How to avoid tying these two methods together with global mutable state?

Question

I'm in the process of reading Code Complete 2 and learned that using global state is a no-no. What can I do to avoid using global state in this situation?

Some background information: I have two different methods (formAdded and formRemoved), each of which is called depending on whether an Add button is clicked or a Remove button is clicked. timesSignerIsRequired is a class variable, and these two methods are tied together by it, which seems bad. Here is my code.

formAdded: function(ev) {
    var formId = $(ev.currentTarget).data('formid');
    var self = this;
    var forms = Forms;
    $.each(forms, function(index, form) {
        if (form.id == formId) {
            //found this form - now find all signer ID's required with the current accountTypeId
            var requiredSigners = form[this.appModel.get('accountTypeId')];
            for (var i = 0; i < requiredSigners; i++) {
                self.timesSignerIsRequired[i] += 1;

                if (!signerIsRendered(i)) {
                    //render signer into view
                }
            }
        }
    });
}

formRemoved: function(ev) {
    var formId = $(ev.currentTarget).data('formid');
    var self = this;
    var forms = Forms;
    $.each(forms, function(index, form) {
        if (form.id == formId) {
            //found this form - now find all signer ID's required with the current accountTypeId
            var requiredSigners = form[self.appModel.get('accountTypeId')];
            for (var i = 0; i < requiredSigners; i++) {
                self.timesSignerIsRequired[i] -= 1;

                if (self.timesSignerIsRequired[i] <= 0) {
                    //remove signer from the view
                }
            }
        }
    });
}

Any suggestions?

Answer 1

timesSignerIsRequired is not global state, it's a field on your object. It's okay for the methods of an object to access the fields (including private fields) of that same object.