Checks needed when adding a new local data source.

[forman]

From @HelenClifton on June 29, 2017 13:16

Expected behavior

When adding a new local data source, would expect cate to do some checks to see if the folder selected is valid

Actual behavior

It is possible to add an empty folder as a new local data source.
It is possible to add a folder containing no netCDF files as a new local data source.

Steps to reproduce the problem

1. In data sources panel, click "add local data source"

2. Chose a folder which does not contain any files
   

3. Click "Add"

4. Open the new data set

5. Observe there is a new resource created of type "NoneType"
   

Specifications

cate 0.8.0-rc6
Internet Explorer 11
Windows 7 Professional

Copied from original issue: CCI-Tools/cate-desktop#27

[forman]

See

• Problem with empty data sources #218
• Empty local data sources #269