.gitignore

__pycache__/
*.pyc

htmlfill.py

"""Jinja2 x htmlfill

Known bugs: Can't skip empty dictionaries when htmlfilling is not needed.

# AUTHOR: HYUNJUN KIM <kim@hyunjun.kr>
# LICENSE: Distributed under MIT License.
"""

import formencode.htmlfill
import jinja2
import jinja2.ext
import jinja2.nodes


class FormFillExtension(jinja2.ext.Extension):
    """Jinja2 Extension for convenient using of HTML ``<form>`` element.
    Works with `FormEncode htmlfill`__ ::

       {% formfill {'username': 'james'}
              with {'username': 'Invalid Username'} %}
       <form action="u/signin" method="POST">
           <input type="text" name="username" />
           <form:error name="username">
           <input type="password" name="password" />
       </form>
       {% endformfill %}

    Above code will be rendered like below ::

       <form action="u/signin" method="POST">
           <input type="text" name="username" class="error" value="james" />
           <ul class="errors"><li>Invalid Username</li></ul>
           <input type="password" name="password" value="" />
       </form>

    __ http://www.formencode.org/en/latest/htmlfill.html

    .. seealso::

       gist --- `formencode htmlfill in jinja2 template`__

    __ https://gist.github.com/4595277

    """
    
    tags = set(['formfill'])

    def parse(self, parser):
        lineno = parser.stream.next().lineno
        defaults = parser.parse_expression()
        errors = jinja2.nodes.Const({})
        name = parser.stream.next_if('name')
        if name is not None:
            if name.value == 'with':
                errors = parser.parse_expression()
        if isinstance(defaults, jinja2.nodes.Name):
            defaults = jinja2.nodes.Getattr(jinja2.nodes.ContextReference(),
                                            defaults.name, self.environment)
        if isinstance(errors, jinja2.nodes.Name):
            errors = jinja2.nodes.Getattr(jinja2.nodes.ContextReference(),
                                          errors.name, self.environment)
        body = parser.parse_statements(['name:endformfill'], drop_needle=True)
        body = [jinja2.nodes.CallBlock(
            self.call_method('_htmlfill_support', (defaults, errors)),
            [], [], body).set_lineno(lineno)]
        return body

    def _htmlfill_support(self, defaults, errors, caller):
        formatters = {
            'default': lambda msg: u'<ul class="errors"><li>{0}</li></ul>' \
                                   .format(msg)
        }
        return formencode.htmlfill.render(caller(), defaults, errors,
                                          error_formatters=formatters)

test_htmlfill.py

import pytest
import jinja2
import htmlfill


@pytest.fixture
def jinja_env():
    env = jinja2.Environment(extensions=[htmlfill.FormFillExtension])
    return env


def test_formfill(jinja_env):
    template = '''
    {% formfill {'username': 'james'} with {'username': 'Invalid Username'} -%}
    <form action="u/signin" method="POST">
        <input type="text" name="username" />
        <form:error name="username">
        <input type="password" name="password" />
    </form>
    {%- endformfill %}'''
    expected = '''
    <form action="u/signin" method="POST">
        <input type="text" name="username" class="error" value="james" />
        <ul class="errors"><li>Invalid Username</li></ul>
        <input type="password" name="password" value="" />
    </form>'''
    result = jinja_env.from_string(template).render()
    assert result == expected


def test_formfill_without_errors(jinja_env):
    template = '''
    {% formfill {'username': 'james'} -%}
    <form action="u/signin" method="POST">
        <input type="text" name="username" />
        <form:error name="username">
        <input type="password" name="password" />
    </form>
    {%- endformfill %}'''
    expected = '''
    <form action="u/signin" method="POST">
        <input type="text" name="username" value="james" />
        
        <input type="password" name="password" value="" />
    </form>'''
    result = jinja_env.from_string(template).render()
    assert result == expected


def test_formfill_without_args(jinja_env):
    template = '''
    {% formfill -%}
    <form action="u/signin" method="POST">
        <input type="text" name="username" />
        <input type="password" name="password" />
    </form>
    {%- endformfill %}'''
    template2 = '''
    {% formfill {'username': 'james'} with -%}
    <form action="u/signin" method="POST">
        <input type="text" name="username" />
        <input type="password" name="password" />
    </form>
    {%- endformfill %}'''
    with pytest.raises(jinja2.TemplateSyntaxError):
        jinja_env.from_string(template).render()
    with pytest.raises(jinja2.TemplateSyntaxError):
        jinja_env.from_string(template2).render()


def test_formfill_with_wrong_args(jinja_env):
    template = '''
    {% formfill 'user.signin' -%}
    <form action="u/signin" method="POST">
        <input type="text" name="username" />
        <input type="password" name="password" />
    </form>
    {%- endformfill %}'''
    with pytest.raises(AttributeError) as exc:
        jinja_env.from_string(template).render()
    assert "'str' object has no attribute 'get'" in str(exc)
    template2 = '''
    {% formfill {'username': 'james'} with ['Invalid Username'] -%}
    <form action="u/signin" method="POST">
        <input type="text" name="username" />
        <input type="password" name="password" />
    </form>
    {%- endformfill %}'''
    with pytest.raises(AttributeError) as exc:
        jinja_env.from_string(template2).render()
    assert "'list' object has no attribute 'get'" in str(exc)