import markdown from "markdown-it";
const md = markdown({
  xhtmlOut: true,
  breaks: true
});

export default class ExpandablePanelController {
  constructor($sce) {
    "ngInject";
    Object.assign(this, {
      $sce,
      expandable: false,
      expanded: false,
      parsed: ""
    });
  }
  $onChanges(changes) {
    if (changes.content && changes.content.currentValue) {
      let content = changes.content.currentValue;
      // more then 10 lines?
      if (content.match(/\n/mg).length > 9) {
        this.expandable = true;
      }

      if (this.markdown) {
        this.parsed = this.$sce.trustAsHtml(md.render(content));
      }
    }
  }
  toggle() {
    this.expanded = !this.expanded;
  }
}

import markdown from "markdown-it";
const md = markdown({
  xhtmlOut: true,
  breaks: true
});

export default class ExpandablePanelController {
  constructor($timeout, $sce) {
    "ngInject";
    Object.assign(this, {
      expandable: false,
      expanded: false,
      parsed: ""
    });
    $timeout( () => {

      // more then 10 lines?
      if (this.content.match(/\n/mg).length > 9) {
        this.expandable = true;
      }

      if (this.markdown) {
        this.parsed = $sce.trustAsHtml(md.render(this.content));
      }

    });
  }
  toggle() {
    this.expanded = !this.expanded;
  }
}

--- 
+++ 
@@ -5,25 +5,27 @@
 });
 
 export default class ExpandablePanelController {
-  constructor($timeout, $sce) {
+  constructor($sce) {
     "ngInject";
     Object.assign(this, {
+      $sce,
       expandable: false,
       expanded: false,
       parsed: ""
     });
-    $timeout( () => {
-
+  }
+  $onChanges(changes) {
+    if (changes.content && changes.content.currentValue) {
+      let content = changes.content.currentValue;
       // more then 10 lines?
-      if (this.content.match(/\n/mg).length > 9) {
+      if (content.match(/\n/mg).length > 9) {
         this.expandable = true;
       }
 
       if (this.markdown) {
-        this.parsed = $sce.trustAsHtml(md.render(this.content));
+        this.parsed = this.$sce.trustAsHtml(md.render(content));
       }
-
-    });
+    }
   }
   toggle() {
     this.expanded = !this.expanded;
Use $onChanges to react to updated content
