Filters

All versions of Preview HTML since 1.3 can generate HTML from other file types using custom filters.

Defining a custom filter

The format of a filter definition is illustrated here.

A sample configuration can also be found in the plugin's installation folder:

Fully installed Notepad++ editions

(64-bit) %ProgramFiles%\Notepad++\plugins\PreviewHTML\filters.sample.ini

(32-bit) %ProgramFiles(x86)%\Notepad++\plugins\PreviewHTML\filters.sample.ini

Portable Notepad++ editions

$(PORTABLE_NPP_DIR)\plugins\PreviewHTML\filters.sample.ini

Important

The generator program must:

1. be usable from a command line such as the Command Prompt or PowerShell;
2. print an HTML string to standard output — your filter definition should not redirect output to a file on disk

For example, this filter will be activated by opening any file with the extension .md, .mkd or .markdown:

[markdown]
Extension=.md,.mkd,.markdown
Command=pandoc -t html -f gfm "%1"

Note

The above example assumes that pandoc is already visible to the system's %PATH%. For programs not in the %PATH%, you must provide the program's complete file name in your Command key, for example:

; ...
Command="C:\Notepad++\tools\comrak\comrak.exe" "%1"

Editing Filters.ini

Save your filter definitions in the plugin's configuration folder with the file name Filters.ini.

The path to the configuration folder depends on how Notepad++ was installed:

Fully installed Notepad++ editions

%AppData%\Notepad++\plugins\Config\PreviewHTML\Filters.ini

Portable Notepad++ editions

$(PORTABLE_NPP_DIR)\plugins\Config\PreviewHTML\Filters.ini

To make sure you are editing the correct file, do the following:

• Install the plugin and (re)start Notepad++

• From the toolbar menu, select Plugins > Preview HTML > Edit filter definitions

Note

Changes to Filters.ini are applied immediately — there is no need to restart the application.

Example