I hope I'm using the terminology correctly.  What I mean is this:  fix $K = \mathbb{R}$ or $\mathbb{C}$ (I'm interested in both cases).  Which topological spaces $X$ have the property that for every open set $U$, every continuous function $f : U \to K$ is a quotient of continuous functions $\frac{g}{h}$ where $g, h : X \to K$ and $h \neq 0$ on $U$?