Facing 'Field expression not allowed for generic SObject' in my class

Question

//ICRE
Map<String,String> objName = new Map<String,String>();
for(Schema.SObjectType f : Schema.getGlobalDescribe().Values()){
    if(f.getDescribe().isCustom()){
        objName.put(f.getDescribe().getLabel(),f.getDescribe().getName());
    }
}                                    

if(objName.containsKey('ICRE')){
    Map<Id,sObject> mapClonedICRE = new Map<Id,sObject>();
    string sObj = objName.get('ICRE');
    system.debug('sObj::'+sObj);
    sObject oInstance;                                    
    sDynamicQuery = this.dynamicQuery(sObj);
    query = 'SELECT ' + sDynamicQuery + ' FROM '+ sObj +' WHERE Product__c IN :lstProdOfSourceEE limit 5000';
    lstofICRE = Database.query(query);
    system.debug('lstofICRE::'+lstofICRE);

    for(sObject oICRE :lstofICRE){        
        oInstance = Schema.getGlobalDescribe().get(sObj).newSObject();                                         
        oInstance = oICRE.clone(false, false, false, false); 
        system.debug('oInstanceNew::'+oInstance);  
        //oInstance.oInstance.get('ownerId') = userinfo.getuserid();
        /*oInstance.ownerId = userinfo.getuserid();                                                                                                                           
          if(mapClonedPrdwithSourcePrdId.containskey(oICRE.Product__c)){
            oInstance.Product__c = mapClonedPrdwithSourcePrdId.get(oICRE.Product__c).Id;
          }else{
            oInstance.Product__c = null;
          }

          if(oICRE.Start_Date__c != null)
            oInstance.Start_Date__c = String.valueOf(oTargetEE.get('Start_Date__c'));                                            

          if(oICRE.End_Date__c != null)
            oInstance.End_Date__c = oTargetEE.End_Date__c;

          if(oInstance.Product__c != null){
            mapClonedICRE.put(oICRE.Id, oInstance);
          }*/                                       
    }
    if(!mapClonedICRE.isEmpty()){
        Insert mapClonedICRE.values();
        system.debug('ICRE::'+mapClonedICRE.values().size());
        system.debug('ICRECon::'+mapClonedICRE.values());
    }
}

Error on this Line -

oInstance.Product__c = mapClonedPrdwithSourcePrdId.get(oICRE.Product__c).Id;

Answer 1

The error is pretty descriptive of your issue.

A 'field expression' is something like myObjectInstance.myField, using dot notation on an object instance to get or set the value of a field.

As the error states, you aren't allowed to do this on generic SObject instances.

Taking a look at some very specific parts of your provided code, we see this

for(sObject oICRE :lstofICRE){
    // other code

    oInstance.Product__c = mapClonedPrdwithSourcePrdId.get(oICRE.Product__c).Id;

    // more code
}

oICRE and oInstance are generic sObjects in this loop, so oInstance.Product__c and oICRE.Product__c are the specific parts of the line giving you your error.

To work around that, you need to use the SObject.get(_field_) method (when you need to fetch a value from an SObject) and the SObject.put(_field_, _value_) (when you need to set a value on an SObject) methods instead

for(sObject oICRE :lstofICRE){
    // other code

    // Instead of using dot notation, you'll need to use the get() and put() methods
    //   and pass a string matching the API name of your target field
    oInstance.put('Product__c',  mapClonedPrdwithSourcePrdId.get(oICRE.get('Product__c')).Id);

    // more code
}

There are a few other instances in your provided class where you attempt to directly reference a field on a generic SObject (like if(oICRE.Start_Date__c != null)). You'll need to do the same thing (use get() and/or put()) to those as well.

Answer 2

Please use

//ICRE
Map<String,String> objName = new Map<String,String>();
for(Schema.SObjectType f : Schema.getGlobalDescribe().Values()){
    if(f.getDescribe().isCustom()){
        objName.put(f.getDescribe().getLabel(),f.getDescribe().getName());
    }
}                                    

if(objName.containsKey('ICRE')){
    Map<Id,sObject> mapClonedICRE = new Map<Id,sObject>();
    string sObj = objName.get('ICRE');
    system.debug('sObj::'+sObj);
    sObject oInstance;                                    
    sDynamicQuery = this.dynamicQuery(sObj);
    query = 'SELECT ' + sDynamicQuery + ' FROM '+ sObj +' WHERE Product__c IN :lstProdOfSourceEE limit 5000';
    lstofICRE = Database.query(query);
    system.debug('lstofICRE::'+lstofICRE);

    for(sObject oICRE :lstofICRE){        
        oInstance = Schema.getGlobalDescribe().get(sObj).newSObject();                                         
        oInstance = oICRE.clone(false, false, false, false); 
        system.debug('oInstanceNew::'+oInstance);  
        //oInstance.oInstance.get('ownerId') = userinfo.getuserid();
        /*oInstance.ownerId = userinfo.getuserid();                                                                                                                           
          if(mapClonedPrdwithSourcePrdId.containskey(oICRE.Product__c)){
            oInstance.put('Product__c', mapClonedPrdwithSourcePrdId.get(oICRE.Product__c).Id);
            //oInstance.Product__c = mapClonedPrdwithSourcePrdId.get(oICRE.Product__c).Id;
          }else{
            oInstance.put('Product__c', null);
            //oInstance.Product__c = null;
          }

          if(oICRE.Start_Date__c != null)
            oInstance.put('Start_Date__c', String.valueOf(oTargetEE.get('Start_Date__c'));
            //oInstance.Start_Date__c = String.valueOf(oTargetEE.get('Start_Date__c'));                                            

          if(oICRE.End_Date__c != null)
            oInstance.put('End_Date__c', oTargetEE.End_Date__c);
            //oInstance.End_Date__c = oTargetEE.End_Date__c;

          if(oInstance.get('Product__c') != null){
            mapClonedICRE.put(oICRE.Id, oInstance);
          }*/                                       
    }
    if(!mapClonedICRE.isEmpty()){
        Insert mapClonedICRE.values();
        system.debug('ICRE::'+mapClonedICRE.values().size());
        system.debug('ICRECon::'+mapClonedICRE.values());
    }
}