mirror of
https://github.com/superseriousbusiness/gotosocial.git
synced 2024-11-22 19:56:39 +00:00
101 lines
3.8 KiB
Markdown
101 lines
3.8 KiB
Markdown
|
# Sprig: Template functions for Go templates
|
||
|
|
||
|
[![GoDoc](https://img.shields.io/static/v1?label=godoc&message=reference&color=blue)](https://pkg.go.dev/github.com/Masterminds/sprig/v3)
|
||
|
[![Go Report Card](https://goreportcard.com/badge/github.com/Masterminds/sprig)](https://goreportcard.com/report/github.com/Masterminds/sprig)
|
||
|
[![Stability: Sustained](https://masterminds.github.io/stability/sustained.svg)](https://masterminds.github.io/stability/sustained.html)
|
||
|
[![](https://github.com/Masterminds/sprig/workflows/Tests/badge.svg)](https://github.com/Masterminds/sprig/actions)
|
||
|
|
||
|
The Go language comes with a [built-in template
|
||
|
language](http://golang.org/pkg/text/template/), but not
|
||
|
very many template functions. Sprig is a library that provides more than 100 commonly
|
||
|
used template functions.
|
||
|
|
||
|
It is inspired by the template functions found in
|
||
|
[Twig](http://twig.sensiolabs.org/documentation) and in various
|
||
|
JavaScript libraries, such as [underscore.js](http://underscorejs.org/).
|
||
|
|
||
|
## IMPORTANT NOTES
|
||
|
|
||
|
Sprig leverages [mergo](https://github.com/imdario/mergo) to handle merges. In
|
||
|
its v0.3.9 release, there was a behavior change that impacts merging template
|
||
|
functions in sprig. It is currently recommended to use v0.3.10 or later of that package.
|
||
|
Using v0.3.9 will cause sprig tests to fail.
|
||
|
|
||
|
## Package Versions
|
||
|
|
||
|
There are two active major versions of the `sprig` package.
|
||
|
|
||
|
* v3 is currently stable release series on the `master` branch. The Go API should
|
||
|
remain compatible with v2, the current stable version. Behavior change behind
|
||
|
some functions is the reason for the new major version.
|
||
|
* v2 is the previous stable release series. It has been more than three years since
|
||
|
the initial release of v2. You can read the documentation and see the code
|
||
|
on the [release-2](https://github.com/Masterminds/sprig/tree/release-2) branch.
|
||
|
Bug fixes to this major version will continue for some time.
|
||
|
|
||
|
## Usage
|
||
|
|
||
|
**Template developers**: Please use Sprig's [function documentation](http://masterminds.github.io/sprig/) for
|
||
|
detailed instructions and code snippets for the >100 template functions available.
|
||
|
|
||
|
**Go developers**: If you'd like to include Sprig as a library in your program,
|
||
|
our API documentation is available [at GoDoc.org](http://godoc.org/github.com/Masterminds/sprig).
|
||
|
|
||
|
For standard usage, read on.
|
||
|
|
||
|
### Load the Sprig library
|
||
|
|
||
|
To load the Sprig `FuncMap`:
|
||
|
|
||
|
```go
|
||
|
|
||
|
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")
|
||
|
)
|
||
|
|
||
|
|
||
|
```
|
||
|
|
||
|
### Calling the functions inside of templates
|
||
|
|
||
|
By convention, all functions are lowercase. This seems to follow the Go
|
||
|
idiom for template functions (as opposed to template methods, which are
|
||
|
TitleCase). For example, this:
|
||
|
|
||
|
```
|
||
|
{{ "hello!" | upper | repeat 5 }}
|
||
|
```
|
||
|
|
||
|
produces this:
|
||
|
|
||
|
```
|
||
|
HELLO!HELLO!HELLO!HELLO!HELLO!
|
||
|
```
|
||
|
|
||
|
## Principles Driving Our Function Selection
|
||
|
|
||
|
We followed these principles to decide which functions to add and how to implement them:
|
||
|
|
||
|
- Use template functions to build layout. The following
|
||
|
types of operations are within the domain of template functions:
|
||
|
- Formatting
|
||
|
- Layout
|
||
|
- Simple type conversions
|
||
|
- Utilities that assist in handling common formatting and layout needs (e.g. arithmetic)
|
||
|
- Template functions should not return errors unless there is no way to print
|
||
|
a sensible value. For example, converting a string to an integer should not
|
||
|
produce an error if conversion fails. Instead, it should display a default
|
||
|
value.
|
||
|
- Simple math is necessary for grid layouts, pagers, and so on. Complex math
|
||
|
(anything other than arithmetic) should be done outside of templates.
|
||
|
- Template functions only deal with the data passed into them. They never retrieve
|
||
|
data from a source.
|
||
|
- Finally, do not override core Go template functions.
|