Toes to the Edge

I have a need to have multiple sections of name/value pairs with a header on some pages. Something like:

<div class="row">
    <div class="span6">
        <div class="row"><div class="span3"><h2>History:</h2></div></div>
        <div class="row"><div class="span2">Date added to fleet:</div><div class="span2">{{plane.dateAddedToFleet}}</div></div>
        <div class="row"><div class="span2">Total Flight Time:</div><div class="span2">{{plane.totalFlightTime|asTime}}</div></div>
        <div class="row"><div class="span2">Total Number of Flights:</div><div class="span2">{{plane.totalNumberOfFlights}}</div></div>
    </div>
</div>

So that’s wrong. I first tried creating a custom tag to render the entire section that would be used like this within the django template:

{% specgroup "History" "Date added to fleet" plane.dateAddedToFleet "Total Flight Time:" plane.totalFlightTime|asTime "Total Number of Flights" plane.totalNumberOfFlights %}

The custom tag code for the above is:

# tags for groups of fields (such as on plane detail page)
@register.simple_tag
def specgroup(*args):
    """group header label1 value1 label2 value2 ...."""
    header= args[0]
    logging.getLogger().error(header)
    html = """
<div class="row">
    <div class="span6">
        <div class="row"><div class="span3"><h2>%s:</h2></div></div>
"""%header
    # parse remainder of args as  label1 value1 label2 value2 etc....
    data = args[1:]
    diter = iter(data)
    for d in diter:
        data = {}
        data["label"] = d
        data["value"] = diter.next()
        html += """  <div class="row"><div class="span2">%(label)s:</div><div class="span2">%(value)s</div></div>"""%data
    html += """
    </div>
</div>"""
    return html 

You cannot split the arguments across multiple lines to clean up the mess that is the call to the custom tag. So back to the drawing board.

I compromised with this:

{% specheader "History" %}
{% specdata "Date added to fleet" plane.dateAddedToFleet %}
{% specdata "Total Flight Time" plane.totalFlightTime|asTime %}
{% specdata "Total Number of Flights" plane.totalNumberOfFlights %}
{% specend %} 

The custom tags to implement this are:

@register.simple_tag
def specheader(header):
    return """
<div class="row">
    <div class="span6">
        <div class="row"><div class="span3"><h2>%s:</h2></div></div>"""%header

@register.simple_tag
def specdata(label,value):
    return '<div class="row"><div class="span2">%s:</div><div class="span2">%s</div></div>'%(label, value)

@register.simple_tag
def specend():
    return "</div></div>"

Which is also cleaner than the all-in-one tag.

It’s not for me, but Skylar Savland on github created a Django Template macros with args and kwargs gist that is another solution to this problem.

I’d love to hear ideas that solve this problem in a better way.

I was playing around with James Socol’s django-ratelimit tonight. It provides a decorator to rate-limit view functions. Very nice! I wanted to use it for login blocking, and some minor changes helped this out. My forked version of django-ratelimit is a available on GitHub It adds a message when a call is blocked and the ability to clear the count for given user.

Adding it to django-userena sign-in was as simple as:

in userena/views.py:

from ratelimit.decorators import ratelimit, clear
@ratelimit(field='identification',rate="5/m", method="POST", block=True, error_message="You have too many invalid login attempts.  Please try again later")
@secure_required
def signin(request, auth_form=AuthenticationForm,.....
.
.
.
     #after successful login
     clear(request, field='identification') ### clear rate limiting 

Here is a simple custom tag to render a users avatar (‘mugshot’) when using Django Userena. It optionally takes width and or height in pixels.

Place the following code in /templatetags/my_app_tags.py:

your_app/
    models.py
    templatetags/
        __init__.py
        my_app_tags.py

from django import template
register = template.Library()

from django import template
register = template.Library()

@register.simple_tag(takes_context=True)
def avatar(context, height=None, width=None):
    """ returns html for avatar, optional height/width supplied """
    user = context['user']
    widthAttr = 'width="%s"'%width if width is not None else ""
    heightAttr = 'height="%s"'%height if height is not None else ""
    return """<img %s %s class="avatar" src="%s"" alt="avatar image"  />"""%(heightAttr, widthAttr, user.get_profile().get_mugshot_url())

The following template shows how this could be used

{% load myapp_tags %}

{% avatar %}
{% avatar height=5 %}
{% avatar width=150 %}
{% avatar width=100 height=100 %}