How do you check if a parent SObject has any children Sobjects in a VisualForce page without a wrapper class?

gistfile1.txt

When looping through a set of Salesforce.com SObjects from a VisualForce page, you may want to test whether the SObject has any children without wrapping the SObjects in a wrapper class. Here's how:

Controller:
Create a property in the controller that is a map of the parent IDs and Boolean flag.

public Map<Id, Boolean> hasChildren {
  get {
    if (this.hasChildren == null) {
      for (Parent__c parent : [select id, (select id from children__r) from parent__c]) {
        if (parent.children__r.size() > 0) {
          this.hasChildren.put(parent.id,true);
        } else {
          this.hasChildren.put(parent.id,false);
        }
      }
    }
    return this.hasChildren;
  }
  set {
    this.hasChildren = value;
  }
}

Visualforce Page:
Use dynamic bindings to check if the parent has any children while looping in Visualforce. This example renders the text if there are children.

<apex:repeat value="{!parents}" var="parent">
  <apex:outputtext value="-----" rendered="{!hasChildren[parent.id]}" />
</apex:repeat>

Nice!