How to use referencing functions inside a viewDefintion of a Managed App

Question

How to use referencing functions inside a viewDefintion of a Managed App

Steven Hardy 0

In our managed app, we deploy and manage an nva resource. In the createUiDefinition, we make use of Microsoft.Solutions.ArmApiControl to fetch the available versions for a given nva sku, so the user can select it via a Microsoft.Common.Dropdown. The "path" for the ArmApiControl requires the subscription id, which can be gotten via the reference function "subscription().id" then concat into the final desired path.

This works fine for the main createUiDefinition.

In our viewDefinition, we have added custom "commands" buttons that open up they're own CreateUiDef's, to allow the user to update the deployed resource to a different version. We want to be able to show the same dropdown in this view, however it seems that all the reference functions do not work, and subscription().id is empty.

Simplified create ui definition that works (dropdown shows available nva versions for first arbirtrary sku):

{
  "$schema": "https://schema.management.azure.com/schemas/0.1.2-preview/CreateUIDefinition.MultiVm.json#",
  "handler": "Microsoft.Azure.CreateUIDef",
  "version": "0.1.2-preview",
  "parameters": {
    "basics": [
      {}
    ],
    "steps": [
      {
        "name": "step1",
        "label": "Step 1",
        "elements": [
          {
            "name": "details",
            "type": "Microsoft.Solutions.ArmApiControl",
            "toolTip": "The versions of the current sku.",
            "request": {
              "method": "GET",
              "path": "[concat(subscription().id, '/providers/Microsoft.Network/networkVirtualApplianceSkus?api-version=2024-07-01')]"
            }
          },
          {
            "name": "version",
            "type": "Microsoft.Common.DropDown",
            "label": "Version",
            "defaultValue": "[first(coalesce(first(steps('step1').details.value), parse('{\"properties\":{}}')).properties.availableVersions)]",
            "constraints": {
              "allowedValues": "[map(coalesce(first(steps('step1').details.value), parse('{\"properties\":{}}')).properties.availableVersions, (version) => parse(concat('{\"label\":\"',version,'\",\"value\":\"',version,'\"}')))]",
              "required": true
            },
            "visible": true
          }
        ]
      }
    ],
    "outputs": {
      "version": "[steps('step1').version]"
    }
  }
}

Simplified viewDefinition that does not work (exact same dropdown but in the "update" action button):

{
  "$schema": "https://schema.management.azure.com/schemas/viewdefinition/0.0.1-preview/ViewDefinition.json#",
  "contentVersion": "0.0.0.1",
  "views": [
    {
      "kind": "Overview",
      "properties": {
        "header": " ",
        "commands": [
          {
            "path": "update",
            "displayName": "Update",
            "icon": "Polychromatic.Gear",
            "createUIDefinition": {
              "$schema": "https://schema.management.azure.com/schemas/0.1.2-preview/CreateUIDefinition.MultiVm.json#",
              "handler": "Microsoft.Azure.CreateUIDef",
              "version": "0.1.2-preview",
              "parameters": {
                "steps": [
                  {
                    "name": "step1",
                    "label": "Step 1",
                    "elements": [
                      {
                        "name": "details",
                        "type": "Microsoft.Solutions.ArmApiControl",
                        "toolTip": "The versions of the current sku.",
                        "request": {
                          "method": "GET",
                          "path": "[concat(subscription().id, '/providers/Microsoft.Network/networkVirtualApplianceSkus?api-version=2024-07-01')]"
                        }
                      },
                      {
                        "name": "version",
                        "type": "Microsoft.Common.DropDown",
                        "label": "Version",
                        "defaultValue": "[first(coalesce(first(steps('step1').details.value), parse('{\"properties\":{}}')).properties.availableVersions)]",
                        "constraints": {
                          "allowedValues": "[map(coalesce(first(steps('step1').details.value), parse('{\"properties\":{}}')).properties.availableVersions, (version) => parse(concat('{\"label\":\"',version,'\",\"value\":\"',version,'\"}')))]",
                          "required": true
                        },
                        "visible": true
                      }
                    ]
                  }
                ],
                "outputs": {
                  "properties": {
                    "version": "[steps('step1').version]"
                  }
                }
              }
            }
          }
        ]
      }
    }
  ]
}

Pranay Reddy Madireddy 4,090 Reputation points Microsoft External Staff

2025-04-29T19:38:13.13+00:00
Hi Steven Hardy

Unfortunately, the behavior you're seeing could be due to how the context is set up in the view definition compared to the create UI definition. Generally, reference functions might have differing scopes based on where they are called.

Here are a few things you might want to try or consider:

Review Scope of Reference Functions: Functions like subscription().id might not be available in the context of the view definition. Ensure that you're accessing them appropriately in the right context.

Check Visibility and Constraints: Sometimes the visibility constraints in the view might affect how the parameters are being interpreted. Double-check those settings to ensure they’re appropriate.

Try Debugging in the Portal: If you haven't already, use Azure's debugging tools to check if there are any errors or messages that could give you insight into why the subscription ID is returning empty.

Consult Documentation: Since the functionality can be nuanced, reviewing Microsoft's documentation regarding the use of reference functions in view definitions could point out any limitations or additional requirements you might need to meet.

let us know if any help, we will always help as you needed.!

Please do not forget to "Accept the answer” and upvote it wherever the information provided helps you, this can be beneficial to other community members.it would be greatly appreciated and helpful to others.
Pranay Reddy Madireddy 4,090 Reputation points Microsoft External Staff

2025-05-01T01:15:38.34+00:00

Hi Steven Hardy

In Azure Managed Applications, referencing functions such as subscription().id within the viewDefinition can lead to unexpected behavior due to differences in context evaluation. Specifically, the viewDefinition runs in a different scope than the createUiDefinition, and it does not have access to the same resource context. This means that functions which work in createUiDefinition like subscription() may not resolve correctly in the viewDefinition.

In your scenario, the outputs from createUiDefinition are passed only to the main ARM template, not directly to the viewDefinition. As a result, you cannot dynamically retrieve values like the subscription ID within the viewDefinition using standard ARM functions.

To work around this limitation, you might consider the following approaches:

Use Static or Predefined Values: If your use case allows, define a fixed list of values in the viewDefinition rather than relying on dynamic data.

Pass Required Parameters: Evaluate whether needed context such as the subscription ID can be passed from the main ARM template to the viewDefinition via parameters.

Refactor Logic: Consider restructuring your application flow to handle required values within the main template and pass only what’s necessary into the viewDefinition.

Unfortunately, due to current limitations, dynamic evaluation of certain context-based functions within viewDefinition isn't supported, so achieving your intended behavior may require adjustments to the template's structure.

https://learn.microsoft.com/en-us/azure/azure-resource-manager/templates/scope-functions?source=recommendations&tabs=azure-powershell

https://learn.microsoft.com/en-us/azure/azure-resource-manager/managed-applications/concepts-view-definition?source=recommendations

let us know if any help, we will always help as you needed.!

Please do not forget to "Accept the answer” and upvote it wherever the information provided helps you, this can be beneficial to other community members.it would be greatly appreciated and helpful to others.

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Pranay Reddy Madireddy 4,090 Reputation points Microsoft External Staff

2025-04-29T19:38:13.13+00:00

Hi Steven Hardy

Unfortunately, the behavior you're seeing could be due to how the context is set up in the view definition compared to the create UI definition. Generally, reference functions might have differing scopes based on where they are called.

Here are a few things you might want to try or consider:

Review Scope of Reference Functions: Functions like subscription().id might not be available in the context of the view definition. Ensure that you're accessing them appropriately in the right context.

Check Visibility and Constraints: Sometimes the visibility constraints in the view might affect how the parameters are being interpreted. Double-check those settings to ensure they’re appropriate.

Try Debugging in the Portal: If you haven't already, use Azure's debugging tools to check if there are any errors or messages that could give you insight into why the subscription ID is returning empty.

Consult Documentation: Since the functionality can be nuanced, reviewing Microsoft's documentation regarding the use of reference functions in view definitions could point out any limitations or additional requirements you might need to meet.

let us know if any help, we will always help as you needed.!

Please do not forget to "Accept the answer” and upvote it wherever the information provided helps you, this can be beneficial to other community members.it would be greatly appreciated and helpful to others.

Answer 1

Hi Steven Hardy

Understanding the Scope of Referencing Functions:

Referencing functions such as subscription(), resourceGroup(), location(), basics(), and steps() are designed to operate within the context of the main createUiDefinition.json file. These functions rely on the deployment context established during the creation of the managed application. When you define a nested createUiDefinition within a viewDefinition.json, the context may not be fully established, leading to the unavailability or incorrect evaluation of these functions.

Limitations in viewDefinition.json:

The viewDefinition.json file allows you to customize the managed application's overview and other views. However, it operates separately from the main createUiDefinition.json and does not inherently have access to the same deployment context. As a result, referencing functions that depend on deployment context may not function as expected within viewDefinition.json.

Potential Workarounds:

While there is no direct support for referencing functions within viewDefinition.json, you can consider the following approaches:

1.Pass Parameters Explicitly: Instead of relying on referencing functions, pass the necessary parameters explicitly from the main createUiDefinition.json to the nested createUiDefinition within the viewDefinition.json. This approach ensures that the required values are available without depending on the evaluation of referencing functions.

2.Use Static Values: If the values for the dropdown options are known and unlikely to change, you can hardcode them into the nested createUiDefinition. This eliminates the need for dynamic evaluation but reduces flexibility.

3.Implement Custom Logic: Develop custom logic within your application to handle the dynamic fetching of values. This might involve using Azure Functions or other services to retrieve the necessary data and pass it to the UI components.

The inability to use referencing functions within viewDefinition.json is a known limitation due to the separate evaluation contexts of the main createUiDefinition.json and viewDefinition.json. To work around this, consider passing parameters explicitly, using static values, or implementing custom logic to provide the necessary data to your UI components.

Please let me know if you face any challenge here, I can help you to resolve this issue further
Please do not forget to "Accept the answer” and “upvote it” wherever the information provided helps you, this can be beneficial to other community members.it would be greatly appreciated and helpful to others.

Steven Hardy 0 Reputation points

2025-04-30T15:18:18.5566667+00:00

Due to the way Managed Applications work, I do not think there is even a way to achieve option 1) (as the outputs from the createUiDefinition are passed to the main arm template, not the viewDefinition), and without referencing functions to get subscription/resource context 3) is also impossible.

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How to use referencing functions inside a viewDefintion of a Managed App

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