System notes
============

~/.bashrc:

alias cp='cp -i'
alias mv='mv -i'
alias rm='rm -i'

alias ls='ls -F'
alias ll='ls -lF'

alias j=jobs
alias k=kill

~/.vimrc:

set ai sm sw=4 ts=8 expandtab
map g G

If you're using vi/m, learn to use it effectively:
* Move char, word, line, to blank line, to top/middle/bottom of page, to top/bottom of file
* x/X, dw, dd,
* insert (new line) before/after current position
* Change char/word/line
* Global search and replace

Linux:

* Learn most common commands: directory navigation, job control, history, autoexpansion,
  input/output redirection, grep, file permissions, etc.
* Keep simple, clear directory structures, e.g.
  ~/7401ICT/assign1/..., not ~/courses/7401ICT/assign1/mysite/...
  
Databases:

* Learn database shell commands
* SQLite database (and directory containing the database) must be readable and writable 
  (by the user running the (Django) server)
* Design tables so that every table represents a single entity or a single relationship
  (BCNF)

Django manage.py commands:

validate
syncdb
shell
dbshell
runserver 0.0.0.0:8xxx (no need to know IP address)

Django development:

* Pay attention to detail!

* Use examples.  Don't start from scratch.

* Learn your way around the Django documentation:
  - www.djangobook.com
  - docs.djangoproject.com

* Learn to use generic views

* Define __unicode__(self) in every model
* Define get_absolute_url(self) in every model

* Add django.contrib.admin and django.contrib.admindocs to INSTALLED_APPs to use admin
* Use admin.py to register specific models with admin

* Use forms.py or <model>_forms.py to define forms
* Learn to use ModelForm

* Always give patterns names
* Learn to use {{ object.get_absolute_url }}, {% url pattern_name %}, 
  HttpResponseRedirect(reverse('pattern_name', args=(...)))
  
* Development steps
  - Design URLs (/things/, /things/id/, /things/create/, /things/id/update/, etc.)
  - Design mapping from URLs to views (similar consistent naming scheme for views)
  - Design models
  - (Register models with admin)
  - Design forms (from models)
  - Implement views (when generic views are inadequate)
  - Design templates, use inheritance
  - Avoid absolute URLs everywhere except in URLconfs (urls.py)
  
* Develop incrementally.

Debugging:

* Read error messages carefully.  
  (They're not good, but they're better than PHP's.)
* Include print statements liberally to see variable values, e.g.:
  print "variable =", variable.
  Output appears in server log, doesn't affect admin or public interface.
* Divide and conquer to find errors, i.e., comment out blocks of code, repeatedly,
  to find location of error.
* Think.  Explain the problem to a friend.
  

Last updated: $Date: 2008/09/11 07:49:44 $, by Rodney Topor