Server mode does not serve index.html by default when accessing IP:PORT

[triuk]

When running WebUI in server mode, it behaves like a web server. However, opening the root URL (IP:PORT) in a browser does not load the custom UI page. Instead, users must manually enter IP:PORT/index.html.

Expected behavior:
Navigating to IP:PORT should automatically serve index.html.

Actual behavior:
Opening IP:PORT results in a Not Found response, so the user has to access IP:PORT/index.html explicitly.

Suggested fix:
Default the server root to index.html.
In C, this is currently handled by:

const char* url = webui_start_server(myWindow, "/full/root/path");

I am doing cpp, so one workaround was overriding the start behavior manually, for example:

static std::string start_server(webui::window &win, const std::string &file)
{
    // Store start page
    detail::g_start_page = file;

    // Install VFS middleware
    win.set_file_handler(detail::vfs_router);

    // Extract native window ID (WebUI stores it as the first field)
    size_t id = *reinterpret_cast<size_t *>(&win);

    // ALLOW PUBLIC ACCESS
    webui_set_public(id, true);

    // Start server
    const char *url = webui_start_server(id, file.c_str());
    if (!url)
        return {};

    return std::string(url);
}

// Usage
start_server(window_, "index.html");

Key detail:
The default-page behavior depends entirely on the wrapper implementing VFS routing – e.g. in this wrapper:

static std::string g_start_page = "index.html";

static const void *vfs_router(const char *filename, int *length)
{
    if (strcmp(filename, "/") == 0) {
        static thread_local std::string tmp;
        tmp = "/" + g_start_page;
        filename = tmp.c_str();
    }
    return vfs(filename, length);
}

But for example, Python wrapper has no mechanism to override this, therefore default behavior must be implemented in WebUI core to be consistent across languages.

Request:
Add automatic serving of the configured start page when / is requested, so that entering IP:PORT loads the UI without requiring /index.html.

[AlbertShown]

Thank you @triuk for pointing this out. Fixed 6c8b11d

[triuk]

Could you please write an example, how to use it? Because no matter what I write to the cpp:

window_.set_file_handler(vfs);
std::string_view url = window_.start_server("index.html or whatever");

It always loads index.css when I enter IP:PORT in my browser.

[AlbertShown]

When you said It always loads index.css I got the issue, in my test case I don't have index.css so it loads index.html, but your case VFS loads the first index.XXX finds in the files list.

WebUI library core loads only {"index.ts", "index.js", "index.html", "index.htm"} (Reference Link). But VFS loads first index.XXX and that's the problem.

Python Issue:
https://github.com/webui-dev/webui/blob/main/examples/C/virtual_file_system/vfs.py#L28

            # Check for index files
            if filename.startswith("index."):
                dir_path = os.path.dirname(relative_path)
                if dir_path not in index_files:
                    index_files[dir_path] = relative_path

[AlbertShown]

I will fix it later, but you @triuk have free time, please update the Python script to look for {"index.ts", "index.js", "index.html", "index.htm"} only. If you are busy I can fix it later.

[triuk]

Yes, I have index.css, index.html, index.js in the folder. It'd be nice if you could specify the "index" file for load in the start_server() if possible.
By updating to {"index.ts", "index.js", "index.html", "index.htm"} only, will not there still be an issue with index.html vs. index.js ?

[triuk]

I replaced this:

# Check for index files
if filename.startswith("index."):
    dir_path = os.path.dirname(relative_path)
    if dir_path not in index_files:
        index_files[dir_path] = relative_path

with this:

# Check for index files
prefer_order = ("index.html", "index.htm", "index.ts", "index.js")

if filename in prefer_order:
    dir_path = os.path.dirname(relative_path)

    if dir_path in index_files:
        current = os.path.basename(index_files[dir_path])
        # Overwrite lower priority index
        if prefer_order.index(filename) < prefer_order.index(current):
            index_files[dir_path] = relative_path
    else:
        index_files[dir_path] = relative_path

it works (based on the priority list), but it is not universal. The argument in

start_server("you just need string no matter what it says")

does not have any effect as it is hardcoded in vfs.h this way.

I suggest: making the same behavior for start_server() like you have for show_browser() where you specify the "index" in argument and it actually loads the file.
I am not sure how feasible it is, as my knowledge of the code (and skill) does not reach that far unfortunately.

[AlbertShown]

The file vfs.h is generated by Python script, please after you fix the Python, test it like this:

python vfs.py "/path/to/your/root/UI/folder" "vfs.h"

Then, recompile your C++ project.

The goal is that vfs.h will have only the correct index file and not index.css file. Something like this:

static const char* index_files[] = {
    "/", "/index.html", // <--- Fixed Python script should ignore your index.css file and not add it to index_files[]
    NULL
};

[AlbertShown]

I suggest: making the same behavior for start_server() like you have for show_browser()

WebUI does nothing about handling files when VFS is used by user, the goal of VFS is that user handle the files (HTTP Header + files body) in the way the user wants. So, to fix this index.css issue all we have to do is making Python script generate vfs.h that has only the correct index file in index_files[]