Remove special characters from logic app string

Question

I am aware that we can use replace() function to remove individual special characters and replace them with ''.But I want to remove all special characters from the logic app string variable and allow only content which is a-zA-Z and 0-9. Can you please give the approach

Answer 1

Hi MS Techie,

Unfortunately, Azure Logic Apps built-in functions have the below considerations on your use case:

• Logic Apps does not support regular expressions.
• JavaScript inline code action to remove special characters require an automation account and It doesn't support get variable as arguments.

So you have alternatives solution to remove this characthers:

• Create an Azure Function in a supported language (like JavaScript or C#) that takes a string as input, removes special characters using a regular expression, and returns the cleaned string.
• Create an HTTP Trigger eather to your Azure Function or another APi service that it can be called via an HTTP request to remove the special characters
• Last workaround with Javascript inline code action and workflow context but require an automation account

Remove special character with javascript inline code action:

Asociate the Integration account to logic apps on workflow settiong (This automation account must to be in the same azure region)

This is an example workflow removing the special characters :

{
    "definition": {
        "$schema": "https://schema.management.azure.com/providers/Microsoft.Logic/schemas/2016-06-01/workflowdefinition.json#",
        "actions": {
            "Execute_JavaScript_Code": {
                "inputs": {
                    "code": "var reg = /[^a-zA-Z0-9]/g;\r\nvar nospecial = workflowContext.actions.variable.inputs.variables[0].value;\r\nreturn nospecial.replace(reg, '');"
                },
                "runAfter": {
                    "variable": [
                        "Succeeded"
                    ]
                },
                "type": "JavaScriptCode"
            },
            "variable": {
                "inputs": {
                    "variables": [
                        {
                            "name": "specialVariable",
                            "type": "string",
                            "value": "NoSpecial$$%%^&&>-?+yes"
                        }
                    ]
                },
                "runAfter": {},
                "type": "InitializeVariable"
            }
        },
        "contentVersion": "1.0.0.0",
        "outputs": {},
        "parameters": {},
        "triggers": {
            "Recurrence": {
                "evaluatedRecurrence": {
                    "frequency": "Month",
                    "interval": 3
                },
                "recurrence": {
                    "frequency": "Month",
                    "interval": 3
                },
                "type": "Recurrence"
            }
        }
    },
    "parameters": {}
}

The execution will be successfull:

I hope this information help you.

Luis