<section>
    <title>Pure Client Javascript Adapter</title>
    <para>
        The Keycloak Server comes with a Javascript library you can use to secure pure HTML/Javascript applications.  It
        works in the same way as other application adapters except that your browser is driving the OAuth redirect protocol
        rather than the server.
    </para>
    <para>
        The
        disadvantage of using this approach is that you end up having a non-confidential, public client.  This can be mitigated
        by registering valid redirect URLs.  You are still vulnerable if somebody hijacks the IP/DNS name of your pure
        HTML/Javascript application though.
    </para>
    <para>
        To use this adapter, you must first configure an application (or client) through the <literal>Keycloak Admin Console</literal>.
        You should select <literal>public</literal> for the <literal>Client Type</literal> field. As public clients can't
        be verified with a client secret you are required to configure one or more valid redirect uris as well.
        Once you've configured the application click on the <literal>Installation</literal> tab and download the <literal>keycloak.json</literal>
        file. This file should be hosted in your web-server at the same root as your HTML pages. Alternatively you can either
        specify the URL for this file, or manually configure the adapter.
    </para>
    <para>
        Next you have to initialize the adapter in your application. An example on how to do this is shown below.
<programlisting><![CDATA[
<head>
    <script src="http://<keycloak server>/auth/js/keycloak.js"></script>
    <script>
        var keycloak = Keycloak();
        keycloak.init().success(function(authenticated) {
            alert(authenticated ? 'authenticated' : 'not authenticated');
        }).error(function() {
            alert('failed to initialize');
        });
    </script>
</head>
]]></programlisting>
        To specify the location of the keycloak.json file:
<programlisting><![CDATA[
var keycloak = Keycloak('http://localhost:8080/myapp/keycloak.json'));
]]></programlisting>
        Or finally to manually configure the adapter:
        <programlisting><![CDATA[
var keycloak = Keycloak({
    url: 'http://keycloak-server/auth',
    realm: 'myrealm',
    clientId: 'myapp'
});
]]></programlisting>
        You can also pass <literal>login-required</literal> or <literal>check-sso</literal> to the init function. Login
        required will redirect to the login form on the server, while check-sso will redirect to the auth server to check
        if the user is already logged in to the realm. For example:
<programlisting><![CDATA[
keycloak.init('login-required')
]]></programlisting>
    </para>

    <para>
        After you login, your application will be able to make REST calls using bearer token authentication.  Here's
        an example pulled from the <literal>customer-portal-js</literal> example that comes with the distribution.
<programlisting><![CDATA[
<script>
    var loadData = function () {
        document.getElementById('username').innerText = keycloak.username;

        var url = 'http://localhost:8080/database/customers';

        var req = new XMLHttpRequest();
        req.open('GET', url, true);
        req.setRequestHeader('Accept', 'application/json');
        req.setRequestHeader('Authorization', 'Bearer ' + keycloak.token);

        req.onreadystatechange = function () {
            if (req.readyState == 4) {
                if (req.status == 200) {
                    var users = JSON.parse(req.responseText);
                    var html = '';
                    for (var i = 0; i < users.length; i++) {
                        html += '<p>' + users[i] + '</p>';
                    }
                    document.getElementById('customers').innerHTML = html;
                    console.log('finished loading data');
                }
            }
        }

        req.send();
    };

    var loadFailure = function () {
        document.getElementById('customers').innerHTML = '<b>Failed to load data.  Check console log</b>';

    };

    var reloadData = function () {
        keycloak.updateToken().success(loadData).error(loadFailure);
    }
</script>

<button onclick="loadData()">Submit</button>
]]></programlisting>
     </para>
    <para>
        The <literal>loadData()</literal> method builds an HTTP request setting the <literal>Authorization</literal>
        header to a bearer token.  The <literal>keycloak.token</literal> points to the access token the browser obtained
        when it logged you in.  The <literal>loadFailure()</literal> method is invoked on a failure.  The <literal>reloadData()</literal>
        function calls <literal>keycloak.onValidAccessToken()</literal> passing in the <literal>loadData()</literal> and
        <literal>loadFailure()</literal> callbacks.  The <literal>keycloak.onValidAcessToken()</literal> method checks to
        see if the access token hasn't expired.  If it hasn't, and your oauth login returned a refresh token, this method
        will refresh the access token.  Finally, if successful, it will invoke the success callback, which in this case
        is the <literal>loadData()</literal> method.
    </para>

    <para>
        To refresh the token if it's expired call the <literal>updateToken</literal> method. This method returns a promise
        object which can be used to invoke a function on success or failure. This method can be used to wrap functions
        that should only be called with a valid token. For example the following method will refresh the token if it
        expires within 30 seconds, and then invoke the specified function. If the token is valid for more than 30 seconds it
        will just call the specified function.
<programlisting><![CDATA[
keycloak.updateToken(30).success(function() {
    // send request with valid token
}).error(function() {
    alert('failed to refresh token');
);
]]></programlisting>
    </para>

    <section>
        <title>JavaScript Adapter reference</title>

        <section>
            <title>Constructor</title>
<programlisting><![CDATA[
new Keycloak();
new Keycloak('http://localhost/keycloak.json');
new Keycloak({ url: 'http://localhost/auth', realm: 'myrealm', clientId: 'myApp' });
]]></programlisting>
        </section>

        <section>
            <title>Properties</title>

            <itemizedlist>
                <listitem>authenticated - true if the user is authenticated</listitem>
                <listitem>token - the base64 encoded token that can be sent in the <literal>Authorization</literal> header in requests to services</listitem>
                <listitem>tokenParsed - the parsed token</listitem>
                <listitem>subject - the user id</listitem>
                <listitem>idToken - the id token if claims is enabled for the application, null otherwise</listitem>
                <listitem>realmAccess - the realm roles associated with the token</listitem>
                <listitem>resourceAccess - the resource roles assocaited with the token</listitem>
                <listitem>refreshToken - the base64 encoded token that can be used to retrieve a new token</listitem>
                <listitem>refreshTokenParsed - the parsed refresh token</listitem>
            </itemizedlist>
        </section>

        <section>
            <title>Methods</title>

            <itemizedlist>
                <listitem>init - called to initialize the adapter. Returns promise to set functions to be invoked on success or error</listitem>
                <listitem>login(options) - redirects to login form on (options is an optional object with redirectUri and/or prompt fields)</listitem>
                <listitem>createLoginUrl(options) - returns the url to login form on (options is an optional object with redirectUri and/or prompt fields)</listitem>
                <listitem>logout(options) - redirects to logout (options is an optional object with redirectUri)</listitem>
                <listitem>createLogoutUrl(options) - returns the url to logout (options is an optional object with redirectUri)</listitem>
                <listitem>accountManagement - redirects to account management</listitem>
                <listitem>createAccountUrl - returns the url to account management</listitem>
                <listitem>hasRealmRole(role) - returns true if the token has the given realm role</listitem>
                <listitem>hasResourceRole(role, resource) - returns true if the token has the given role for the resource (resource is optional, if not specified clientId is used)</listitem>
                <listitem>loadUserProfile() - loads the users profile. Returns promise to set functions to be invoked on success or error</listitem>
                <listitem>isTokenExpired(minValidity) - returns true if the token has less than minValidity seconds left before it expires (minValidity is optional, if not specified 0 is used)</listitem>
                <listitem>updateToken(minValidity) - refreshes the token if the token expires within minValidity seconds (minValidity is optional, if not specified 0 is used). Returns promise to set functions to be invoked on success or error</listitem>
            </itemizedlist>
        </section>

        <section>
            <title>Callback Events</title>

            <para>The adapter supports setting callback listeners for certain events. For example:
<programlisting><![CDATA[
keycloak.onAuthSuccess = function() { alert('authenticated'); }
]]></programlisting>
            </para>

            <itemizedlist>
                <listitem>onReady(authenticated) - called when the adapter is initialized</listitem>
                <listitem>onAuthSuccess - called when a user is successfully authenticated</listitem>
                <listitem>onAuthError - called if there was an error during authentication</listitem>
                <listitem>onAuthRefreshSuccess - called when the token is refreshed</listitem>
                <listitem>onAuthRefreshError - called if there was an error while trying to refresh the token</listitem>
                <listitem>onAuthLogout - called when the user is logged out (only relevant to Cordova)</listitem>
            </itemizedlist>
        </section>
    </section>
</section>