Merge pull request #3 from uramirez8707/multi_file_yaml

multi file data override yaml

data_override/README.MD

@@ -24,6 +24,13 @@ If it is desired to interpolate the data to a region of the model grid. The foll
 - **lat_start:** The starting longitude in the same units as the grid data in the file
 - **lon_end:** The ending longitude in the same units as the grid data in the file
 
+If it is desired to use multiple(3) input netcdf files instead of 1. The following **optional** keys are available.
+- **is_multi_file:** Set to `True` is using the multi-file feature
+- **prev_file_name:** The name of the first file in the set
+- **next_file_name:** The name of the third file in the set
+
+Note that **file_name** must be the second file in the set. **prev_file_name** and/or **next_file_name** are required if **is_multi_file** is set to `True`
+
 #### 2. How to use it?
 In order to use the yaml data format, [libyaml](https://github.com/yaml/libyaml) needs to be installed and linked with FMS. Additionally, FMS must be compiled with -Duse_yaml macro. If using autotools, you can add `--with-yaml`, which will add the macro for you and check that libyaml is linked correctly.
 ```

data_override/include/data_override.inc

@@ -576,6 +576,23 @@ subroutine read_table_yaml(data_table)
          call get_value_from_key(file_id, entry_id(i), "fieldname_file", data_table(i)%fieldname_file, &
            & is_optional=.true.)
 
+         data_table(i)%multifile = .false.
+         call get_value_from_key(file_id, entry_id(i), "is_multi_file", data_table(i)%multifile, &
+           & is_optional=.true.)
+
+         if (data_table(i)%multifile) then
+          data_table(i)%prev_file_name = ""
+          data_table(i)%next_file_name = ""
+          call get_value_from_key(file_id, entry_id(i), "prev_file_name", data_table(i)%prev_file_name, &
+            & is_optional=.true.)
+          call get_value_from_key(file_id, entry_id(i), "next_file_name", data_table(i)%next_file_name, &
+            & is_optional=.true.)
+          if (trim(data_table(i)%prev_file_name) .eq. "" .and. trim(data_table(i)%next_file_name) .eq. "") &
+            call mpp_error(FATAL, "The prev_file_name and next_file_name must be present if is_multi_file. "//&
+              "Check your data_table.yaml entry for field:"//trim(data_table(i)%gridname)//":"//&
+              trim(data_table(i)%fieldname_code))
+         endif
+
          data_table(i)%file_name = ""
          call get_value_from_key(file_id, entry_id(i), "file_name", data_table(i)%file_name, &
            & is_optional=.true.)