kiran-db/build/DB.js

This is how javascript managa json data as the database

"use strict";
var __importDefault = (this && this.__importDefault) || function (mod) {
    return (mod && mod.__esModule) ? mod : { "default": mod };
};
Object.defineProperty(exports, "__esModule", { value: true });
const fs_1 = __importDefault(require("fs"));
const path_1 = __importDefault(require("path"));
class DB {
    constructor(name) {
        this.data = [];
        this.error = { exists: false, message: '' };
        this.selected = [];
        this.selection = false;
        this.name = name + '.json';
        this.makesure();
    }
    makesure() {
        const filename = path_1.default.join(path_1.default.resolve(), 'dbs', this.name);
        if (!fs_1.default.existsSync(filename))
            fs_1.default.writeFileSync(filename, '[]');
    }
    rewrite(affectedIDs) {
        const filename = path_1.default.join(path_1.default.resolve(), 'dbs', this.name);
        const datastring = JSON.stringify(this.data);
        try {
            fs_1.default.writeFileSync(filename, datastring);
            console.log('Database re-written');
        }
        catch (_a) {
            this.error = { exists: true, message: 'Failed to re-write database!' };
        }
        this.end();
        return this.error.exists ? this.error : { ok: true, affectedIDs };
    }
    getselected(field) {
        return this.selected.map((selected) => selected[field]);
    }
    getincrementid() {
        const lastdata = this.data[this.data.length - 1];
        return lastdata ? lastdata.id + 1 : 1;
    }
    loopcreate(newdata, status) {
        newdata.forEach((data) => {
            const created = this.create(data);
            status.push(created);
        });
        return status;
    }
    end() {
        this.selected = [];
        this.selection = false;
    }
    create(newdata) {
        if (Array.isArray(newdata))
            return this.loopcreate(newdata, []);
        this.data = this.read();
        const id = this.getincrementid();
        this.data.push(Object.assign({ id }, newdata));
        return this.rewrite(id);
    }
    read() {
        if (this.selection)
            return this.selected;
        const filename = path_1.default.join(path_1.default.resolve(), 'dbs', this.name);
        const datastring = fs_1.default.readFileSync(filename, 'utf8');
        return JSON.parse(datastring);
    }
    update(newdata) {
        const selectedids = this.getselected('id');
        if (!selectedids.length)
            return { ok: false, message: 'No item selected!' };
        this.data = this.data.map((data) => {
            if (selectedids.includes(data.id))
                for (let [key, val] of Object.entries(newdata))
                    data[key] = val;
            return data;
        });
        return this.rewrite(selectedids);
    }
    delete() {
        const selectedids = this.getselected('id');
        if (!selectedids.length)
            return { ok: false, message: 'No item selected' };
        this.data = this.data.filter((data) => {
            if (!selectedids.includes(data.id))
                return data;
        });
        return this.rewrite(selectedids);
    }
    where(callback) {
        this.selection = false;
        this.data = this.read();
        this.selected = this.data.filter(callback);
        this.selection = true;
        return this;
    }
    join(other, field) {
        const selectedids = this.getselected('id');
        if (!selectedids.length) {
            console.log('No selected items');
            return [];
        }
        else
            console.log('Joining into ' + other);
        const selecteddata = this.selected.map(selected => {
            const joinmodel = new Join(other);
            const joindata = joinmodel.where((data) => selectedids.includes(data[field])).read();
            selected[other] = joindata;
            return selected;
        });
        this.end();
        return selecteddata;
    }
}
exports.default = DB;
class Join extends DB {
    constructor(name) {
        super(name);
    }
}