After creating a tableau webconnector to extract data from an internal API, I used earthquakeUSGS.html as a reference (https://github.com/tableau/webdataconnector). The API responds with json data (see code below). Utilizing the "Web data connector simulator 2.0" was smooth until I encountered an issue with fetching table data. Being new to JavaScript, I suspect that my error lies in the script itself. To navigate through the data, I followed Korijn's advice on iterating through nested JSON object arrays on this post: https://stackoverflow.com/questions/15268594/iterate-through-nested-json-object-array
The Issue: It is likely related to the JavaScript iterator navigating over the json objects. If someone could review the json data (below) and examine my iterator, it would be greatly appreciated as this hurdle prevents me from successfully fetching the necessary data.
test.js
(function() {
// Creating the connector object
var myConnector = tableau.makeConnector();
// Defining the schema
myConnector.getSchema = function(schemaCallback) {
var cols = [{
id: "prog",
alias: "PrognosisTime",
dataType: tableau.dataTypeEnum.string
}, {
id: "start",
alias: "Start",
dataType: tableau.dataTypeEnum.date
}, {
id: "val",
alias: "Value",
dataType: tableau.dataTypeEnum.float
}];
var tableSchema = {
id: "table",
alias: "187",
columns: cols
};
schemaCallback([tableSchema]);
};
// Data retrieval process
myConnector.getData = function(table, doneCallback) {
$.getJSON("http://myapi.com/119%2C7777/Flattened?start=today&end=today&timeZone=CET&asOf=now&aggregation=None", function(resp) {
var feat = resp.features,
tableData = [];
tableData.push(
{"table":feat.properties.table}
);
// Iterating over the JSON object
//var SeriesId = feat.SeriesId
for(var i = 0; i <feat.DataPoints.length; i++){
var PrognosisTime = feat.DataPoints.PrognosisTime;
var Start = feat.DataPoints.Start;
var Value = feat.DataPoints.Value;
}
table.appendRows(tableData);
doneCallback();
});
};
tableau.registerConnector(myConnector);
// Event listeners upon form submission by user
$(document).ready(function() {
$("#submitButton").click(function() {
tableau.connectionName = "Neas"; // This will be the data source name in Tableau
tableau.submit(); // Sends the connector object to Tableau
});
});
})();
json from API
[
{
"SeriesId": 119,
"DataPoints": [
{
"PrognosisTime": null,
"Start": "2016-08-24T00:00:00",
"Value": 26.19
},
{
"PrognosisTime": null,
"Start": "2016-08-24T01:00:00",
"Value": 23.9
},
{
"PrognosisTime": null,
"Start": "2016-08-24T02:00:00",
"Value": 22.82
}
]
},
{
"SeriesId": 7777,
"DataPoints": [
{
"PrognosisTime": null,
"Start": "2016-08-24T00:00:00",
"Value": 36.39
},
{
"PrognosisTime": null,
"Start": "2016-08-24T00:15:00",
"Value": 28.81
},
{
"PrognosisTime": null,
"Start": "2016-08-24T00:30:00",
"Value": 24.28
}
]
}
]