@zeroid/trimble.identity.clientcredentialtokenprovider/ClientCredentialTokenProvider.js

An implementation of ITokenProvider for OAuth client credential grant type

// implements ITokenProvider
(function (root, factory) {
    if (typeof define === 'function' && define.amd) {
        // AMD
        define(['@zeroid/trimble.httpclient'], factory);
    } else if (typeof exports === 'object') {
        // CommonJS
        module.exports = factory(require('@zeroid/trimble.httpclient'));
    } else {
        // Browser globals (Note: root is window)
        root.ClientCredentialTokenProvider = factory(root.HttpClient);
    }
}(this, function (HttpClient) {

    var _clientCredentialTokenProvider = function (endpointProvider, consumerKey, consumerSecret) {
        this._endpointProvider = endpointProvider;
        this._consumerKey = consumerKey;
        this._consumerSecret = consumerSecret;
        this._accessToken = null;
        this._tokenExpiry = new Date(0);
    }

    _clientCredentialTokenProvider.prototype._refreshToken = function () {
        var self = this;
        return new Promise(function (resolve, reject) {
            self._endpointProvider.retrieveTokenEndpoint()
                .then((endpoint) => {
                    var basicHeader = 'Basic ' + btoa(self._consumerKey + ':' + self._consumerSecret);
                    var requestSettings = {
                        headers: {
                            authorization: basicHeader,
                            "content-type": 'application/x-www-form-urlencoded',
                            accept: 'application/json'
                        }
                    };
                    var content = 'grant_type=client_credentials';
                    new HttpClient().httpPost(endpoint, content, requestSettings)
                        .then((json) => {
                            var result = JSON.parse(json);
                            self._accessToken = result.access_token;
                            var now = new Date();
                            self._tokenExpiry = new Date(now.getTime() + result.expires_in*1000);
                            resolve();
                        })
                        .catch(() => { reject(); })
                })
                .catch(() => { reject(); });
        });
    };

    _clientCredentialTokenProvider.prototype.retrieveToken = function () {
        var self = this;
        return new Promise(function (resolve, reject) {
            if (self._tokenExpiry < new Date())
                self._refreshToken()
                    .then(() => { resolve(self._accessToken); })
                    .catch(() => { reject(); });
            else
                resolve(this._accessToken);
        });
    };

    // Exposed public methods
    return _clientCredentialTokenProvider;
}));