Azure Functions not accepting an url-encoded value as a query parameter?

Question

I am trying to use a domain as a query param in an Azure Function app.

Something like this:

/api/foo/bar/{url}

/api/foo/bar/https%3a%2f%2flocalhost%3a3000

This doesn't hit the function (although it works locally, although is automatically decodes the : which is annoying), is this as expected? (it does work if I had it as a query string)

Answer 1

You need to use the double encoded URL in the request while running in function app. Pass https%253a%252f%252flocalhost%253a3000 instead of https%3a%2f%2flocalhost%3a3000 while invoking the function in function app.

I have below function code which is deployed to function app.

[FunctionName("Function1")]
public static async Task<IActionResult> 
    Run([HttpTrigger(AuthorizationLevel.Anonymous, 
                     "get", "post", 
                      Route = "foo/bar/{encodedUrl}")] 
                           HttpRequest req,
        string encodedUrl, ILogger log)
{
    log.LogInformation("C# HTTP trigger function processed a request.");

    string decodedUrl = HttpUtility.UrlDecode(encodedUrl);

    string name = req.Query["name"];

    string requestBody = await new StreamReader(req.Body).ReadToEndAsync();
    dynamic data = JsonConvert.DeserializeObject(requestBody);
    name = name ?? data?.name;

    string responseMessage = string.IsNullOrEmpty(name)
        ? $"This HTTP triggered function executed successfully. The decoded URL is: {decodedUrl}. Pass a name in the query string or in the request body for a personalized response."
        : $"Hello, {name}. This HTTP triggered function executed successfully. The decoded URL is: {decodedUrl}.";

    return new OkObjectResult(responseMessage);
}

I am passing the value of encodedUrl as https%253a%252f%252flocalhost%253a3000 and it worked as expected.