I discovered today that you actually need to request four permissions to be able to get photos of a user’s friends otherwise you’ll just get an empty array back from the graph API.
With just friends_photos you’ll get

{'data': []}

when you request photos using the graph api via:

https://graph.facebook.com/[uid]/photos?access_token=[access_token]

Instead you have to get four permissions:
friends_photos,user_photos,user_photo_video_tags,friends_photo_video_tags
and then you will get back the photos you need.

With the Facebook python SDK this looks like:

facebook_obj.graph.get_connections([uid], "photos")

Overview

Tonight I wanted to put together a simple form in the sidebar of a Django page that submits via ajax and then reloads with a new version of the same form.  Hunch.com sort of does this (they don’t use a form), but they have a question that, when answered, comes back with a new question so that the site can continuously learn new tidbits about you:

At first it seemed I would need to first pass an object to my index view and load the form template by passing along the context.  This seemed roundabout though as the index didn’t need to see the object at all.  The solution I settled on was to create one form view that returns a json object containing information that would fill the form.  I would request this via ajax at page load and with subsequent form submissions.  The code remains reusable and no efforts are duplicated.

The View
The view is pretty simple. Handle the post request if it is a post then return a json object representing our form information.

def item_form(request):
     if request.method == "POST":
         form = ItemForm(request.POST)
         ... handle form validation ...
 
     itemset = Item.objects.all()
     data = serializers.serialize("json", itemset)
     return HttpResponse(data, mimetype="application/javascript")

The Template
First we’ll write the html and then fill in the javascript. Notice that I’ve left some of the elements empty as these will be filled in when we get passed back a json object. We’ll write a javascript function submit_item_form to handle posting the appropriate form fields via ajax. It is advisable to hide the sidebar-item element to begin with and then show it after loading content so that the form appears gracefully with the page load.

<div class="sidebar-item">
	<form action="/ajax/item_form" method="post" id="item_form">
		<h2></h2>
		<img src="" class="small-item-image" />
		<input type="text" name="name" value="" />
		<input type="submit" value="Submit" 
                      onclick="submit_item_form('item_form'); return false;"/>
	</form>
</div>

Next the jquery that loads the json object. Jquery’s getJSON method automatically parses the response string into a json object.

$(function() {
	$.getJSON("/ajax/item_form", function(data) {
		fill_item_form(data);
	});
});

And then the method that loads the data returned into our prefilled form:

function fill_item_form(json)
{
	var item = json[0]; // we'll only use 1 item for this example
 
	$(".sidebar-item h2").html(item.fields.title);
	$(".sidebar-item .small-item-image").attr("src", item.fields.photo_url);
 
	$(".sidebar-item").show();
}

Now we need to handle the form submission and we’re golden:

function submit_item_form(form_id)
{
	$.ajax({
		type: "POST",
		url: "/ajax/item_form",
		data: $('#' + form_id).serialize(),
		dataType: "json",
		success: function(json){
		     fill_item_form(json);
	        }
	});
}

Now the same function that loads our content reloads the content we get back after submitting the form so that a new form can be submitted.

I picked up Logicomix in Moe’s Books in Berkeley yesterday.  It’s a graphic novel that tells the story of Bertrand Russell’s tortured quest to discover the logical foundations of mathematics.  It is fascinating because it focuses in such detail on the torment of these great minds who spent their lives chasing after an impossibility.  Russell’s ultimate goal was to begin with a set of well-defined axioms and prove all mathematical truths from those axioms.  The goal of this program was to eliminate all paradox and uncertainty from the foundation of mathematics, generally represented by the “obvious” statements that had been used in proof before Russell’s time.

Russell first ruins the foundations of set theory with a paradox: does the set of all non-self-referential sets contain itself?  I love the way the book describes Russell’s emotion toward his discovery though.  It says that Russell felt like a devout Catholic journalist uncovering the Pope’s ignominy.  The rest of Russell’s story follows the same path: ups and downs tormented by the impossibility of a universal set of axioms.  For some reason the graphic novel format, with its incredibly detailed comics, does a phenomenal job of telling the story.  I have not been able to put it down.  It’s a quick, fun, intriguing read that really gets into the character of Russell.