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Brett's Notes

Web Stuff

HTML Templating

HTML templating can be done with the core html/template package, or with something like templ if you want a more JSX style syntax.

html/template

The package lets you parse and execute HTML templates, from strings or external template files.

You can interpolate values by passing them as the second argument to Execute(io.Writer, any) and accessing the values struct with ..

It’s also possible to range over values with {{range.value}}stuff to do{{end}}.

Functions can be passed to the template by adding .Funcs() before parsing the template and passing a template.FuncMap of string function names keying function values.

If you don’t want HTML/CSS/JS escaped, wrap it in template.HTML/CSS/JS. Won’t need to do this for manually constructed stuff but some other packages escape by default.

  • Parse(string) (*Template, error): Parse the template from a string.
  • ParseFS(fs.FS, ...string) (*Template, error): Parse the template from a filesystem, using the provided list of glob paths which can contain * wildcards.
  • Execute(io.Writer, any) error: Execute the template and write it to w.
  • ExecuteTemplate(name string, w io.Writer, data any) error: Execute the template named name and write it to w.

templ

Web Servers

Generally created by calling ListentAndServe(addr string, handler http.Handler), which starts a web server listinging on the port provided by addr and creating a goroutine for every request, which is run against handler.

The handler interface requires a ServeHTTP(ResponseWriter, *Request) method and is usually implemented by creating a struct to hold the necessary data, as well as a ServeHTTP method. If you don’t need the data storage features of a struct, you can create the handler with http.HandlerFunc(func) which allows you to use the passed regular function as a HTTP handler. The passed function must take the expected arguments for a HTTPHandler.