I am using the google translate api to translate data from a json file to french locale and then write it back to a file. I am using a recursive function to iterate over the json file since it is deeply nested. However the execution is not waiting till the translation is completed before it writes to the file. I have tried using callback and promise approaches but i couldn't get it right.
Just for it to work as I required an output as an emergency I have set a timout before the write method is called. It work but I would like to learn the appropriate/correct approach to implement this.
const fs = require('fs')
const {Translate} = require('@google-cloud/translate').v2
require('dotenv').config()
process.env['NODE_TLS_REJECT_UNAUTHORIZED'] = 0
const credentials = JSON.parse(process.env.credentials)
const translate = new Translate({
credentials,
projectId: credentials.project_id,
})
let data = {}
// writeJSONTofile should be executed only after readJSONFile execution is completed
//read file
const readJSONFile = () => {
try {
data = JSON.parse(fs.readFileSync('...\\locale\\en.json'))
iterateAndTranslate(data)
setTimeout(() => {
writeJSONToFile()
}, 25000)
} catch (error) {
console.log(error)
}
}
// iterate, translate, reassign
const iterateAndTranslate = async (data) => {
for(key in data) {
if (typeof data[key] === 'object' && data[key] !== null) {
iterateAndTranslate(data[key])
} else{
data[key] = await translateText(data[key], 'fr')
}
}
}
//translate method
const translateText = async (text, targetLanguage) => {
try {
let [response] = await translate.translate(text, targetLanguage)
return response
} catch (error) {
console.log(error)
return 0
}
}
const writeJSONToFile = async () => {
var outputFileName = 'C:\\test\\test.json'
await fs.writeFileSync(outputFileName, JSON.stringify(data,null,4), (err) => {
if(err) {
console.log(err)
} else {
console.log('Done!')
}
})
}
// start from here
readJSONFile()
You have a few issues with your code.
global variable and mutate it instead of getting input and returning output.varasync-await on the writeJSONToFile functionSee my view of point about the possible solution.
const fs = require("fs");
const { Translate } = require("@google-cloud/translate").v2;
require("dotenv").config();
process.env["NODE_TLS_REJECT_UNAUTHORIZED"] = 0;
const credentials = JSON.parse(process.env.credentials);
const translate = new Translate({
credentials,
projectId: credentials.project_id,
});
// writeJSONTofile should be executed only after readJSONFile execution is completed
//read file
const readJSONFile = async () => {
try {
const data = JSON.parse(fs.readFileSync("...\\locale\\en.json"));
return iterateAndTranslate(data);
} catch (error) {
console.log(error);
}
return {};
};
// iterate, translate, reassign
const iterateAndTranslate = async (data) => {
for (let key in data) {
if (typeof data[key] === "object" && data[key] !== null) {
await iterateAndTranslate(data[key]);
} else {
data[key] = await translateText(data[key], "fr");
}
}
return data;
};
//translate method
const translateText = async (text, targetLanguage) => {
try {
let [response] = await translate.translate(text, targetLanguage);
return response;
} catch (error) {
console.log(error);
}
return null;
};
const writeJSONToFile = (data) => {
let outputFileName = "C:\\test\\test.json";
fs.writeFileSync(outputFileName, JSON.stringify(data, null, 4), (err) => {
if (err) {
console.log(err);
} else {
console.log("Done!");
}
});
};
// start from here
const run = async () => {
const data = await readJSONFile();
writeJSONToFile(data);
};
run();
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