Org mode has an amazing feature - org-capture. I only started using it recently but it's really awesome.

What took me so long?

Probably that the manual seemed a little intimidating.

It really isn't hard, though. Combined with what I'll go over in the next video and post (and a future one for Google calendar sync) it's what I use for:

• recording blog ideas
• managing bookmarks
• taking short Notes
• managing my calendar.

I use the binding:

(global-set-key (kbd "C-c c")
       'org-capture)

By default, running org-capture brings up a form to capture a "task" but things get really cool when you start making your own capture templates. With capture templates, you can speed up recording information and then tell org-mode to store it where you want it.

Here are my template settings.

(setq org-capture-templates
      '(("a" "Appointment" entry (file  "~/Dropbox/orgfiles/gcal.org" "Appointments")
	 "* TODO %?\n:PROPERTIES:\n\n:END:\nDEADLINE: %^T \n %i\n")
	("n" "Note" entry (file+headline "~/Dropbox/orgfiles/notes.org" "Notes")
	 "* Note %?\n%T")
	("l" "Link" entry (file+headline "~/Dropbox/orgfiles/links.org" "Links")
	 "* %? %^L %^g \n%T" :prepend t)
	("b" "Blog idea" entry (file+headline "~/Dropbox/orgfiles/i.org" "Blog Topics:")
	 "* %?\n%T" :prepend t)
	("t" "To Do Item" entry (file+headline "~/Dropbox/orgfiles/i.org" "To Do Items")
	 "* %?\n%T" :prepend t)
	("j" "Journal" entry (file+datetree "~/Dropbox/journal.org")
	 "* %?\nEntered on %U\n  %i\n  %a")
	("s" "Screencast" entry (file "~/Dropbox/orgfiles/screencastnotes.org")
	 "* %?\n%i\n")))

Let's look at the Blog entry:

("b" "Blog idea" entry (file+headline "~/Dropbox/orgfiles/i.org" "Blog Topics:")
 "* %?\n%T" :prepend t)

It's a list with a bunch of options. The first string b is the key to type to select this template, Blog idea is the actual name for this template.

The next item, entry describes the type of template you're creating. entry says you're going to create an org node with a headline which can then be added to an org-file. You can also have your template create things like an org list item a checkbox checkitem or even plain text. You can see the full set of options here.

Next, in parentheses, you have the target - where to store the captured info. The Blog idea template says file+headline followed by a filename in quotes and a headline in quotes. This says to store the new org heading you're capturing in the file "~/Dropbox/orgfiles/i.org" under the heading "Blog Topics:" Contrast this to the appointments template which just specifies file and a filename. The appointments template will just append the new appointment to its specified file whereas Blog idea will prepend (due to the :prepend option at the end of the template) to the "Blog Topics:" heading in i.org.

After this we have the actual template: "* %?\n%T" - the %? and %T are placeholders for substitutions. The %T prompts for a date with a timestamp and the %? is where to leave the cursor for final input before saving the capture.

Finally, :prepend and other options can be found at the above link.

All the substitutions can be found in the docs.

Once you've set up your templates, it's quick and easy to capture information.

This video shows the basics. The next one shows how to pop up a capture even when you're not in emacs and how I use org-capture to maintain my web bookmarks.

More information on capture templates can be found here.

Relevant links:

• Video series overview page:
  • http://cestlaz.github.io/stories/emacs
• Code:
  • https://github.com/zamansky/using-emacs/tree/master

I haven't spoken much about the class I've been teaching this semester. It's an intro CS course - a programming heavy intro. I decided to use Python with a transition at the end to C++. The transition is to mirror Hunter's normal first CS course that ends with a C++ intro to prepare the students for next semester's CS course which is a more intense OOP class using C++ - the language we use in our core courses.

Throughout the semester I've tried to use a variety of interesting application areas so as to try to give the students some idea of the possibilities that studying CS will open up for them.

After covering Python dictionaries and lists I thought we'd play by building an inverted Index.

The basic idea is to map a set of words back to source files. For example, given the following four one line files:

You could build a data structure mapping each word back to the file(s) that contain it (partially shown here),

You can, of course, store more information - how many times a word appears in a file, where it appears, etc.

This is a fairly easy structure to build. A dictionary where the keys are the words in the file and the values are lists of the documents containing the words.

  inverted_index = {
      'if' : ['file.01','file.02','file.03','file.04'],
      'you' : ['file.01','file.02','file.03','file.04'],
      'prick' : ['file.01'],
      'us' : ['file.01','file.02','file.03','file.04'],
      'do' : ['file.01','file.02','file.03'],
      ...
}

In addition to letting us work with dictionaries and lists, we can also review file access and even the python CSV module if we want.

We can immediately write simple queries – "what document(s) contain the word 'prick,' but things get more interesting if you write functions to perform and and or queries - "what document(s) contain the words 'prick' or 'do'" for instance.

Why are we building this (besides as a data structure and programming exercise)? I've seen a number of references to using an inverted index when building a web search engine. In fact, I think that's something you do early on in the Udacity Mooc. I just wanted to play with information retrieval.

I remembered that there was a collection of information, including last statements from executed offenders in Texas. Someone conveniently converted it into a Google Spreadsheet. The format's a little different from our simple four file example but then there's more data. It's straightforward enough to download the spreadsheet as a CSV file and then read it with a Python program that builds it into an inverted index.

Now we have some interesting data to play with.

How many offenders used words like "sorry" or "apologize?" How about references to religion? We can do all sorts of and and or queries.

We just played with this a bit but I could see all sorts of explorations. What about taking some great work of literature and turning it into an inverted index by chapter. You could query characters or certain words and see where and when they appear in the book. A new and different way of exploring literature.

So, there you have it - an interesting little project we played with this past semester. We did it in an intro Python course but I could see it as an interesting project in AP CS A using hashmaps and lists.

Quick post today.

The video goes over web-mode - my preferred weapon for html and all the goodies you embed in an html file.

It's multi-modal so it acts sensibly regardless of wether you're editing html, css, javascript or even templates in a single file.

Note: In the video, web-mode wasn't automatically inserting quotes. I had to set hte following variable to fix this:

(setq web-mode-enable-auto-quoting t)

Giving the final configuration I'm currently using:

  (use-package web-mode
    :ensure t
    :config
	 (add-to-list 'auto-mode-alist '("\\.html?\\'" . web-mode))
	 (setq web-mode-engines-alist
	       '(("django"    . "\\.html\\'")))
	 (setq web-mode-ac-sources-alist
	       '(("css" . (ac-source-css-property))
		 ("html" . (ac-source-words-in-buffer ac-source-abbrev))))

(setq web-mode-enable-auto-closing t)
(setq web-mode-enable-auto-quoting t)) ; this fixes the quote problem I mentioned

The web-mode documentation has more information including a nice chart of all the key bindings.

Relevant links:

• Video series overview page:
  • http://cestlaz.github.io/stories/emacs
• Code:
  • https://github.com/zamansky/using-emacs/tree/master

Another quick hit today.

This video is really setting the stage for hte next two, where I talk about org-mode capturing.

Today, we're demoing the use of the emacs server and client.

Back in the old days, emacs took a LOOONG time to load. A complex conviguration could take on the order of 10 to 20 seconds. This resulted in people loading emacs at the start of the day and leaving it up forever. While load times aren't much of an issue anymore, it's still nice to leave emacs around all the time.

That's where running emacs as a server comes in.. I set up a keyboard shortcut my window manager to run:

emacsclient -a "" -c

Rather than trying to run emacs, this tries to connect to an already running emacs server. The -c creates a new frame. Instead if you use -t it will open emacs in the terminal. The -a "" tells emacs to run itself as a server (daemon) if it isn't already running.

Later on, running emacsclient -c will very quickly bring up a new frame to the server.

In addition to instant loading, Running emacs this way has the advantage, or some may say disadvantage of keeping buffers around forever since you just keep emacs up and running.

Relevant links:

• Video series overview page:
  • http://cestlaz.github.io/stories/emacs
• Code:
  • https://github.com/zamansky/using-emacs/tree/master

Today's video is a bit of a follow up on the last one as well as a few miscillaneous configuration.

We got some comments on alternate ways to load a file if it exists - it's always cool to see how different people end up doing similar things.

We then talk about three little configurations. Two I found out about reading Jon Sander's (jcs) blog Irreal. Jon's blog is a terrific source of emacs info - if you don't subscribe, you should.

I go over using counsel for working with the kill-ring. The command counsel-yank-pop acts as a replamcement for yank-pop and it lets you easily yank anything from the kill ring - not just the most previously killed/whacked piece.

You just hit M-y and then either keep hitting it or use up and down to select what you want to yank.

Here's the original post from Irreal: http://irreal.org/blog/?p=5707.

I then briefly talk about smoothing things over between the system clipboard and the kill ring, also from Irreal: http://irreal.org/blog/?p=5702.

Finally, I talk about auto-revert-mode - this monitors files on your file system and when they change, they reload your buffer. I find this very useful to keep multiple machines in sync when I'm working with files in a could based filesystem like Dropbox or Owncloud.

Relevant links:

• Video series overview page:
  • http://cestlaz.github.io/stories/emacs
• Code:
  • https://github.com/zamansky/using-emacs/tree/master

Over on Facebook, my Alma Mater and long time employer, Stuyvesant High School seems to be making a big push to up it's Regeneron Science Talent Search game. For those of you who aren't familiar, that's the latest incarnation of the Westinghouse Science Talent Search from back in my day.

It seems that Stuyvesant hasn't had that many semi finalists, finalists, and winners over the past few years and isn't happy about it. The result is a bunch of social media reminding us of old winners and trying to raise funds to get us back to the glory days.

I'd rather they spent there time, energy, and money elsewhere.

When I was a young teacher, I was enamored with those types of results. When my kids did well on a USACO competition, for example, I felt pretty good about myself.

Then one day, I had an epiphany. I was looking over the results of a big USACO competition. My kids came in 4th, 5th, and I think fifteenth. I was feeling pretty good about myself but then I realized that Dan, Evan, and Jon - my three top scorers would probably have done just fine without me. Sure, I do believe that I was able to help them in their growth as both computer scientists and as people but they were already off the charts smart.

The same is true about the Science Talent Search (STS) winners. A friend of mine ran Stuyvesant's math research class for a number of years. He had a pretty impressive string of finalists and winners. How did he do it?

• Identify Stuyvesant's top talent - the ones already most likely to succeed in the STS.
• Pawn them off on a lab or professor.

The Stuy class, by and large, did little or nothing for these kids yet we would hold them up as shining examples of how wonderful we were.

When I had my epiphany, I started designing my intro class and focusing my efforts on the whole school population. The results? Scores of people succeeding in tech who never would have considered it otherwise.

While my super high achievers have indeed gone on to successful lives and careers, some of my most successful graduates, by any number of measures have been the students who would otherwise have gotten lost in the crowd at Stuy.

The truth is, many of Stuyvesant's STS winners would have been STS winners regardless of where they went. We may or may not have helped them along the way but STS results are not the measure of a great school.

Improving a school, any school, for all its students might not help in those bogus national ratings but that really should be what we're about.

Some of the videos I want to make are going to be much easier to do if I'm working in my own account where my whole file tree is available.

It's also a little annoying changing between my full emacs config and the one I'm developing here.

So, I decided to move to this config for my real config and as I make more videos move parts of my old configuration over to this new one.

The only problem is that I need some of my current config right now – things like my email setup.

This video talks about how I'm going to set things up to take care of everything.

Relevant links:

• Video series overview page:
  • http://cestlaz.github.io/stories/emacs
• Code:
  • https://github.com/zamansky/using-emacs/tree/master

This post points to the next three videos in the Flask series.

The first covers setting up a droplet (virtual server) on DigitalOcean. The second, deploying a flask application using Green Unicorn, and the third, using sshfs to remotely mount your files from your DO box to your local machine and how to set up DNS using FreeDNS.

To help you on your way with DigitalOcean, here are links to a few of their tutorials

• Server Setup (Ubuntu)
• Connecting to your droplet with ssh
• Setting up ssh keys
• Getting started with Linux (series)

In general, there are lots of great tutorials and guides at the Digital Ocean Community.

I meant to cover these last time but decided not to so as to keep the videos to about 10 minutes each.

First up this time round is iedit - a really cool mode that lets you select all the instances of the marked selection at the same time and edit them all at once. By default it's bound to C-l.

For example, let's say you had the following code:

def f(somevar):
    somevar = somevar + 1
    return somevar

You could mark one instance of somevar, hit C-; and you'd be editing them all at once. When you're done, you hit C-; again and everything is un-selected.

There are other ways to modify multiple instances of a selection. You can always search and replace or use Magnar Sveen's really cool multiple cursors package and I'm sure there are others but I like iedit since it's small and simple. It also works for rectangular editing but I didn't cover that in the video. I'll probably demo it when I cover rectangular editing in general.

Iedit has limitations. For insance, since it works globally, it isn't perfect for renaming variables. If the above code snippet was part of a larger program with many other instances of somevar, iedit wouldn't, by itself, be as useful.

You could reach for a language specific refactoring package but for me, that's where narrowing comes in. You can mark a region and tell emcas to narrow-to-region which hides everything outside the region and temporarily (until you widen) treats the region as the whole document.

So, you could narrow to the section of code you want to edit and then use iedit from within.

To make things easier, I grabed narrow-or-winden-dwim from Endless Parentheses.

I think the video makes the behaviour pretty clear.

Enjoy

Relevant links:

• Video series overview page:
  • http://cestlaz.github.io/stories/emacs
• Code:
  • https://github.com/zamansky/using-emacs/tree/master