Troubleshooting
***************


Nette Is Not Working, White Page Is Displayed
---------------------------------------------
- Try putting `ini_set('display_errors', '1'); error_reporting(E_ALL);` after `declare(strict_types=1);` in the `index.php` file to force the display of errors
- If you still see a white screen, there is probably an error in the server setup and you will discover the reason in the server log. To be sure, check if PHP is working at all by trying to print something using `echo 'test';`.
- If you see an error *Server Error: We're sorry! ...*, continue with the next section:


Error 500 *Server Error: We're sorry! ...*
------------------------------------------
This error page is displayed by Nette in production mode. If you are seeing it on a developer machine, [switch to developer mode |application:bootstrap#Development vs Production Mode].

If the error message contains `Tracy is unable to log error`, find out why the errors cannot be logged. You can do this by, for example, [switching |application:bootstrap#Development vs Production Mode] to developer mode and calling `Tracy\Debugger::log('hello');` after `$configurator->enableTracy(...)`. Tracy will tell you why it can't log.
The cause is usually [insufficient permissions |#Setting Directory Permissions] to write to the `log/` directory.

If the sentence `Tracy is unable to log error` is not in the error message (anymore), you can find out the reason for the error in the log in the `log/` directory.

One of the most common reasons is an outdated cache. While Nette cleverly automatically updates the cache in development mode, in production mode it focuses on maximizing performance, and clearing the cache after each code modification is up to you. Try to delete `temp/cache`.


Error `#[\ReturnTypeWillChange] attribute should be used`
---------------------------------------------------------
This error occurs if you have upgraded PHP to version 8.1 but are using Nette, which is not compatible with it. So the solution is to update Nette to a newer version using `composer update`. Nette has supported PHP 8.1 since version 3.0. If you are using an older version (you can find out by looking in `composer.json`), [upgrade Nette |migrations:] or stay with PHP 8.0.


Setting Directory Permissions
-----------------------------
If you're developing on macOS or Linux (or any other Unix based system), you need to configure write privileges to the web server. Assuming your application is located in the default directory `/var/www/html` (Fedora, CentOS, RHEL)

```shell
cd /var/www/html/MY_PROJECT
chmod -R a+rw temp log
```

On some Linux systems (Fedora, CentOS, ...) SELinux may be enabled by default. You may need to update SELinux policies, or set paths of `temp` and `log` directories with correct SELinux security context. Directories `temp` and `log` should be set to `httpd_sys_rw_content_t` context; for the rest of the application -- mainly `app` folder -- `httpd_sys_content_t` context will be enough. Run on the server as root:

```shell
semanage fcontext -at httpd_sys_rw_content_t '/var/www/html/MY_PROJECT/log(/.*)?'
semanage fcontext -at httpd_sys_rw_content_t '/var/www/html/MY_PROJECT/temp(/.*)?'
restorecon -Rv /var/www/html/MY_PROJECT/
```

Next, the SELinux boolean `httpd_can_network_connect_db` needs to be enabled to permit Nette to connect to the database over network. By default, it is disabled. The command `setsebool` can be used to perform this task, and if the option `-P` is specified, this setting will be persistent across reboots.

```shell
setsebool -P httpd_can_network_connect_db on
```


How to Change or Remove `www` Directory from URL?
-------------------------------------------------
The `www/` directory used in the sample projects in Nette is the so-called public directory or document-root of the project. It is the only directory whose contents are accessible to the browser. And it contains the `index.php` file, the entry point that starts a web application written in Nette.

To run the application on the hosting, you need to set the document-root to this directory in the hosting configuration. Or, if the hosting has a pre-made folder for the public directory with a different name (for example `web`, `public_html` etc.), simply rename `www/`.

The solution **isn't** to "get rid" of the `www/` folder using rules in the `.htaccess` file or in the router. If the hosting would not allow you to set document-root to a subdirectory (i.e. create directories one level above the public directory), look for another. You would otherwise be taking a significant security risk. It would be like living in an apartment where you can't close the front door and it's always wide open.


How to Configure a Server for Nice URLs?
----------------------------------------
**Apache**: extension mod_rewrite must be allowed and configured in a `.htaccess` file.

```apacheconf
RewriteEngine On
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule !\.(pdf|js|ico|gif|jpg|png|css|rar|zip|tar\.gz)$ index.php [L]
```

To alter Apache configuration with .htaccess files, the AllowOverride directive has to be enabled. This is the default behavior for Apache.

**nginx**: the `try_files` directive should be used in server configuration:

```nginx
location / {
	try_files $uri $uri/ /index.php$is_args$args;  # $is_args$args is important
}
```

Block `location` must be defined exactly once for each filesystem path in `server` block. If you already have a `location /` block in your configuration, add the `try_files` directive into the existing block.


Links Are Generated Without `https:`
------------------------------------
Nette generates links with the same protocol as the current page is using. So on the `https://foo` page, it generates links starting with `https:` and vice versa.
If you're behind an HTTPS-stripping reverse proxy (for example, in Docker), then you need to [set up a proxy|http:configuration#HTTP proxy] in configuration to make the protocol detection work properly.

If you use Nginx as a proxy, you need to have redirection set up like this:

```
location / {
	proxy_set_header Host $host;
	proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
	proxy_set_header X-Forwarded-Proto $scheme;
	proxy_set_header X-Forwarded-Port  $server_port;
	proxy_pass http://IP-aplikace:80;  # IP or hostname of the server/container where the application is running
}
```

Next, you need to specify the IP proxy and, if applicable, the IP range of your local network where you run the infrastructure:

```neon
http:
	proxy: IP-proxy/IP-range
```


Use of Characters { } in JavaScript
-----------------------------------
Characters `{` and `}` are used for writing Latte tags. Everything (except space and quotation mark) following the `{` character is considered a tag. If you need to print character `{` (often in JavaScript), you can put a space (or other empty character) right after `{`. By this you avoid interpreting it as a tag.

If it's necessary to print these characters in a situation where they would be interpreted as a tag you can use specials tags to print out these characters - `{l}` for `{` and `{r}` for `}`.

```
{is tag}
{ is not tag }
{l}is not tag{r}
```


Notice `Presenter::getContext() is deprecated`
----------------------------------------------

Nette is by far the first PHP framework that switched to dependency injection and led programmers to use it consistently, starting from the presenters. If a presenter needs a dependency, [it will ask for it|dependency-injection:passing-dependencies].
In contrast, the way we pass the entire DI container to a class and it pulls the dependencies from it directly is considered an antipattern (it's called a service locator).
This way was used in Nette 0.x before the advent of dependency injection, and its relic is the method `Presenter::getContext()`, long ago marked as deprecated.

If you port a very old Nette application, you may find that it still uses this method. So since version 3.1 of `nette/application` you will encounter the warning `Nette\Application\UI\Presenter::getContext() is deprecated, use dependency injection`, since version 4.0 you will encounter the error that the method does not exist.

The clean solution, of course, is to redesign the application to pass dependencies using dependency injection. As a workaround, you can add your own `getContext()` method to your base presenter and bypass the message:

```php
abstract BasePresenter extends Nette\Application\UI\Presenter
{
	private Nette\DI\Container $context;

	public function injectContext(Nette\DI\Container $context)
	{
		$this->context = $context;
	}

	public function getContext(): Nette\DI\Container
	{
		return $this->context;
	}
}
```


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