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BartleBlog change: Mako Templates

Since the very be­gin­ning, Bartle­Blog has been us­ing Cher­ry­Tem­plate for its out­put for­mat­ting need­s. I like it, be­cause it's very sim­ple.

How­ev­er, it had grown rather cum­ber­some.

Specif­i­cal­ly, most pages in a blog are sort of a page tem­plate with a body tem­plate in­side (the main con­tent).

To do that on Cher­ry­Tem­plate, I used a two-­pass ap­proach: gen­er­ate the body, then pass it as pa­ram­e­ter to the page tem­plate.

Which is a pain in some cas­es be­cause you end ba­si­cal­ly hav­ing to do a ren­der­ing func­tion for each kind of page, or some crazy-evil func­tion (what I did).

Ex­plor­ing the dif­fer­ent python tem­plate en­gi­nes, I ran in­to Mako and de­cid­ed to give it a whirl. It looks good.

The ap­proach is a bit dif­fer­en­t, it is much more pow­er­ful, but you can still use it sim­ply if you can.

And the main fea­ture was tem­plate in­her­i­tance. Us­ing that, no more in­ner and out­er tem­plates, baby!

Oh, and per­for­mance is bet­ter:

Cherry

real    31m44.732s
user    21m18.336s
sys     2m7.628s


Mako

real    24m54.472s
user    19m9.508s
sys     1m56.375s

This is for com­plete­ly reren­der­ing the whole 7 years, 574 post­s, 40 stat­ic ar­ti­cles, 14 cat­e­go­ry blog, and there is tons of op­ti­miza­tions to be done.

BTW: this is how you reren­der the whole blog:

from BartleBlog.backend.blog import Blog
Blog().renderFullBlog()

Sometimes I am stupid. Then again, it doesn't matter, because I am lucky!

I am work­ing on chang­ing Bartle­Blog so it can be used from scratch. That may sound odd but be­cause I have been us­ing it since day 2 to post this blog, it has grown very or­gan­i­cal­ly, mean­ing there are things that on­ly work be­cause of the way I used it while de­vel­op­ing it.

So, I cre­at­ed a test user, and cre­at­ed a test blog there, and I am work­ing, and de­cide to do an­oth­er from-scratch test, and...

I delet­ed my pro­duc­tion copy.

Yes. The one that gen­er­ates this blog. So this blog dis­ap­peared. Be­cause I used the wrong ter­mi­nal win­dow.

And I had one-week old back­up­s.

So I felt very very stupid.

Be­cause un­delet­ing in Lin­ux is a joke.

So I was think­ing how to spend a few hours recre­at­ing the last week of post­s, and what­ev­er, when I no­ticed on the taskbar... bartle­blog was still run­ning.

Which means that the DB was still open by a process. Which mean­s...

[ralsina@monty bartleblog]$ ps ax | grep python
17063 pts/1    S     24:33 python bartleblog.py
17161 ?        S      0:04 konqueror [kdeinit] -mimetype text/html http://www.google.com/search?q=python+copy+file&ie=UTF-8&oe=UTF-8
17454 pts/1    D+     0:00 grep python
[ralsina@monty bartleblog]$ su
Password:
[root@monty bartleblog]# cd /proc/17063/fd
[root@monty fd]# ls
0  1  10  11  12  2  3  4  5  6  7  8  9
[root@monty fd]# ls -l
total 0
lrwx------ 1 ralsina users 64 2007-05-13 21:07 0 -> /dev/pts/1
lrwx------ 1 ralsina users 64 2007-05-13 21:07 1 -> /dev/pts/1
lrwx------ 1 ralsina users 64 2007-05-13 21:07 10 -> socket:[159486]
lrwx------ 1 ralsina users 64 2007-05-13 21:07 11 -> socket:[159488]
lrwx------ 1 ralsina users 64 2007-05-13 21:07 12 -> /mnt/centos/home/ralsina/.bartleblog/blog.db (deleted)
lrwx------ 1 ralsina users 64 2007-05-13 21:07 2 -> /dev/pts/1
lr-x------ 1 ralsina users 64 2007-05-13 21:07 3 -> /mnt/centos/home/ralsina/Desktop/proyectos/bartleblog/bartleblog/BartleBlog/ui/bartleblog.py
lr-x------ 1 ralsina users 64 2007-05-13 21:07 4 -> pipe:[159481]
l-wx------ 1 ralsina users 64 2007-05-13 21:07 5 -> pipe:[159481]
lr-x------ 1 ralsina users 64 2007-05-13 21:07 6 -> pipe:[159482]
l-wx------ 1 ralsina users 64 2007-05-13 21:07 7 -> pipe:[159482]
lr-x------ 1 ralsina users 64 2007-05-13 21:07 8 -> pipe:[159485]
l-wx------ 1 ralsina users 64 2007-05-13 21:07 9 -> pipe:[159485]
[root@monty fd]# cp 12 /root/db
[root@monty fd]# ls -l ~/db
-rw-r--r-- 1 root root 3582976 2007-05-13 21:07 /root/db
[root@monty fd]# sqlitebrowser ~/db
[root@monty fd]# cp ~/db /home/ralsina/.bartleblog/blog.db

And I got the data­base back.

If you don't un­der­stand how that worked.... here's the ex­pla­na­tion:

  • On unix, files are re­al­­ly un­linked (re­­moved from di­rec­­to­ries) when no process has them open. Even then, the da­­ta is not delet­ed, but find­­ing it is much hard­er.

  • On /proc/PID you can see the file de­scrip­­tors each process has open.

  • You can ac­­tu­al­­ly copy a file de­scrip­­tor.

So I went and copied the open file. And got it back. And this blog did­n't go away.

So I am luck­y! Stupid. But luck­y!

New Bartleblog Feature: Menu Editor

Took a while to im­ple­men­t, but Bartle­Blog fi­nal­ly got a func­tion­al menu ed­i­tor:

bartleblog12.png

Right now, it on­ly works with the mootool­s-based menu gad­get, but I will start work­ing on the ya­hoo menu ver­sion in a mo­men­t.

The on­ly thing not work­ing is the pre­view but­ton, be­cause it needs more sup­port on the back­end side.

Python Trick: Save anything in config files

The Python con­fig ob­jects are con­ve­nient and sim­ple, but they have a prob­lem: you can on­ly save strings. That means you need to store num­bers as strings and re­mem­ber to use the get­int()/get­float() meth­ods (or co­erce by hand!), which is er­ror prone and an­ti-python­ic. Stor­ing a list is even ugli­er.

You could store ascii pick­les, but those are pret­ty un­pleas­ant to read in some cas­es.

Here's my so­lu­tion: En­code it us­ing a JSON en­coder first! (I am us­ing demj­son)

Sil­ly ob­vi­ous code frag­men­t:

def getValue(section,key,default=None):
    try:
        return JSON().decode(conf.get (section,key))
    except:
        return default

def setValue(section,key,value):
    value=JSON().encode(value)
    try:
        r=conf.set(section,key,value)
    except ConfigParser.NoSectionError:
        conf.add_section(section)
        r=conf.set(section,key,value)
    f=open(os.path.expanduser('~/.bartleblog/config'),'w')
    conf.write(f)
    return r

With just a lit­tle ef­fort you can have a read­able ascii typed python con­fig file.


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