Sections

Another feature, inspired not by the Junos CLI, but by the F5 CLI is sections. Sections let the user focus on a particular part of the CLI. Taking the example from the walkthrough, we can focus on the items in the shopping list.

Let’s add some commands to our layout to handle this:

layout = {
    '/': {
        '?': 'Go to top level',
        None: jsh.set_section(None)
    },
    '/item': {
        '?': 'Work on items',
        None: jsh.set_section('item')
    },
    'add': {
        '?': 'Add stuff',
        'item': {
            '?': 'Add item to shopping list',
            str: {
                '?': ('item', 'Item description'),
                None: add_item
            }
        }
    },
    'remove': {
        '?': 'Get rid of stuff',
        'item': {
            '?': 'Remove item from shopping list',
            '\t': complete_items,
            str: {
                '?': ('item', 'Item to remove'),
                None: remove_item
            }
        }
    },
    'show': {
        '?': 'Display various information',
        'list': {
            '?': 'Display shopping list',
            None: show_list
        },
        'pid': {
            '?': 'Display my PID',
            None: show_pid
        },
        'version': {
            '?': 'Display my version',
            None: show_version
        }
    },
    'exit': {
        '?': 'Quit this silly application',
        None: jsh.exit
    }
}

This now lets us interact with the CLI like this:

> ?
Possible completions:
  /        Go to top level
  /item    Work on items
  add      Add stuff
  exit     Quit this silly application
  remove   Get rid of stuff
  show     Display various information
> add ?
Possible completions:
  item   Add item to shopping list
> /item
> add ?
Possible completions:
  <item>   Item description
> add carrots
> add potatoes
> show list
Items:
carrots
potatoes
> remove potatoes
> show list
Items:
carrots
>

Being inside the “item” section means that we can (and, in fact, must) miss out the second word of a command when that word is item.

Finally, it would be nice if the CLI told us which section we are currently in. We can do this by customising the prompt and including the string {section} in it, which will be replaced by the name of the current section:

cli = jsh.JSH(
    layout,
    prompt='shopping{section}> '
)

This gives us this:

shopping> /item
shopping(item)> /
shopping>

We can customise the brackets around the section name, for example:

cli = jsh.JSH(
    layout,
    prompt='shopping{section}> ',
    section_delims=('/', '')
)

This gives:

shopping> /item
shopping/item> /
shopping>

However, section support is quite basic at the moment and needs more work. It’s currently nowhere near what the F5 CLI does.