Power Apps Custom Pages JS Library - PowerThomas

JS library of useful functions to use within Power Apps Model-driven Apps and Custom Pages. Currently one function is documented below. More to come.

Install & import

1. Download the JS file
2. Open the file in any preferred IDE and replace the PowerThomas namespace with your own (on top and at bottom)
3. Add it as a JavaScript Web Resource in your Power Platform solution

Function

OpenPage

Opens a Page.

Params

Use them in this order:

#	Type	Name	Description
1	{object}	executionContext	The event context from which this function is executed. For a command bar button: on forms this is PrimaryControl, on views/subgrids this is SelectedControl.
2	{number}	sourceType	The type of source from where the Page is opened. 1 = form, 2 = view/subgrid.
3	{string}	pageTitle	The title of the Page to open.
4	{string}	pageType	The type of Page, e.g. "custom".
5	{string}	pageLogicalName	The logical name of the Page to open.
6	{string}	entityLogicalName	The logical name of the entity from which the page is opened.
7	{number}	target	How to open the Page. 1 = full page, 2 = dialog.
8	{number}	position	If the target is set to 2, this defines the type of dialog. 1 = centered, 2 = sidepane.
9	{number}	widthValue	The width of the page.
10	{number}	heightValue	The height of the page.
11	{string}	widthUnit	The unit used to determine the width, e.g. "px" or "%".
12	{string}	heightUnit	The unit used to determine the height, e.g. "px" or "%".
13	{boolean}	refreshOnClose	Whether to refresh the current context once the Page is closed (successfully). On forms: refresh form + ribbon. On views/subgrids: refresh grid (if supported).
14	{boolean}	navigateToOverviewOnClose	If true, it navigates to the overview of the current entity once the Page is closed (successfully).

---

Fetching the recordId inside your Custom Page

When you open a custom page via OpenPage, the recordId (and other context parameters) are passed as query string parameters.

Inside your custom page, retrieve them using the Param() function:

// Retrieve the recordId and entity logical name
Set(varRecordId, Param("recordId"));
Set(varEntityName, Param("entityName"));

// Example: use recordId to load a row
// Replace 'your_table' and 'your_tableid' with your actual Dataverse logical names
EditForm(Form1);
Form1.Item = LookUp([@your_table], your_tableid = GUID(varRecordId));

Available Params

• recordId → The GUID of the record (if opened from a form or subgrid).
• entityName → Logical name of the entity.
• name → Logical name of the custom page.
• Any other values provided via pageInput in JavaScript.

💡 Tip: Wrap Param("recordId") in GUID() when using it in Dataverse lookups or Patch calls:

GUID(Param("recordId"))

---

Notes

• Ensure sourceType is numeric (1 or 2) in the Command Designer.
• On forms, trySave is executed to persist changes and surface validation messages before navigating.
• On views/subgrids, the selected record is resolved from SelectedControl → Grid → SelectedRows → Row → Data → Entity → Id.