Error Handling Rest Api Webservice

Question

What I need to do is create a validation in my Rest Api class that if a field is null or empty it will throw a response error.

I don't know what's wrong with my code it says Method does not exist or incorrect signature: isNotNullorEmpty(Decimal)

This is my code

Hoping someone can help me,

I also tried not using isNotNullorEmpty global class but it's not returning properly just a simple Test.AccountID = null for the fields that require validation but it's not returning properly.

@restResource(urlMapping='/buyproduct/*')
global with sharing class buyProduct{

    global with sharing class Wrapper1{

        public string AccountID {get;set;}
        public List<Wrapper2> wrapper2 {get;set;}
    }
    global with sharing class Wrapper2{
        public decimal Quantity {get;set;}
        public string ProductCode{get;set;}
        public date StartDate;

    }

     global class ResponseWrapper{
         public String Status;
         public String Message;
         public String ErrorCode;
         public string AccountID;
     }


    global static boolean isNotNullorEmpty(string str)
    {
        return str!=null || !String.isBlank(str);
    }


        @httpPost
    global static ResponseWrapper getID(Wrapper1 test){

        ResponseWrapper response = new ResponseWrapper();      
        Wrapper2 wrp = new Wrapper2();

        if(isNotNullorEmpty(Test.AccountID) && isNotNullorEmpty(wrp.Quantity) && isNotNullorEmpty(wrp.ProductCode)){        

        Subscription_Order__c so = new Subscription_Order__c();
        so.Account__c = test.AccountId;
        insert so;
        System.debug('#####1' + so.Id);


        Map<String,Id> prdCode = new Map<String,Id>();

        List<Product__c> prd = [Select Id, ProductCode__c from Product__c];

        for(Product__c pc : prd){
            prdCode.put(pc.ProductCode__c, pc.Id);
        }

        List<OrderProduct__c> opList = new List<OrderProduct__c>();
        for(Wrapper2 soW : test.wrapper2){
            OrderProduct__c op = new OrderProduct__c();
            op.Subscription_Order__c = so.Id;
            op.Subscription_Product__c = prdCode.get(soW.ProductCode);
            op.Quantity__c = soW.Quantity;
            op.Start_Date__c = soW.StartDate;
            opList.add(op);

            response.Status = 'Create Account Complete';
                response.Message = 'Successful';

                response.ErrorCode = 'Invalid';
        }
        insert opList;
        }
        else if(!isNotNullorEmpty(test.AccountId)){
            response.Status = 'Error';
                response.Message = 'Exception : Required field missing [AccountID]';
                response.ErrorCode = 'ERROR 400 : Bad Request';
                response.AccountID = 'Invalid';
        }
        else if(!isNotNullorEmpty(wrp.Quantity)){
            response.Message = 'Exception : Required field missing [Quantity]';
                response.ErrorCode = 'ERROR 400 : Bad Request';
                response.AccountID = 'Invalid';
        }
        else if (!isNotNullorEmpty(wrp.ProductCode)){
                response.Message = 'Exception : Required field missing [Product Code]';
                response.ErrorCode = 'ERROR 400 : Bad Request';
                response.AccountID = 'Invalid';
        }
        return response;
    }

}

Answer 1

Seems like you need to validate different type of fields, so use Object as an parameter to make it dynamic.

Method would be like:

global static boolean isNotNullorEmpty(Object str) {
    return str != null && !String.isBlank(String.valueOf(str));
}

And condition would be like as follows:

if(isNotNullorEmpty(Test.AccountID) && 
    isNotNullorEmpty(wrp.Quantity) && 
    isNotNullorEmpty(wrp.ProductCode)){  
    // your logic
}

Answer 2

You method signature accepts a string as a parameter, and returns a Boolean....

global static boolean isNotNullorEmpty(string str)
{
    return str!=null || !String.isBlank(str);
}

But your error message indicates that you are calling the method with a decimal data type....

Method does not exist or incorrect signature: isNotNullorEmpty(Decimal)

Look through your code and find out where you are calling that method with a decimal data type (maybe here...)

    else if(!isNotNullorEmpty(wrp.Quantity)){
        response.Message = 'Exception : Required field missing [Quantity]';
            response.ErrorCode = 'ERROR 400 : Bad Request';
            response.AccountID = 'Invalid';
    }

That's what's causing your compiler error. Maybe that else if(...) just needs a different condition.