Logic App: How to create email sending notification with multiple attachments?

Question

Hi,

I'm trying to create a logic app workflow with HTTP trigger which will receive the following payload.

{
    "email_body": "Hi Users,<br>Please find the files attached.",
    "email_recipients": "recipients@xyz.com;",
    "email_subject": "Do not reply - processed files",
    "email_attachments": [{
            "container_name": "bronze",
            "blob_name": "rootfolder/subfolders/folium_map.html"
        }, {
            "container_name": "bronze",
            "blob_name": "rootfolder/subfolders/stdout.txt"
        }, {
            "container_name": "bronze",
            "blob_name": "rootfolder/subfolders/stderr.txt"
        }
    ]
}

Upon receiving such request, I need to send an email containing the attachments depending of however many is defined in the "email_attachments" array. I will need to lookup the content of such blob from my data lake. Here's my code:

{
    "definition": {
        "$schema": "https://schema.management.azure.com/providers/Microsoft.Logic/schemas/2016-06-01/workflowdefinition.json#",
        "actions": {
            "For_each": {
                "actions": {
                    "Append_to_array_variable": {
                        "inputs": {
                            "name": "attachments",
                            "value": {
                                "ContentBytes": "@{body('Read_blob_content')?['content']}",
                                "Name": "@{body('Read_blob_content')?['blob_name']}"
                            }
                        },
                        "runAfter": {
                            "Read_blob_content": [
                                "SUCCEEDED"
                            ]
                        },
                        "type": "AppendToArrayVariable"
                    },
                    "Read_blob_content": {
                        "inputs": {
                            "parameters": {
                                "blobName": "@items('For_each')?['items(''For_each'')']?['blob_name']",
                                "containerName": "@items('For_each')?['items(''For_each'')']?['container_name']"
                            },
                            "serviceProviderConfiguration": {
                                "connectionName": "AzureBlob-4",
                                "operationId": "readBlob",
                                "serviceProviderId": "/serviceProviders/AzureBlob"
                            }
                        },
                        "type": "ServiceProvider"
                    }
                },
                "foreach": "@triggerBody()?['email_attachments']",
                "runAfter": {
                    "Initialize_variable_-_attachments": [
                        "SUCCEEDED"
                    ]
                },
                "runtimeConfiguration": {
                    "concurrency": {
                        "repetitions": 1
                    }
                },
                "type": "Foreach"
            },
            "Initialize_variable_-_attachments": {
                "inputs": {
                    "variables": [
                        {
                            "name": "attachments",
                            "type": "array"
                        }
                    ]
                },
                "runAfter": {},
                "type": "InitializeVariable"
            },
            "Response": {
                "inputs": {
                    "body": "@concat('Email sent to ',triggerBody()?['email_recipients'], ' with the subject of \"',triggerBody()?['email_subject'],'\"')",
                    "headers": {
                        "Content-Type": "application/json"
                    },
                    "statusCode": 200
                },
                "kind": "http",
                "runAfter": {
                    "Send_an_email_from_a_shared_mailbox_(V2)": [
                        "Succeeded"
                    ]
                },
                "type": "Response"
            },
            "Send_an_email_from_a_shared_mailbox_(V2)": {
                "inputs": {
                    "body": {
                        "Attachments": "@variables('attachments')",
                        "Body": "<p>@{triggerBody()?['email_body']}</p>",
                        "Importance": "Normal",
                        "MailboxAddress": "sender@xyz.com",
                        "Subject": "@triggerBody()?['email_subject']",
                        "To": "@triggerBody()?['email_recipients']"
                    },
                    "host": {
                        "connection": {
                            "referenceName": "office365"
                        }
                    },
                    "method": "post",
                    "path": "/v2/SharedMailbox/Mail"
                },
                "runAfter": {
                    "For_each": [
                        "SUCCEEDED"
                    ]
                },
                "type": "ApiConnection"
            }
        },
        "contentVersion": "1.0.0.0",
        "outputs": {},
        "triggers": {
            "manual": {
                "inputs": {
                    "schema": {
                        "properties": {
                            "email_attachments": {
                                "items": {
                                    "properties": {
                                        "blob_name": {
                                            "type": "string"
                                        },
                                        "container_name": {
                                            "type": "string"
                                        }
                                    },
                                    "required": [
                                        "container_name",
                                        "blob_name"
                                    ],
                                    "type": "object"
                                },
                                "type": "array"
                            },
                            "email_body": {
                                "type": "string"
                            },
                            "email_recipients": {
                                "type": "string"
                            },
                            "email_subject": {
                                "type": "string"
                            }
                        },
                        "type": "object"
                    }
                },
                "kind": "Http",
                "type": "Request"
            }
        }
    },
    "kind": "Stateful"
}

When I called the workflow, it ended with the following error:

InvalidTemplate

Unable to process template language expressions for action 'For_each' at line '0' and column '0': 'The template language expression 'triggerBody()?['email_attachments']' cannot be evaluated because property 'email_attachments' cannot be selected. Property selection is not supported on values of type 'String'. Please see https://aka.ms/logicexpressions for usage details.'.

I tried using array(triggerBody()?['email_attachments']) in the "Select An Output From Previous Steps" field on the "For each" action, but that doesn't help either.

Can anyone help shedding a light of how I can achieve that please?

Thanks in advance.

Answer 1

Hello @Nico Wijaya - Thanks for reaching out, and posting on the MS Q&A.

The expression @triggerBody()?['email_attachments'] used for the Foreach loop is valid and works for me, however, the following used in the Read Blob action looks invalid:

"parameters": {
  "blobName": "@items('For_each')?['items(''For_each'')']?['blob_name']",
  "containerName": "@items('For_each')?['items(''For_each'')']?['container_name']"
}

Specifically, the repeating use of Foreach in @items('For_each')?['items(''For_each'')'] and the double quotes surrounding the second Foreach ['items(''For_each'')'] looks invalid to me.

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