The request was to connect a parent folder and find its Python files, notebooks and materials in a tree on the left, while keeping work available when the explorer was collapsed or resized. Reading that record and the actual implementation, I separated displaying filenames from deciding which files may be opened. A rendered tree alone cannot establish a file-access boundary.
Start with names and state from one level
The original listing function obtains a project's registered root and reads the requested directory's immediate entries. It returns metadata such as names, relative paths, kinds, sizes and blocked state. It does not prefetch every file body or execute Python. Hidden names may appear too, so the scope of metadata disclosure remains part of authorization.
The interface requests a directory when it is expanded and opens lower directories separately as needed. Request cancellation and response-generation checks connect the UI against attaching an old response to a later folder state. I distinguish reading that source from actually testing delays and folder changes in the original interface. This review starts no existing server or notebook.
Be precise about what pagination limits
The interface offers batches of two hundred, and the server accepts offset and limit. That does not mean the implementation reads only the first two hundred names from disk. It sorts the entire immediate directory before slicing the returned page. Avoiding recursive collection of all descendants and bearing the cost of one very large directory are different properties.
This distinction affects interface promises. A smaller page does not establish a proportional reduction in scanning cost. Creation or deletion between pages can also shift ordering. I do not turn a displayed entry count into a claim that every file body was reviewed or that the entire tree was preserved at one fixed instant.
A blocked-looking control still needs a server-side check
The server rejects relative inputs that contain parent traversal or an absolute location. It also checks that the registered root has not resolved somewhere different, then resolves the requested target and checks membership in that root. A link or junction placed inside a folder can lead outside it. A string prefix matching the root's name is not enough to determine physical membership.
The original listing returns outward-pointing entries as blocked and the interface displays that state. A disabled-looking button alone does not create the boundary, however. The direct file-information API uses the same resolver. A file seen in a list is therefore assessed again when opening is requested. Authentication and project selection remain separate responsibilities of the host.
Connect to the existing editor and recheck the selected project
After the file-information request completes, openFile checks that the initially captured project is still selected. It then sends the relative path to the existing Jupyter frame, where docmanager:open opens the document. Clicking a listing is not described as permission to switch to another project's editor or execute that file. The caller also waits for a separate opened response.
Collapsed state and width are stored as display preferences, while the parent retains running project frames separately. Collapsing the explorer is therefore modeled separately from terminating an editor. The historical documents and conversation explicitly leave actual feature verification to the user. I did not borrow that source and build report as new proof of kernel preservation, keyboard behavior or a small-screen interface test.
An allowed explorer folder is not a kernel-wide sandbox
A listing API restricted to a root does not restrict a Python kernel's operating-system access to that same location. Connecting an explorer does not automatically expand the chat's file-edit permissions either. Listing, document opening, saving and execution have different responsibilities. Being adjacent in one interface does not make them one grant of authority.
The same principle can be useful in a website administration library. Finding a filename and serving its original bytes each require the relevant current permission and path checks. As the interface becomes more convenient, the language describing actual request boundaries needs to become more precise. Making all files discoverable should not silently promise to retrieve and execute every file body.
Isolate metadata in the shared example
The existing confirmed-folder iterator copies and moves source and working copies, so it is not a component to execute unchanged for browsing. The new independent module returns only one-level listings and regular-file metadata. To keep its policy narrow, it rejects even internal links and documents that difference from the original source, which can permit internally resolved links.
Twenty tests run with owned synthetic folders and actual Windows junctions, followed by extracted-ZIP checks and verification of the public file's bytes and hash. These checks use no customer material, original controller or Jupyter instance. They do not establish an OS sandbox against hostile changes between path checks. The shared code stays alongside the host's remaining authentication, opening, saving and execution responsibilities.