribute.

<apex:outputPanel rendered="{!relatedTo.Site_Audit__r.size = 0}">
  No Records
</apex:outputPanel>
<apex:outputPanel rendered="{!relatedTo.Site_Audit__r.size != 0}">
  <apex:repeat var="auditList" value="{!relatedTo.Site_Audit__r}">
    ...
  </apex:repeat>
</apex:outputPanel>