BUGFIX: Reset focused fusion path to null whenever the edit-/preview-mode changes

[grebaldi]

fixes: #3335

The Problem

When focusing a node inside the <ContentCanvas/>, the associated fusionPath of that content element will be saved to the redux store. When the current edit-/preview-mode is then changed, said fusionPath is no longer valid (because the content element will be rendered through an entirely different path).

This confuses the <InlineUI/> component. It uses the stored fusionPath to locate the DOM node inside the <ContentCanvas/> that it attaches itself to. Since the fusionPath is invalid after the switch, the DOM node can longer be found and the <InlineUI/> becomes invisible.

The solution

The code responsible for locating nodes inside the <ContentCanvas/> can be found here:

neos-ui/packages/neos-ui-guest-frame/src/dom.js

Lines 73 to 77 in b424a7a

	export const findNodeInGuestFrame = (contextPath, fusionPath) => fusionPath ? findInGuestFrame(
	`[data-__neos-node-contextpath="${contextPath}"][data-__neos-fusion-path="${fusionPath}"]`
	) : findInGuestFrame(
	`[data-__neos-node-contextpath="${contextPath}"]`
	);

It anticipates situations in which no fusionPath is set (which is the case when selecting a node in the <ContentTree/> component for example). Basically, if there's no fusionPath it selects the first node that matches the focused contextPath, which I found quite acceptable for switching between edit-/preview-modes.

Therefore, I altered the CR.Nodes reducer to set the focused fusionPath to null whenever the UI.EditPreviewMode.SET action occurs. With this, the <InlineUI/> component no longer disappears when the edit-/preview-mode is switched.

[grebaldi]

Hmm... I do not understand why the E2E tests fail (but they do so consistently). From the log I take that moving multiple nodes in the Document Tree via Drag and Drop leads to an unexpected state, but I cannot reproduce the issue.

[grebaldi]

Well... The nth run did pass 😅

[crydotsnake]

Thx! Works as expected 🙂

[markusguenther]

Thanks @grebaldi