function updateContentTarget()

in packages/web-components/fast-element/src/templating/binding.ts [80:141]
42 lines of code
12 McCabe index (conditional complexity)

function updateContentTarget(this: BindingBehavior, value: any): void {
    // If there's no actual value, then this equates to the
    // empty string for the purposes of content bindings.
    if (value === null || value === undefined) {
        value = "";
    }

    // If the value has a "create" method, then it's a template-like.
    if (value.create) {
        this.target.textContent = "";
        let view = this.target.$fastView as ComposableView;

        // If there's no previous view that we might be able to
        // reuse then create a new view from the template.
        if (view === void 0) {
            view = value.create() as SyntheticView;
        } else {
            // If there is a previous view, but it wasn't created
            // from the same template as the new value, then we
            // need to remove the old view if it's still in the DOM
            // and create a new view from the template.
            if (this.target.$fastTemplate !== value) {
                if (view.isComposed) {
                    view.remove();
                    view.unbind();
                }

                view = value.create() as SyntheticView;
            }
        }

        // It's possible that the value is the same as the previous template
        // and that there's actually no need to compose it.
        if (!view.isComposed) {
            view.isComposed = true;
            view.bind(this.source, this.context!);
            view.insertBefore(this.target);
            this.target.$fastView = view;
            this.target.$fastTemplate = value;
        } else if (view.needsBindOnly) {
            view.needsBindOnly = false;
            view.bind(this.source, this.context!);
        }
    } else {
        const view = this.target.$fastView as ComposableView;

        // If there is a view and it's currently composed into
        // the DOM, then we need to remove it.
        if (view !== void 0 && view.isComposed) {
            view.isComposed = false;
            view.remove();

            if (view.needsBindOnly) {
                view.needsBindOnly = false;
            } else {
                view.unbind();
            }
        }

        this.target.textContent = value;
    }
}