How I wrote Ulauncher extension for most used timedate macros

Why?

I wrote a lot. And in my writings I use timestamps, dates, times, time-ranges.

I use following datetime formats

• 2020-11-01
• 15-18
• 14:58

For them I used custom bash scripts which were copying to clipboard the date formats I wanted. These scripts were manually added to Linux's custom shortcuts.

Example of bash script:

#!/bin/sh
alias setclip='xclip -selection c'
alias getclip='xclip -selection clipboard -o'
printf $(date +"%Y-%m-%d") | setclip

Initially, I was really happy but after some time number of custom scripts increased. I had difficulties with remembering them.

How?

I stumbled to Ulauncher and it is downed on me that I could create extension for these timedate scripts.

For people who don't know, Ulauncher is application launcher to which many developers write many extensions.

Some examples:

• emoji extension
• process murderer
• google translate
• spotify player

Here is the tutorial link for extension development.

About my extension

Ulauncher requires that extension must have manifest.json file to operate.

Example of manifest.json

{
  "required_api_version": "^2.0.0",
  "name": "Timestamp macros",
  "description": "Copy to clipboard the most used timedate formats",
  "developer_name": "Nurgazy Nazhimidinov",
  "icon": "images/icon.png",
  "options": {
    "query_debounce": 0.05
  },
  "preferences": [
    {
      "id": "time_kw",
      "type": "keyword",
      "name": "Timemacros",
      "default_value": "tm"
    }
  ]
}

It says that if you write keyword Timemacros, extension will be on launcher(WARNING not clicked).

---

if you write Timemacros and click

or

write tm and SPACE, then KeywordQueryEventListener(EventListener) will invoked.

Here is the code:

class DemoExtension(Extension):

    def __init__(self):
        super(DemoExtension, self).__init__()
        self.subscribe(KeywordQueryEvent, KeywordQueryEventListener())

class KeywordQueryEventListener(EventListener):

    def on_event(self, event, extension):
        items = []
        logger.info('preferences %s' % json.dumps(extension.preferences))
        logger.info(event.get_keyword()) # gives the keyword 'tm'
        items.append(ExtensionResultItem(icon='images/icon.png',
                                         name='YYYY-MM-DD',
                                         description='{0:%Y-%m-%d}'.format(datetime.datetime.now()),
                                         on_enter=CopyToClipboardAction('{0:%Y-%m-%d}'.format(datetime.datetime.now()))))

        items.append(ExtensionResultItem(icon='images/icon.png',
                                         name='HH:mm',
                                         description='{0:%H:%M}'.format(datetime.datetime.now()),
                                         on_enter=CopyToClipboardAction(
                                             '{0:%H:%M}'.format(datetime.datetime.now()))))

        items.append(ExtensionResultItem(icon='images/icon.png',
                                         name='YYYY-MM-DD HH:mm',
                                         description='{0:%Y-%m-%d %H:%M}'.format(datetime.datetime.now()),
                                         on_enter=CopyToClipboardAction(
                                             '{0:%Y-%m-%d %H:%M}'.format(datetime.datetime.now()))))

        return RenderResultListAction(items)


if __name__ == '__main__':
    DemoExtension().run()

As you can see KeywordQueryEventListener(EventListener) and on_event is run and RenderResultListAction(items) is returned and presented to user.

Our items would be

• YYYY-MM-DD
• HH:mm
• YYYY-MM-DD HH:mm

Here is the screenshot of items:

Code for item:

items.append(ExtensionResultItem(icon='images/icon.png',
                                         name='YYYY-MM-DD',
                                         description='{0:%Y-%m-%d}'.format(datetime.datetime.now()),
                                         on_enter=CopyToClipboardAction('{0:%Y-%m-%d}'.format(datetime.datetime.now()))))

Explanation for ExtensionResultItem:

name - title shown to user, look at screenshot above

description - subtext which is also shown to user, look at screenshot above

on_enter - most important part, says what to do if user clicks on this items. In my case, it is CopyToClipboardAction action which copies data to clipboard.

Summary

At the end, I developed extension with enabled me to discard my custom bash scripts and forget about keyboard shortcuts for them.

Source code on Github

Deprecated bash scripts 😄

From personal blog: https://www.nurgasemetey.com/2020/extension-ulauncher/