Flask 템플릿 엔진 Jinja2

# Jinja2 Library: Flask Template Engine (http://jinja.pocoo.org)
# Types
String, XML, HTML, JSON, Image, Video, etc

# example
{% extends "application.html" %}
{% block body %}
  <ul>
    {% for song in songs %}
      <li><a href="{{song.url}}"> {{song.title}} </a></li>
    {% endfor %}
  </ul>
{% endblock %}

render_template("xx.html", username="Jade")
{# comment #}

from flask import render_template

@app.route("/")
def tmpl():
  return render_template("index.html")

# ./templates/index.html
<pre>
ttt 한글
{% if True %}
  TTT
{% endif %}qqq
</pre>

# trim_blocks app config
app.jinja_env.trim_blocks = True

# ./templates/index.html
<pre>
ttt 한글
{%- if True -%}
  TTT
{%- endif -%}qqq
</pre>

# invalid
{% - if True - %}

# quotation escape
{{ abc } efg }}
{{ "}}>> <strong>Strong</strong>"}} or {{ '}}>> <strong>Strong</strong>' | escape }}

# cf. safe string & striptags
{{ "<strong>Strong</strong>" | safe}}
{{ "<strong>Strong</strong>" | striptags}}

# {% raw %} ~ {% endraw %} : display souce code
{% raw %}
  {% if True %}
    TTT
  {% endif %}
{% endraw %}

# from flask import Markup
return render_template("index.html"), markup=Markup("<b>B</b>"))

# Example: Markup()
mu = Markup("<h1>iii = <i>%s</i></h1>")
h = mu % "Italic"
print("h=", h)
return render_template("index.html", markup=Markup(h))

# Markup.escape() & unescape()
bold = Markup("<b>Bold</b>")
bold2 = Markup.escape("<b>Bold</b>")
bold3 = bold2.unescape()

print(bold, bold, bold3)
=> <b>Bold</b> <bgt;Bold</b> <b>Bold</b>

# {% for var in iter %} ... {% endfor %}
{% for item in items %}
  ...item 처리..
{% endfor %}

# Example
lst = [ ("만남", "김건모"), ("만남", "노사연")]
return render_template("index.html", lst=lst)

<ul>
  {% for item in lst %}
    <li>{{item[0]}}: {{item[1]}}</li>
  {% endfor %}
</ul>

{% for title, name in lst %}
  <li>{{title}}: {{name}}</li>
{% endfor %}

# for loop 속에서 기본으로 제공되는 object : '현재 for loop의 self'
- loop.index: 1부터 시작하는 index 값 (cf. loop.index0)
- loop.revindex: n-1 내림차순 index값 (cf. loop.revindex0)
- loop.first: boolean(isThisFirstItem), loop의 첫번째인지의 여부
- loop.last: boolean(isThisLastItem), loop의 마지막인지의 여부
- loop.length: size

# loop.cycle (특정 주기로 수행)
<ul>
  {% for item in lst %}
    <li class="{{loop.cycle('aaa', 'bbb')}}">{{item[0]}}: {{item[1]}}</li>
  {% endfor %}
</ul>

# data의 세번째 인자로 숨김 여부 추가
lst = [(1,"만남","김건모",false), (2,"만남","노사연",True), (3,"만남","익명",False)]
return render_template("index.html", lst=lst)

# index.html
<ul>
  {% for rank, title, name, hide in lst if not hide %}
    <li class="{{loop.cycle('aaa', 'bbb')}}">{{title}}: {{name}}</li>
  {% endfor %}
</ul>

# for else
{% for title, name, isShow in lst if not isShow %}
    <li class="{{loop.cycle('aaa', 'bbb', '')}}">{{title}}: {{name}}</li>
{% else %}
  <li>There is no data.</li>
{% endif %}

# loop(data)
a = (1, "만남1", "김건모", False, [])
b = (2, "만남2", "노사연", True, [a])
c = (3, "만남3", "익명", False, [a,b])
d = (4, "만남4", "익명", False, [a,b,c])

return render_template("index.html", lst=[a,b,c,d])

# index.html
<ul>
  {% for rank, title, name, hide, ref in lst recursive %}
    <li class="{{loop.cycle('aaa','bbb')}}">
      <small>{{rank}} / {{loop.length}}</small> {{title}}: {{name}}
      {%- if ref -%}
        <ul class='sub'>{{ loop(ref) }}</ul>
      {%- endif -%}
    </li>
  {% endfor %}
</ul>

# grammar
{% if <Condition> %}
  ...
{% endif %}

# Example
{% if lst %}
  {% for ... %}
{% endif %}

# if else (elif)
{% if <Condition> %}
  ...
{% elif <Other Condition> %}
  ...
{% else %}
  ...
{% endif %}

# set value
{% set title = 'ABC' %}

# access parent(outer) loop
<ul>
  {% for rank, title, name, hide, ref in lst2 recursive %}
  <li>
    {{loop.index}} - {{title}}: {{name}}
    {%- if ref -%}
      {% set outer_loop = loop %}
      {% for ref_song in ref %}
        <p>{{outer_loop.index}} - {{loop.index}} : {{ ref_song[1] }}</p>
      {% endfor %}
    {%- endif -%}
  </li>
  {% endfor %}
</ul>

# url_for('folder', filename='filename.ext')
<link rel="stylesheet" href="{{ url_for('static', filename='style.css') }}">

# url_for('router-link')
Copyright <a href="/tmpl">Happy Coding</a>
Copyright <a href="{{ url_for('tmpl') }}">Happy Coding</a>

# Base Template: 구조 및 자리 잡기용 (layout.html)
<body>
  <h1>{% block <block-name> %}{% endblock %} - Layout Title</h1>
</body>

# extends the base layout html
{% extends "layout.html" %}

# mapping block : block 사용, 순서 무관! (in main.html)
{% block <block-name> %}AAAAA{% endblock %}

# super() : import html from same block-name
{% block <block-name> %}
  {{ super() }}
  <p>TTT</p>
{% endblock %}

# layout.html
{% block outer_block %}
  <h3>
    {% block inner_block %}{% endblock inner_block %} -
  </h3>
{% endblock outer_block %}

# main.html
{% block outer_block %}
  <p>111111111</p>
  {% block inner_block %}BBBBBB{% endblock inner_block %}
{% endblock outer_block %}

# Base Template: 구조 및 자리 잡기용 (layout.html)
<body>
  <h1>{% block <block-name> %}{% endblock %} - Layout Title</h1>
</body>

# extends the base layout html (main.html)
{% extends "layout.html" %}

# mapping block : block 사용, 순서 무관! (in main.html)
{% block <block-name> %}AAAAA{% endblock %}

# super() : import html from same block-name
{% block <block-name> %>
  {{ super() }}
  <p>TTT</p>
{% endblock %}

# layout.html
{% block outer_block %}
  <h3>
    {% block inner_block %}{% endblock inner_block %} -
  </h3>
{% endblock outer_block %}

# main.html
{% block outer_block %}
  <p>1111111111</p>
  {% block inner_block %}BBBBB{% endlock inner_block %}
{% endblock outer_block %}

# layout.html
<h2>{% block title2 %}{% endblock %} - Layout Title2</h2>

# main.html
{% for item in [1,2] %}
  {% block title2 scoped %}<p>XXXXXXXXXXX {{item}}</p> {% endblock %}
{% endfor %}