graphspathstikz-pgf
I am drawing edges in a graph using a command like
\path (nodeName1) edge [->] (nodeName2)
The only way I have learned what options can go into the square brackets after "edge" is by looking at examples. Where can I find everything that can possibly be used as an option here?
You can use the decorate operation (don't use rounded corners with decoration or read carefully the answer to How to draw a decorated rectangle with rounded corners?):
\documentclass[tikz, border=10pt]{standalone}
\usepackage{tikz}
\usetikzlibrary{decorations.pathmorphing}
\begin{document}
\begin{tikzpicture}
\draw[thick, fill=brown!70]
%
decorate[decoration={zigzag,segment length=1.0mm, amplitude=.2mm}]
{(0,0) -- ++(0,.5) -- ++(4,0) -- ++(0,-.5) }
%
[rounded corners=1ex]-- ++(0, -.5) -- ++(-4,0) -- cycle;
\end{tikzpicture}
\end{document}
The labels seem to be placed with the auto option enabled, which places the node/label on the side of the line, in your MWE above it. As such you can add the swap option to move the label to the other side.
\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{graphdrawing,positioning,graphs}
\usegdlibrary{layered, trees}
\begin{document}
\begin{tikzpicture}
\begin{graph}
{1 -> [edge label=hello]
2 -> [edge label=hello,swap]
3};
\end{graph}
\end{tikzpicture}
\end{document}
Best Answer
Saying
is the same as saying
every edgeis a style that by defaults just containsdraw. This means that you can pass any option to theedgeoperation that you could also pass to a\path [draw]operation (e.g. colours, line thicknesses, decorations, etc.).