Linux application: Tips and tricks

ONLINE HELP
WINDEV, WEBDEV AND WINDEV MOBILE

Version:

Home | Sign in | English

This content has been translated automatically. Click here to view the French version.

Help / Developing for Linux

Overview
Function not available
A function is not available on Linux: how can I adapt my existing code?
Unavailable control
Using the available controls
I must modify the UI of a window. How can I be sure to use controls that are available for all my configurations?
Paths of files
Tree structure
Case and accented characters

WINDEV

WEBDEV

WINDEV Mobile

Others

See also

Linux application: Tips and tricks

Available only with this kind of connection

Overview

In multi-configuration Windows/Linux applications, various limitations may arise: unmanaged fields, unavailable functions, etc.

The possible solutions are presented in this help page.

Function not available

A function is not available on Linux: how can I adapt my existing code?

Some functions or properties may not be available in Linux configuration:

because they have no reason to exist (the RegistryXXX functions for example).
because the associated controls are not available (TreeXXX functions).
because they are not yet available in this version.

For a given treatment or event (click code of a Button control for example), the <ExecutionTarget...> statement is used to define the code that will be executed according to the current platform.

For example, for a Linux application, you can indicate the specific code to be executed:

<SI CibleExécution=ApplicationLinux>
// Traitement spécifique à la plateforme Linux
<FIN>

Likewise, if a section of code is only available on Windows, you can use the following code:

<SI CibleExécution=ApplicationWindows>
// Traitement spécifique à la plateforme Windows
<FIN>

Note: A wide range of execution targets Exist. You can combine them in the same statement.

Unavailable control

Some fields are not yet available in the Linux framework, such as TreeView control, Table control, Bar Code control and Shape control..

At runtime in Linux, if one single control is not supported in the window, none of the controls will be displayed and a WLanguage error will occur.

In this case, several possibilities exist.

The control can be deleted
It is a "minor" control (the Shape control for example, used to identify areas in the UI). Depending on the case, you have the ability to:

delete it,
replace it by an image or by an "empty" static with a border.

The control can be moved
It is an important control that cannot be deleted but that can be moved into another window (a Bar Code control for example). In this case, you must:

create a new window intended to the display of the control.
move the control into this new window.
add into the source window a button used to open the created window. This button must not be accessible in Linux.

The control cannot be deleted or moved
It is an important control that cannot be deleted or moved (a TreeView control or a TreeView Table table for example). In this case, the only solution consists in duplicating the window in order for each configuration to have its OWN window.

To duplicate a window:

In the window editor, go to the "Home" tab, "General" group, expand "Save" and select "Save as".
Give a new name to the window. A suffix can be added to the name according to the platform ("WIN_ CustomerForm_Linux" for example).
Use a conditional target-code to call the window adapted to the runtime platform.

Caution: This solution should be used with caution and for windows with low code and interface requirements.. Indeed, once the window has been doubled, all modifications, corrections, etc. must be made twice, with the not inconsiderable risk of oversights..

Using the available controls

I must modify the UI of a window. How can I be sure to use controls that are available for all my configurations?

WINDEV, WEBDEV and WINDEV Mobile clearly indicate the controls and the control parameters that are not available in one or more project configurations.

The different types of controls
The options and the buttons found in the toolbar that are used to create the controls are grayed if the current configuration does not support this type of control.
If you use a control that is not available in one of the project configurations, an error is displayed in the error pane.
The options of controls
Some control parameters may not be available according to the runtime platform.
These parameters can be modified in the control description window, but they will be signaled:
- in gray if the parameter is not available for any of the project configurations.
- in purple if the parameter is available for some configurations and not available for other configurations.

Paths of files

Differences can be noticed in the file management between Windows and Linux:

regarding the tree structure of the files.
regarding the case and the accented characters.

Tree structure

The separator used in the tree structure of the paths differs according to the platform:

"\" in Windows,
"/" in Linux.

Two WLanguage functions can be used to manage this problem:

fSep returns the separator corresponding to the platform currently run. This function is used to build a path regardless of the current platform.
```
// Construit le chemin du fichier de configuration 
sFichierConfig = fExeDir() + fSep() + "config.ini"
```
Note: the CompleteDir function is used to add the correct separator to a tree structure.. However, the code becomes less readable after 2 inclusions.

fSeparator is used to retrieve a path with normalized separators. This function is very useful if the application uses paths stored/built on a different platform.

sFichierConfig = ".\Temp\MonFichier.txt"
// Normalise le chemin 
sFichierConfig = fSeparator(sFichierConfig) 
// Sous Windows: ".\Temp\MonFichier.txt"
// Sous Linux : "./Temp/MonFichier.txt"

Case and accented characters

Unlike Windows, Linux is case-sensitive.

For example, the following command line:

// Ouvre le fichier "MonFichier.Txt"
fOpen("MonFichier.txt")

will not open the "myfile.txt" file in Linux while it will be properly opened in Windows.

Therefore, don't forget to check the case of the files on disk and the case used in the WLanguage code.