# [pongo](https://en.wikipedia.org/wiki/Pongo_%28genus%29)2
[](https://pkg.go.dev/github.com/flosch/pongo2)
[](https://travis-ci.org/flosch/pongo2)
pongo2 is a Django-syntax like templating-language ([official website](https://www.schlachter.tech/solutions/pongo2-template-engine/)).
Install/update using `go get` (no dependencies required by pongo2):
```sh
go get -u github.com/flosch/pongo2/v4
```
Please use the [issue tracker](https://github.com/flosch/pongo2/issues) if you're encountering any problems with pongo2 or if you need help with implementing tags or filters ([create a ticket!](https://github.com/flosch/pongo2/issues/new)).
## First impression of a template
```django
Our admins and users
{# This is a short example to give you a quick overview of pongo2's syntax. #}
{% macro user_details(user, is_admin=false) %}
This user registered {{ user.register_date|naturaltime }}.
The user's biography:
{{ user.biography|markdown|truncatewords_html:15 }}
read more
{% if is_admin %}
This user is an admin!
{% endif %}
{% endmacro %}
Our admins
{% for admin in adminlist %} {{ user_details(admin, true) }} {% endfor %}
Our members
{% for user in userlist %} {{ user_details(user) }} {% endfor %}
```
## Features
- Syntax- and feature-set-compatible with [Django 1.7](https://django.readthedocs.io/en/1.7.x/topics/templates.html)
- [Advanced C-like expressions](https://github.com/flosch/pongo2/blob/master/template_tests/expressions.tpl).
- [Complex function calls within expressions](https://github.com/flosch/pongo2/blob/master/template_tests/function_calls_wrapper.tpl).
- [Easy API to create new filters and tags](http://godoc.org/github.com/flosch/pongo2#RegisterFilter) ([including parsing arguments](http://godoc.org/github.com/flosch/pongo2#Parser))
- Additional features:
- Macros including importing macros from other files (see [template_tests/macro.tpl](https://github.com/flosch/pongo2/blob/master/template_tests/macro.tpl))
- [Template sandboxing](https://godoc.org/github.com/flosch/pongo2#TemplateSet) ([directory patterns](http://golang.org/pkg/path/filepath/#Match), banned tags/filters)
## Caveats
### Filters
- **date** / **time**: The `date` and `time` filter are taking the Golang specific time- and date-format (not Django's one) currently. [Take a look on the format here](http://golang.org/pkg/time/#Time.Format).
- **stringformat**: `stringformat` does **not** take Python's string format syntax as a parameter, instead it takes Go's. Essentially `{{ 3.14|stringformat:"pi is %.2f" }}` is `fmt.Sprintf("pi is %.2f", 3.14)`.
- **escape** / **force_escape**: Unlike Django's behaviour, the `escape`-filter is applied immediately. Therefore there is no need for a `force_escape`-filter yet.
### Tags
- **for**: All the `forloop` fields (like `forloop.counter`) are written with a capital letter at the beginning. For example, the `counter` can be accessed by `forloop.Counter` and the parentloop by `forloop.Parentloop`.
- **now**: takes Go's time format (see **date** and **time**-filter).
### Misc
- **not in-operator**: You can check whether a map/struct/string contains a key/field/substring by using the in-operator (or the negation of it):
`{% if key in map %}Key is in map{% else %}Key not in map{% endif %}` or `{% if !(key in map) %}Key is NOT in map{% else %}Key is in map{% endif %}`.
## Add-ons, libraries and helpers
### Official
- [pongo2-addons](https://github.com/flosch/pongo2-addons) - Official additional filters/tags for pongo2 (for example a **markdown**-filter). They are in their own repository because they're relying on 3rd-party-libraries.
### 3rd-party
- [beego-pongo2](https://github.com/oal/beego-pongo2) - A tiny little helper for using Pongo2 with [Beego](https://github.com/astaxie/beego).
- [beego-pongo2.v2](https://github.com/ipfans/beego-pongo2.v2) - Same as `beego-pongo2`, but for pongo2 v2.
- [macaron-pongo2](https://github.com/macaron-contrib/pongo2) - pongo2 support for [Macaron](https://github.com/Unknwon/macaron), a modular web framework.
- [ginpongo2](https://github.com/ngerakines/ginpongo2) - middleware for [gin](github.com/gin-gonic/gin) to use pongo2 templates
- [Build'n support for Iris' template engine](https://github.com/kataras/iris)
- [pongo2gin](https://gitlab.com/go-box/pongo2gin) - alternative renderer for [gin](github.com/gin-gonic/gin) to use pongo2 templates
- [pongo2-trans](https://github.com/digitalcrab/pongo2trans) - `trans`-tag implementation for internationalization
- [tpongo2](https://github.com/tango-contrib/tpongo2) - pongo2 support for [Tango](https://github.com/lunny/tango), a micro-kernel & pluggable web framework.
- [p2cli](https://github.com/wrouesnel/p2cli) - command line templating utility based on pongo2
- [Pongo2echo](https://github.com/stnc/pongo2echo) - pongo2 echo framework stability renderer [stnc]
- [Pongo2gin](https://github.com/stnc/pongo2gin) - pongo2 gin minimal framework stability renderer [stnc]
Please add your project to this list and send me a pull request when you've developed something nice for pongo2.
## Who's using pongo2
[I'm compiling a list of pongo2 users](https://github.com/flosch/pongo2/issues/241). Add your project or company!
## API-usage examples
Please see the documentation for a full list of provided API methods.
### A tiny example (template string)
```go
// Compile the template first (i. e. creating the AST)
tpl, err := pongo2.FromString("Hello {{ name|capfirst }}!")
if err != nil {
panic(err)
}
// Now you can render the template with the given
// pongo2.Context how often you want to.
out, err := tpl.Execute(pongo2.Context{"name": "florian"})
if err != nil {
panic(err)
}
fmt.Println(out) // Output: Hello Florian!
```
## Example server-usage (template file)
```go
package main
import (
"github.com/flosch/pongo2/v4"
"net/http"
)
// Pre-compiling the templates at application startup using the
// little Must()-helper function (Must() will panic if FromFile()
// or FromString() will return with an error - that's it).
// It's faster to pre-compile it anywhere at startup and only
// execute the template later.
var tplExample = pongo2.Must(pongo2.FromFile("example.html"))
func examplePage(w http.ResponseWriter, r *http.Request) {
// Execute the template per HTTP request
err := tplExample.ExecuteWriter(pongo2.Context{"query": r.FormValue("query")}, w)
if err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
}
}
func main() {
http.HandleFunc("/", examplePage)
http.ListenAndServe(":8080", nil)
}
```