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diff --git a/2024/captions/emacsconf-2024-water--watering-my-digital-plant-with-emacs-timers--christopher-howard--main--chapters.vtt b/2024/captions/emacsconf-2024-water--watering-my-digital-plant-with-emacs-timers--christopher-howard--main--chapters.vtt new file mode 100644 index 00000000..cb5646ed --- /dev/null +++ b/2024/captions/emacsconf-2024-water--watering-my-digital-plant-with-emacs-timers--christopher-howard--main--chapters.vtt @@ -0,0 +1,26 @@ +WEBVTT + + +00:00:02.679 --> 00:00:25.676 +Introduction + +00:00:28.823 --> 00:00:47.234 +What is Astrobotany? + +00:00:48.914 --> 00:01:22.096 +What is Gemini? + +00:01:25.337 --> 00:03:34.999 +How do you play Astrobotany? + +00:03:37.000 --> 00:06:35.750 +Timers + +00:06:37.792 --> 00:09:03.843 +The code + +00:09:05.724 --> 00:13:02.246 +Managing the plant + +00:13:09.560 --> 00:13:47.471 +Conclusion diff --git a/2024/captions/emacsconf-2024-water--watering-my-digital-plant-with-emacs-timers--christopher-howard--main.vtt b/2024/captions/emacsconf-2024-water--watering-my-digital-plant-with-emacs-timers--christopher-howard--main.vtt new file mode 100644 index 00000000..2293a61e --- /dev/null +++ b/2024/captions/emacsconf-2024-water--watering-my-digital-plant-with-emacs-timers--christopher-howard--main.vtt @@ -0,0 +1,662 @@ +WEBVTT captioned by sachac + +NOTE Introduction + +00:00:02.679 --> 00:00:06.782 +Welcome to Watering My Digital Plant with Emacs Timers, + +00:00:07.503 --> 00:00:11.384 +a talk by Christopher Howard for Emacs Conference 2024. + +00:00:11.385 --> 00:00:16.989 +The goal of this talk is to give + +00:00:17.010 --> 00:00:19.431 +a brief introduction to Emacs timers + +00:00:20.892 --> 00:00:23.334 +using the illustration of how I created + +00:00:23.394 --> 00:00:25.676 +a bot for the Astrobotany service. + +NOTE What is Astrobotany? + +00:00:28.823 --> 00:00:30.004 +What is Astrobotany? + +00:00:30.924 --> 00:00:32.384 +Let me jump to the home page. + +00:00:38.649 --> 00:00:42.411 +Astrobotany is a botany game or a simulation + +00:00:42.611 --> 00:00:45.072 +that is played using the Gemini protocol + +00:00:45.893 --> 00:00:47.234 +and gemtext documents. + +NOTE What is Gemini? + +00:00:48.914 --> 00:00:49.615 +What is Gemini? + +00:00:50.700 --> 00:00:53.563 +The Gemini protocol is a small web protocol, + +00:00:54.263 --> 00:00:57.246 +similar to the HyperText Transfer Protocol, + +00:00:58.047 --> 00:01:00.109 +but with differing goals of simplicity, + +00:01:00.789 --> 00:01:03.712 +non-extensibility, and protecting privacy. + +00:01:05.453 --> 00:01:09.057 +Gemtext is a simple hyperlinking document format, + +00:01:09.557 --> 00:01:14.242 +the analog of the HyperText Markup Language, or HTML. + +00:01:16.095 --> 00:01:17.075 +Much more could be said + +00:01:17.135 --> 00:01:18.516 +about the design and goals + +00:01:18.576 --> 00:01:19.756 +of the Gemini project, + +00:01:20.236 --> 00:01:22.096 +but that is not the focus of this talk. + +NOTE How do you play Astrobotany? + +00:01:25.337 --> 00:01:27.057 +And how do you play Astrobotany? + +00:01:28.418 --> 00:01:30.518 +First, you need to get a Gemini client + +00:01:31.138 --> 00:01:32.838 +or what you might call a browser. + +00:01:34.079 --> 00:01:35.599 +Many clients are available, + +00:01:36.259 --> 00:01:39.860 +but I am using Elpher, a Gemini client for Emacs. + +00:01:41.340 --> 00:01:43.161 +Once you have your client running, + +00:01:43.801 --> 00:01:46.361 +navigate to the home page for Astrobotany, + +00:01:46.782 --> 00:01:48.842 +which is shown in this window. + +00:01:50.783 --> 00:01:53.023 +You'll see the URL for the home page + +00:01:53.103 --> 00:01:54.704 +displayed at the top of the window. + +00:01:57.865 --> 00:01:59.625 +On your first visit to Astrobotany, + +00:02:00.406 --> 00:02:02.586 +you will need to create a client certificate, + +00:02:03.426 --> 00:02:05.507 +which will be used instead of a password. + +00:02:06.067 --> 00:02:07.548 +Your Gemini client will help you + +00:02:07.588 --> 00:02:08.768 +to create the certificate. + +00:02:12.102 --> 00:02:16.306 +Then you will go to the Visit Your Plant page + +00:02:22.472 --> 00:02:24.553 +in order to view your plant, + +00:02:28.297 --> 00:02:32.781 +to water it, and to collect things from it, + +00:02:33.141 --> 00:02:37.928 +including money. So here you see + +00:02:37.968 --> 00:02:39.429 +the plant that I'm currently growing + +00:02:40.229 --> 00:02:41.910 +in glorious ASCII graphics. + +00:02:43.070 --> 00:02:46.691 +There's also a color version available from this page. + +00:02:56.895 --> 00:02:57.935 +Back at the home page, + +00:02:59.536 --> 00:03:00.836 +you can do other things + +00:03:02.537 --> 00:03:05.358 +like go to the item shop, + +00:03:07.165 --> 00:03:10.247 +to buy items like badges, fertilizer, + +00:03:11.607 --> 00:03:13.348 +or post on the message board. + +00:03:15.849 --> 00:03:18.991 +In Astrobotany, gardener bots are fully legal. + +00:03:20.852 --> 00:03:23.153 +And to do an action on your plant, + +00:03:23.693 --> 00:03:24.814 +like watering the plant, + +00:03:25.454 --> 00:03:26.915 +all your bot needs to do is + +00:03:27.035 --> 00:03:30.917 +to access the appropriate Gemini URL or page + +00:03:31.537 --> 00:03:33.998 +while presenting the appropriate certificate + +00:03:34.419 --> 00:03:34.999 +for your plant. + +NOTE Timers + +00:03:37.000 --> 00:03:39.862 +And this brings us to Emacs timers. + +00:03:42.904 --> 00:03:45.906 +So the main function of interest to us + +00:03:46.626 --> 00:03:49.288 +is the run-at-time function. + +00:04:00.714 --> 00:04:03.235 +Here is the help documentation, + +00:04:03.395 --> 00:04:07.036 +which is available in any recent Emacs installation. + +00:04:10.157 --> 00:04:13.277 +As you see, the purpose of the function + +00:04:13.498 --> 00:04:16.718 +is to perform an action at a specific time + +00:04:20.920 --> 00:04:25.801 +to repeat it after a specific number of seconds. + +00:04:29.770 --> 00:04:32.573 +And so basically, all you have to do is + +00:04:32.673 --> 00:04:35.795 +pass in a function to run-at-time, + +00:04:36.436 --> 00:04:39.058 +telling Emacs how soon you want to run the function, + +00:04:39.999 --> 00:04:41.541 +and then how often you want to run the + +00:04:41.581 --> 00:04:42.461 +function after that. + +00:04:44.403 --> 00:04:46.605 +The function has a variety of options for + +00:04:46.645 --> 00:04:48.887 +specifying the time parameter, + +00:04:49.347 --> 00:04:52.030 +that is, how soon you want the function to run. + +00:04:55.307 --> 00:04:57.428 +For our application, in which we'll be + +00:04:57.508 --> 00:04:58.409 +running our functions + +00:04:58.649 --> 00:05:01.030 +once or twice a day at specific times, + +00:05:03.152 --> 00:05:04.513 +it is most useful to + +00:05:04.553 --> 00:05:06.954 +specify the number of seconds until the event. + +00:05:08.515 --> 00:05:09.876 +This does, however, require + +00:05:10.436 --> 00:05:11.977 +calculating the number of seconds + +00:05:12.097 --> 00:05:15.399 +until a specific time of day. I will + +00:05:15.419 --> 00:05:16.800 +provide code for this shortly. + +00:05:18.860 --> 00:05:20.803 +The run-at-time function does allow you to + +00:05:20.864 --> 00:05:23.308 +specify the time parameter as a string, + +00:05:24.029 --> 00:05:25.672 +representing the hours and minutes. + +00:05:26.413 --> 00:05:32.149 +For example, 05:40. + +00:05:32.150 --> 00:05:34.051 +However, there is an oddity in the + +00:05:34.091 --> 00:05:35.392 +design of run-at-time, + +00:05:36.372 --> 00:05:41.395 +such that if the specified time of day has + +00:05:41.455 --> 00:05:42.216 +already passed, + +00:05:43.196 --> 00:05:44.877 +then the timer will run immediately, + +00:05:45.578 --> 00:05:46.638 +rather than in the future, + +00:05:46.958 --> 00:05:47.839 +as you might expect. + +00:05:49.280 --> 00:05:51.441 +This can be problematic, for example, + +00:05:51.661 --> 00:05:54.663 +if run-at-time is being called from your init file, + +00:05:55.583 --> 00:05:57.624 +since the timer will run immediately + +00:05:58.245 --> 00:06:00.426 +every time you restart Emacs for any reason. + +00:06:02.526 --> 00:06:04.691 +I noticed recently that run-at-time + +00:06:04.791 --> 00:06:07.217 +also allows you to pass in a value + +00:06:07.317 --> 00:06:17.657 +from encode-time, which maybe does what we want, + +00:06:18.378 --> 00:06:20.760 +but I never bothered with testing that. + +00:06:21.340 --> 00:06:23.041 +Actually, I have a vague memory of + +00:06:23.181 --> 00:06:25.743 +once looking into it and it didn't seem to do what I + +00:06:25.783 --> 00:06:29.286 +wanted, but honestly I can't clearly remember, + +00:06:29.946 --> 00:06:31.667 +so you may want to look into that yourself. + +00:06:32.728 --> 00:06:34.209 +What I ended up using was just + +00:06:34.309 --> 00:06:35.750 +passing in a number of seconds. + +NOTE The code + +00:06:37.792 --> 00:06:39.413 +So now we'll move over to the code. + +00:06:46.764 --> 00:06:49.426 +So I'll skip down here first + +00:06:49.966 --> 00:06:52.447 +to the code that I wrote for calculating the number of + +00:06:52.527 --> 00:06:52.887 +seconds. + +00:06:54.408 --> 00:06:57.790 +It's a function that calculates the number of seconds + +00:06:58.050 --> 00:07:01.012 +until a particular time of day in the future. + +00:07:04.214 --> 00:07:09.277 +You can see that you pass in the hour as a number from + +00:07:09.278 --> 00:07:19.137 +0 to 23 and the minutes as a number from 0 to 59. And + +00:07:20.078 --> 00:07:22.539 +here's the code, which will also be available later. + +00:07:25.700 --> 00:07:29.202 +I wrote another function, secs-until-weekly, + +00:07:29.522 --> 00:07:32.464 +which we do not need for this talk, + +00:07:32.604 --> 00:07:34.685 +but which is useful if you're running + +00:07:34.745 --> 00:07:36.746 +events which need to happen once per week. + +00:07:39.264 --> 00:07:44.025 +This function also requires a target hour + +00:07:44.085 --> 00:07:48.926 +and a target minute, but also requires passing in a + +00:07:48.966 --> 00:08:00.548 +target day. And while we're on the subject of timers + +00:08:00.568 --> 00:08:02.588 +specifically, I should mention that + +00:08:02.648 --> 00:08:05.929 +Emacs has a very useful function called list-timers. + +00:08:07.577 --> 00:08:09.959 +So if I call the interactive function list-timers, + +00:08:11.560 --> 00:08:14.542 +it will give me a list of all the timers + +00:08:14.842 --> 00:08:15.542 +currently running. + +00:08:16.723 --> 00:08:19.625 +This page shows not only which timers exist, + +00:08:20.186 --> 00:08:22.807 +but also how long it will be until they run again, + +00:08:23.848 --> 00:08:26.750 +along with the periodic repeat value that you + +00:08:26.770 --> 00:08:27.390 +specified. + +00:08:29.992 --> 00:08:33.034 +Furthermore, any timer can be canceled by moving point + +00:08:33.514 --> 00:08:38.515 +over the timer and running timer-list-cancel, + +00:08:38.696 --> 00:08:42.556 +which on my system is bound to the letter c by default. + +00:08:43.537 --> 00:08:45.417 +This is very helpful while you are developing + +00:08:45.497 --> 00:08:46.537 +some timer function. + +00:08:48.438 --> 00:08:52.158 +So I could cancel the timer that I already have running + +00:08:53.779 --> 00:08:55.059 +for shaking the plant, + +00:08:57.420 --> 00:08:59.360 +as well as the one for watering the plant. + +00:09:02.842 --> 00:09:03.843 +and back to the code. + +NOTE Managing the plant + +00:09:05.724 --> 00:09:08.566 +So now we'll talk about the actual code for + +00:09:08.646 --> 00:09:09.567 +managing the plant. + +00:09:14.210 --> 00:09:16.031 +So you see I have a variable set up here + +00:09:16.471 --> 00:09:19.353 +that specifies where the certificate file, + +00:09:20.994 --> 00:09:23.836 +the public certificate file, as well as + +00:09:23.936 --> 00:09:26.458 +the secret key file is located. + +00:09:27.918 --> 00:09:29.459 +This is where it is in my system. + +00:09:30.119 --> 00:09:33.181 +Of course, depending on your specific Gemini client, + +00:09:33.481 --> 00:09:36.722 +it may be in a different space and will likely have a + +00:09:36.762 --> 00:09:37.303 +different name. + +00:09:41.045 --> 00:09:43.486 +And here is the code for watering the plant, + +00:09:44.526 --> 00:09:45.967 +which I can call interactively. + +00:09:49.412 --> 00:09:52.334 +And the core of it here is that it uses the + +00:09:52.834 --> 00:09:57.937 +gmni utility, a command line utility to + +00:10:00.998 --> 00:10:06.982 +call a particular URL while also loading up + +00:10:07.702 --> 00:10:10.564 +or presenting the required certificate. + +00:10:12.505 --> 00:10:16.447 +So in this case, you can see it is the URL that is + +00:10:16.567 --> 00:10:18.088 +required for watering the plant. + +00:10:19.827 --> 00:10:24.952 +This idea is very simple and the gmni client + +00:10:26.353 --> 00:10:30.097 +or gmni command line program + +00:10:30.758 --> 00:10:31.999 +makes this very simple to do. + +00:10:34.554 --> 00:10:36.535 +Here's another function for shaking the plant. + +00:10:37.696 --> 00:10:40.758 +Again it is almost identical except that we + +00:10:40.958 --> 00:10:43.300 +use a different URL, + +00:10:44.180 --> 00:10:46.982 +one for shaking the plant instead of watering it. + +00:10:47.562 --> 00:10:49.183 +And again we want to shake the plant + +00:10:50.044 --> 00:10:51.745 +in order to get money to fall off of it. + +00:10:55.847 --> 00:10:59.290 +You need to water your plant at least once per day or + +00:11:00.791 --> 00:11:01.251 +it'll die. + +00:11:02.930 --> 00:11:09.953 +I usually water mine twice and just in case something + +00:11:10.013 --> 00:11:13.314 +happens where Emacs was turned off because of + +00:11:13.414 --> 00:11:15.035 +power outage or something like that + +00:11:15.595 --> 00:11:17.196 +that I'm more likely to get it watered, + +00:11:19.036 --> 00:11:21.957 +and I shake it once per day because there isn't + +00:11:23.398 --> 00:11:25.339 +any purpose to shaking it more than that. + +00:11:25.619 --> 00:11:27.240 +If you try to shake it more than that, + +00:11:27.420 --> 00:11:29.560 +then money no more money will fall off, + +00:11:30.321 --> 00:11:30.821 +or not much. + +00:11:37.242 --> 00:11:39.526 +So you see down here, I have the code that + +00:11:39.627 --> 00:11:41.209 +actually calls run-at-time. + +00:11:42.560 --> 00:11:45.141 +I left here commented my original forms of this + +00:11:45.661 --> 00:11:50.024 +which used the just specify directly the time of day. + +00:11:50.644 --> 00:11:52.225 +As I mentioned the problem with that + +00:11:53.505 --> 00:11:54.466 +was that it would... + +00:11:54.786 --> 00:11:57.187 +these functions would also get called + +00:11:59.208 --> 00:12:02.649 +whenever I restarted Emacs for any + +00:12:02.709 --> 00:12:04.250 +reason and that was kind of annoying. + +00:12:05.011 --> 00:12:07.352 +So instead we have here the functions down here + +00:12:07.452 --> 00:12:09.533 +which uses secs-until-daily + +00:12:10.913 --> 00:12:11.754 +to water the plant + +00:12:12.294 --> 00:12:14.756 +and then secs-until-daily to shake the plant. + +00:12:16.057 --> 00:12:20.821 +You see, I've specified the plant to get watered + +00:12:21.181 --> 00:12:26.025 +at 4 in the morning and then the function is run again + +00:12:26.125 --> 00:12:31.269 +after that, every 43,200 seconds, which translates to + +00:12:31.389 --> 00:12:32.270 +every 12 hours, + +00:12:33.711 --> 00:12:36.353 +and then I shake the plants, shake the plant + +00:12:38.760 --> 00:12:43.341 +every morning at 4.15 a.m. and once every [24] hours. + +00:12:45.742 --> 00:12:46.802 +With a little bit more + +00:12:46.902 --> 00:12:49.483 +sophistication, a little bit more work on the code, + +00:12:50.143 --> 00:12:53.964 +I could actually have multiple plants be watering and + +00:12:54.264 --> 00:12:57.985 +shaking multiple plants with multiple certificates, + +00:12:58.105 --> 00:12:59.885 +but I never got around to that. + +00:13:00.946 --> 00:13:02.246 +Didn't seem worth the bother to me. + +NOTE Conclusion + +00:13:09.560 --> 00:13:12.964 +So thank you for watching my video, + +00:13:13.825 --> 00:13:16.227 +Watering My Digital Plant with Emacs Timers. + +00:13:16.628 --> 00:13:18.189 +You'll see at the bottom of this page + +00:13:19.491 --> 00:13:21.613 +links to the code for this talk + +00:13:22.354 --> 00:13:24.096 +as well as other things that I mentioned + +00:13:24.677 --> 00:13:27.819 +like the source code for the + +00:13:27.979 --> 00:13:30.100 +Elpher Gemini client, + +00:13:30.801 --> 00:13:33.282 +the URL for the Astrobotany capsule, + +00:13:34.203 --> 00:13:36.865 +as well as a link to more information about + +00:13:36.925 --> 00:13:41.407 +Project Gemini and my own personal Gemini capsule + +00:13:42.808 --> 00:13:45.129 +that's being run off my own server at home. + +00:13:46.790 --> 00:13:47.471 +Thank you very much. |