example: cycle on irregular intervals

[oliver-sanders]

Closes #6336
Requires cylc/cylc-doc#759

Not perfect, but it saves us duping this support.

Check List

• I have read CONTRIBUTING.md and added my name as a Code Contributor.
• Contains logically grouped changes (else tidy your branch by rebase).
• Does not contain off-topic changes (use other PRs for other changes).
• Applied any dependency changes to both setup.cfg (and conda-environment.yml if present).
• Tests are included (or explain why tests are not needed).
• Changelog entry included if this is a change that can affect users
• Cylc-Doc pull request opened if required at cylc/cylc-doc/pull/XXXX.
• If this is a bug fix, PR should be raised against the relevant ?.?.x branch.

[oliver-sanders]

(Code blocks currently render as errors due to a shortcoming in the Cylc lexer)

[oliver-sanders]

(Code blocks currently render as errors due to a shortcoming in the Cylc lexer)

cylc/cylc-sphinx-extensions#86 will fix the issue. That PR needs to be merged & released before this one is (as it will cause cylc-doc build errors otherwise).

Now sorted.

[oliver-sanders]

@wxtim, this should now build correctly. Please can you give it a whirl and a once-over.

[wxtim]

any reason why -p (which expands everything), not -j which just expands the jinja2?

[oliver-sanders]

I think -p intelligently decides whether to use Jinja2 or EmPy pre-processing which makes it a little more generic / flexible.

[oliver-sanders]

-p and -j are otherwise equivalent:

cylc-flow/cylc/flow/scripts/view.py

Lines 126 to 143 in a722b26

	for line in read_and_proc(
	flow_file,
	get_template_vars(options),
	viewcfg={
	'mark': options.mark,
	'single': options.single,
	'label': options.label,
	'empy': options.empy or options.process,
	'jinja2': options.jinja2 or options.process,
	'contin': options.cat or options.process,
	'inline': (
	options.jinja2 or options.empy or
	options.inline or options.process
	),
	},
	opts=options,
	):
	print(line)

[wxtim]

I'm not sure what this item illustrates in this example.

[oliver-sanders]

It demonstrates how to tie together bits of your workflow that follow regular cycling with bits that follow irregular cycling.

[oliver-sanders]

Not all irregular cycling workflows are going to need this, but some will, so I added some text explaining the strftime and loop.first thinggies to help users with more advanced problems.

[oliver-sanders]

Just waiting on the upstream PR...

[oliver-sanders]

Done.