How can I tell Notepad++ to always use a particular language with a particular file extension

Question

I've associated .xul with Notepad++ so if I double-click on a .xul file, it will open in Notepad++. But Notepad++ doesn't know that XUL is just a particular type of XML, so I then have to manually click on "Language > XML" to get XML syntax highlighting. Is there a way that I can tell it: "every time you open a file with the extension .xul, automatically switch to the XML language"?

Answer 1

All you have to do is tell Notepad++ that "xul" files are actually "XML" files.

1. Go to Settings > Style Configurator
2. Under Language, scroll down and highlight "XML"
3. At the bottom, under User ext. type in "xul"
4. Press Save & Close
5. Open your file and it should now highlight properly.

Some other helpful links:

• Assigning custom extensions to a language’s syntax highlighting in Notepad++
• Associating file extensions with highlighters

Answer 2

Here is the instructions for user defined languages. With pictures.

Select: Language --> Define Your Language:

Make sure you omit "." from extension in the Ext. box, or it wont work:

Answer 3

Update for version 7.5+ and for multiple extensions

1) Settings > Style Configurator

2) look under "Languages:" , choose your target language.

3) look at textbox under "User ext. :"

Simple type the extension you wish to associate for that language. For multiple file extensions, it should be separated via SPACE. Do not use any "." period/dot characters.

EG. for SQL i used the following extensions for table, view, stored proc and user defined functions:

tab viw prc udf

Answer 4

See Doltknuckle's answer which is great. This answer may help should you find syntax highlighting going a bit haywire. Based on x64 v7.8.6 on Windows.

NPP keeps styling configuration in two files in %APPDATA%\Notepad++:

• langs.xml
• stylers.xml

langs.xml is used for built-in languages (like C++ and XML). To find the current "in-built" file types associated with XML, search for name="xml". In the ext section you will find the file types that use XML syntax highlight. In v7.8.6, xul is already assigned to XML so no action is required.

stylers.xml is used for the actual styling applied to each language. It is also where user extensions (User ext.) are saved. To see the extra extensions that have been assigned to XML, search for name="xml".

Many applications re-cycle file extensions. For example .ts files are Javascript files, but also XML files used by Qt Linguist. You may find yourself assigning EXTA to STYLEA (or EXTA may already be assigned to STYLEA), forgetting about it, and later assigning EXTA to STYLEB. NPP will not warn you and you may start to see unexpected syntax highlighting.

This background information may help you find and correct the problem.

As an concrete example, assign cpp to Verilog (clearly a mistake, it is just by way of example). Now all .cpp files will have Verilog and not C++ highlighting.

This may or may not be a bug/limitation in NPP. Certainly a "conflict warning" when you load Settings > Style Configurator... would help. But with so many file extensions out there this may not be possible to resolve. Be aware and hope this helps someone!