Generating PDFs from Ruby on Rails
The problem
Ruby on Rails provides various helpers for generating dynamic web content but sometimes you need documents that users can easily store and share between them. The ubiquitous file format for this is Adobe PDF nowadays.
The common solution fro this problem is Prawn [github, introduction]. Alas it requires a custom DSL for document description, no existing Rails views or partials can be reused. An alternative is princeXML which transforms HTML/CSS into pdf through an external binary. This would allow reuse of existing templates and knowledge (think CSS designers) but has the downside of its price tag of $3800.
The solution
Enters wicked_pdf: it utilizes wkhtmltopdf to create a PDF document from a Rails HTML template. HTML rendering is done through the well-known webkit-engine. This allows developers to do PDFs in the right way™: define the document’s structure through a simple HTML document and theme them through CSS. You’ll get the automatic benefit of themability: exchange the CSS and you have another format. There are also lots of CSS artists out there that can supply you with different designs.
Smoking..
I’m within my sixth week of non-smoking, it gets better but still I do feel the urge to smoke sometimes, restrained only by the knowledge that I’ll become hooked again as soon as I lighten up another one.
The permanent cravings are gone, conversations with smokers tend to be strain my will but are easily survivable. Standing in the blue smoke still tempts.
But why? I don’t even like the taste. I’ve left behind the illusion that smoking calmes me down or teaches me how to breathe more slowly. My in-official title for smokers, suicidal misanthrope, remains to sound good. Temptation arises from time to time.
Slowly I understand those aggressive ex-smokers. Through a general smoking ban temptations would get rarer. Distrusting collectivism and state-imposed regulations my non-smoking gets a game against myself: do I need higher interventions to finally quit?
Computers provide users with various communication channels (as facebook, twitter, chat programs like ICQ, jabber, Skype). Each channel usually provides an own program for interacting with other users using that channel. To prevent users from being overwhelmed Ubuntu added the notifier-applet. It unifies all different communication notifications into one simple panel applet.
I am using Skype for most of my online communication, mostly because other people are using it and there are strange firewalls at work preventing most other protocols. Alas there’s no support for Skype out of the box and the skype linux crew is kinda slow (Skype 2.1, anyone?). Enters me who needed some diversion from master thesis writing..
indicator-applet with skype
May I introduce indicator-skype-client.py: it’s a small script, written in two or three hours (most of the time spent upon finding strange bugs in python-indicate). It currently provides a list of unread messages. When a username is clicked the corresponding skype window is opened or created. By clicking on the Skype label its main window is displayed. So far it works.. various updates will follow.
How to install?
Just start the python script while skype is already running. Skype will ask if you want to allow the script to access its data, just answer yes. The script will do the rest. It does not install itself into the user session, so you’ll have to start it if you want skype notifications.
TODOs
- There are various workarounds in the code (for example I needed an empty callback to get things displayed), work out those bugs
- currently there’s a hard refresh every 5 seconds (in addition to incoming message detection). This will have to go and be replaced with a more dynamic scheme.
- detect if an unread conversation was openend within Skype and do not display this conversation
- somehow automatically start the script when Skype or the indication-applet starts
So some things are missing, but the script is already workable. Have fun (and please provide patches if you fix problems (: ).
another month has passed..
Time flies by.. the last six week were more of the same: master thesis and other smallish stuff. The master thesis is getting along nicely albeit slow. At least I’ve got the first credentials for the practical part (Praktikum in German) now the two missing things are the Seminar and the Thesis itself. The later is currently around 95pages, its content slowly gets in shape. I still hope to finish somewhere around the middle of October.
I’ve just discovered an expired life insurance plan which will be reinvested into new stocks. Over the last year I had loses in the one-digit percent range, let’s see how the next year goes.
So far life’s good, I’m stocked up on concert tickets again. You can find me at the following shows:
| Date | Location | Band |
|---|---|---|
| 26.10. | Arena | Dredg |
| 4.11. | Porgy&Bess | Max Herre |
| 8.11. | Szene | Blumentopf |
| 10.11. | Arena | White Lies |
| 22.11. | Flex | Silversun Pickups |
| 29.11. | Gasometer | Alice In Chains |