Error occurred trying to load the template for sending preview email: DML currently not allowed. 


I'm getting above error even after adding allowDML="true" to component.

Could any one help on this?


VF template :


<messaging:emailTemplate subject="Alert: WON Opportunity -" recipientType="User" relatedToType="Opportunity">

      <messaging:htmlEmailBody >

      <c:opportunityAttachedFiles componentValue="{!relatedTo.Id}"/>

      </messaging:htmlEmailBody>

</messaging:emailTemplate>


VF Component :


<apex:component controller="OpportunityAttachments" allowDML="true" access="global">

    <apex:attribute name="componentValue" description="Attribute on the component."
                  type="Id" required="required" assignTo="{!opptyId}"/>
    <apex:dataTable value="{!OpptyFilesLink}" var="att">
        <apex:column >
            <apex:facet name="header">File Name</apex:facet>
            {!att.Name}
        </apex:column>
        <apex:column >
            <apex:facet name="header">File Link</apex:facet>
            {!att.DistributionPublicUrl}
        </apex:column>
    </apex:dataTable>
</apex:component>


Controller :


public class OpportunityAttachments {
    public Id opptyId;
    
    public void setopptyId (Id oppId) {
        opptyId = oppId;
    }
    
    public String getopptyId() {
        return opptyId;
    }
    
    public List<ContentDistribution> getOpptyFilesLink(){
        List<ContentDistribution> lstTobeInserted = new List<ContentDistribution>();
        List<ContentDistribution> lstToReturn = new List<ContentDistribution>();
        Set<Id> setContentDocumentId = new Set<Id>();
        List<ContentDocumentLink> lstContentDocumentLink = new List<ContentDocumentLink>();
        if(String.ValueOf(opptyId) != null && String.ValueOf(opptyId) != ''){
            lstContentDocumentLink = [SELECT ContentDocumentId,Id,IsDeleted,LinkedEntityId,ShareType,SystemModstamp,Visibility FROM ContentDocumentLink where LinkedEntityId =: opptyId];
        }
        if(!lstContentDocumentLink.isEmpty()){
            for(ContentDocumentLink obj : lstContentDocumentLink){
                setContentDocumentId.add(obj.ContentDocumentId);
            }
            
            for(ContentDocument obj :[SELECT ArchivedById,ArchivedDate,ContentModifiedDate,ContentSize,CreatedById,CreatedDate,Description,FileExtension,FileType,Id,IsArchived,IsDeleted,LastModifiedById,LastModifiedDate,LastReferencedDate,LastViewedDate,LatestPublishedVersionId,OwnerId,ParentId,PublishStatus,SharingOption,SystemModstamp,Title FROM ContentDocument where Id=: setContentDocumentId]){
                ContentDistribution cd = new ContentDistribution();
                //cd.ContentDocumentId = obj.ContentDocumentId;
                cd.name = obj.Title;
                cd.ContentVersionId = obj.LatestPublishedVersionId;
                cd.PreferencesAllowOriginalDownload = false;
                cd.PreferencesAllowPDFDownload = false;
                cd.PreferencesAllowViewInBrowser = true;
                lstTobeInserted.add(cd);
            }
            Database.upsert(lstTobeInserted,ContentDistribution.Name.getDescribe().getSObjectField(),false);
        }
        set<Id> getLatest = new set<Id>();
        for(ContentDistribution obj : [Select ContentDocumentId,Name,ContentVersionId,DistributionPublicUrl from ContentDistribution order by CreatedDate DESC]){     
            if(!getLatest.contains(obj.ContentDocumentId)){
                getLatest.add(obj.ContentDocumentId);
                lstToReturn.add(obj);
            }
        }
        return lstToReturn;
    }
}


Thanks,

GM