Thursday, January 22, 2015

Sometimes solution for: Cannot read property "aDataSort" of undefined

At my company, we use DataTables frequently.  (Code available at

Like my last post, I wanted to put up another post either to help others, or more likely, help myself when I can't solve the answer.

When I'm building out my datatables, I am often converting from an older syntax to the (currently) latest version.   I bang my head on the wall for at least 30 minutes over this error in the Javascript console:

Cannot read property "aDataSort" of undefined

Take this Datatable setup.

In my case, this is my (overly simplified) columnDefs section of my Datatable definition

, 'columnDefs': [
 { 'title':'ID', 'name': 'BatchID', 'data': 'BatchID' }
, { ''title':'Type', 'name': 'Type', 'data': 'Type' }
, { 'title':'Status', 'name': 'Status', 'data': 'Status'

This error is thrown because I'm missing (what should be an obvious addition) below:

var nColNumber = -1;
, 'columnDefs': [
  { 'targets': [ ++nColNumber ], 'title':'ID', 'name': 'BatchID', 'data': 'BatchID' }
, { 'targets': [ ++nColNumber ], 'title':'Type', 'name': 'Type', 'data': 'Type' }
, { 'targets': [ ++nColNumber ], 'title':'Status', 'name': 'Status', 'data': 'Status'

When you build your Datatable with a columnDefs configuration option, it's obviously VERY important to tell it the "target" of the definition.   I typically have only an empty <table id="someID"></table> definition in my HTML, then build it completely from Javascript.

I use the ++nColNumber, simply so I can easily move columns around later, and not have to renumber them, and I try to always reference columns by name not position, such as for hiding and showing columns at runtime.

Hope this helps someone solve this issue!

- Will Belden
January 22, 2015

Tuesday, January 13, 2015

Javascript DataTables and TN4 error on Sorting

This is just a quick note for myself.  Perhaps it will help others.  Mind you, I feel like this is a workaround, not an actual solution.

I have an ajax sourced DataTable.  (If you're not familliar with these, see:  They really are awesome.)

This particular table is struggling with handling the refresh of the table based on clicking a sortable (orderable) column header.

The TN4 error is reported against columns that have a "render" function associated with them.  Removing the render() function removes the problem, but I need those functions or they wouldn't be there.

Adding a "defaultContent" value to the column definition, however, seems to alleviate the issue.  I think the problem is somehow related to the sorting feature clearing the data, then the render function says "Um, you asked for row.clientName, but....there's no data, so there's certainly no "clientName" in the (missing) data."

I have other tables that do NOT have this issue, but this seems to be a workaround.

Now I can remember next time.

- Will Belden
January 13, 2015