Fire a Slack Notification via CURL

slack_notification.php

<?php

// (string) $message - message to be passed to Slack
// (string) $room - room in which to write the message, too
// (string) $icon - You can set up custom emoji icons to use with each message
public static function slack($message, $room = "engineering", $icon = ":longbox:") {
        $room = ($room) ? $room : "engineering";
        $data = "payload=" . json_encode(array(
                "channel"       =>  "#{$room}",
                "text"          =>  $message,
                "icon_emoji"    =>  $icon
            ));
	
	// You can get your webhook endpoint from your Slack settings
        $ch = curl_init("WEBHOOK ENDPOINT GOES HERE");
        curl_setopt($ch, CURLOPT_CUSTOMREQUEST, "POST");
        curl_setopt($ch, CURLOPT_POSTFIELDS, $data);
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
        $result = curl_exec($ch);
        curl_close($ch);
	
	// Laravel-specific log writing method
        // Log::info("Sent to Slack: " . $message, array('context' => 'Notifications'));

        return $result;
    }

I found a way to avoid URL encoding issues with the payload - curl also allows you to pass an associative array for the post parameters rather than a GET-style &-delimited string. If you're getting 'Payload was not valid JSON' messages back from Slack because you have odd characters in your text, you might want to try passing the POST data this way instead. Gist at https://gist.github.com/pugwonk/f2cdd9d83d964627c335

How would you add an attachment to that ? I can't figure it out.

Thanks a lot!

curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
you save my night yvonnel098

Thanks for this!

@pugwonk Hello - I'm having similar URL-encoding issues. I tried your suggestion of curl_setopt($ch, CURLOPT_POSTFIELDS, array('payload' => $data)); which let me pass just about any character through without causing the Slack invalid_payload error - brilliant! :)

But the actual message came through to Slack in url-encoded form instead of readable text :( I think Slack have changed how they handle this since your post.

I'm doing $message = urlencode($message); - if I don't then I can't get proper formatting in the Slack message (it displays \n instead of actually putting in a line-break for example).

Has anyone else spotted anything like this?

Here's my code (roughly!):

            $message = urlencode($message); // Contains things like 'This is the message to the channel:\n\nHere is the second line with some *bold text* hopefully!'

            $channel = '#the-channel-to-post-to';
            $data = 'payload=' . json_encode(array(
                    'channel'  => $channel,
                    'text'     => $message,
            ));

            $url = 'MY_WEBHOOK_URL';

            $ch = curl_init();
            curl_setopt($ch, CURLOPT_URL, $url);
            curl_setopt($ch, CURLOPT_CUSTOMREQUEST, 'POST');
            curl_setopt($ch, CURLOPT_POSTFIELDS, $data);
            curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
            curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
            $result = curl_exec($ch);
            if ($result === false) {
                echo 'Curl error: ' . curl_error($ch);
            }

            curl_close($ch);

Thanks :)

If it helps anyone, I got around most of the encoding problems by passing the parts of my $message through this function:

function htmlReplace($string) {
    // https://api.slack.com/docs/message-formatting#how_to_escape_characters
    // Also use backslashes to escape double quotes/backslashes themselves,
    // that would otherwise break the JSON.
    // (deal with the slashes before the quotes otherwise the escaped quotes would be re-escaped!)
    return str_replace(array('&', '<', '>', '\\', '"'), array('&amp;', '&lt;', '&gt;', '\\\\', '\"'), $string);
}

Thank you

Thank you!

Top job exactly what I was looking for.

How are you able to set the channel? When I'm giving permission for my app to use the Incoming Webhook, I get a unique URL for every single Channel. I can send the channel all day long, but it's the URL that defines which channel it goes to. Is there a generic URL that I can't find? Or is there a permission I need to create that I am overlooking?

hello
i want to use slack rest api in curl to create a channel not with webhook but that is not working plz help me

Those this still work i am getting an error missing_text_or_fallback_or_attachments

thanks, it's help me so mush :)

in symfony nexylan / slack-bundle, we use "withIcon" to change the icon but here how to do it ?

Brilliant, thanks. emoji icons aren't working for me but, besides that, it's a very useful function!