is there a way to get string (data) from text file stored in s3 in Alexa localisation.js file? - amazon-web-services

Question

Problem:
I am trying to get the data from a text file stored in s3, I get it right in intent handler using a sync await but I want to get string in localisation file as I am trying to implement the solution in 2 languages.
I am getting err saying skill does not respond correctly.
This is file.js
const AWS = require('aws-sdk');
//========================
// This step is not required if you are running your code inside lambda or in
// the local environment that has AWS set up
//========================
const s3 = new AWS.S3();
async function getS3Object (bucket, objectKey) {
try {
const params = {
Bucket: 'my-bucket',
Key: 'file.txt',
};
const data = await s3.getObject(params).promise();
let dat = data.Body.toString('utf-8');
return dat;
} catch (e) {
throw new Error(`Could not retrieve file from S3: ${e.message}`);
}
}
module.exports = getS3Object;
this is the localisation.js file code
const dataText = require('file.js');
async let textTitle = await dataText().then(); **// this does not work**
module.exports = {
en: {
translation: {
WELCOME_BACK_MSG : textTitle,
}
},
it: {
translation: {
WELCOME_MSG: textTitle,
}
}
}

Answer 1

The problem is that in your localisation.js file you are trying to export something that is obtained via an asynchronous function call, but you cannot do that directly, module.exports is assigned and returned synchronously. Please, see for instance this SO question and answer for an in-deep background.
As you are mentioning Alexa skill, and for the name of the file, localisation.js, I assume you are trying something similar to the solution proposed in this GitHub repository.
Analyzing the content of the index.js file they provide, it seems the library is using i18next for localisation.
The library provides the concept of backend if you need to load your localisation information from an external resource.
You can implement a custom backend, although the library offers one that could fit your needs, i18next-http-backend.
As indicated in the documentation, you can configure the library to fetch your localization resources with this backend with something like the following:
import i18next from 'i18next';
import Backend from 'i18next-http-backend';
i18next
.use(Backend)
.init({
backend: {
// for all available options read the backend's repository readme file
loadPath: '/locales/{{lng}}/{{ns}}.json'
}
});
Here in SO you can find a more complete example.
You need to provide a similar configuration to the localisation interceptor provided in the Alexa skill example project, perhaps something like:
import HttpApi from 'i18next-http-backend';
/**
* This request interceptor will bind a translation function 't' to the handlerInput
*/
const LocalizationInterceptor = {
process(handlerInput) {
const localisationClient = i18n
.use(HttpApi)
.init({
lng: Alexa.getLocale(handlerInput.requestEnvelope),
// resources: languageStrings,
backend: {
loadPath: 'https://your-bucket.amazonaws.com/locales/{{lng}}/translations.json',
crossDomain: true,
},
returnObjects: true
});
localisationClient.localise = function localise() {
const args = arguments;
const value = i18n.t(...args);
if (Array.isArray(value)) {
return value[Math.floor(Math.random() * value.length)];
}
return value;
};
handlerInput.t = function translate(...args) {
return localisationClient.localise(...args);
}
}
};
Please, be aware that instead of a text file you need to return a valid son file with the appropriate translations:
{
"WELCOME_MSG" : "Welcome!!",
"WELCOME_BACK_MSG" : "Welcome back!!"
}