AirtableGoogleTranslatorApp.js

//select source langauge using ISO 2 letter code
let source = "en";

// Translate API key
let key="YourAPIcodeHere";  // <= change your API here

// Select table
let table = await input.tableAsync('Select table');

// Get language list from columns
let fields = [];
for (let field of table.fields) {
    if (field.name !== "plugin_name" && field.name !== "text_name" && field.name !== "text_code"  ){
      fields.push(field.name);
    }
    
}
//console.log(fields);

//set counter for total
let counter = 0;

//iterate over all columns/fields with all languages
for (let field of fields){

  //get records data for Name and selected Language only
  let records = await table.selectRecordsAsync({fields:["text_code", field]});
  //output.inspect(records);

  //select records for selected language where language field is empty and 
  //text _code(translation text) exists
  let nonEmptyRecords = records.records.filter(record => {
      let target = record.getCellValue(field);
      let source = record.getCellValue('text_code');
      return !target && source;
  });
  //console.log(nonEmptyRecords.length);

  //convert to simple array with records to translate
  let recordsToTranslate =  [];

  for (let record of nonEmptyRecords)
  {
      recordsToTranslate.push({
        "id" : record.id,
        "name" : record.getCellValue("text_code")
      });
  }
  let totalNumberToTranslate = recordsToTranslate.length;
  if (totalNumberToTranslate === 0) {
    output.markdown(`Skipping ${field} no missing translations.`);
    continue;
  }
  output.markdown(`Translating ${totalNumberToTranslate} records to ${field}`);
  //output.inspect(recordsToTranslate)

  //prepare variables for http fetch request to API
  let q = [];
  let target = field.split("_")[0];  // changing locale ( BCP 47 ) to  ISO 639-1
  let url=`https://translation.googleapis.com/language/translate/v2?format=text&${source}=en&key=${key}&target=${target}`;


  // batch translate and update records in increments of 50
  while (recordsToTranslate.length > 0) {

    //prepare batch of 50
    let batch = recordsToTranslate.slice(0, 50);
    q = batch.map(recordsToTranslate => recordsToTranslate.name);
    //output.inspect(batch);

    // json for fetch request
    let data = {
        "q": q
    };

    //fetch POST request with all params
    let apiResponse = await fetch(url,{
        method: 'POST', // *GET, POST, PUT, DELETE, etc.
        mode: 'cors', // no-cors, *cors, same-origin
        //cache: 'no-cache', // *default, no-cache, reload, force-cache, only-if-cached
        //credentials: 'same-origin', // include, *same-origin, omit
        //headers: {
        //  'Content-Type': 'application/json'
          // 'Content-Type': 'application/x-www-form-urlencoded',
        //},
        redirect: 'follow', // manual, *follow, error
        referrerPolicy: 'no-referrer', // no-referrer, *no-referrer-when-downgrade, origin, origin-when-cross-origin, same-origin, strict-origin, strict-origin-when-cross-origin, unsafe-url
        body: JSON.stringify(data) // body data type must match "Content-Type" header
      });


    //extract translation array from the response
    let response = await apiResponse.json();
    response = response.data.translations ;
    //output.inspect(response);

    //create batch of records to update
    let updateRecords =[];
    for (let i = 0; i < batch.length; i++) {
      
      updateRecords.push({
        id: batch[i].id,
        fields: { 
              [field]: response[i].translatedText
        }
      });
      

    }

    //update airtable for empty records
    await table.updateRecordsAsync(updateRecords);
    
    recordsToTranslate = recordsToTranslate.slice(50);
    output.text(`Updated ${totalNumberToTranslate-recordsToTranslate.length}/${totalNumberToTranslate} records`);

  }

 counter++; 
}

output.markdown(`**Updated total ${counter} languages.**`);