build: update dgeni templates to include deprecated tag description

tools/dgeni/common/decorators.ts

@@ -85,13 +85,19 @@ export function getBreakingChange(doc: ApiDoc): string | null {
   return breakingChange ? breakingChange.description : null;
 }
 
+export function getDeprecationMessage(doc: ApiDoc): string | null {
+  const deprecatedMessage = findJsDocTag(doc, 'deprecated');
+  return deprecatedMessage ? deprecatedMessage.description : null;
+}
+
 /**
  * Decorates public exposed docs. Creates a property on the doc that indicates whether
- * the item is deprecated or not.
+ * the item is deprecated or not and set deprecation message.
  */
 export function decorateDeprecatedDoc(doc: ApiDoc & DeprecationInfo) {
   doc.isDeprecated = isDeprecatedDoc(doc);
   doc.breakingChange = getBreakingChange(doc);
+  doc.deprecatedMessage = getDeprecationMessage(doc);
 
   if (doc.isDeprecated && !doc.breakingChange) {
     console.warn('Warning: There is a deprecated item without a @breaking-change tag.', doc.id);

tools/dgeni/common/dgeni-definitions.ts

@@ -12,6 +12,7 @@ import {NormalizedFunctionParameters} from './normalize-function-parameters';
 export interface DeprecationInfo {
   isDeprecated: boolean;
   breakingChange: string | null;
+  deprecatedMessage: string | null;
 }
 
 /** Interface that describes Dgeni documents that have decorators. */

tools/dgeni/templates/macros.html

@@ -1,5 +1,7 @@
 {% macro deprecationTitle(doc) %}
-  {%- if doc.breakingChange -%}
-    title="Will be removed in v{$ doc.breakingChange $} or later"
+  {%- if doc.breakingChange and doc.deprecatedMessage -%}
+    deprecated-message="{$ doc.deprecatedMessage $} Will be removed in v{$ doc.breakingChange $} or later."
+  {% else %}
+    deprecated-message="{$ doc.deprecatedMessage $}"
   {%- endif -%}
 {% endmacro %}