functions. These deal with common problems like registering your
module in the template include-path. `civix` may automatically
overwrite this file, so generally do not edit it.
-***info.xml*** is a manifest that describes your extension – the name, license, version number, etc. You should edit most information in this file. The information contained in this file will also be used if published on civicrm.org.
-***myextension.php*** stores source code for all your hooks. It includes a few default hook implementations which will make development easier. You can add and remove hooks as you wish. (Note: This file name is different in each module – it is based the module's *[short-name](/extensions/index.md#extension-names)*.)
-***myextension.civix.php*** contains auto-generated helper functions. These deal with common problems like registering your
module in the template include-path. `civix` may automatically overwrite this file, so generally do not edit it.
## Extension Directory Structure
In addition, civix creates some empty directories. These directories are
reminiscent of the directory structure in CiviCRM core:
In addition, civix creates some empty directories. These directories are reminiscent of the directory structure in CiviCRM core:
-***CRM/Myextension/*** stores PHP class files. Classes in this
folder should be prefixed with "CRM\_Myextension\_"
-***CRM/Myextension/*** stores PHP class files. Classes in this folder should be prefixed with "CRM\_Myextension\_".
-***templates/*** stores Smarty templates.
-***xml/*** stores XML configuration files (such as URL routes and schema xml)
-***build/*** stores exportable .zip files
-***xml/*** stores XML configuration files (such as URL routes and schema xml).
-***build/*** stores exportable .zip files.
When adding files into these directories it is advisable to follow similar patterns to that in CiviCRM Core
e.g. BAO files should go in "CRM\_Myextension\BAO\", likewise with Form and Page. This ensures that for developers
that seek to modify or improve the extension files can be found in standard locations.
When adding files into these directories it is advisable to follow similar patterns to that in CiviCRM Core e.g. BAO files should go in "CRM\_Myextension\BAO\", likewise with Form and Page. This ensures that for developers that seek to modify or improve the extension files can be found in standard locations.
## The Big `E`
There are many times when you need to reference something from the
extension -- e.g. its name, its file-path, or its translated messages.
There are many times when you need to reference something from the extension -- e.g. its name, its file-path, or its translated messages.
For example, this code displays a translated message (using the translation
data for this extension):
For example, this code displays a translated message (using the translation data for this extension):
```php
if($welcoming){
...
...
@@ -54,9 +40,7 @@ if ($welcoming) {
Repeatedly entering the name of the extension is a bit tiresome.
For code generated by `civix` v17.08.0+ (or suitably
includes the `E` helper which provides easier access:
For code generated by `civix` v17.08.0+ (or suitably [upgraded](https://github.com/totten/civix/blob/master/UPGRADE.md)), `civix` includes the `E` helper which provides easier access:
```php
useCRM_Mymodule_ExtensionUtilasE;
...
...
@@ -68,9 +52,7 @@ if ($welcoming) {
}
```
Note that `E` is an alias. It stands for "extension" -- as in "the current
extension that I'm writing". It's a very thin class that provides small
helpers for looking up your extension's resources, e.g.
Note that `E` is an alias. It stands for "extension" -- as in "the current extension that I'm writing". It's a very thin class that provides small helpers for looking up your extension's resources, e.g.
*`E::ts($text)` -- Translate a string (using the extensions' translation file)
*`E::path($file)` -- Get the path to a resource file (within this extension)
