codebird-js

A Twitter library in JavaScript.

Copyright (C) 2010-2013 J.M. <me@mynetx.net>

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program. If not, see http://www.gnu.org/licenses/.

Versions

• JavaScript: https://github.com/mynetx/codebird-js
• PHP: https://github.com/mynetx/codebird-php

1. Authentication

---

To authenticate your API requests on behalf of a certain Twitter user (following OAuth 1.0a), take a look at these steps:

<script type="text/javascript" src="sha1.js"></script>
<script type="text/javascript" src="codebird.js"></script>

<script type="text/javascript">
var cb = new Codebird;
cb.setConsumerKey("YOURKEY", "YOURSECRET");
</script>

You may either set the OAuth token and secret, if you already have them:

cb.setToken("YOURTOKEN", "YOURTOKENSECRET");

Or you authenticate, like this:

// gets a request token
cb.__call(
    "oauth_requestToken",
    {oauth_callback: "oob"},
    function (reply) {
        // stores it
        cb.setToken(reply.oauth_token, reply.oauth_token_secret);

        // gets the authorize screen URL
        cb.__call(
            "oauth_authorize",
            {},
            function (auth_url) {
                window.codebird_auth = window.open(auth_url);
            }
        );
    }
);

Now you need to add a PIN box to your website. After the user enters the PIN, complete the authentication:

cb.__call(
    "oauth_accessToken",
    {oauth_verifier: document.getElementById("PINFIELD").value},
    function (reply) {
        // store the authenticated token, which may be different from the request token (!)
        cb.setToken(reply.oauth_token, reply.oauth_token_secret);

        // if you need to persist the login after page reload,
        // consider storing the token in a cookie or HTML5 local storage
    }
);

1.1. Application-only auth

Some API methods also support authenticating on a per-application level. This is useful for getting data that are not directly related to a specific Twitter user, but generic to the Twitter ecosystem (such as search/tweets).

To obtain an app-only bearer token, call the appropriate API:

cb.__call(
    "oauth2_token",
    {},
    function (reply) {
        var bearer_token = reply.access_token;
    }
);

I strongly recommend that you store the obtained bearer token in your database. There is no need to re-obtain the token with each page load, as it becomes invalid only when you call the oauth2/invalidate_token method.

If you already have your token, tell Codebird to use it:

cb.setBearerToken("YOURBEARERTOKEN");

For sending an API request with app-only auth, see the ‘Usage examples’ section.

1.2. Authenticating using a callback URL, without PIN

1. Before sending your user off to Twitter, you have to store the request token and its secret, for example in a cookie.
2. In the callback URL, extract those values and assign them to the Codebird object.
3. Extract the oauth_verifier field from the request URI.

In Javascript, try extracting the URL parameter like this:

var cb          = new Codebird;
var current_url = location.toString();
var query       = current_url.match(/\?(.+)$/).split("&");
var parameters  = {};
var parameter;

cb.setConsumerKey("STUFF", "HERE");

for (var i = 0; i < query.length; i++) {
    parameter = query[i].split("=");
    if (parameter.length === 1) {
        parameter[1] = "";
    }
    parameters[decodeURIComponent(parameter[0])] = decodeURIComponent(parameter[1]);
}

// check if oauth_verifier is set
if (typeof parameters.oauth_verifier !== "undefined") {
    // assign stored request token parameters to codebird here
    // ...
    cb.setToken(stored_somewhere.oauth_token, stored_somewhere.oauth_token_secret);

    cb.__call(
        "oauth_accessToken",
        {
            oauth_verifier: parameters.oauth_verifier
        },
        function (reply) {
            cb.setToken(reply.oauth_token, reply.oauth_token_secret);

            // if you need to persist the login after page reload,
            // consider storing the token in a cookie or HTML5 local storage
        }
    );
}

Does that work properly?

2. Usage examples

---

Heads up

Because the Consumer Key and Token Secret are available in the code it is important that you configure your app as read-only at Twitter, unless you are sure to know what you are doing.

When you have an access token, calling the API is simple:

cb.setToken("YOURTOKEN", "YOURTOKENSECRET"); // see above

cb.__call(
    "statuses_homeTimeline",
    {},
    function (reply) {
        console.log(reply);
    }
);

Tweeting is as easy as this:

cb.__call(
    "statuses_update",
    {"status": "Whohoo, I just tweeted!"},
    function (reply) {
        // ...
    }
);

For more complex parameters (see the Twitter API documentation), giving all parameters in an array is supported, too:

var params = {
    screen_name: "mynetx"
};
cb.__call(
    "users_show",
    params,
    function (reply) {
        // ...
    }
);

When uploading files to Twitter, the array syntax is obligatory, and the media have to be base64-encoded:

var params = {
    "status": "The bird is flying high. #larry",
    "media[]": "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"
);
cb.__call(
    "statuses_updateWithMedia",
    params,
    function (reply) {
        // ...
    }
);

Requests with app-only auth

To send API requests without an access token for a user (app-only auth), add another parameter to your method call, like this:

cb.__call(
    "search_tweets",
    "q=Twitter",
    function (reply) {
        // ...
    },
    true // this parameter required
);

Bear in mind that not all API methods support application-only auth.

3. Mapping API methods to Codebird function calls

---

As you can see from the last example, there is a general way how Twitter’s API methods map to Codebird function calls. The general rules are:

1. For each slash in a Twitter API method, use an underscore in the Codebird function.

   Example: statuses/update maps to cb.__call("statuses_update", ...).

2. For each underscore in a Twitter API method, use camelCase in the Codebird function.

   Example: statuses/home_timeline maps to cb.__call("statuses_homeTimeline", ...).

3. For each parameter template in method, use UPPERCASE in the Codebird function. Also don’t forget to include the parameter in your parameter list.

   Examples:

   • statuses/show/:id maps to cb.__call("statuses_show_ID", 'id=12345', ...).
   • users/profile_image/:screen_name maps to cb.__call("users_profileImage_SCREEN_NAME", "screen_name=mynetx", ...).

4. HTTP methods (GET, POST, DELETE etc.)

---

Never care about which HTTP method (verb) to use when calling a Twitter API. Codebird is intelligent enough to find out on its own.

5. Response codes

---

The HTTP response code that the API gave is included in any return values. You can find it within the return object’s httpstatus property.

5.1 Dealing with rate-limits

Basically, Codebird leaves it up to you to handle Twitter’s rate limit.
The library returns the response HTTP status code, so you can detect rate limits.

I suggest you to check if the reply.httpstatus property is 400 and check with the Twitter API to find out if you are currently being rate-limited. See the Rate Limiting FAQ for more information.

6. API calls and the same-origin policy

---

Normally, browsers only allow requests being sent to addresses that are on the same base domain. This is a security feature called the “same-origin policy.” However, this policy is in your way when you try to access the (remote) Twitter API domain and its methods.

6.1 Cross-domain requests

With Codebird, don’t worry about this. We automatically send cross-domain requests using a secured proxy that sends back the required headers to the user’s browser.

This CORS proxy is using an encrypted SSL connection.
We do not record data sent to or from the Twitter API. Using Codebird’s CORS proxy is subject to the Acceptable use policy.

If your JavaScript environment is not restricted under the same-origin policy (for example in node-js), it is recommended that you turn off the CORS compatibility like this:

cb.setUseProxy(false);

6.2 Support for Internet Explorer 7 to 9

Cross-domain requests work well in any browser except for Internet Explorer 7-9. Codebird cannot send POST requests in these browsers. For IE7-9, Codebird works in limited operation mode:

• Calls to GET methods work fine,
• calling POST methods is impossible.

6.3 Using your own proxy server

The source code of the CORS proxy is publicly available. If you want to, set up your own instance on your server. Afterwards, tell Codebird the address:

cb.setProxy("https://example.com/codebird-cors-proxy/");

Heads up! Follow the notes in the codebird-cors-proxy README for details.

7. Using multiple Codebird instances

---

By default, each Codebird instance works on its own.

If you need to run requests to the Twitter API for multiple users at once, Codebird supports this automatically. Just create a new object:

var cb1 = new Codebird;
var cb2 = new Codebird;

Please note that your OAuth consumer key and secret is shared within multiple Codebird instances, while the OAuth request and access tokens with their secrets are not shared.

How Do I…?

…get user ID, screen name and more details about the current user?

When the user returns from the authentication screen, you need to trade the obtained request token for an access token, using the OAuth verifier. As discussed in the section ‘Usage example,’ you use a call to oauth/access_token to do that.

The API reply to this method call tells you details about the user that just logged in. These details contain the user ID and the screen name.

Take a look at the returned data as follows:

{
    oauth_token: "14648265-rPn8EJwfB**********************",
    oauth_token_secret: "agvf3L3**************************",
    user_id: 14648265,
    screen_name: "mynetx",
    httpstatus: 200
}

If you need to get more details, such as the user’s latest tweet, you should fetch the complete User Entity. The simplest way to get the user entity of the currently authenticated user is to use the account/verify_credentials API method. In Codebird, it works like this:

cb.__call(
    "account_verifyCredentials",
    {},
    function (reply) {
        console.log(reply);
    }
);

I suggest to cache the User Entity after obtaining it, as the account/verify_credentials method is rate-limited by 15 calls per 15 minutes.

…walk through cursored results?

The Twitter REST API utilizes a technique called ‘cursoring’ to paginate large result sets. Cursoring separates results into pages of no more than 5000 results at a time, and provides a means to move backwards and forwards through these pages.

Here is how you can walk through cursored results with Codebird.

1. Get the first result set of a cursored method:

cb.__call(
    "followers_list",
    {},
    function (result1) {
        // ...
    }
);

2. To navigate forth, take the next_cursor_str:

var nextCursor = result1.next_cursor_str;

3. If nextCursor is not 0, use this cursor to request the next result page:

    if (nextCursor > 0) {
        cb.__call(
            "followers_list",
            {cursor: nextCursor},
            function (result2) {
                // ...
            }
        );
    }

To navigate back instead of forth, use the field resultX.previous_cursor_str instead of next_cursor_str.

It might make sense to use the cursors in a loop. Watch out, though, not to send more than the allowed number of requests to followers/list per rate-limit timeframe, or else you will hit your rate-limit.