Some basic guidance on Rose metadata

It is important that the appearance of inputs across the GUI panels conform to the same standards. This ensures that users of each model become familiar with how the panels work and are present with a consistent set of information, such as follows:

[namelist:<namelist>=<variable>]
description=<what is the variable for?>
help=<detailed information about the variable>
sort-key=<XY>
url=<http://jules-lsm.github.io/latest/namelists/<namelist>.nml.html#<NAMELIST>::<item>>
etc

where JULES namelist items should only contain the url= field and not the help= field regardless of the repository they reside in. Each input is presented in the GUI as:

variable name
short description of the variable name

Either the help text is displayed or web help opened when one clicks the variable name. If both fields exist the Web help is opened preferentially. If a url= is present the help= field should be removed to avoid duplication.

Shared namelists

Shared namelist items, or items which exist in more than one repository, should have identical metadata regardless of the repository where they reside (e.g. JULES items in the UM metadata). The only caveats are where a trigger or a fail-if reference a namelist item from the parent model (e.g. UM).

Shared JULES metadata is in the process of being migrated to rose-meta/jules-shared, which resides in the JULES repository. The sub-directories are imported by rose-meta/um-atmos and rose-meta/jules-standalone and is manually synced with a copy in LFRic. Please see Sharing JULES metadata for more details including what should be in jules-shared and in jules-standalone, jules-lfric or um-atmos. When developing shared JULES metadata, you will need linked tickets. The metadata migration is currently dictated by LFRic porting of science, although the ultimate aim is to have a single source of truth.

Please see the rose config-edit example for an illustration of how to pick up jules-shared changes from a JULES working copy.

The following sections provide some general guidance as to how to structure your metadata.

Number of panels

If you have a particularly long namelist, consider dividing up the number of panels to ensure that the user doesn’t have to deal with a particularly long panel with lots of switches. However, switches which relate to each other should always be on the same panel.

Sort Keys and triggers

Please use sort-keys to order the appearance of items in your panels, otherwise they will appear in alphabetical order. This means that sometimes items that are triggered on and off will appear far away from the item that triggered them.

Please provide triggers for all variables where possible. It is much better and cleaner to only see inputs that need to be set rather than everything.

Tip

The GUI provides an option to un-hide triggered variables if one wants to see them all.

Please set compulsory=true for items and use triggers for when it is not required. The settings of all variables will then be present, in all apps to aid configuration management. When a variable is triggered off, it will be commented out in the apps e.g. !!variable.

Important

If any variable (new or existing) has received a new compulsory=true setting please use an upgrade macro to add that variable to apps with a valid value.

Note

While it is possible to trigger a variable based on AND logic (e.g. where some condition on variable1 and another condition on variable2 trigger variable3), cumbersome triggering of this nature is best avoided.

It is not possible to trigger a variable based on OR logic.

Viewing metadata changes as you go along

One can easily review their metadata changes with the rose config editor, opening up an example app file. For example:

cd <path of working copy of branch>/rose-stem/app/um_n48_eg
rose config-edit -M <path of working copy of branch/rose-meta/>

If making jules-shared changes, when reviewing these changes from a different parent repository, you will first need to set the ROSE_META_PATH system variable:

export ROSE_META_PATH=<path of working copy of JULES branch/rose-meta/>

or add the path instead as a colon separated list:

rose config-edit -M <path of working copy of branch/rose-meta/>:<path of working copy of JULES branch/rose-meta/>

then once the app opens click on the LHS appname to display the app meta panel. Update this to HEAD rather than the version number and apply.

Please note that if you have used an upgrade macro on the app then the meta line at the top of the app file will have changed (e.g. meta=um-atmos/vn11.0_t46). Since no metadata exists at this version rose edit will produce an error saying that it cannot find it, instead it will use the metadata in e.g. um-atmos/HEAD. Please click OK and continue.

Your updates should now appear.

Ensuring metadata changes are valid

Developments to the metadata can be checked for errors by running rose metadata-check

rose metadata-check -C /path/to/rose-meta/<config>/HEAD

where the -C option can be omitted if inside the directory containing the metadata file.

Note

If there are jules-shared changes then these need to be added to the metadata path even in the JULES repository. As the metadata checker does not have the -M option, this has to be done using the ROSE_META_PATH environnment variable as in the previous example.

If the metadata checker returns “not a configuration metadata directory” then this may indicate that the wrong path has been set.