Go Template

Go Template. If you are a Go programmer then Go Templates makes a lot of sense.

Blurb

Package template implements data-driven templates for generating textual output.

Summary

Garden stance: We assess Go Template for our estate.

When to use: Evaluate on a project when the capability clearly fits the requirement.

When to skip: When a simpler alternative already covers the need.

Details

Things to know

The language is fully described in the programming documentation. Basically, it reads text for embeds. Anytime you want to drop to code you use {{ ... }}. The output of that block is then inserted in place. Data can be accessed with $ (main object), or . (current scope). There are a relatively small set of built-ins like range, or block.

The main object ($) and all functions have to be registered directly in the go code. Meaning that different usages have very different behaviors. Sprig is a very common library of template functions that should be loaded to make the templates really useful.

Example

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import (
 "github.com/Masterminds/sprig/v3"
 "html/template"
)

// This example illustrates that the FuncMap *must* be set before the
// templates themselves are loaded.
tpl := template.Must(
 template.New("base").Funcs(sprig.FuncMap()).ParseGlob("*.html")
)

template.FuncMap is a map[string]any and can be used to add any functions to the list, including internally developed ones.