API Only sends 1 chunk of metadata when called - node.js

Question

I have a problem with my API that sends metadata when called from my smart contract of website. Its NFT tokens and my database is postgres and API is node.js
The problem is when I mint 1 NFT metadata works perfect, but if I mint 2 or more it will only ever send 1 chunk of data? So only 1 NFT will mint properly and the rest with no data?
Do I need to set a loop function or delay? Does anyone have any experience with this?
Any help would be much appreciated.
Below is the code from the "controller" folder labeled "nft.js"
const models = require("../../models/index");
const path = require("path");
const fs = require("fs");
module.exports = {
create_nft: async (req, res, next) => {
try {
const dir = path.resolve(__dirname + `../../../data/traitsfinal.json`);
const readCards = fs.readFileSync(dir, "utf8");
const parsed = JSON.parse(readCards);
console.log("ya data ha final ??", parsed);
parsed.forEach(async (item) => {
// return res.json(item)
let newNft = await models.NFT.create({
name: item.Name,
description: item.Description,
background: item.Background,
body: item.Body,
mouth: item.Mouth,
eyes: item.Eyes,
head_gear: item.Head_Gear,
tokenId: item.tokenId,
image: item.imagesIPFS,
});
});
return res.json({
data: "nft created",
error: null,
success: true,
});
} catch (error) {
console.log("server error", error.message);
next(error);
}
},
get_nft: async (req, res, next) => {
try {
const { id } = req.params;
// console.log("id ?????????",id)
// console.log("type of ",typeof(id))
// const n=Number(id)
// console.log("type of ",typeof(id))
const nft = await models.NFT.findByPk(id);
if (!nft) {
throw new Error("Token ID invalid");
}
if (!nft.isMinted) {
throw new Error("Token not minted");
}
console.log(nft);
// }
const resObj = {
name: nft.name,
description: nft.description,
image: `https://gateway.pinata.cloud/ipfs/${nft.image}`,
attributes: [
{ trait_type: "background", value: `${nft.background}` },
{ trait_type: "body", value: `${nft.body}` },
{ trait_type: "mouth", value: `${nft.mouth}` },
{ trait_type: "eyes", value: `${nft.eyes}` },
{ trait_type: "tokenId", value: `${nft.tokenId}` },
{
display_type: "number",
trait_type: "Serial No.",
value: id,
max_value: 1000,
},
],
};
return res.json(resObj);
} catch (error) {
console.log("server error", error.message);
next(error);
}
},
get_nft_all: async (req, res, next) => {
try {
// console.log("id ?????????",id)
// console.log("type of ",typeof(id))
// const n=Number(id)
// console.log("type of ",typeof(id))
const nft = await models.NFT.findAndCountAll({
limit: 10
});
// console.log(nft);
if (!nft) {
throw new Error("Token ID invalid");
}
// if (nft.isMinted) {
// throw new Error("Token not minted");
// }
// console.log(nft);
// }
var resObjarr = [];
for (var i = 0; i < nft.rows.length; i++) {
resObj = {
name: nft.rows[i].name,
description: nft.rows[i].description,
image: `https://gateway.pinata.cloud/ipfs/${nft.rows[i].image}`,
attributes: [
{ trait_type: "background", value: `${nft.rows[i].background}` },
{ trait_type: "body", value: `${nft.rows[i].body}` },
{ trait_type: "mouth", value: `${nft.rows[i].mouth}` },
{ trait_type: "eyes", value: `${nft.rows[i].eyes}` },
{ trait_type: "tokenId", value: `${nft.rows[i].tokenId}` },
{
display_type: "number",
trait_type: "Serial No.",
value: nft.rows[i].id,
max_value: 1000,
},
],
};
resObjarr.push(resObj);
}
console.log(JSON.stringify(resObjarr))
return res.json(resObjarr);
} catch (error) {
console.log("server error", error.message);
next(error);
}
},
mint: async (req, res, next) => {
try {
const { id } = req.params;
const updated = await models.NFT.findByPk(id);
if (!updated) {
throw new Error("NFT ID invalid");
}
if (updated.isMinted) {
throw new Error("NFT Already minted");
}
updated.isMinted = true;
updated.save();
return res.json({
data: "Token minted successfully",
error: null,
success: true,
});
} catch (error) {
console.log("server error", error.message);
next(error);
}
},
};
Below is from the routes folder.
const router = require("express").Router();
const auth=require("../middleware/auth")
const {
create_nft,
get_nft,
get_nft_all,
mint
} = require("../controller/nft");
router.post(
"/create",
create_nft
);
router.get(
"/metadata/:id",
get_nft
);
router.get(
"/metadata",
get_nft_all
);
router.put(
"/mint/:id",
mint
);
module.exports = router;

Answer 1

Looking your code,you may having some kind of asyncrhonous issue in this part:
parsed.forEach(async (item) => {
// return res.json(item)
let newNft = await models.NFT.create({
name: item.Name,
description: item.Description,
background: item.Background,
body: item.Body,
mouth: item.Mouth,
eyes: item.Eyes,
head_gear: item.Head_Gear,
tokenId: item.tokenId,
image: item.imagesIPFS,
});
});
Because .forEach is a function to be used in synchronous context and NFT.create returns a promise (that is async). So things happens out of order.
So one approach is to process the data first and then perform a batch operation using Promise.all.
const data = parsed.map(item => {
return models.NFT.create({
name: item.Name,
description: item.Description,
background: item.Background,
body: item.Body,
mouth: item.Mouth,
eyes: item.Eyes,
head_gear: item.Head_Gear,
tokenId: item.tokenId,
image: item.imagesIPFS,
})
})
const results = await Promise.all(data)
The main difference here is Promise.all resolves the N promises NFT.create in an async context in paralell. But if you are careful about the number of concurrent metadata that data may be too big to process in parallel, then you can use an async iteration provided by bluebird's Promise.map library.
const Promise = require('bluebird')
const data = await Promise.map(parsed, item => {
return models.NFT.create({
name: item.Name,
description: item.Description,
background: item.Background,
body: item.Body,
mouth: item.Mouth,
eyes: item.Eyes,
head_gear: item.Head_Gear,
tokenId: item.tokenId,
image: item.imagesIPFS,
})
})
return data