You can use a variable to pass a parameter between pages. You do this by marking the variable as an input parameter, specifying how it becomes part of the contract to navigate to that page. You can also mark it as required, implying that it must be set in order to navigate to that page.

1. Create your variable or constant on the Variables tab for your scope.
2. In the variable or constant's properties, select an Input Parameter option (default is Disabled):
   • Click Enabled to pass the variable's value as an input parameter.
   • Click Required to require that the variable's value must be passed as an input parameter.
   
   

   
   Description of the illustration var-input-parameter-appui.png

   
   

   Tip:

   To display a list of values retrieved from a service (like a REST endpoint) for your input parameter, you can update the variable's JSON by adding @dt metadata and setting subtype to lov. Here's an example of the regionName variable set up to retrieve a list of values based on the response from a REST endpoint:

   "regionName": {
      "type": "string",
      "input": "fromCaller",
      "required": true,
      "@dt": {
        "subtype": "lov",
        "valueOptions": {
          "service": {
            "request": {
               "endpoint": "site_my2410appuiExtension:Countries/getAll"
             },
            "response": {
               "mapping": {
                 "value": "id",
                 "label": "name"
               },
               "itemsPath": ""
             }
           }
         }
       }
     }

   See Customize the JSON with Metadata for LOV metadata details.

3. If you want to pass the parameter on the URL of the pages or flows that you are invoking (by adding ?paramName=Value to the end of the URL), select Pass on URL. This option allows you to bookmark pages that will show specific data based on the parameter.
4. Optionally, set a default value.

Tip:

If you have a large number of variables defined, click and select Input Parameters Only to filter and view only those variables used as input parameters.

When a variable marked as an optional or required input parameter is used in your app, you can set its value on a page to see how the page displays:

1. Switch to the Page Designer tab.
2. Click in the toolbar to open the Page Input Parameters dialog. You'll see a list of input parameters for the page, including those from its parent flows and pages (if defined).
3. Set the parameter value and click Set Parameters.
   
   
   Description of the illustration var-input-parameter-designer-appui.png
   
   

   If the variable was marked as a required input parameter but a value isn't assigned to it, you'll see a red dot on the Page Input Parameters icon, like this: . Click the icon then to set the missing parameter. Required parameters appear at the top in the Page Input Parameters dialog and are marked with an asterisk (*).

   When a default value is set for the variable used as an input parameter, it will show when a value is yet to be assigned to the parameter. Deleting an assigned value will automatically apply the default value.