8.18 Removing Igredients Safely

BurgerBuilder.js

BurgerBuilder.js

import React, { Component, Fragment } from "react";
import BuildControls from "../components/Burger/BuildControls/BuildControls";
import Burger from "../components/Burger/Burger";

const INGREDIENT_PRICES = {
  salad: 0.5,
  cheese: 0.4,
  meat: 1.3,
  bacon: 0.7,
};

class BurgerBuilder extends Component {
  // constructor(props) {
  //     super(props);
  //     this.state = {...}
  // }
  state = {
    ingredients: {
      salad: 0,
      bacon: 0,
      cheese: 0,
      meat: 0,
    },
    totalPrice: 4,
  };

  addIngredientHandler = (type) => {
    const oldCount = this.state.ingredients[type];
    const updateCount = oldCount + 1;
    const updatedIngredients = {
      ...this.state.ingredients,
    };
    updatedIngredients[type] = updateCount;
    const priceAddition = INGREDIENT_PRICES[type];
    const oldPrice = this.state.totalPrice;
    const newPrice = oldPrice + priceAddition;
    this.setState({ totalPrice: newPrice, ingredients: updatedIngredients });
  };

  removeIngredientHandler = (type) => {
    const oldCount = this.state.ingredients[type];
    if (oldCount <= 0) {
      return;
    }
    const updateCount = oldCount - 1;
    const updatedIngredients = {
      ...this.state.ingredients,
    };
    updatedIngredients[type] = updateCount;
    const priceDeduction = INGREDIENT_PRICES[type];
    const oldPrice = this.state.totalPrice;
    const newPrice = oldPrice - priceDeduction;
    this.setState({ totalPrice: newPrice, ingredients: updatedIngredients });
  };

  render() {
    const disabledInfo = {
      ...this.state.ingredients,
    };

    for (let key in disabledInfo) {
      disabledInfo[key] = disabledInfo[key] <= 0;
    }

    return (
      <Fragment>
        <Burger ingredients={this.state.ingredients} />
        <BuildControls
          ingredientAdded={this.addIngredientHandler}
          ingredientRemoved={this.removeIngredientHandler}
          disabled={disabledInfo}
        />
      </Fragment>
    );
  }
}
export default BurgerBuilder;

BuildControls.js

BuildControls.js

import React from "react";
import BuildControl from "./BuildControl/BuildControl";
import classes from "./BuildControls.module.css";
const controls = [
  { label: "Salad", type: "salad" },
  { label: "Bacon", type: "bacon" },
  { label: "Cheese", type: "cheese" },
  { label: "Meat", type: "meat" },
];

const buildControls = (props) => (
  <div className={classes.BuildControls}>
    {controls.map((ctrl) => (
      <BuildControl
        key={ctrl.label}
        label={ctrl.label}
        added={() => props.ingredientAdded(ctrl.type)}
        removed={() => props.ingredientRemoved(ctrl.type)}
        disabled={props.disabled[ctrl.type]}
      />
    ))}
  </div>
);

export default buildControls;

BuildControl.js

BuildControl.js

import React from "react";
import classes from "./BuildControl.module.css";

const buildControl = (props) => (
  <div className={classes.BuildControl}>
    <div className={classes.Label}>{props.label}</div>
    <button
      className={classes.Less}
      onClick={props.removed}
      disabled={props.disabled}
    >
      Less
    </button>
    <button className={classes.More} onClick={props.added}>
      More
    </button>
  </div>
);

export default buildControl;