Merge pull request #67 from SparkPost/FAD-3599-doc

Add docs for hooks

Author: rajumsys

docs/hooks.md

@@ -0,0 +1,29 @@
+## Plugin Hooks
+SparkPost's WordPress plugin has a number of hooks that can be used to modify how it works and/or inject new functionality around its lifecycle.
+
+### Convention
+Hook names are prefixed with `wpsp_`.
+
+### List of hooks
+
+| Hook Name                    | Type |  Description (Purpose)
+| -------------                |-------------|:----------------:|
+| wpsp_get_settings            | Filter   | Tap into settings objects  
+| wpsp_init_mailer             | Action   | Modify/replace http mailer instance
+| wpsp_get_http_lib            | Filter   | Modify/replace http library
+| wpsp_before_send             | Action   |
+| wpsp_after_send              | Action   |   
+| wpsp_handle_response         | Filter   |  Custom handler for http response. **Return a boolean to indicate the success or failure of the transmission and to stop further processing.**
+| wpsp_recipients              | Filter   |
+| wpsp_open_tracking           | Filter   |   
+| wpsp_click_tracking          | Filter   |
+| wpsp_template_id             | Filter   |  Use a different template ID
+| wpsp_substitution_content_tag_name| Filter   |  Use a different tag for content substitution. By default you needed to use `content` tag
+| wpsp_sender_email            | Filter   |
+| wpsp_sender_name             | Filter   |
+| wpsp_response_body           | Filter   |
+| wpsp_api_key                 | Filter   |  Use different API Key/Password
+| wpsp_request_headers         | Filter   |
+| wpsp_reply_to                | Filter   |
+| wpsp_body_headers            | Filter   |   
+| wpsp_smtp_msys_api           | Filter   |

mailer.http.class.php

@@ -77,7 +77,7 @@ protected function get_request_body()
         $body = array();
 
         // add recipients
-        $body['recipients'] = apply_filters('wpsp_recipients', $this->get_recipients());
+        $body['recipients'] = $this->get_recipients();
 
         // enable engagement tracking
         $body['options'] = array(
@@ -410,6 +410,6 @@ protected function get_headers()
           $formatted_headers['CC'] = $this->stringify_recipients($cc);
         }
 
-        return apply_filters('spwp_body_headers', $formatted_headers);
+        return apply_filters('wpsp_body_headers', $formatted_headers);
     }
 }