Template Helpers



Helpers

In addition to Go’s text/template defaults, hof adds the following functions

There are a number of additional helpers provided.

Notes:

  • Many of these are based on the Go stdlib functions with the same name.
  • Args can be literal, a .Variable, or the result of another function. See Go’s documentation
  • It can be advantagous to do as many manipulations in CUE rather than in the template system.

Encode to a data format:

  • json ({{ json .Data }})
  • yaml ({{ yaml .Data }})
  • toml ({{ toml .Data }})
  • xml ({{ xml .Data }})

Value helpers:

  • dict ({{ ... (dict "key1" "val1" "key2" .Value ...) }}) - create a map on the fly, useful for passing multiple values to partials
  • lookup ({{ lookup "path.to.value" .Value }}) - returns the value at hofstadter-io/dotpath from the given value
  • pretty ({{ pretty .Value }}) uses https://github.com/kr/pretty
  • printf ({{ printf "%s %d" .String .Number }})

Casings conversion helpers:

  • lower ({{ lower .String }}) (lowercase)
  • upper ({{ upper .String }}) (UPPERCASE)
  • title ({{ title .String }}) (Titlecasestring
  • pascal ({{ pascal .String }}) (PascalCaseString)
  • camel ({{ camel .String }}) (camelCaseString)
  • Camel ({{ Camel .String }}) (camel + title)
  • snake ({{ snake .String }}) (snake_case_string)
  • SNAKE ({{ SNAKE .String }}) (SNAKE_CASE_STRING)
  • kebab ({{ kebab .String }}) (kebab-case-string)
  • KEBAB ({{ KEBAB .String }}) (KEBAB-CASE-STRING)

String processing helpers:

  • indent ({{ indent .String " " }})
  • concat ({{ concat "foo" "bar" }})
  • join ({{ join ", " "foo" "bar" }})
  • contains ({{ contains .String .Substr }})
  • split ({{ split .String .Separator }})
  • replace ({{ replace .String .Old .New .Count }})
  • hasprefix ({{ hasprefix .String .Prefix }})
  • hassuffix ({{ hassuffix .String .Suffix }})
  • trimprefix ({{ trimprefix .String .Prefix }})
  • trimsuffix ({{ trimsuffix .String .Suffix }})
  • trimto (alias for trimto_first)
  • trimfrom (alias for trimfrom_first)
  • trimto_first ({{ trimto_first .String .Substr .Keep }}) Trim a string until the first Substring, possibly keeping the substring
  • trimfrom_first ({{ trimfrom_first .String .Substr .Keep }})
  • trimto_last ({{ trimto_last .String .Substr .Keep }})
  • trimfrom_last ({{ trimfrom_last .String .Substr .Keep }})
  • substr ({{ substr .String .StartInt .EndInt }})
  • getprefix ({{ getprefix .String .Substr }}) (opposite of trimprefix)
  • getsuffix ({{ getsuffix .String .Substr }})
  • getbetween ({{ getbetween .String .LhsSubstr .RhsSubstr }})

Other helpers:

  • identity ({{ identity .Value }}) - returns Value, ah maths
  • gokind ({{ gokind .Value }}) - returns the Go reflect.Kind as a string
  • builtin ({{ builtin }}) - returns true if the string is a known Go builtin
  • file ({{ file "path/to/file.txt" }}) - loads a file from disk
2022 Hofstadter, Inc