RadGrid batch edit original value blank validation exception

[Michael]

I have a RadGrid using BatchEdit mode. The automated validation is working fine, but I want to program in an exception: blank values are not allowed for fields, but the database is full of records with existing blank values. I want the validation to accept a blank value if the existing record already has a blank value.

Here is my validation method. Note that the attribute OriginalValue doesn't exist; it's part of my trying to find the original value, but adding it turned out to be problematic.

        function BlankFieldValidator(sender, args) {
            if (args.Value.length == 0) {
                if (sender.getAttribute("OriginalValue").length != 0) {
                    args.IsValid = false;
                }
            }
        }

In debugging the page, I can examine the sender and args objects, but I see nothing that contains the original value in it. I conclude it must be in the Telerik data structure somewhere, since one can still click Cancel Changes to revert all changes to the RadGrid.

What is a good method for retrieving the original value to compare to the edited value?

[Vasko]

Hello Michael,

To achieve the desired behavior, I suggest trying the following approach:

• In the Grid markup, add the onBatchEditOpened and onBatchEditCellValueChanged client-side events: 

  // Omitted for clearance
      <ClientSettings>
          <ClientEvents OnBatchEditOpened="onBatchEditOpened" OnBatchEditCellValueChanged="onBatchEditCellValueChanged" />
      </ClientSettings
  

• In the <script> tag, add the following logic in order to compare the original and edited values: 

  <script>
      var originalValue // Declare the original and edited values of the cell
      var editedValue
  
      var originalValues = {} // Store the values in objects so we can access them later
      var editedValues = {}
  
      function onBatchEditOpened(sender, args) {
          var rowId = args.get_row() // Assuming you have a way to uniquely identify each row, such as an ID
          var cell = args.get_cell(); // Get the cell being edited
          var textConttent = $(cell)[0].textContent.trim("/")  // Get the cell's text content
  
          var columnUniqueName = args.get_columnUniqueName(); // Get the clicked column's unique name
  
          if (!originalValues[rowId]) {
              originalValues[rowId] = {}; // Store the original value
          }
          originalValues[rowId][columnUniqueName] = textConttent
  
          originalValue = originalValues[rowId][columnUniqueName]
  
          console.log(originalValue)
      }
  
      function onBatchEditCellValueChanged(sender, args) {
          var rowId = args.get_row() // Do the same thing, but for the new value 
          var cell = args.get_cell(); 
          var textConttent = $(cell)[0].textContent.trim("/") 
  
          var columnUniqueName = args.get_columnUniqueName();
  
          if (!editedValues[rowId]) {
              editedValues[rowId] = {};
          }
          editedValues[rowId][columnUniqueName] = textConttent
  
          editedValue = editedValues[rowId][columnUniqueName]
  
          console.log(editedValue)
  
          compareValues() // Call the function whenever you have changed the value of the cell
      }
  
      function compareValues() {
          if (originalValue && editedValue) {
              // Your logic here
          }
      }
  </script>

Give the aforementioned method a try and tell me if it's of use to you.

Kind regards,
Vasko
Progress Telerik

[Michael]

It seems ridiculous to make an additional in-memory copy of all of the data when the data is already in the grid. I'm a big fan of data normalization.

I ended up with a different solution which is still not ideal, but seems to work so far in testing: using the OnBatchEditCellValueChanging method of ClientEvents, with a much shorter Javascript function:

        function CheckForBlankValue(sender, args) {
            var columnName = args._columnUniqueName;
            if (args.get_editorValue().length == 0 && columnName != "Weight") { //Weight has separate validation, and blank turns into the minumum value
                if (args._cellValue.length > 0) {
                    args.set_cancel(true);
                    // Show error message for blank
                    alert(`${columnName} is not allowed to be blank.`);
                    return;
                }
            }

It would be nicer to pop up "Required!" in red by validation, but otherwise the functionality works for the use case.