How to creating a Google Alert programmatically

Question

Can I create a Google alert ( http://www.google.com/alerts ) programmatically using C# and consume the feed to show in an asp.net application? I know that Google does not provide an api to do that. I need your suggestions / ideas.

Thanks in advance,

Answer 1

Sorry, this isn't C#, but should be a help to anyone who wants to implement something like this. This PHP code creates the feed and returns the RSS URL for consumption.

Based on code from this page:

Login to Google with PHP and Curl, Cookie turned off?

function createAlert($search) {

        $USERNAME = 'EMAIL_ADDRESS';
        $PASSWORD = 'PASSWORD';
        $COOKIEFILE = 'cookies.txt';

        $ch = curl_init();
        curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 30);
        curl_setopt($ch, CURLOPT_USERAGENT, "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1)");
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
        curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
        curl_setopt($ch, CURLOPT_FOLLOWLOCATION, 1);
        curl_setopt($ch, CURLOPT_COOKIEJAR, $COOKIEFILE);
        curl_setopt($ch, CURLOPT_COOKIEFILE, $COOKIEFILE);
        curl_setopt($ch, CURLOPT_HEADER, 0);
        curl_setopt($ch, CURLOPT_RETURNTRANSFER,1);
        curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 120);
        curl_setopt($ch, CURLOPT_TIMEOUT, 120);

        curl_setopt($ch, CURLOPT_URL,
        'https://accounts.google.com/ServiceLogin?hl=en&service=alerts&continue=http://www.google.com/alerts/manage');
        $data = curl_exec($ch);

        $formFields = $this->getFormFields($data);

        $formFields['Email']  = $USERNAME;
        $formFields['Passwd'] = $PASSWORD;
        unset($formFields['PersistentCookie']);

        $post_string = '';
        foreach($formFields as $key => $value) {
        $post_string .= $key . '=' . urlencode($value) . '&';
        }

        $post_string = substr($post_string, 0, -1);

        curl_setopt($ch, CURLOPT_URL, 'https://accounts.google.com/ServiceLoginAuth');
        curl_setopt($ch, CURLOPT_POST, 1);
        curl_setopt($ch, CURLOPT_POSTFIELDS, $post_string);

        $result = curl_exec($ch);

        if (strpos($result, '<title>Redirecting') === false) {
            var_dump($result);
            die("Login failed");
        } else {
            curl_setopt($ch, CURLOPT_URL, 'http://www.google.com/alerts');
            curl_setopt($ch, CURLOPT_POST, 0);
            curl_setopt($ch, CURLOPT_POSTFIELDS, null);

            $result = curl_exec($ch);

            // Create alert

            preg_match('/<input type="hidden" name="x" value="([^"]+)"/', $result, $matches);

            $post = array(
                "x" => $matches[1],     // anti-XSRF key
                "q" => $search,     // Search term  
                "t" => 7,       // Result type (everything)
                "f" => 1,       // Frequency (once a day)
                "l" => 1,       // How many (all results)
                "e" => "feed"       // Type of delivery (RSS)
            );

            $post_string = '';

            foreach($post as $key => $value) {
                $post_string .= $key . '=' . urlencode($value) . '&';
            }

            $post_string = substr($post_string, 0, -1);

            curl_setopt($ch, CURLOPT_URL, 'http://www.google.com/alerts/create');
            curl_setopt($ch, CURLOPT_POST, 1);
            curl_setopt($ch, CURLOPT_POSTFIELDS, $post_string);

            $result = curl_exec($ch);
            $matches = array();
            preg_match('#<a href="(http://www.google.com/alerts/feeds/[\d/]+)"#', $result, $matches);

            $top_alert = $matches[1];

            return $top_alert;
        }
    }


    function getFormFields($data)
    {
        if (preg_match('/(<form.*?id=.?gaia_loginform.*?<\/form>)/is', $data, $matches)) {
            $inputs = $this->getInputs($matches[1]);

            return $inputs;
        } else {
            die("didn't find login form");
        }
    }

    function getInputs($form)
    {
        $inputs = array();

        $elements = preg_match_all('/(<input[^>]+>)/is', $form, $matches);

        if ($elements > 0) {
            for($i = 0; $i < $elements; $i++) {
                $el = preg_replace('/\s{2,}/', ' ', $matches[1][$i]);

                if (preg_match('/name=(?:["\'])?([^"\'\s]*)/i', $el, $name)) {
                    $name  = $name[1];
                    $value = '';

                    if (preg_match('/value=(?:["\'])?([^"\'\s]*)/i', $el, $value)) {
                        $value = $value[1];
                    }

                    $inputs[$name] = $value;
                }
            }
        }

        return $inputs;
    }

Answer 2

Since that's just an HTML form which posts to http://www.google.com/alerts/create?gl=us&hl=en (localization aside, of course), you could programmatically do the same thing. Since (as you mentioned) there's no public API for this, any part of that page/form/URL/etc. could change at any time, and break your application.