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Accepted
Claudio
Asked: 2022-03-23 09:26:17 +0800 CST 2022-03-23 09:26:17 +0800 CST

How to send the products to buy to api mercadopago?

  • 772

From Angular I send to node/express an array with the products that the user is going to buy.

From node/express I save the data that comes from the req.body in a buy array like this:

let compra: [] = [];

compra = req.body; // guardo en el array la data del body

console.log(compra);

This is the console output:

[
   'Borges Cuenta Buenos Aires',
   '1230.00',
   1,
  'Fuertes, Libres Y Nómadas', 
   '1290.00', 
 ]

Mercadopago now uses this structure to store the products to be purchased:

 // Crea un objeto de preferencia
      let preference = {
        items: [
          {    
            title: 'Mi producto',
            unit_price: 100,
            quantity: 1
          },
        ],
      };

      mercadopago.preferences
        .create(preference)
        .then(function (response) {
          console.log(response.body);
          // redirije a pagina de mercadopago
          res.redirect(response.body.init_point);
        })
        .catch(function (error) {
          console.log(error);
        });

So the idea is to save in this preference object , the products that arrive in the req.body , try doing this:

let compra: [] = [];
  
  let items: [
    {
      title: "";
      unit_price: 0;
      quantity: 0;
    }
  ];
  
  compra = req.body;
  
  // paso la data del array compra al array items.
  for(let i = 0; i < compra.length; i++){
    items[i].title = compra[i];
    items[i].unit_price = compra[i];
    items[i].quantity = compra[i];
  }

 // console.log de los datos del array items
  for(let item of items){
    console.log('item: ' + item);
  }

But node shows an error: TypeError: Cannot read property '0' of undefined: .

nodejs

2 Answers

  1. I think the problem you're having is that you're trying to fill items[]with the buy values ​​by trying to access the elements based on the length of compra. The error you get is because you define it itemsas an array of a single element, but comprait has more elements and at the moment forwhere the second iteration is done, you end up doing something like:

    items[2].title = compra[2];

    Which is a problem because it exists compra[2], but it doesn't exist items[2]. I suggest you define an empty array as items and fill it using a method like push, something like this:

    let items = [];

compra = req.body;

for (let i = 0; i < compra.length; i++) {
  //Asumo que las propiedades existen en compra[i] con el mismo nombre
  items.push({
    title: compra[i].title,
    unit_price: compra[i].unit_price,
    quantity: compra[i].quantity
  });
}

    Or better yet, using for ... of:

    let items = [];

compra = req.body;

for (e of compra) {
  //Asumo que las propiedades existen en compra[i] con el mismo nombre
  items.push({
    title: e.title,
    unit_price: e.unit_price,
    quantity: e.quantity
  });
}

    UPDATE

    Assuming that the data arrives as an array that follows a defined structure in which every 3 elements represent a purchase, then I propose something like:

    const CANTIDAD_PROPIEDADES = 3;

let items = [];

compra = req.body;

for (let i = 0; i < compra.length / CANTIDAD_PROPIEDADES; i++) {
  let base = i * CANTIDAD_PROPIEDADES;
  items.push({
    title: compra[base],
    unit_price: compra[base + 1],
    quantity: compra[base + 2]
  });
}

    I suggest that each element should be individually encapsulated, this structure that is being used is not adequate and does not take advantage of the language that you are using. It is more complicated to read, requires more code, is more prone to errors, requires additional verification, and is not easily scalable.

    A suitable format for comprawould be something like:

    [
    {
      title: 'Borges Cuenta Buenos Aires';
      unit_price: '1230.00';
      quantity: 1;
    },
    {
      title: 'Fuertes, Libres Y Nómadas';
      unit_price: '1290.00';
      quantity: 1;
    },
 ]
    • 1
  2. Best Answer

    Following the advice, a solution to load the products of the req.body in the preference object was:

    1. Create an interface in node/ expresscompramp :

    export interface Compramp{
    title: string,
    unit_price: number,
    quantity: number 
}

    In the checkout function of the controller.ts

    // SDK de Mercado Pago
const mercadopago = require("mercadopago");
// importo la interfaz
import { Compramp } from '../compramp';
import { Request, Response } from "express";

mercadopago.configure({ 
  // acces token de produccion del vendedor
  access_token:
    "APP_USR-xxxxxxxx-xxxxxxxxxxxxxxx-xxxxxx",
});

export const checkout = async (
  req: Request,
  res: Response
): Promise<Response> => {
 
  let compra = [{
    title: '',
    unit_price: 0,
    quantity: 0
  }]

  let items: Compramp[] = [];

  compra = req.body; // guardo la data del req.body en array compra

  // cargo la data del array compra en el array items
  for(let data of compra){
    items.push({
      title: data.title,
      unit_price: parseInt(data.unit_price.toString()),
      quantity: parseInt(data.quantity.toString())
    });
  }

  for(let p of items){
    console.log(p);
  }

  try {  
    // cargo la data de items en el objeto preference
    let preference = {
      items
    }
      mercadopago.preferences
      .create(preference)
      .then(function (response) {
        console.log(response.body);
        // redirije a pagina de mercadopago 
        res.redirect(response.body.init_point);
      })
      .catch(function (error) {
        console.log(error);
      });

  } catch (e) {
    console.log(e);
    return res.status(500).json("Internal server error");
  }
};

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