Skip to main content

Debug Modern POS using .NET Reflector

Respect to all those POS developers. It really requires some dedication and focus to be a POS developer. This is an example of something I would have not figured out without my colleagues.


We were working on a development project and we struggled to make sense out of the error.

The error we got was complaining about the a method to validate the Unit of measure and Quantity. I was sure the object was not null and I had passed the right thing to it. Unit of measure and quantity fields were populated correctly. The modification was overriding the price.

System.NullReferenceException was unhandled by user code
   HResult=-2147467261
   Message=Object reference not set to an instance of an object.
   Source=Microsoft.Dynamics.Commerce.Runtime.Workflow
   StackTrace:
        at Microsoft.Dynamics.Commerce.Runtime.Workflow.CartWorkflowHelper.ValidateCartLineUnitOfMeasureAndQuantity(RequestContext context, Cart newCart, SalesTransaction salesTransaction, Dictionary`2 salesLineByLineId, CartLineValidationResults cartLineValidationResults)
        at Microsoft.Dynamics.Commerce.Runtime.Workflow.CartWorkflowHelper.ValidateUpdateCartRequest(RequestContext context, SalesTransaction salesTransaction, SalesTransaction returnedSalesTransaction, Cart newCart, Boolean isGiftCardOperation, IDictionary`2 productByRecordId)
        at Microsoft.Dynamics.Commerce.Runtime.Workflow.SaveCartRequestHandler.Process(SaveCartRequest request)
        at Microsoft.Dynamics.Commerce.Runtime.SingleRequestHandler`2.Execute(Request request)
        at Microsoft.Dynamics.Commerce.Runtime.CommerceRuntime.Execute[TResponse](Request request, RequestContext context, IRequestHandler handler, Boolean skipRequestTriggers)
        at ECL.Commerce.Runtime.Donation.TriggerHandlers.SaveCartRequestHandler.Process(SaveCartRequest request)
        at Microsoft.Dynamics.Commerce.Runtime.SingleRequestHandler`2.Execute(Request request)
        at Microsoft.Dynamics.Commerce.Runtime.CommerceRuntime.Execute[TResponse](Request request, RequestContext context, IRequestHandler handler, Boolean skipRequestTriggers)
   InnerException

After many hours over the course a few days we struggled. A colleague suggested to use .NET reflector (this is where you need an experienced retail developer). Using this tool, I was able to make sense of the problem.


Below are the steps to use .NET reflector.

1. Download .NET reflector

https://www.red-gate.com/products/dotnet-development/reflector/

2. Install following wizard. You can use the trial for 14 days or just active it with your serial number

When you install – I would recommend both the desktop and the visual studio extension

image

3. Select the assembly to debug. There are a couple of ways you can do that.

Select using the .NET Reflector > Generate PDBs (this will pop up a dialog to select the assembly)

image

Alternatively, from your solution explorer. Select the dll that is referenced and click on Enable Debugging.
image

4. This will launch the object browser.

Navigate to the method that caused the error. Then right click, Go to Decompiled Definition

image

5. I put a breakpoint and run through the process.

What I found was that it code used the salesTransaction object rather than the cartLine to get the unit of measure. Causing a cryptic error about unit of measure/quantity. In other words, I needed to create the cart line and save it to commit it to the salesTransaction first. Then after that process is finished, I can then override the price. i.e. 2 steps rather than trying to it all in one process.

image

I hope I don’t get in trouble of advising people to use .NET reflector by blogging here. I just don’t see how else I would have figure this thing out.

Popular posts from this blog

AX - How to use Map and MapEnumerator

Similar to Set class, Map class allows you to associate one value (the key) with another value. Both the key and value can be any valid X++ type, including objects. The types of the key and the value are specified in the declaration of the map. The way in which maps are implemented means that access to the values is very fast. Below is a sample code that sets and retrieves values from a map. static void checkItemNameAliasDuplicate(Args _args) { inventTable inventTable; Map map; MapEnumerator mapEnumerator; NameAlias nameAlias; int counter = 0; ; map = new Map(Types::String, Types::Integer); //store into map while select inventTable { nameAlias = inventTable.NameAlias; if (!map.exists(nameAlias)) { map.insert(nameAlias, 1); } else { map.insert(nameAlias, map.lookup(nameAlias) + 1); } } //retrieve fro

AX - How to use Set and SetEnumerator

The Set class is used for the storage and retrieval of data from a collection in which the values of the elements contained are unique and serve as the key values according to which the data is automatically ordered. You can create a set of primitive data types or complex data types such as a Class, Record or Container. Below is sample of a set of records. static void _Set(Args _args) {     CustTable       custTable;     Set             set = new Set(Types::Record);     SetEnumerator   setEnumerator;     ;     while select custTable     {         if (custTable && !set.in(custTable))         {             set.add(custTable);         }     }     if (!set.empty())     {         setEnumerator = set.getEnumerator();         setEnumerator.reset();         while (setEnumerator.moveNext())         {             custTable = setEnumerator.current();             info(strfmt("Customer: %1",custTable.AccountNum));         }     } } Common mistake when creating a set of recIds

Import document handling (attachment) files #MSDyn365FO

Out of the box you have limited data entities for migrating attachments. If you search what is already in the AOT, you will see a few various examples. I suggest you look at the LedgerJournalAttachmentsEntity as it is the simplest and cleans to copy from. I wont go into detail but I will give a quick run down of what it looks like. Use the DocuRefEntity as your main datasource. It does most of the work for you. Set your table you want to import for as the child datasource Add the Key You will need to add the postLoad method. There is minor code to update the virtual field FileContents. Below is an export I did for the general journal attachments. The import zip structure should be the same way. It will create the usual artifacts such as the excel, manifest and package header xml files. You will see a Resources folder under that. If you drill down to the resources you will see the attachments. This is an export and it used the document GUID for uniqueness. The other thing is the extensi