support templates for gitlab issue descriptions

docs/Guides/Gitlab.md

@@ -111,6 +111,23 @@ as an attachment. For example:
     ) to channel: 'gitlab', file: input.png
 ```
 
+## Description Templates
+
+You can use a template file for the description if you wish. To do this:
+
+- ensure any variables needed in the template are included in the `issue(...)` section as attributes
+- add a `template : "<path to your template file>"` attribute also.
+- do not include the description attribute
+
+For example:
+
+```
+    send issue(                                                                         
+        title: 'Results of Experiment',
+        template: 'templates/experiment_results.md'
+    ) to channel: 'gitlab', file: input.png
+```
+
 ## Gitlab Actions
 
 You can cause various actions to occur such as adding and removing labels, assigning issues

src/main/groovy/bpipe/NotificationManager.groovy

@@ -229,6 +229,9 @@ class NotificationManager {
                 templateName = cfg.template
             }
         }
+        else {
+            log.info "Using template $templateName for notification $evt"
+        }
 
         // Is it customized for this event?
         if(cfg.containsKey("templates")) {

src/main/groovy/bpipe/Sender.groovy

@@ -64,6 +64,11 @@ class Sender {
      */
     def content
 
+    /**
+     * Some sender contexts may specify a template explicitly
+     */
+    String template
+
     String defaultSubject
 
     Map details = [:]
@@ -113,6 +118,8 @@ class Sender {
 
     Sender issue(Map details) {
         this.content = details
+        if(details?.template)
+            this.template = details.template
         this.contentType = "application/json"
         this.defaultSubject = details.title
         return this
@@ -284,6 +291,14 @@ class Sender {
             "send.branch" : ctx.branch.name 
         ]
 
+        if(this.template) {
+            log.info "Template $template found in notification details"
+            props["template"] = this.template
+        }
+        else {
+            log.info "No template in details"
+        }
+
         if('url' in details) {
             props["send.url"] = details.url
         }