Adding text to edges

In diagrams, we often see that apart from text in diagram nodes, we can have text on the connecting lines or arrows. That’s an essential feature of TikZ’s edge operation.

Let’s continue our example from the previous section and add a text label to the edge. It will read pdflatex in a tiny typewriter font printed above the edge. This label is itself a node, so we insert this right after the edge:

node[font=\tiny\ttfamily, above] {pdflatex}

The full command becomes as follows:

\draw (tex) edge[->]
  node[font=\tiny\ttfamily, above] {pdflatex} (pdf);

Compile, and you get this picture:

Figure 4.2 – An edge with a text label

Admittedly, this is a pretty verbose syntax. Luckily, TikZ provides a shorter way; this is called the quotes syntax because you can add edge label texts by enclosing the text in quotes as an option to the edge. That’s basically edge["text"]. We...