Awesome
pongo2
pongo2 is a Django-syntax like templating-language (official website).
Install/update using go get
(no dependencies required by pongo2):
go get -u github.com/flosch/pongo2/v6
Please use the issue tracker if you're encountering any problems with pongo2 or if you need help with implementing tags or filters (create a ticket!).
:question: Looking for a Go developer/consultant? I'm available for hire. :man_technologist:
First impression of a template
<html>
<head>
<title>Our admins and users</title>
</head>
{# This is a short example to give you a quick overview of pongo2's syntax. #}
{% macro user_details(user, is_admin=false) %}
<div class="user_item">
<!-- Let's indicate a user's good karma -->
<h2 {% if (user.karma>= 40) || (user.karma > calc_avg_karma(userlist)+5) %} class="karma-good"{% endif %}>
<!-- This will call user.String() automatically if available: -->
{{ user }}
</h2>
<!-- Will print a human-readable time duration like "3 weeks ago" -->
<p>This user registered {{ user.register_date|naturaltime }}.</p>
<!-- Let's allow the users to write down their biography using markdown;
we will only show the first 15 words as a preview -->
<p>The user's biography:</p>
<p>
{{ user.biography|markdown|truncatewords_html:15 }}
<a href="/user/{{ user.id }}/">read more</a>
</p>
{% if is_admin %}
<p>This user is an admin!</p>
{% endif %}
</div>
{% endmacro %}
<body>
<!-- Make use of the macro defined above to avoid repetitive HTML code
since we want to use the same code for admins AND members -->
<h1>Our admins</h1>
{% for admin in adminlist %} {{ user_details(admin, true) }} {% endfor %}
<h1>Our members</h1>
{% for user in userlist %} {{ user_details(user) }} {% endfor %}
</body>
</html>
Features
- Syntax- and feature-set-compatible with Django 1.7
- Advanced C-like expressions.
- Complex function calls within expressions.
- Easy API to create new filters and tags (including parsing arguments)
- Additional features:
- Macros including importing macros from other files (see template_tests/macro.tpl)
- Template sandboxing (directory patterns, banned tags/filters)
Caveats
Filters
- date / time: The
date
andtime
filter are taking the Golang specific time- and date-format (not Django's one) currently. Take a look on the format here. - 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" }}
isfmt.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 aforce_escape
-filter yet.
Tags
- for: All the
forloop
fields (likeforloop.counter
) are written with a capital letter at the beginning. For example, thecounter
can be accessed byforloop.Counter
and the parentloop byforloop.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 - 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 - A tiny little helper for using Pongo2 with Beego.
- beego-pongo2.v2 - Same as
beego-pongo2
, but for pongo2 v2. - macaron-pongo2 - pongo2 support for Macaron, a modular web framework.
- ginpongo2 - middleware for gin to use pongo2 templates
- Build'n support for Iris' template engine
- pongo2gin - alternative renderer for gin to use pongo2 templates
- pongo2-trans -
trans
-tag implementation for internationalization - tpongo2 - pongo2 support for Tango, a micro-kernel & pluggable web framework.
- p2cli - command line templating utility based on pongo2
- pongorenderer - minimal pongo2 renderer for Echo web framework
- pongo2gcloud - Google Cloud Storage loader for pongo2 template files
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. 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)
// 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)
package main
import (
"github.com/flosch/pongo2/v6"
"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)
}