WDC Promise Samples

install-promise.html

<script src="es6-promise.min.js"></script>
<script src="jquery.min.js"></script>
<script src="wdc-sdk.js"></script>
<script src="your_wdc.js"></script>

thread-of-execution-loop.js

var pageNumbers = [1, 2, 3],
    allResults = [];

// Loop through all pages.
pageNumbers.forEach(function (page) {
  $.getJSON('https://api.example.com?page=' + page, function (response) {
    console.log('Later: Got data for page ' + page);
    allResults.push(response.records);
  });
});

console.log('First: No data yet!');

thread-of-execution.js

$.getJSON('https://api.example.com', function (response) {
  // Executed later, once api.example.com responds with data.
  console.log('Second: Just got data!');
});

// Executed immediately, even before the API responds.
console.log('First: No data yet!');

wdc-naive-promise.js

// Return a Promise for the given URL.
var returnApiDataFor = function(url) {
  return new Promise(function(fulfill, reject) {
    // When the promise is invoked, send the request.
    $.getJSON(url, function (response) {
      // Fulfill the promise with data returned.
      fulfill(response.records);
    });
  });
};

// Invoke the promise for a given URL.
returnApiDataFor('https://api.example.com')
  // Once the promise is fulfilled...
  .then(function (records) {
    // Pass data to Tableau.
    tableau.dataCallback(records);
  });

wdc-no-promise.js

myConnector.getTableData = function(lastRecordToken) {
  // If Tableau gave a page, use it. But default to 1.
  var pageNumber = lastRecordToken ? lastRecordToken + 1 : 1;

  // Load this page of data from the API.
  $.getJSON('https://api.example.com?page=' + pageNumber, function (response) {
    // Check if the current page is not the last page.
    var hasMoreData = pageNumber < response.metadata.lastPage;

    // Pass data and current page back to Tableau. If
    // hasMoreData evaluated to TRUE, Tableau will call
    // getTableData again using this pageNumber value.
    tableau.dataCallback(response.records, pageNumber, hasMoreData);
  });
}

wdc-promise-all.js

// Use the same Promise return helper from above.
var returnApiDataFor = function(url) {
  return new Promise(function(fulfill, reject) {
    $.getJSON(url, function (response) {
      fulfill(response.records);
    });
  });
};

// Define a helper to map a URL and page list to Promises.
var allPromisesFor = function(baseUrl, pages) {
  // Map each page to a URL wrapped in a Promise to retrieve its data.
  return pages.map(function(pageNumber) {
    return returnApiDataFor(baseUrl + '?page=' + pageNumber);
  });
};

// Invoke all Promises for a given base URL and pages.
Promise.all(allPromisesFor('https://api.example.com', [1, 2, 3])
  // Once all promises are fulfilled...
  .then(function (recordSet) {
    var allRecords = [];

    // Concatenate / union all page responses to a single array.
    recordSet.forEach(function(records) {
      allRecords = allRecords.concat(records);
    });

    // Pass the complete data set to Tableau.
    tableau.dataCallback(allRecords);
  });

Hi is there any more information on how this could be used in a complete example? Promises are already confusing enough, so i can't figure out how i would incorporate promises into a really basic WDC that works of the tableau examples. How exact would the my.connector.getData change when using promises, do you still keep the table structure?