Axborot texnologiyalari va kommunikatsiyalarini rivojlantirish vazirligi muhammad al-xorazmiy nomidagi toshkent axborot texnologiyalari universiteti “Individual loyiha” ishi

Baza qismini kodlari.
import React, { createContext, useReducer } from "react";
import { v4 as uuidv4 } from 'uuid';

const SET_DATE = "SET_DATE";

const SET_TASK = "SET_TASK";
const SAVE_TASK = "SAVE_TASK";
const DELETE_TASK = "DELETE_TASK";

const getDatabase = ()=> {

let db = localStorage.getItem("$calendar_db");
if(!db) {
db = [];
setDatabase(db);
} else {
db = JSON.parse(db);
db.map(task=> task.date = new Date(task.date));
}
return db;
}

const setDatabase = (db)=> {

localStorage.setItem("$calendar_db", JSON.stringify(db));
}

export const CalendarContext = createContext();

export const sameDay = (a, b) => {

return a.getDate() === b.getDate()
&& a.getMonth() === b.getMonth()
&& a.getFullYear() === b.getFullYear();
}

function CalendarState(props) {

const initialState = {
date: new Date(),
days: [],
task: null
};

// Dispatch

const [state, dispatch] = useReducer((state, action) => {
switch (action.type) {
case SET_DATE: // Set current date

const date = action.payload;

// Calendar Start Day
const d1 = new Date(date.getFullYear(), date.getMonth() , 1);
d1.setDate(d1.getDate() - (d1.getDay() === 0 ? 7 : d1.getDay()));
// Calendart End Day
const d2 = new Date(date.getFullYear(), date.getMonth() + 1, 0);
if(d2.getDay() !== 0) d2.setDate(d2.getDate() + (7 - d2.getDay()));
const db = getDatabase();
const days = [];
do { // Obtain tasks
d1.setDate(d1.getDate() + 1); // iterate
days.push({
date: new Date(d1.getTime()),
tasks: db.filter((task)=> sameDay(d1, task.date))
});
} while(!sameDay(d1, d2));
return { // Update state
...state,
date: date,
days: days
}
case SET_TASK:
return {
...state,
task: action.payload
}
case SAVE_TASK: {
let db = getDatabase();
const task = action.payload;
if(!task.id) { // new Task
task.id = uuidv4();
db.push(task);
} else {
db = db.map(t=> {
return t.id === task.id ? task : t;
})
}
setDatabase(db);
return {
...state
}
}
case DELETE_TASK : {
let db = getDatabase();
db = db.filter((task)=> {
return task.id !== action.payload;
});
setDatabase(db);
return {
...state,
}
}
default:
break;
}
}, initialState);

// CRUD
const setDate = (date)=> {

dispatch({
type: SET_DATE,
payload: date
});
}

const setTask = (task)=> {

dispatch({
type: SET_TASK,
payload: task
});
}

const saveTask = (task)=> {

dispatch({
type: SAVE_TASK,
payload: task
})
}

const deleteTask = (taskId)=> {

dispatch({
type: DELETE_TASK,
payload: taskId
})
}
return (
value={{

date: state.date,

days: state.days,
task: state.task,

setDate,
setTask,

saveTask,
deleteTask
}}
>
{props.children}

);
}

export default CalendarState;