eGroupWare Application Development

This document explains eGroupWare's infrastructure and API, along with what is required to integrate applications into it.

Contents

1. Introduction
2. 1. Overview of application writing
   2. What does the eGroupWare API provide?
3. Guidelines
4. 1. Requirements
   2. Writing/porting your application
5. Installing your application
6. 1. Overview
   2. Automatic features
   3. Adding files, directories and icons.
   4. Making eGroupWare aware of your application
   5. Hooking into Administration page
   6. Hooking into Preferences page
7. Infrastructure
8. 1. Overview
   2. Directory tree
   3. Translations
9. The API
10. 1. Introduction
    2. Basic functions
    3. Application Functions
    4. File functions
    5. Email/NNTP Functions
11. Configuration Variables
12. 1. Introduction
    2. User information
    3. Group information
    4. Server information
    5. Database information
    6. Mail information
    7. NNTP information
    8. Application information
13. Using Language Support
14. 1. Overview
    2. How to use lang support
    3. Common return codes
15. Using Templates
16. 1. Overview
    2. How to use PHPLIB templates
    3. How to use eTemplate templates
17. About this document
18. 1. New versions
    2. Comments
    3. History
    4. Copyrights and Trademarks
    5. Acknowledgments and Thanks

1  Introduction

eGroupWare is a web based groupware application framework (API), for writing applications. Integrated applications such as email, calendar, todo list, address book, and file manager are included.

1.1  Overview of application writing

We have attempted to make writing application for eGroupWare as painless as possible. We hope any pain and suffering is cause by making your application work, but not dealing with eGroupWare itself.

1.2  What does the eGroupWare API provide?

The eGroupWare API handles session management, user/group management, has support for multiple databases, using the PHPLIB database abstraction method, we support templates using the PHPLIB Templates class, a file system interface, and even a network i/o interface.

On top of these standard functions, eGroupWare provides several functions to give you the information you need about the users environment, and to properly plug into eGroupWare.

2  Guidelines

2.1  Requirements

These guidelines must be followed for any application that wants considered for inclusion into eGroupWare deluxe:

• It must run on PHP4.1.0
• SQL statements must be compatible with both MySQL, PostgreSQL, M$ SQL Server and SAP-DB
• It must use our default header.inc.php include.
• It must use our $GLOBALS['phpgw']->link($url) for all links (this is for session support).
• It must use "POST" for form submit methods.
• It must respect eGW group rights and eGW user permissions.
• It must use our directory structure, template support and lang (multi-language) support.
• Where possible it should run on both Unix and NT platforms.
• For applications that do not meet these requirements, they can be available to users via the eGroupWare "3rd Party Apps" listing on our website. If you need help converting your application to templates and our lang support, we will try to connect you with someone to help.

2.2  Writing/porting your application

Include files

Each PHP page you write will need to include the header.inc.php along with a few variables.
This is done by putting this at the top of each PHP page.

<?php
$GLOBALS['phpgw_info']['flags']['currentapp'] = 'appname';
include('../header.inc.php');
?>

• The phpgwAPI - The eGroupWare API will be loaded.
• The eGW navbar will be loaded (by default, but can be disabled until a later point.
• appname/inc/functions.inc.php - This file is loaded just after the phpgwAPI and before any HTML code is generated. This file should include all your application specific functions.. You are welcome to include any additional files you need from within this file.
  Note: Depricated and not used for OOP (/index.php?menuaction=app.obj.method) calls.
• appname/inc/header.inc.php - This file is loaded just after the system header/navbar, and allows developers to use it for whatever they need to load.
  Note: Depricated and not used for OOP (/index.php?menuaction=app.obj.method) calls.
• appname/inc/footer.inc.php - This file is loaded just before the system footer, allowing developers to close connections and whatever else they need.
  Note: Depricated and not used for OOP (/index.php?menuaction=app.obj.method) calls.
• The eGW footer will be loaded, which closes several connections.

3  Installing your application

3.1  Overview

It is fairly simple to add and delete applications to/from eGroupWare.

3.2  Automatic features

To make things easy for developers we go ahead and load the following files.

• appname/inc/functions.inc.php - This file should include all your application specific functions.
  Note: Depricated and not used for OOP (/index.php?menuaction=app.obj.method) calls.
• appname/inc/header.inc.php - This file is loaded by $phpgw->common->header just after the system header/navbar, and allows developers to use it for whatever they need to load.
  Note: Depricated and not used for OOP (/index.php?menuaction=app.obj.method) calls.
• appname/inc/footer.inc.php - This file is loaded by $phpgw->common->footer just before the system footer, allowing developers to close connections and whatever else they need.
  Note: Depricated and not used for OOP (/index.php?menuaction=app.obj.method) calls.

3.3  Adding files, directories and icons.

You will need to create the following directories for your code
(replace 'appname' with your application name)

--appname

  +--inc

  |   |--functions.inc.php

  |   |--header.inc.php

  |   |--hook_preferences.inc.php

  |   |--hook_admin.inc.php

  |   +--footer.inc.php

  +--js

  |   |--base

  |   +--js_package_name

  +--setup

  |   |--default_records.inc.php

  |   |--setup.inc.php

  |   +--tables_current.inc.php

  +--templates

      +--default

3.4  Making eGroupWare aware of your application

To make the application aware of your application, add your application details to the applications table. This can be done via the GUI administration screen, or via a SQL script. The script below should only be used during initial development. You should use the eGroupWare setup system for install and updating the final version of your application.

INSERT INTO phpgw_applications (app_name, app_title, app_enabled)
        VALUES('appname', 'The App name', 1);

3.5  Hooking into Administration page

When a user goes to the Administration page, it starts appname/inc/hook_admin.inc.php for each application that is enabled, in alphabetical order of application title. If the file exists, it is include()d in the hopes it will display a selection of links to configure that application.

Simple Example:

<?php
// Old linear script style
$file['Site Configuration'] = $GLOBALS['phpgw']->link('myapp/myAdminPage.php');
// OR - OOP Style
$file['Site Configuration'] = $GLOBALS['phpgw']->link('/index.php',
                                        array(menuaction => 'myapp.uiobj.admin_method');
display_section('myapp',$file);
?&#gt;

• Links are relative to the admin/index.php file, not your application's base directory. (so use "appname" in your link() calls)
• The file is brought in with include() so be careful to not pollute the name-space too much

3.6  Hooking into Preferences page

The mechanism to hook into the preferences page is identical to the one used to hook into the administration page, however it looks for appname/inc/hook_preferences.inc.php instead of appname/inc/hook_admin.inc.php. The same functions and variables are defined.

4  Infrastructure

4.1  Overview

eGroupWare attempts to provide developers with a sound directory structure to work from.
The directory layout may seem complex at first, but after some use, you will see that it is designed to accommodate a large number of applications and functions.

4.2  Directory tree

--eGroupWare
  |
  +--admin
  |
  +--docs (installation docs)
  |
  +--files (Note: must be out of webserver document root!)
  |   |
  |   +--groups
  |   |
  |   +--homes
  |   |
  |   +--users
  |
  +--phpgwapi
  |   |
  |   +--cron (eGroupWare's optional daemons)
  |   |
  |   +--doc (developers docs)
  |   |
  |   +--inc
  |   |   |
  |   |   +--class.phpgw.inc.php
  |   |   |
  |   |   +--phpgw_info.inc.php
  |   |   |
  |   |   +--class.common.inc.php
  |   |   |
  |   |   +--etc..
  |   |
  |   +--js (javascript)
  |   |   |
  |   |   +--base
  |   |   |
  |   |   +--js_package_name
  |   |
  |   +--manual
  |   |
  |   +--setup
  |   |   |
  |   |   +--baseline.inc.php
  |   |   |
  |   |   +--default_records.inc.php
  |   |   |
  |   |   +--tables_current.inc.php
  |   |   |
  |   |   +--tables_update.inc.php
  |   |
  |   +--templates
  |   |   |
  |   |   +--default
  |   |   |   |
  |   |   |   +--images
  |   |   |
  |   |   +--verilak
  |   |       |
  |   |       +--images
  |   |
  |   +--themes
  |       |
  |       +--default.theme
  |
  +--preferences
  |
  +--setup

4.3  Translations

The translations are now being done thru the database, and may be configurable to use other mechanisms in future releases.

You can use the developer_tools translations application for creating the "lang files", which will be installed through the setup application. Alternatively you can edit the files manually. The file naming convention for the lang files is phpgw_<langcode>.lang. The files are stored in the app/setup directory. The format of the files is as follows:

english phrase in lower case    appname **      Translated phrase in desired case.

• replace ** with the desired language code, as used in the filename
• tabs are used to deliniate "columns"

5  The API

5.1  Introduction

eGroupWare attempts to provide developers with a useful API to handle common tasks.

To do this we have created a multi-dimensional class $GLOBALS['phpgw']->.

This allows for terrific code organization, and help developers easily identify the file that the function is in. All the files that are part of this class are in the inc/core directory and are named to match the sub-class.

Example: $phpgw->send->msg() is in the inc/phpgwapi/class.send.inc.php file.

5.2  Basic functions

$GLOBALS['phpgw']->link

$GLOBALS['phpgw']->link($url, $args)
Add support for session management. ALL links must use this, that includes href's form actions and header location's.

If you are just doing a form action back to the same page, you can use it without any parameters.

This function is right at the core of the class because it is used so often, we wanted to save developers a few keystrokes. Example:

<form name=copy method=post action="<?php echo $GLOBALS['phpgw']->link();?>">
/* If session management is done via passing url parameters */
/* The the result would be */
/* <form name=copy method=post action="somepage.php?sessionid=87687693276?kp3=kjh98u80"> */

5.3  Application Functions

$GLOBALS['phpgw']->common->phpgw_header

$GLOBALS['phpgw']->phpgw_header()
Print out the start of the HTML page, including the navigation bar and includes appname/inc/header.php, if using deprecated linear scripts style.

$GLOBALS['phpgw']->common->phpgw_footer

$GLOBALS['phpgw']->phpgw_footer()
Prints the system footer, and includes appname/inc/footer.php

$GLOBALS['phpgw']->common->appsession

$GLOBALS['phpgw']->common->appsession($data)
Store important information session information that your application needs.
$GLOBALS['phpgw']->appsession will return the value of your session data is you leave the parameter empty [i.e. $GLOBALS['phpgw']->appsession()], otherwise it will store whatever data you send to it.
You can also store a comma delimited string and use explode() to turn it back into an array when you receive the value back.

Example:

$GLOBALS['phpgw']->common->appsession("/path/to/something");
echo "Dir: " . $GLOBALS['phpgw']->common->appsession();

5.4  File functions

See Virtual File System (VFS) Developers Guide for more info.

5.5  Email/NNTP Functions

$phpgw->send->msg

$phpgw->msg->send($service, $to, $subject, $body, $msgtype, $cc, $bcc)
Send a message via email or NNTP and returns any error codes.
Example:

$to = 'someuser@domain.com';
$subject = 'Hello buddy';
$body = "Give me a call\n Been wondering what your up to.";
$errors = $GLOBALS['phpgw']->msg->send('email', $to, $subject, $body);

6  Configuration Variables

6.1  Introduction

eGroupWare attempts to provide developers with as much information about the user, group, server, and application configuration as possible.

To do this we provide a multi-dimensional array called "$GLOBALS['phpgw_info']", which includes all the information about your environment.

Due to the multi-dimensional array approach. getting these values is easy.

Here are some examples:

<?php
// To do a hello username
echo "Hello " . $GLOBALS['phpgw_info']['user']['fullname'];
//If username first name is John and last name is Doe, prints: 'Hello John Doe'
?>
<?php
// To find out the location of the imap server
echo 'IMAP Server is named: ' . $GLOBALS['phpgw_info']['server']['imap_server']; 
//If imap is running on localhost, prints: 'IMAP Server is named: localhost'
?>

6.2  User information

6.3  Group information

6.4  Server information

6.5  Database information

It is unlikely you will need these, because $GLOBALS['phpgw']->db will already be loaded as a database for you to use.

6.6  Mail information

It is unlikely you will need these, because most email needs are services thru core eGroupWare functions.

$phpgw_info[``server''][``mail_server''] = Address of the IMAP server. Usually this is set to localhost.

$phpgw_info[``server''][``mail_server_type''] = IMAP or POP3

$phpgw_info[``server''][``imap_server_type''] = Cyrus or Uwash

$phpgw_info[``server''][``imap_port''] = This is usually 143, and should only be changed if there is a good reason.

$phpgw_info[``server''][``mail_suffix] = This is the domain name, used to add to email address

$phpgw_info[``server''][``mail_login_type''] = This adds support for VMailMgr. Generally this should be set to 'standard'.

$phpgw_info[``server''][``smtp_server''] = Address of the SMTP server. Usually this is set to localhost.

$phpgw_info[``server''][``smtp_port''] = This is usually 25, and should only be changed if there is a good reason

6.7  NNTP information

$phpgw_info[``server''][``nntp_server''] = Address of the NNTP server.

$phpgw_info[``server''][``nntp_port''] = This is usually XX, and should only be changed if there is a good reason.

$phpgw_info[``server''][``nntp_sender''] = Unknown

$phpgw_info[``server''][``nntp_organization''] = Unknown

$phpgw_info[``server''][``nntp_admin''] = Unknown

6.8  Application information

Each application has the following information available.

$phpgw_info[``apps''][``appname''][``title''] = The title of the application.

$phpgw_info[``apps''][``appname''][``enabled''] = If the application is enabled. True or False.

$phpgw_info[``server''][``app_include_dir''] = Location of the current application include files.

$phpgw_info[``server''][``app_template_dir''] = Location of the current application tpl files.

$phpgw_info[``server''][``app_lang_dir''] = Location of the current lang directory.

$phpgw_info[``server''][``app_auth''] = If the server and current user have access to current application

$phpgw_info[``server''][``app_current''] = name of the current application.

7  Using Language Support

7.1  Overview

eGroupWare is built using a multi-language support scheme. This means the pages can be translated to other languages very easily. Translations of text strings are stored in the eGroupWare database, and can be modified by the eGroupWare administrator.

7.2  How to use lang support

The lang() function is your application's interface to eGroupWare's internationalization support.

While developing your application, just wrap all your text output with calls to lang(), as in the following code:

$x = 42;
echo lang("The counter is %1",$x)."<br>";

When a translation is not found, the original text will be returned with a * after the string. This makes it easy to develop your application, then go back and add missing translations (identified by the *) later.

Without a specific translation in the lang table, the above code will print:

The counter is 42*<br> 

il contatore è 42<br&#gt;

The lang function

lang($key, $m1="", $m2="", $m3="", $m4="", $m5="", 
        $m6="", $m7="", $m8="", $m9="", $m10="")

[$key ] 

is the string to translate and may contain replacement directives of the form %n.

[$m1 ] 

is the first replacement value or may be an array of replacement values (in which case $m2 and above are ignored).

[$m2 - $m10 ] 

the 2nd through 10th replacement values if $m1 is not an array.

Adding translation data

The TranslationTools (former developer_tools) allow easily create new translations of eGW applications.
A developer also can use them to create the english lang-file by searching for new phrases in his sources.

The lang table

The translation class uses the lang table for all translations. We are concerned with 4 of the columns to create a translation:

[message_id ] 

The key to identify the message (the $key passed to the lang() function). This is written in English.

[app_name ] 

The application the translation applies to, or common if it is common across multiple applications.

[lang ] 

The code for the language the translation is in.

[content ] 

The translated string.

7.3  Common return codes

If you browse through the eGroupWare sources, you may notice a pattern to the return codes used in the higher-level functions. The codes used are partially documented in the doc/developers/CODES file.

Codes are used as a simple way to communicate common error and progress conditions back to the user. They are mapped to a text string through the check_code() function, which passes the strings through lang() before returning.

For example, calling

echo check_code(13);

Your message has been sent

8  Using Templates

8.1  Overview

eGroupWare is built using a templates based design. This means the display pages, stored in tpl files, can be translated to other languages, made to look completely different.

8.2  How to use PHPLIB templates

For Further info read the PHPLIBs documentation for their template class. http://phplib.sanisoft.com

8.3  How to use eTemplate templates

eTemplate is a new widget-based template system, which is used eg. for the InfoLog application.
There's a Tutorial and a Referenz documentation availible.

9  About this document

9.1  New versions

The newest version of this document can be found on our website http://www.eGroupWare.org.

9.2  Comments

Comments on this HOWTO should be directed to the eGroupWare developers mailing list (subscription at www.sourceforge.net/egroupware/).

9.3  History

This document was written by Dan Kuykendall.

2000-09-25 documentation on lang(), codes, administration and preferences extension added by Steve Brown.

2001-01-08 fixed directory structure, minor layout changes, imported to lyx source - Darryl VanDorp

2001-01-08 fixed directory structure, minor layout changes, imported to lyx source - Darryl VanDorp

2004-02-22 imported skwashd's changes and adapted for eGroupWare - Ralf Becker

9.4  Copyrights and Trademarks

Copyright © Free Software Foundarion. Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.1 or any later version published by the Free Software Foundation.

A copy of the license is available at http://www.gnu.org/copyleft/gpl.html

9.5  Acknowledgments and Thanks

Thanks to Joesph Engo for starting eGroupWare (at the time called webdistro). Thanks to all the developers and users who contribute to making eGroupWare such a success.

$Id: index.html,v 1.5 2004/02/23 00:24:21 ralfbecker Exp $