Remind Me: Initial Data in a Django class-based Form

Posted on April 23, 2011 by Jeff Forman

I love Django‘s class-based way of handling forms. You name the class, articulate each field (data point of your form), and attach it to a view. Voila. But what happens when you want some initial data in the form?

Initial to the rescue!

What your class might look like:

class PersonForm(forms.Form):
    first_name = forms.CharField(max_length=100)
    last_name = forms.CharField(max_length=100)
    gender = forms.CharField(max_length=1)
    hair_color = forms.CharField(max_length=256)

If you now wanted to initialize your form for males with blonde hair, include this snippet in your view:

form = PersonForm(initial = { 'gender' : "M", 'hair_color' : "blonde" } )

Then pass that form as part of your render return:

return render_to_response('add_person.htm', { 'form' : form })

This post is brought to you by #neverwantingtosearchtheinternetforthisagain, and StackOverflow for inspiration.

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Boston Barcamp 6, Day Two

Posted on April 17, 2011 by Jeff Forman

Finally got this post out after having a bit of a busy week.
 

Location based networking, anurag wakhlu (coloci inc)
http://goo.gl/mxAtd
* location based apps: where are you now? or where will you be?
* where are you now: foursquare, gowalla, loopt, etc
* where will you be: coloci, fyesa, tripit, plancast
* interest based networking: the reason to talk to someone who is near you. tie an interest: sending someone a coupon when they are near starbucks. if they arent near starbucks, what good is a coupon?
* proactive coupons: dont wait for a check-in. if someone is 2 blocks from starbucks, send them a notification for coupon. ex// minority report. walk by a billboard, recognizes you, tailors ad specifically to you.
52% of US consumers willing to share location for retail perks.
* foursquare background checkin? automatically check you in when you are in a close enough vicinity to a location
* Do privacy concerns have a potential impact on services becoming more popular? ex// European privacy laws about broadcasting who you are, where you are, etc.
* Have to trust your device that when you disallow authority to know your location, it actually does not broadcast where you are.
* Trade off of convenience versus privacy. Debit card is a lot more convenient than cash, people are more than likely to give up privacy.
* If you really want to not be tracked, you really need to disconnect yourself from the computer. Go cash only. Re-education might help. “You might already be sharing this info somewhere else, so what difference is it now that you do it via your phone?”
* Tracking someone’s history via CSS visited tag. Firefox supposedly has fixed this issue where websites cannot do this anymore.
* Using EZpass, who is responsible for giving a ticket if you did 60 miles in faster than 60 minutes? Using your location to know your broke the law.
At the start, Anurag gave a wonderfully succint history of location based networking, highighting the current giants like Foursquare and Facebook Places. We talked about how the potential is there to enable your phone to alert you about consumer deals in your vicinity, having more of a ‘push’ aspect to networking, or your phone could alert you to friends being near as well. Eventually though, the attendants turned the talk into a big privacy discussion. Not necessarily as flame-worthy as it could have been, but still talking about how much of our information we want to broadcast and allow to advertisers. Broadcasting location and private information. Could the situation eventually get to the point like Minority Report where your phone is overtly/covertly broadcasting who you are to potential advertisers or other potentially nefarious people.

Economics of open source
* reputation is a kind of currency. ancillary benefits of ‘being known.’ ex// popular github repo, can get you a book deal, flown to conferences, etc.
* are we cheapening what we do by giving it away? software produces so much cash for people. not everything is oss. still need people to customize it and apply.
* discussion: can donations kill a project? the comptroller decides who gets money, and those who donate time but dont get paid feel slighted, and the project can take a nose dive.
Content of presentation was a bit bland/dry, but the discussion was involved. War story: giving training away for free when a company charges for it. you are hurting the ecosystem by giving it away rather than someone paying for it. This was fairly interesting, delving past the common topic of software being ‘free as in beer.’

Interviewing well as a coder round table
* feel okay sitting there for a couple minutes thinking. Dont feel stressed to start writing code right away.
* some questions to ask you to regurgitate syntax. what happens if you get confused between languages.
* design issues “show us where you would add X feature.” stylistics versus code syntax.
* code portfolios: employers look at your github profile. see the code you’ve written. if your code is ‘too good’, employer wants you to find bugs in their code.
* how to practice your whiteboarding skills? codekata: short programming problems.
* asking questions that there is no solution to. can you be an asshole interviewing?
* be prepared for personal questions because employers will google you and find your personal interests
* spin negative questions as positive: what do you see improving in your work environment?
* questions back to employee: what do you hope to improve for our company?
* if you list a skill in your skills list, be ready to whiteboard the code.

Can the internet make you healthier? jason jacobs, runkeeper founder
* convergence of health/athletic data and IT
* virtual coaching: ahead/behind pace, in-app reminders to go faster or slower on their iOS app.
The more data you have over what you’re doing physically, can help you react. How am I doing against my peers? This was interesting, since Jason sees his company’s first product ‘Run Keeper’ as the jumping off point to more athletic-body sensing applications. The point was raised about what point does the app which suggests a certain pace while running, dance the line of being medical advice. I think it is a good point, that the app needs more information about your health before suggesting a certain distance or pace for exercise. I’ll be curious myself as I use the app more, how I am improving athletically.

Overall, I found the signal-to-noise ratio of the unconference to be very high. For my first Barcamp, I would suggest it to all technically-inclined folks who just want to let their interests and imaginations plot the course of which talks they attend. I know I will be a repeat attendee.

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Barcamp Boston 6, Day One

Posted on April 10, 2011 by Jeff Forman

Having never been to a Barcamp before, I knew the overall structure of the conference, but was curious if I would actually like it. Truth be told, I found it full of content, without a lot of fluff, even for the talks I sat in on where I had no prior knowledge. My notes follow, thanks to the great OSX app Notational Velocity hooked up to Simplenote. My overall thoughts in italic after each post.:

how to give a presentation people love and learn from
break presentation into 7-10 minute chunks
then transition 7 minutes into the talk to another topic, to keep people’s attention
insert emotion, a story. rather than just X happened.
(For a talk to be this meta, a presentation about giving presentations, I was not hooked. There weren’t any real nuggets of information here that made me sit up and say “Wow, I haven’t been doing this in the presentation I make.”)

how to run a startup like genghis khan, by @wufoo
* work like a nomad
* build an audience first. protect your audience. make the audience part of the show.
* make developers handle support requests. once devs get same question two or three times, they go in and fix the code so they dont get the question again.
(Presenter absolutely killed it. Engaging, fast talking (without mumbling), great slides that presented the information in clear and sometimes humorous ways. Made me think more about engaging the people I am trying to convince to my way of thinking)

android developer: war stories and antipatterns
yoni, lead android dev at scavngr
* dont code splashscreens. more of an iOS thing. if you have to preload data, show a progress bar in the app already open
* dont force orientation (landscape/portrait). support both
* dont assume their screen size. use relative layouts
(I went into this talk curious and with no prior experience or knowledge of writing an Android app. I don’t even own an Android phone. This was much more a round table, with those devs in the room very willing to share their experiences and war stories. I found they really had good experiential tips, rather than “This is the best practice” and moving on.)

ask a plasma physics grad student anything
(I must say this was completely over my head. The student at the front of the room, from MIT’s Plasma Science and Fusion Center, seemed to know his stuff and was genuienly interested in challenging the audience. What blew me away was the knowledge of the audience, asking very pointed questions with what sounded like real science to back it up.)

building fast websites, making users happy (@jonathanklein)
* google injected 400ms delay into search page, dropped 0.76% searches/users over time.
* phpied.com/the-performance-business-pitch
* faster sites rank better in google. site speed is part of search ranking.
* what’s load time? server side generation time, client side render time. 80-90% of load time takes place on the client.
* best practices:
* reduce http requests: combine css/js, use image sprites (one download and cut up into multiple images).
* minify css/jss: strip comments out and white space. (yuy, java library). will rename variables into shortest name possible
* gzip all text: html, css, js
* for graphics, use png8 (restricts you to 256 different colors in the image)
* jpegs can be saved at 75% quality
* image compressor: smush.it (from yahoo dev network), lossless compression.
* measuring performance
* google webmaster tools, www.webpagetest.org
* yotta, firebug, yslow, page speed, dynatrace ajax edition
(For an ops guy, I was really interested in this talk. Jonathan blew through his material at break-neck speed, but covered the topics and answered questions without feeling like the talk was broken up. Some really good information through his experiences, and things I would like to dig into more myself.)

nosql round table
* some are relational, others are key value
* redis, redis + resque
* cassandra
* mongodb
* why nosql over mysql? no schema, lack of migrations from version to version. being able to store different things. replication (single threaded)
* keeping mysql in sync with nosql layer about: broadcast updates from mysql over rapidmq(?).  nosql service grabs update from mysql.
* solutions that they discarded:
* cassandra: v0.6, latency spikes between nodes. node would get flagged as awol. cascading failure because data gets rebalanced. use “hinted handoff” to prefer the direction of the failover. supposedly better in v0.7. documentation is messy.
* in the cloud or in a dc? mostly EC2. local storage with evs slave.
* search via solr
(Another one where I went in having nothing but curiosity, since noSQL is one of the popular buzz words these days. Very engaged audience who shared war stories, both good and bad, implementing noSQL solutions in their workplaces. Left me with a stalk of websites to dig into.)

agile development war stories
* problems it tries to solve: waste. business approach.
* more collab between business and engineering. dont just throw the ‘stories’ from biz over the wall.
* focus on testable behavior. how can we test each iteration? should be part of the original story.
* be smaller, quicker, more iterative. ex// dont go off for 18 months planning your solution. business might change underneath you
* people do “agile but..” and tend to modify the methodology.
* burn down?
* should tasks stay <1 day? sounds a bit unreasonable, since “speeding up the server by 20%” is unable to be done in one day. task size should have a reason.
* average sprint time: 2 weeks
* do a code review before the planning meeting. so estimations on a piece of work can be completed in the meeting. ex// dont trace the code for the 1st time in a meeting.
* software to track scrums/managing stories: soft2, scrum ninja, team foundations studio (windows), white boards, index cards on a wall, ibm rational, pivotal tracker (good for distributed teams), mingle from softworks.
(Another highly-concentrated buzzword round table where I was more curious than anything. Some real good information about what works and what doesn’t when it comes to managing time and projects. Lots to read up on here, and see if I can apply it to my daily work life.)

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Boston Pillow Fight 2011

Posted on April 3, 2011 by Jeff Forman

The wife was off doing some graduate school work for the afternoon, so I took the camera and headed down to the Boston/Cambridge Pillow Fight in Cambridge Common to see exactly what all the hoopla was all about. Apparently this is an international event. I was not dissapointed. The Facebook Group for the event had over 3700 RSVP’s, and there were half as many photographers and on-lookers as actual participants.

One of my favorite pictures from the event:

Pillow Fight Warrior

Album for the event on my Picasa Web Album.

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New toy, Nikon style.

Posted on March 27, 2011 by Jeff Forman

It had only been ‘recently’ that I had purchased myself a micro four-thirds digital camera for my honeymoon. It took pretty good pictures, and I loved its compactness when roaming around Portugal for 10 days. But I had always wanted a bit more control over the photos I took; whether it was exposure modification, lense type, or overall flexiblity for shooting in different situations (low light at night).

‘Lo and behold, Nikon announced the D7000. It had all the features of my Father’s D90, but with better HD video capture, an upgraded AF sensor and a whole host of other functionality too long to list. Patiently I waited for my bonus to be direct deposited, reading up on the manual (a hefty 350 pages), investigating some photography walks and classes in the area. Now in my hot little hands:

The weather finally reached an acceptable temperature where it was just above the level of being uncomfortable for an afternoon stroll. I wandered my way through Somerville and Cambridge on my way through Harvard Square. I captured the below uniquely-painted house. I was mainly playing around with Aperture-priority today, but look forward to digging into more of the image control options to bring out different detail.

Overall the camera is great, not too heavy for a couple hours slung over my shoulder, even with the included Nikon strap and an 18-105mm lens connected. The Op/Tech neoprene strap I have on order should make things a heck of a lot more comfortable when that arrives. I am really looking forward to the weather warming up when I can explore more of Boston with the camera and take it up into the mountains for some day-hikes.

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