grails-view-models | Since Grails

grails-view-models is a Java library. grails-view-models has no bugs, it has no vulnerabilities, it has a Permissive License and it has low support. However grails-view-models build file is not available. You can download it from GitHub.

Since Grails is already founded on the MVC pattern, the idea of MVVM takes on a slightly different meaning to what it does to desktop developers. In the context of a Grails application, a “View Model” is an abstraction of the view oriented properties of an aspect of the application model. Consider the following example. Your application lists one or more products on a screen. If the price of a product is less than $10, you want the product name to display in a different colour. Where does this characteristic belong? It most certainly does not belong on your Product domain class for obvious reasons. There are two feasible options; a taglib or a snippet of Groovy code in the view GSP. Using a taglib is a reasonable choice here, but taglibs are inconvenient to test and it doesn't seem right to create a tag to do a calculation (i.e. tags are inherently focussed on creating HTML representations of things). Using inline snippets of Groovy is very convenient, but difficult to test and prone to decay over time. The MVVM pattern (as we are interpreting it) suggest that a specialised object should be created that implements the view level concerns of the product. Enter ProductViewModel. Now instead of passing your Product instance to the view, you pass an instance of ProductViewModel.