Google DataTable requires label (not id) to be set to "group"

[Crashthatch]

At the moment, if you create a google.visualization.DataTable with columns with ids "start", "end", "content" and "group", the group column is ignored. Setting the LABEL (not ID) of the group column to "group" fixes the problem and groups are shown.

I traced the problem to timeline.js, line 266, the findColumnId function should be using dataTable.getColumnId(i) rather than dataTable.getColumnLabel(i). Or possibly both should be checked?

[RCura]

Hi,

Actually, as an user, I consider this as a feature, that I do use a lot :
A DataTable column label can be changed (with DT.setColumnLabel(columnIndex, label), while an ID can't.
So, when using big tables, it's really a plus to be able to change the label, to represent different things dynamically, instead of creating a whole new table with different IDs.

So, for my part, I'm using unspecific column ids when creating my tables, and then, I set the labels according to what I want to show. And I really like the way CHAP is using Labels and not IDs 😉

[Crashthatch]

Fair enough, but it's quite unintuitive (took me ~30 mins to figure out) when the following works for Start, End and Content, but not Group:

$data['cols'] = array( array( 'id' => "start", "type" => "datetime" ), array( 'id' => "end", "type" => "datetime" ), array( 'id' => "content", "type" => "string" ), array( 'id' => "group", ['label' => 'group' IS REQUIRED HERE FOR THIS COLUMN NOT TO BE IGNORED], "type" => "string" ) ); ... var data = new google.visualization.DataTable( <?php echo json_encode( $data ); ?> );

I'd suggest either changing the other columns to work the same way (use label, rather than ID), or fall back to id if label is not specified.

It should at least be mentioned in the documentation.

[josdejong]

Thanks Crashthatch, good point. Originally the columns where hard coded (start=0, end=1, content=2, optional group=3), but that changed recently by introducing a second optional column, className.

I have made the usage of columns more flexible now:

• First the timeline tries to read the column ids.
• if not available, it will read the column labels.
• if both id's and column's are undefined, it will use the default columning: start=0, end=1, content=2

I see you generate your DataTable from php. Note that unless you use some specific functionality offered by Google DataTable (client side querying, sorting, filtering), or read your data from a Google SpreadSheet, it may be faster and easier use plain JSON instead of Google DataTable.