How to specify a filter for installation files
For example, you need to install only some files , depending on user's settings. You can use the If Condition parameter in the Installation Files command, but what should you do if there are many files and conditions. Inserting many Installation Files commands is not a good technique . In this case, the CreateInstall installer allows you to set an unpacking filter for installation files. This function is called for each file before the file is decompressed. If the function returns 1 then the file will be installed. If the function returns 0 then the file will be skipped.
Step 1
Insert the Xfilter variable into the Additional Settings list of Installation Files command. Specify your function name as the value of the variable. Notice, its name must be end with cmdproc!
Xfilter => myfiltercmdproc
Step 2
Insert the Source Code command at the beginning of the installation script. Check the 'External source code' checkbox there. Also, you can use the existing Source code command if it exists in your script. Append the pattern of your function there.
func uint myfiltercmdproc( geafile gf )
{
return 1
}
In this case, our filter function does nothing and allows all files to be unpacked. Look at the fields of the geafile structure. It contains information about the installing file.
type geafile
{
filetime ft // File time
uint size // File size
uint attrib // File attribute
uint hiver // Hi version
uint lowver // Low version
str name // Name of the file
str subfolder // Name of the subfolder
}
Step 3
Now, you can specify a filter for your installation. For example, let's develop a function, which doesn't allow the unpacking of .jpg files if the variable nojpg equals 1.
func uint myfiltercmdproc( geafile gf )
{
if macrox_getint( "nojpg" )
{
str ext = gf.name.fgetext()
ext.lower()
if ext == "jpg" : return 0
}
return 1
}
You can change the filename name and the target subfolder subfolder in the gf variable.