1. A method comprising: storing a template in a source code format, wherein the template comprises instructions that can be dynamically executed to render a web page and the instructions include one or more locations where an input of data is to be received when a web page will be generated based on the template; identifying a first location within the template; determining, from among a plurality of possible encoding formats, a first encoding context for the first location, wherein the first encoding context comprises at least one encoding format that can be properly received at the first location; and verifying, based on the template, whether an error would occur based on a first set of filters already existing at the first location and the first encoding context.