1. A method of generating a representation of a plurality of learned rules from a learning engine of an application firewall based on a history of URL communications with a web server, the method comprising: a) determining, by a learning engine of an application firewall, a plurality of learned rules based on a history of URL communications with a web server, each of the plurality of learned rules assigned a URL string; b) categorizing, by a visualizer, a subset of the plurality of learned rules under a first check type of a plurality of check types; and c) generating, by the visualizer, a tree representation of URL strings of the subset of learned rules, each node of the tree corresponding to a segment of the URL strings identified based on a delimiter for the URL strings.