Hi,

First, I am looking at the source code in PegaCompositeGadgetMgr.js to avoid any confusion.

You listed 2 parameters that simply don't exists:

data-pega-parameters

data-pega-query

These are incorrectly mentioned in some of the articles on the support community.

https://community.pega.com/knowledgebase/articles/previous-and-current-pega-web-mashup-attributes

These two are actually the following:

data-pega-parameters  should be mentioned as data-pega-action-param-parameters

data-pega-query should be mentioned as data-pega-action-param-query

(I will get this fixed)

Now, to answer your question the differences between the following parameters:

data-pega-action-param-query

This is a required parameter of "query" when using the data-pega-action of OpenWorkByURL.

A perfect example is when you want to display a full end user portal in a mashup you have to use this:

data-pega-action ='OpenWorkByURL'
data-pega-action-param-query ='pyActivity=Data-Portal.ShowDesktop'

Every action type may have one or more required parameters and they all use the "data-pega-action-param-[Param_Name]' naming convention.

data-pega-action-param-parameters

These are parameters added to the initial mashup processing and are not specific to the action type being used. Think of these parameters as being specific to client needs to send extra data to PRPC.  This follows a very specific syntax:

data-pega-action-param-parameters="{param1_name:'param1_value',param2_name:'param2_value'}"