DotEnv files for MODX

This MODX plugin lets you override system settings (held in the database) on a per-install basis. Ideal for local changes on your development server (like SMTP server details).

I created this plugin as we forgot to update the SMTP details for our testing environment once, resulting in emails being sent that shouldn't have been.

IMPORTANT!!!

The .env file overrides settings at runtime. If you go and view System Settings in the manager, you will not see the .env changes. This is confusing. Unfortunately, short of destructively changing the values in the database (overwriting them with the .env values) there appears to be no work-around.

Update Event OnSiteSettingsRender may do what's needed... to be investigated unless some kind soul sends me a Pull Request

Installation

Install the plugin from the MODX Package Manager and activate it.

Alternative: installing from this repository

Clone this repository and put it in the core/components directory (this file should be located at core/components/dotenv/README.md)
Go to your MODX Manager, create a new plugin, and point it to the static file core/components/dotenv/plugin.php. Enable it for the OnMODXInit event.

Using DotEnv with MODX

Create a .env file at core/config/.env
If you use Git, add /core/config/.env to your .gitignore. You do not want to commit this file and accidentally deploy it to production -- or to store the sensitive details in it where others can read them.
Update your .htaccess file (if using Apache) or nginx config (if using NGINX) to prevent access via the browser to the .env file. Yes I know you're using this extension in development only, but you do NOT want the chance for anything to go wrong! (This is why sensitive files should not live in the webroot, but MODX does that by default).

For Apache (taken from StackOverflow):
```
<LocationMatch "\/\.">
    Require all denied
</LocationMatch>
```
For NGINX:
```
# Block access to dot files
location ~ /\. {
    deny  all;
}
```
Add some items to the .env file. A great one to test that it works is:
```
site_name="SET IN DOTENV"
```
Check this guide for the syntax rules allowed in .env.

You can use existing System Settings within your settings, like:
```
site_name="SAY ${emailsubject}"
```
Any System Settings can be used (which are in $modx->config, not just settings further up the .env file.
Check it works by clearing your site's cache and browsing to a page, looking at the changed title tag (if you use the sample files above)

Thanks