linkedin_server.js

var Oauth = Package.oauth.Oauth;

var urlUtil = Npm.require('url');

Oauth.registerService('linkedin', 2, null, function(query) {

  var response = getTokenResponse(query);
  var accessToken = response.accessToken;
  var identity = getIdentity(accessToken);
  var profileUrl = identity.siteStandardProfileRequest.url;
  var urlParts = urlUtil.parse(profileUrl, true);

  var serviceData = {
    id: urlParts.query.id || Random.id(),
    accessToken: accessToken,
    expiresAt: (+new Date) + (1000 * response.expiresIn)
  };

  var whiteListed = ['firstName', 'headline', 'lastName'];

  // include all fields from linkedin
  // https://developer.linkedin.com/documents/authentication
  var fields = _.pick(identity, whiteListed);

  // list of extra fields
  // http://developer.linkedin.com/documents/profile-fields
  var extraFields = 'email-address,location:(name),num-connections,picture-url,public-profile-url,skills,languages,three-current-positions,recommendations-received';

  // remove the whitespaces which could break the request
  extraFields = extraFields.replace(/\s+/g, '');

  fields = getExtraData(accessToken, extraFields, fields);

  _.extend(serviceData, fields);
  
  fields.name = identity.firstName + ' ' + identity.lastName;

  return {
    serviceData: serviceData,
    options: {
      profile: fields
    }
  };
});

var getExtraData = function(accessToken, extraFields, fields) {
  var url = 'https://api.linkedin.com/v1/people/~:(' + extraFields + ')';
  var response = Meteor.http.get(url, {
    params: {
      oauth2_access_token: accessToken,
      format: 'json'
    }
  }).data;
  return _.extend(fields, response);
}

// checks whether a string parses as JSON
var isJSON = function (str) {
  try {
    JSON.parse(str);
    return true;
  } catch (e) {
    return false;
  }
}

// returns an object containing:
// - accessToken
// - expiresIn: lifetime of token in seconds
var getTokenResponse = function (query) {
  var config = ServiceConfiguration.configurations.findOne({service: 'linkedin'});
  if (!config)
    throw new ServiceConfiguration.ConfigError("Service not configured");

  var responseContent;
  try {
    // Request an access token
    responseContent = Meteor.http.post(
      "https://api.linkedin.com/uas/oauth2/accessToken", {
        params: {
          grant_type: 'authorization_code',
          client_id: config.clientId,
          client_secret: config.secret,
          code: query.code,
          redirect_uri: Meteor.absoluteUrl("_oauth/linkedin?close")
        }
      }).content;
  } catch (err) {
    throw new Error("Failed to complete OAuth handshake with LinkedIn. " + err.message);
  }

  // If 'responseContent' does not parse as JSON, it is an error.
  if (!isJSON(responseContent)) {
    throw new Error("Failed to complete OAuth handshake with LinkedIn. " + responseContent);
  }

  // Success! Extract access token and expiration
  var parsedResponse = JSON.parse(responseContent);
  var accessToken = parsedResponse.access_token;
  var expiresIn = parsedResponse.expires_in;

  if (!accessToken) {
    throw new Error("Failed to complete OAuth handshake with LinkedIn " +
      "-- can't find access token in HTTP response. " + responseContent);
  }

  return {
    accessToken: accessToken,
    expiresIn: expiresIn
  };
};

var getIdentity = function (accessToken) {
  try {
    return Meteor.http.get("https://www.linkedin.com/v1/people/~", {
      params: {oauth2_access_token: accessToken, format: 'json'}}).data;
  } catch (err) {
    throw new Error("Failed to fetch identity from LinkedIn. " + err.message);
  }
};

LinkedIn.retrieveCredential = function(credentialToken) {
  return Oauth.retrieveCredential(credentialToken);
};