Hoping someone can help with the below code :
This issue im having is that when it triggers validation and prevents render from running unless all required fields have been filled in.
<apex:form >
<apex:pageBlock title="Costing Enquiry Form Edit" mode="maindetail" id="pb">
<apex:pageBlockButtons location="bottom">
<apex:commandButton value="Save" action="{!save}"/>
<apex:commandButton value="Cancel" action="{!cancel}"/>
</apex:pageBlockButtons>
<apex:pageBlockSection title="Information" columns="2">
<apex:inputField value="{!Costing_Enquiry_Form__c.Customer_Name__c}" required="false"/>
<apex:inputField value="{!Costing_Enquiry_Form__c.OwnerId}" required="false"/>
<apex:inputField value="{!Costing_Enquiry_Form__c.Contact_Name__c}" required="false"/>
<apex:inputField value="{!Costing_Enquiry_Form__c.Product_Type__c}" required="true">
<apex:actionSupport event="onchange" reRender="conditional"/>
<!-- triggers validation and prevents rerender from running unless all required fields have been filled in. -->
</apex:inputField>
<apex:inputField value="{!Costing_Enquiry_Form__c.End_User__c}" required="false"/>
<apex:inputField value="{!Costing_Enquiry_Form__c.Target_Selling_Price__c}" required="true"/>
<apex:inputField value="{!Costing_Enquiry_Form__c.Status__c}" required="true"/>
<apex:inputField value="{!Costing_Enquiry_Form__c.Estimated_Quantity__c}" required="true"/>
<apex:inputField value="{!Costing_Enquiry_Form__c.Quote_Number__c}" required="false"/>
<apex:inputField value="{!Costing_Enquiry_Form__c.Sample_Required__c}" required="false"/>
<apex:inputField value="{!Costing_Enquiry_Form__c.Customer_is_currently_using_Seen__c}" required="true"/>
<apex:pageBlockSection id="conditional">
<apex:inputField value="{!Costing_Enquiry_Form__c.ChemCre8_Code__c}" rendered="{!IF(Costing_Enquiry_Form__c.Product_Type__c =='Chemcre8',TRUE,FALSE)}" required="true"/>
<apex:inputField value="{!Costing_Enquiry_Form__c.Bespoke_Garment_Additional_Information__c}" rendered="{!IF(Costing_Enquiry_Form__c.Product_Type__c =='Bespoke Garment',TRUE,FALSE)}" required="true"/>
</apex:pageBlockSection>
<apex:inputField value="{!Costing_Enquiry_Form__c.Required_Standards_CE_Markings__c}" required="true"/>
<apex:pageBlockSectionItem />
<apex:inputField value="{!Costing_Enquiry_Form__c.Special_Requirements_Comments__c}" required="true"/>
<apex:pageBlockSectionItem />
<apex:inputField value="{!Costing_Enquiry_Form__c.Send_to__c}" required="true"/>
</apex:pageBlockSection>
</apex:pageBlock>
</apex:form>
<apex:relatedList list="OpenActivities" />
<apex:relatedList list="ActivityHistories" />
<apex:relatedList list="CombinedAttachments" />