Dashboard: display package data sizes in oplog entry and tree views. (#232)

* Wrong divisor for friendly giga-values

* We want Explorer style for kilo/kibi units; round up

* var -> const - zero idea if this matters

* Include sum of an entry's package data sizes in index

* Method to enurate all properties of a loaded oplog index

* Include bulkdata size in an oplog index

* Found a space that was missing

* Show package data sizes when viewing an oplog entry

* Navigating a component tree would error out at the end of the chain

* Parameterise friendly rounding

* Added size and rawsize columns to oplog tree view

* Sort of parameterised indexer's worker count and page size

* Right-align size columns on entry view page

* Updated frontend .zip archive

* A changelog update

1 files changed, 6 insertions, 3 deletions

diff --git a/src/zenserver/frontend/html/util/component.js b/src/zenserver/frontend/html/util/component.js
index 39a9f2fe6..205aa038e 100644
--- a/src/zenserver/frontend/html/util/component.js
+++ b/src/zenserver/frontend/html/util/component.js
@@ -20,17 +20,20 @@ class ComponentBase
 
 	parent()
 	{
-		return this.new_component(this._element.parentElement);
+		const e = this._element.parentElement;
+		return e ? this.new_component(e) : null;
 	}
 
 	first_child()
 	{
-		return this.new_component(this._element.firstElementChild);
+		const e = this._element.firstElementChild;
+		return e ? this.new_component(e) : null;
 	}
 
 	next_sibling()
 	{
-		return this.new_component(this._element.nextElementSibling);
+		const e = this._element.nextElementSibling;
+		return e ? this.new_component(e) : null;
 	}
 
 	destroy()