Create a mutable global variable in M language

[DevFolorunso]

Hi, community, 

I'm working on a custom connector that needs to authenticate before data representation is done, and to do this I don't want to hardcode the auth credentials in my source code. 

So, I declared a global list variable named

config = {"a"};

and in the shared MyCustomConnector.Contents function, I'm doing a List.ReplaceValue on item "a" in the list above.

shared MyCustomConnector.Contents = (BaseUrl as text, ClientId as text) => 
List.ReplaceValue(config, "a", BaseUrl, Replacer.ReplaceText);

so in my StartLogin function, I can just call the config by index like this.

//Start Login
StartLogin = (resourceUrl, state, display) =>
    let

        AuthorizeUrl ="https://"&Text.From(config{0})&"/oauth/authorize?" & Uri.BuildQueryString(
            [
                client_id = "11",
                response_type="code",
                state = state,
                redirect_uri = redirect_uri
            ]
        )
    in
        [
            LoginUri = AuthorizeUrl,
            CallbackUri = redirect_uri,
            WindowHeight = windowHeight,
            WindowWidth = windowWidth,
            Context = null
        ];

But it appears that, the List.ReplaceValue is not being executed because whenever I try to set credential for authentication, "a" is being passed into the URL. 

Any help will be much appreciated

[lbendlin]

Please read Ben Gribaudo's primer again.

Have a look at the meta data section too.