Base Style property (User Control object)

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Sets the Base Style for a User Control object. All the libraries (ZIP files) with UI design definitions that were previously added to the KB as File objects are offered to select one of them.


Default The User Control object does not have any assigned Base Style.


The material available online about Web Design to integrate into the applications developed with GeneXus is astonishing! There is a boom of the so-called "CSS Frameworks," which complement Javascript development Frameworks (e.g., JQuery). Applications can be made more attractive thanks to CSS Frameworks.

These CSS Frameworks provide hundreds of widgets, compositions, sources, etc.
Some of the most popular ones are as follows:

  • Bootstrap
  • SemanticUI
  • Pure.css
  • Kube
  • Materialize

What is a Base Library

A Base Library is an external resource that uses a CSS Framework. Samples can be: Semantic UI, Bootstrap, etc.

Base Libraries are external CSS & JS & Assets files that are globally installed with GeneXus.

How to create a new Base Library inside a KB

First, to create a Base Library, you have to zip all your required files (CSS, JS, etc.) inside a zip file and save it with .gxlibrary extension.

Then, you can include that Base Library inside your Knowledge Base by creating a new File object and specifying the path to upload your Base Library.

Finally, the Library will be offered for this property so that you can select it.

While several libraries can be included in the KB, it is recommended to use the same Base Style for different objects, to maintain consistency.


1) If you want to just add external references to resources you need to create a references file inside the library, each line of this file will be considered a reference.

For example, you could add a glue.references with the following content:


This means GeneXus will add references to those files when some Theme or User Control uses your Base Library.

2) If you create a User Control object and you set its Base Style property = None, its aesthetic will not be cute. 


This property applies only at design-time.


This property is available since GeneXus 16.


Objects: User Control
Platforms: Web(.Net, Java)