Tag: fun stuff

D3: Taking a dip

By Ashish Datta | 4 Comments on D3: Taking a dip

D3 is a “newish” visualization library that has been getting a lot of attention recently. The New York Times has been using it extensively to create visualizations, and in fact its creator is currently employed by the NYT. I’d been meaning to take D3 for a spin for a while but couldn’t find a dataset I wanted to play with until a few weeks ago.

At the end of November, the LA Times published a dataset titled Capital appreciation bonds which highlighted how various California school districts were funding various projects with extremely high interest rate bonds. The LA Times described the data as:

Hun­dreds of Cali­for­nia school and com­munity col­lege dis­tricts have fin­anced con­struc­tion pro­jects with cap­it­al ap­pre­ci­ation bonds that push re­pay­ment far in­to the fu­ture and ul­ti­mately cost many times what the dis­trict bor­rowed. Gov­ern­ment fin­ance ex­perts con­sider bonds im­prudent if the total cost is more than four times the money bor­rowed or the ma­tur­ity peri­od is great­er than 25 years.

Anyway, you can check out my attempt at a visualization here.

PHP: Quick and dirty CLI tasks

By Ashish Datta | Leave a Comment on PHP: Quick and dirty CLI tasks

Something that comes up every so often in a sufficiently large PHP project is having to write helper scripts that run on the command line to complete various tasks. It might be periodically processing some images, updating cached analytics, etc. If the project is a Symfony project, it’s usually easy enough to add a Symfony task and be able to leverage the Symfony infrastructure to manage the individual “scripts” as tasks. This is equally true with Drupal, using Drush tasks to manage the individual scripts works well and lets you have a single, central spot for all your “helpers”. But what if its a vanilla PHP project or WordPress?

A technique I’ve started using is to create a class and then add each of the tasks as static functions. This allows you to keep all the tasks in one place, reuse code and configurations, and generally mimic how Symfony tasks and Drush work. From there, the file pulls off $argv to figure out what function to call and just passes $argv in as an argument as well.

Here’s a stub of a class to set something like this up:

HTML5: Masking file inputs with CSS3

By Ashish Datta | Leave a Comment on HTML5: Masking file inputs with CSS3

This morning, I was implimenting an AJAX “profile photo uploader” using the new HTML5 File object. With the new File object, you’re able to do a file upload using an AJAX request instead of requiring a form submission to upload the file.

This works great with the caveat that there still needs to be a <input type="file" /> on the page in order for the user to select a file. This presents a UI/UX issue because there isn’t much leway in styling HTML file inputs and consequently the input was looking out of place on our form.

After poking around for a bit I ran across jQuery File Upload which seems to solve this problem. Inspecting the CSS, the CSS “masks” the file input by using a CSS3 “transform” and then setting the opacity value to 0 so the input is visually hidden.

Implimenting the transform+opacity trick was pretty straightforward but the issue I ran into was that I couldn’t get the mouse cursor being displayed to appear as a “hand”, I kept seeing the “text selector” cursor. I had changed the transform being used and unfortunately the jQuery File Upload CSS didn’t have any comments explaining what it was actually doing to get the cursor part of the CSS to work.

It turns out what you want to do is use the CSS3 “transform” function to skew the file input so that the “Browse” button is covering the element that you want to use to trigger the “select file” behavior and then just set the opacity to 0 to make the file input invisible.

You can see the progression here http://jsfiddle.net/jpvWh/2/ The first container has no styling applied on the file input, the second one has the “Browse” button skewed into the right spot and finally the last one has the opacity set to 0. If you change the “cursor” CSS directive on the file input you’ll notice that in the 2nd and 3rd examples the cursor will change wherever your mouse is in the container. Also, you’ll notice that if you click anywhere in the container the “select a file” dialog will get triggered as expected.

Anyway, as always comments/feedback/questions are welcome!

Fun stuff: GitHub random repository browser

By Ashish Datta | 2 Comments on Fun stuff: GitHub random repository browser

Per Roger’s comment as of 11/14/2013 this no longer works :(

Over the weekend, I was looking for a good way to randomly browse GitHub. I hopped over to the GitHub search page but unfortunately there isn’t anyway to randomly search the repositories.

Just for fun, I decided to throw together a random repository browser. Check it out over at http://v3.setfive.com/adatta02_gitstumble/

Recursive templates with UnderscoreJS

By Ashish Datta | 1 Comment on Recursive templates with UnderscoreJS

I was working on a BackboneJS project recently that was using UnderscoreJS for templating and started wondering if its possible to invoke UnderscoreJS recursively.

At face value, the _.template function simply takes a template string and converts it to a first class Javascript function so I figured it would be possible. Out of curiosity, I decided to take a look at how the _. function is actually implemented:

Not any real surprises there – it basically does a series of string replaces on the template you pass in to interpolate any variables you want outputted, converts blocks you want evaluated to regular Javascript, and then injects the object you passed in into the local scope.

Then, the “magic” happens at “var render = new Function(settings.variable || ‘obj’, ‘_’, source);” where a new function is created with a “print” function locally defined and your template converted to a Javascript function.

Here is the “source” string that is passed into “new Function”:

That is the dynamic function generated for the following template:

Since its looking for the “template” function in the global scope it looks like everything should work fine. To test it, I decide to take the Fibonacci sequence and generate boxes for each of the numbers in the sequence up to some N.

Theres a live demo running at http://twitlabs.net/us/ and a Gist of the code is replicated below:

Just for fun, you can also change how the boxes are arranged by toggling between “Stacked” and “Cascaded”.

Anyway, fair warning – I imagine there are some performance implications regarding doing this as well as computational limits. You could potentially cause a stack overflow by consuming your entire stack via the recursion.

As always, questions, comments, concerns welcome!