DEV Community: MedLabs

Play with time on Vlang

MedLabs — Mon, 01 Apr 2024 20:19:22 +0000

Ah, Vlang. The programming language that's so fast and elegant, it makes even the most verbose languages feel like they're wading through molasses. Despite being objectively superior (wink wink), Vlang inexplicably suffers from a vocal minority of haters amongst its more… sluggish… competitors. But hey, who needs friends when you have speed and efficiency on your side, right?
(ok that was a gemini introduction, I'm not a native english speaker)

The standart library of V is very rich and powerful, I will try to demonstrate some of the features of time module from the vlib, using examples.

To begin, we should create a time_example.v file and import the time module :

import time

Now open this page to check the functions of the time module, we're gonna use some of them in this example file. you can add every example of these in a new line.

Create a time variable that contains actual time:

t := time.now() // for me, t is 2024-03-31 21:01:45

You can format your date to `YYYY-MM-DD HH:mm`

println(t.format()) // returns 2024-03-31 21:01

To custom format your date you can use `custom_format()` :

println(t.custom_format("dddd DD/MMM/YYYY")) // returns Sunday 31/Mar/2024

To return only hours and minutes from `t` :

println(t.hhmm()) // returns 21:01

To get Unix timestamp (seconds from 1970-01-01) use `unix_time()`:

println(t.unix_time()) // returns 1711918894

To get only the date in European style use `ddmmy()` :

println(t.ddmmy()) // returns 31.03.2024

To get the month and the day in US format use `md()`:

println("hello user it's ${t.md()}") // returns hello user it's March 31

To check if the year is leap use `is_leap_year()`:

println(t.is_leap_year()) // returns true

Let's create another variable with an earlier date, for that we can use parse() and provide a date string in this format "YYYY-MM-DD HH:mm:ss", a ! or a or {} should append this function.
since we're gonna modify this variable later, we should declare it with mut

mut h := time.parse("2023-10-07 05:10:00")!

To get the Weekday of a date:

println(h.weekday_str()) // returns Sat

To get a long description of the difference between an earlier date and actual date:

println(h.relative()) // returns last Oct 7

To get a short description of the difference:

println(h.relative_short()) // returns 176d ago

To get the duration from `h` in format `hours:minutes:seconds` :

println(time.since(h)) // returns 4241:09:17

To get duration in minutes only as a f64:

println(time.since(h).minutes()) // returns 254469.2992380094

You can calculate the duration between two dates by using `-` :

println(t - h) // return 4241:09:17

You can compare two dates using `==` or `<` :

println(t == h) // returns false
println(h < t) // returns true

Add duration in nanoseconds to a time variable:

println(h.add(1234567890 * 1000000)) // returns 2023-10-21 12:06:07

Add days to a time variable :

println(h.add_days(90)) // returns 2024-01-05 05:10:00

The time module still contains a lot of functions that could make your DX very fast and productive.

You can continue playing with the stopwatch feature, you can check it on : https://modules.vlang.io/time.html

Don't forget, Vlang is still WIP, so probably more useful functions will be added to this module.

using dexie and pinia in the same time

MedLabs — Thu, 07 Apr 2022 01:36:46 +0000

For my app I'm using Vue3, pinia for state management, and dexie as indexedDB wrapper.

my app work this way:

on Mount :

data is fetched from dexie and saved in a pinia state.
then in my component , data is rendered from the state directly...

editing data:

as I add or edit my records: my pinia action functions update data directly on dexie db, then it's refetched on the pinia state.

My question is:

is this a good solution for data management or should I get rid of pinia and only use dexie ?
does the fact that I use two data sources slow my app ?

here is an example of my pinia state:

import { defineStore, acceptHMRUpdate } from 'pinia'
import type { IPatient } from '~/db/model'
import db from '~/db/db'

export const usePatientStore = defineStore('patient', () => {
  const patients = ref<IPatient[]>([])

  // Getters

  const getPatients = computed(() => patients.value)

  const getPatientById = (id: string) => {
    const index = patients.value.findIndex((item: IPatient) => item._id === id)
    return patients.value[index]
  }
  const PatientsNames = () => {
    return patients.value.map((item: IPatient) => item.name)
  }

  const getPatientName = (id: string) => {
    if (id !== '')
      return patients.value.filter((item: IPatient) => item._id === id).map((i: IPatient) => i.name).toString()

    else return ''
  }

  // Actions
  async function fetchPatients() {
    patients.value = await db.table('patients').toArray().then(result => result.filter(el => el.deleted === false))
  }
  function addPatient(payload: IPatient) {
    db.table('patients').add(JSON.parse(JSON.stringify(payload)))
    patients.value.push(payload)
  }
  function editPatient(payload: IPatient) {
    payload.updatedAt = Date.now()
    db.table('patients').update(payload._id, JSON.parse(JSON.stringify(payload)))
    const index: number = patients.value.findIndex((item: IPatient) => item._id === payload._id)
    patients.value[index] = payload
  }
  function deletePatient(id: string) {
    db.table('patients').update(id, JSON.parse(JSON.stringify({ deleted: true, updatedAt: Date.now() })))
    const index: number = patients.value.findIndex((item: IPatient) => item._id === id)
    patients.value.splice(index, 1)
  }

  return {
    patients,
    getPatients,
    getPatientById,
    PatientsNames,
    getPatientName,
    fetchPatients,
    addPatient,
    editPatient,
    deletePatient,
  }
})

if (import.meta.hot)
  import.meta.hot.accept(acceptHMRUpdate(usePatientStore, import.meta.hot))

Learn how to code by customizing ready to go apps

MedLabs — Wed, 11 Mar 2020 21:38:42 +0000

Many tutorials and courses teach you coding by creating an app from scratch. That is a way to learn creating your app or website...
But sometimes, it's hard to complete the tutorial, and you never reopen the tutorial again, then you forget about learning that language or framework...
I bet you have a lot of unfinished tuto-projects in your /dev/ folder, that you just left there, for a while and you think that one day you will finish'em :) You will never do it :) trust me !

Ok, learning the basics is very important !

For example, to learn a framework like Django or Angular, you have to know the basics of Python or Javascript and by then you attack the framework tutos...

By the basics I mean the a + b and a = a++ thing, the if, then and for thing, the function and class stuff...

For my case, I prefer Python on Javascript, but to create a web app nowadays, you can find more tutos and topics about JS frameworks than Django or Ruby On Rails, but I'm not very good at Javascript.
Ok, I cant create a React app using the CLI, I can change the landing page, and put some components copied from snippets websites... but creating a whole React application ? that's impossible for me right now...

Customizing a ready app is the key !

So I just went on Github, and looked for specific apps that use frontend and backend frameworks. (for example an app based on express.js and reactjs)

I clone the app on my "dev" directory
then I run npm install and play with it to be sure what exactly the app does and that it works perfectly...

The idea is not just to clone it, but it's to ** CUSTOMIZE IT ** !!
after cloning the app and running it without any issues, start discovering the directories and the source code of the app.

Try to locate the source code of every component you see in the browser, and try to understand the logic that makes that code showing that component. Then change the variables values of that piece of code and see how it changed on the browser...

After customizing some components, you will learn many things about that framework, and the code powering it, and you know what ? if the licence of that app is MIT, you can make all your customizations, change its name and push it in your repositories, and it's your app now !
Try to do that as much as you can, and you'll learn really faster than by reading a book or watching a video.