Popup/Tooltip content function: allow return undefined

[johnd0e]

In this case Popup/Tooltip is not shown.

Useful when only some sublayers need popups:

• previously: it was necessary to attach independent popups to each sublayer
• now: it's enough to have common content function attached to parent layer

d8a4ba0

diff --git a/src/layer/DivOverlay.js b/src/layer/DivOverlay.js
index efd76f1bba..0005ac6fdc 100644
--- a/src/layer/DivOverlay.js
+++ b/src/layer/DivOverlay.js
@@ -164,7 +164,9 @@ export var DivOverlay = Layer.extend({
 		var node = this._contentNode;
 		var content = (typeof this._content === 'function') ? this._content(this._source || this) : this._content;
 
-		if (typeof content === 'string') {
+		if (!content) {
+			return;
+		} else if (typeof content === 'string') {
 			node.innerHTML = content;
 		} else {
 			while (node.hasChildNodes()) {

---

This change is 

[johnd0e]

Well, I was too optimistic.
It appeared that there much more deep changes needed, as function is called after Popup/Tooltip is already added on map.

So I am not sure how to deal with it best:

• simple approach: just close empty popup.
• complex approach: change whole popup processing chain in order to check content before popup opened.

[johnd0e]

• simple approach: just close empty popup.

9e0ec58

diff --git a/src/layer/DivOverlay.js b/src/layer/DivOverlay.js
index efd76f1bba..9a82ffbce0 100644
--- a/src/layer/DivOverlay.js
+++ b/src/layer/DivOverlay.js
@@ -113,7 +113,10 @@ export var DivOverlay = Layer.extend({
 
 		this._container.style.visibility = 'hidden';
 
-		this._updateContent();
+		if (!this._updateContent()) {
+			this._close();
+			return;
+		}
 		this._updateLayout();
 		this._updatePosition();
 
@@ -164,7 +167,9 @@ export var DivOverlay = Layer.extend({
 		var node = this._contentNode;
 		var content = (typeof this._content === 'function') ? this._content(this._source || this) : this._content;
 
-		if (typeof content === 'string') {
+		if (!content) {
+			return;
+		} else if (typeof content === 'string') {
 			node.innerHTML = content;
 		} else {
 			while (node.hasChildNodes()) {
@@ -173,6 +178,7 @@ export var DivOverlay = Layer.extend({
 			node.appendChild(content);
 		}
 		this.fire('contentupdate');
+		return true;
 	},
 
 	_updatePosition: function () {

Although this works for me, but some tests in PhantomJS failed.
Waiting for advice.

[johnd0e]

Patch reworked, now all tests are happy.
Known drawback: content function now called twice.
I suppose it's acceptable, as we gain much more with new feature.
Or I will be happy to remake the patch, if anyone point me more proper place to fix.

N.B.
openTooltip and openPopup contain pretty the same code, I suppose it'd be better refactored: #6613 (place common function in DivOverlay)

[johnd0e]

Close in favor of #6651