Google Data Studio Community Connector getData() not working as expected

Question

function getData(request){
  try{  
  var options = {
  'method' : 'post',
  'contentType': 'application/json',
  'payload' : JSON.stringify(request)
  };
  response=UrlFetchApp.fetch(getDataUrl, options);

  resData = JSON.parse(response.getContentText())

  return resData

  }catch (e) { 
    e = (typeof e === 'string') ? new Error(e) : e;
    Logger.log("Catch", e);
    throw e;
  }
}

The the above is my getData() function.

My isAdminUser() returns true.

When I try to visualize my data, I get the following error

Data Set Configuration Error

Data Studio cannot connect to your data set.

There was an error requesting data from the community connector. Please report the issue to the provider of this community connector if this issue persists.

Error ID: 3d11b88b https://i.sstatic.net/x3Hki.png

The error code changes every time I refresh data and I can't find any dictionary to map the error id to an error

I tried debugging by logging the request parameter, response.getContentText() and resData variable to make sure I my data is formatted correctly.

Following are the logs printed in Stackdriver logs

request

{configParams={/Personal config data/}, fields=[{name=LASTNAME}]}

response.getContentText()

{"schema":[{"name":"LASTNAME","dataType":"STRING"}],"rows":[{"values":["test"]},{"values":["test"]},{"values":["Dummy"]},{"values":["One"]},{"values":["Nagargoje"]},{"values":[""]},{"values":[""]},{"values":[""]},{"values":[""]},{"values":[""]}],"filtersApplied":false}

resData

{rows=[{values=[test]}, {values=[test]}, {values=[Dummy]}, {values=[One]}, {values=[Nagargoje]}, {values=[]}, {values=[]}, {values=[]}, {values=[]}, {values=[]}], filtersApplied=false, schema=[{name=LASTNAME, dataType=STRING}]}

I am not sure what is wrong with my getData() function.

The Object that I am returning seems to match the structure given here https://developers.google.com/datastudio/connector/reference#getdata

Answer 1

So there was no issue with my getData() function, the issue existed in the manifest file. I was searching about passing parameter via URL and I stumbled upon a field called dataStudio.useQueryConfig and added that to my manifest file and set its value to true. Google Data studio was expecting me to return a query Config for getData(). But what I really wanted was this.

Anyways, I was able to debug it thanks to Matthias for suggesting me to take a look at Open-Source implementations

I implemented JSON connect which worked fine, so I Logged what it was returning in getData() and used that format/structure in my code, but my connector still didn't work.

My next assumption was maybe there is something wrong with my getSchema() return value. So I logged that as well and then copy pasted the hard coded value of both getData() and getSchema() return varaibles from JSON connect.

And even that didn't work, so my last bet was there must be something wrong with the manifest file, maybe the dummy links I added in it must be the issue. Then, after carrying out field by comparison I was finally able to get my community connector working.

This would have been easier to debug if the error messages were a bit helpful and didn't seem so generic.

Answer 2

First: You can always check out the Open-Source implementations that others did for custom Google Data Studio connectors. They are a great source if information. Fore more information checkout the documentation on Open Source Community Connectors.

Second: My implementation is for a time tracking system thus having confidential GDPR relevant data. That's why I can not just give you response messages. But I assembled this code. It contains authentifiction, HTTP GET data fetch and data conversions. Explanation is below the code. Again, checkout the open-source connectors if you need further assistance.

var cc = DataStudioApp.createCommunityConnector();

const URL_DATA = 'https://www.myverysecretdomain.com/api';
const URL_PING = 'https://www.myverysecretdomain.com/ping';
const AUTH_USER = 'auth.user'
const AUTH_KEY = 'auth.key';
const JSON_TAG = 'user';

String.prototype.format = function() {
  // https://coderwall.com/p/flonoa/simple-string-format-in-javascript
  a = this;
  for (k in arguments) {
    a = a.replace("{" + k + "}", arguments[k])
  }
  return a
}

function httpGet(user, token, url, params) {
  try {
    // this depends on the URL you are connecting to
    var headers = {
      'ApiUser': user,
      'ApiToken': token,
      'User-Agent': 'my super freaky Google Data Studio connector'
    };

    var options = {
      headers: headers
    };

    if (params && Object.keys(params).length > 0) {
      var params_ = [];
      for (const [key, value] of Object.entries(params)) {
        var value_ = value;
        if (Array.isArray(value))
          value_ = value.join(',');

        params_.push('{0}={1}'.format(key, encodeURIComponent(value_)))
      }

      var query = params_.join('&');
      url = '{0}?{1}'.format(url, query);
    }

    var response = UrlFetchApp.fetch(url, options);

    return {
      code: response.getResponseCode(),
      json: JSON.parse(response.getContentText())
    }  
  } catch (e) {
    throwConnectorError(e);
  }
}

function getCredentials() {
  var userProperties = PropertiesService.getUserProperties();
  return {
    username: userProperties.getProperty(AUTH_USER),
    token: userProperties.getProperty(AUTH_KEY)
  }
}

function validateCredentials(user, token) {
  if (!user || !token) 
    return false;

  var response = httpGet(user, token, URL_PING);

  if (response.code == 200)
    console.log('API key for the user %s successfully validated', user);
  else
    console.error('API key for the user %s is invalid. Code: %s', user, response.code);

  return response;
}  

function getAuthType() {
  var cc = DataStudioApp.createCommunityConnector();
  return cc.newAuthTypeResponse()
    .setAuthType(cc.AuthType.USER_TOKEN)
    .setHelpUrl('https://www.myverysecretdomain.com/index.html#authentication')
    .build();
}

function resetAuth() {
  var userProperties = PropertiesService.getUserProperties();
  userProperties.deleteProperty(AUTH_USER);
  userProperties.deleteProperty(AUTH_KEY);

  console.info('Credentials have been reset.');
}

function isAuthValid() {
  var credentials = getCredentials()
  if (credentials == null) {
    console.info('No credentials found.');
    return false;
  }

  var response = validateCredentials(credentials.username, credentials.token);
  return (response != null && response.code == 200);
}

function setCredentials(request) {
  var credentials = request.userToken;
  var response = validateCredentials(credentials.username, credentials.token);

  if (response == null || response.code != 200) return { errorCode: 'INVALID_CREDENTIALS' };

  var userProperties = PropertiesService.getUserProperties();
  userProperties.setProperty(AUTH_USER, credentials.username);
  userProperties.setProperty(AUTH_KEY, credentials.token);

  console.info('Credentials have been stored');

  return {
    errorCode: 'NONE'
  };
}

function throwConnectorError(text) {
  DataStudioApp.createCommunityConnector()
    .newUserError()
    .setDebugText(text)
    .setText(text)
    .throwException();
}

function getConfig(request) {
  // ToDo: handle request.languageCode for different languages being displayed
  console.log(request)

  var params = request.configParams;
  var config = cc.getConfig();

  // ToDo: add your config if necessary

  config.setDateRangeRequired(true);
  return config.build();
}

function getDimensions() {
  var types = cc.FieldType;

  return [
    {
      id:'id',
      name:'ID',
      type:types.NUMBER
    },
    {
      id:'name',
      name:'Name',
      isDefault:true,
      type:types.TEXT
    },
    {
      id:'email',
      name:'Email',
      type:types.TEXT
    }
  ];
}

function getMetrics() {
  return [];
}

function getFields(request) {
  Logger.log(request)

  var fields = cc.getFields();

  var dimensions = this.getDimensions();
  var metrics = this.getMetrics();
  dimensions.forEach(dimension => fields.newDimension().setId(dimension.id).setName(dimension.name).setType(dimension.type));  
  metrics.forEach(metric => fields.newMetric().setId(metric.id).setName(metric.name).setType(metric.type).setAggregation(metric.aggregations));

  var defaultDimension = dimensions.find(field => field.hasOwnProperty('isDefault') && field.isDefault == true);
  var defaultMetric = metrics.find(field => field.hasOwnProperty('isDefault') && field.isDefault == true);

  if (defaultDimension)
    fields.setDefaultDimension(defaultDimension.id);
  if (defaultMetric)
    fields.setDefaultMetric(defaultMetric.id);

  return fields;
}

function getSchema(request) {
  var fields = getFields(request).build();
  return { schema: fields };
}

function convertValue(value, id) {  
  // ToDo: add special conversion if necessary
  switch(id) {      
    default:
      // value will be converted automatically
      return value[id];
  }
}

function entriesToDicts(schema, data, converter, tag) {

  return data.map(function(element) {

    var entry = element[tag];
    var row = {};    
    schema.forEach(function(field) {

      // field has same name in connector and original data source
      var id = field.id;
      var value = converter(entry, id);

      // use UI field ID
      row[field.id] = value;
    });

    return row;
  });
}

function dictsToRows(requestedFields, rows) {
  return rows.reduce((result, row) => ([...result, {'values': requestedFields.reduce((values, field) => ([...values, row[field]]), [])}]), []);
}

function getParams (request) { 
  var schema = this.getSchema();
  var params;

  if (request) {
    params = {};

    // ToDo: handle pagination={startRow=1.0, rowCount=100.0}
  } else {
    // preview only
    params = {
      limit: 20
    }
  }

  return params;
}

function getData(request) {
  Logger.log(request)

  var credentials = getCredentials()
  var schema = getSchema();
  var params = getParams(request);

  var requestedFields;  // fields structured as I want them (see above)
  var requestedSchema;  // fields structured as Google expects them
  if (request) {
    // make sure the ordering of the requested fields is kept correct in the resulting data
    requestedFields = request.fields.filter(field => !field.forFilterOnly).map(field => field.name);
    requestedSchema = getFields(request).forIds(requestedFields);
  } else {
    // use all fields from schema
    requestedFields = schema.map(field => field.id);
    requestedSchema = api.getFields(request);
  }

  var filterPresent = request && request.dimensionsFilters;
  //var filter = ...
  if (filterPresent) {
    // ToDo: apply request filters on API level (before the API call) to minimize data retrieval from API (number of rows) and increase speed
    // see https://developers.google.com/datastudio/connector/filters

    // filter = ...   // initialize filter
    // filter.preFilter(params);  // low-level API filtering if possible
  }

  // get HTTP response; e.g. check for HTTT RETURN CODE on response.code if necessary
  var response = httpGet(credentials.username, credentials.token, URL_DATA, params);  

  // get JSON data from HTTP response
  var data = response.json;

  // convert the full dataset including all fields (the full schema). non-requested fields will be filtered later on  
  var rows = entriesToDicts(schema, data, convertValue, JSON_TAG);

  // match rows against filter (high-level filtering)
  //if (filter)
  //  rows = rows.filter(row => filter.match(row) == true);

  // remove non-requested fields
  var result = dictsToRows(requestedFields, rows);

  console.log('{0} rows received'.format(result.length));
  //console.log(result);

  return {
    schema: requestedSchema.build(),
    rows: result,
    filtersApplied: filter ? true : false
  };
}

A sample request that filters for all users with names starting with J.

{
    configParams={}, 
    dateRange={
        endDate=2020-05-14, 
        startDate=2020-04-17
    }, 
    fields=[
        {name=name}
    ], 
    scriptParams={
        lastRefresh=1589543208040
    }, 
    dimensionsFilters=[
        [
            {
                values=[^J.*], 
                operator=REGEXP_EXACT_MATCH, 
                type=INCLUDE, 
                fieldName=name
            }
        ]
    ]
}

The JSON data returned by the HTTP GET contains all fields (full schema).

[ { user: 
     { id: 1,
       name: 'Jane Doe',
       email: 'jane@doe.com' } },
  { user: 
     { id: 2,
       name: 'John Doe', 
       email: 'john@doe.com' } }
]

Once the data is filtered and converted/transformed, you'll get this result, which is perfectly displayed by Google Data Studio:

{
    filtersApplied=true, 
    schema=[
        {
            isDefault=true, 
            semantics={
                semanticType=TEXT, 
                conceptType=DIMENSION
            }, 
            label=Name, 
            name=name, 
            dataType=STRING
        }
    ], 
    rows=[
        {values=[Jane Doe]}, 
        {values=[John Doe]}
    ]
}

Answer 3

getData should return data for only the requested fields. In request.fields should have the list of all requested fields. Limit your data for those fields only and then send the parsed data back.