Godoy's Blog

To investigate, definitely.

2006-04-08T01:03:00.000-03:00

One thing that is worth investigating is CatWalk. I really need to see how I can use it inside my apps to make my life easier... and I also should take a look at its code and templates to see what I can mimic on my systems.

After it was revamped it got incredibly beautiful and pleasant to work with.

So, what's up doc?

2006-04-07T23:53:00.000-03:00

I've been somewhat busy lately. Fixing a lot of things in NeoLab and this week I played with a new application - Market Watch -, for doing some basic market analysis. I also used it to review some approaches and make some tests for improving NeoLab. I found some new bugs in TurboGears (I'm becoming a professional bug finder :-)) and fixed a patch I've sent them about validating "money" fields, of course with I18N in mind.

Here are some screenshots of it.

Coming back...

2006-04-07T23:49:00.000-03:00

I was thinking about abandoning this because of the several problems I had here publishing my blog... I am doing nothing to push it to its limits, but it has already blocked for a few times. I think the system is too fragile... And, without any reason, it unblocks.

I believe that there's something on their Java code... Anyway, I think I'll try a bit more... I am not happy with this interface. I believe, for example, that multiply's interface is much better, but then, it is an "unknown" place for the blogging activity... :-
Too bad... And there there are some restrictions about the number of pictures per post, besides it being less flexible. It is really hard to find somewhere to blog to without using your own server. Who knows I'll just install WordPress or something like that at Wintermute (my server) and blog there... It is more to me than anything else...

Going deeper into the database

2006-03-19T10:09:00.000-03:00

Sometimes we need less abstraction and a more direct access to the database. Doing that when using something like TurboGears + SQLObject means that you have to either access the driver you're using directly -- and get worried with portability -- or to find out how to extract the driver and connection names directly from there.

When would you want that? I have two cases here:

one generic decorator that traps database failure or success and generates a message
some specific methods where I'm using features unsupported by SQLObject (such as array columns)

The first one can be easily solved with:

from siteamostras import model
driver = model.hub.getConnection()._dbConnection.module

While the second requires a bit more digging:

from siteamostras import model
conn = model.hub.getConnection()
conn.query("""insert into neolab.curvas_calibracao (concentracao, leitura,
                                                  incluido_por_id, incluido_em,
                                                  alterado_por_id, alterado_em)
             values ('{1, 3, 5}','{2, 7, 15}', 1, now(), 1, now())""")
hub.commit()  # Because I'm at the interactive prompt!
conn.queryAll('select concentracao[2] from neolab.curvas_calibracao')
# Output: [(Decimal("2.000000"),), (Decimal("2.000000"),), (Decimal("3.000000"),)]

And that's it.

SIC - Serviço de Informação da Carne

2006-03-18T22:43:00.000-03:00

SIC - Serviço de Informação da Carne (pt_BR)

OK. You've bought that amazing piece of meat... How to cook it right? How to cook it so that it doesn't get hard to eat? Here's a page that contains some hints on that. For you that doesn't speak Brazilian Portuguese this won't be all that useful, but you can always try passing it through some translation services... (We have a lot of cuts of meat here and I don't remember seeing all that many around in other places....)

There's the cleanest and easiest way and... there's IE's way.

2006-03-17T20:51:00.000-03:00

I wrote the AJAX that showed the graphics I talked about here, and then I uploaded it to my client to be able to use. Everything went OK and fast while he was using Linux, but when he opened IE... The graphic simply didn's show up.

The code for inserting the results for A, B and R² are the same that I used for the graphic, but I had to change the graphics part to be a DOM replacement instead of inserting the result as "innerHTML". So, I had to create the DOM for the image, get the element that is going to be its parent, insert the image as its child, replace the original parent with the new one that contains the image. The process is simple, but the complexity can be noticed from the description of what happens.

What were the collateral effects? The operation is slower, half the speed it was before.

So, if you want fast code you should take care with IE 'cause your code might not work...

My first "complex" AJAX page

2006-03-16T17:05:00.000-03:00

Today I finished developing my first complex AJAX page. It has three actions:

list all samples without a result for each selected analysis
creates a table to accept calibration readings and concentrations for the given analysis
calculates a curve adjusting it with minimum square fit for the given data on the calibration routine and also plot a graphic from this data

I found the resulting screen very pleasant and clean, and the results and graphic load very fast, but there's a message informing the user about what is happening if he's on a slow machine or slow link :-)

Here's a screenshot.

Later, this courve will be used to correct readings from samples. It is getting really nice and I'll see what else can I do to make things easier. I'm very pleased with this for now, and it came out exactly as I wanted it to be.

Now, I gotta go back and work with the part that will save all that into the database.

Very simple and useful widget

2006-03-16T10:13:00.000-03:00

I was needing a widget that presented data just like TableForm does, but without a form or a submit button, so that I could plug just JavaScript actions to it -- I have some "forms" that prepare the page for data input or do some data manipulation... -- and then, I had the idea: why not just changing TableForm to TableList? :-) Here's the new template. It derives from turbogears.widgets.Form.


class TableList(widgets.Form):
    template = """
    <div xmlns:py="http://purl.org/kid/ns#"
        name="list_${name}"
        py:attrs="form_attrs"
    >
        <div py:for="field in hidden_fields"
            py:replace="field.display(value_for(field), **options_for(field))"
        />
        <table border="0">
            <tr py:for="field in fields">
                <td>
                    <label class="fieldlabel" for="${field.field_id}" py:content="field.label" />
                </td>
                <td>
                    <span py:replace="field.display(value_for(field), **options_for(field))" />
                    <span py:if="error_for(field)" class="fielderror" py:content="error_for(field)" />
                    <span py:if="field.help_text" class="fieldhelp" py:content="field.help_text" />
                </td>
            </tr>
        </table>
    </div>
    """

24 ways

2006-03-15T00:58:00.000-03:00

24 ways

Some interesting -- and not so interesting -- stuff that can be done with (x)HTML, CSS and JavaScript. It is worth some time and investigation.

JavaScript Events and where they can be used

2006-03-14T17:25:00.000-03:00

Here is a list of commonly used event handlers in JavaScript:

onAbort: <img> tags
onBlur: window object, all form objects (ie: <input>), and <frame>.
onClick: Most visible elements such as <a>, <div>, <body>, etc.; Use this to invoke JavaScript if the mouse goes pass some link; Text fields, textareas, and select lists.; Most visible elements such as <a>, <div>, <body>, etc.
onLoad: <body>, <img>, and <frame>
onMouseover: Most visible elements such as <a>, <div>, <body>, etc.
onMouseout: Most visible elements such as <a>, <div>, <body> etc.
onReset: <form> tag, triggered when the form is reset via <input type="reset">.
onSelect: Elements with textual content. Most commonly used inside text fields and textareas.
onSubmit: <form> tag, triggered when the form is submitted.
onUnload: <body>

DHTML JavaScript Tooltips

2006-03-14T17:22:00.000-03:00

DHTML JavaScript Tooltips

This is a nice tooltip library that allows adding tooltips to links and other objects. One interesting thing is that it allows placing arbitrary HTML into de tooltip and this could be used to insert "previews" using some AJAX...

stock.xchng - the leading free stock photography site

2006-03-14T01:41:00.000-03:00

stock.xchng - the leading free stock photography site

This is a very nice repository of photographies that can be used in a variety of places. Some have no use restrictions at all, while other have some restrictions. Checking the license for each picture is always needed.

the occasional occurrence � Blog Archive � CherryPy and WSGI

2006-03-14T01:22:00.000-03:00

the occasional occurrence � Blog Archive � CherryPy and WSGI

So, here it is something to start with WSGI. Since TurboGears uses CherryPy (and Paste), this is something to start and that might become a part of TurboGears soon.

There are, on the other hand, several people working with what is called FirstClass, a WSGI version of TurboGears that should be what TurboGears 1.0 (or 1.1) will be when released. This is really the way to go for future compatibility, but anyway, I need to learn more about WSGI and how it can be useful to me. ;-)

New G2C website

2006-03-14T01:12:00.000-03:00

I've published about the old G2C website but I haven't put up any new pictures of the design we chose. So, here it is ;-)

UPDATE:. The green above is a courtesy of Blogger.com... Maximize the picture for the correct color set.

TurboGears + WSGI

2006-03-14T01:06:00.000-03:00

I definitely have to study more of that combination. It looks like WSGI + TurboGears will be something that will make a lot of code reusable very fast and will also make things easier. Gotta find some time for that, though...

She's gone :-(

2006-03-14T01:03:00.000-03:00

Flávia was here for the last four days. It was nice having her around, going out with her, dating, doing things specially to see her smile... But today, in fact yesterday -- two hours ago --, she went back to Bauru and Unesp... :-(

Flá, I'll miss you.

Inserting data as HTML code inside a Zope page template

2006-03-14T00:50:00.000-03:00

So, having skimmed through the docs and not being able to find anything, I decided asking in a mailing list that I've been barely reading for the last "N" months: Zope-PT.

I am thinking about providing my users the ability to edit data using some kind of WYSIWYG web editor and then being able to format the way data appears on the web, but for that I needed to find some way to insert (x)HTML code at my template.

The answer? Instead of using tal:replace or tal:content I had to use tal:structure :-) Simple as that.

This makes it very cool... And after reading the answer I remembered that a long time ago I've tested this markup and it worked (but my memory was not good enough to remember it before).

Web 2.0

2006-03-09T19:38:00.000-03:00

Web 2.0

Paul Graham's opinion on Web2.0. A very interesting post on the subject.

Playing with R, rpy, statistics and plotting serious graphics

2006-03-08T14:29:00.000-03:00

Last week I found an implementation that allows me using everything from R with Python: rpy. This is a wrapper that exposes everything, including graphics :-)

The nice part is that it allowed be to help the laboratory for which I'm developing a system to get results faster and seeing how good is both their data and calibration courve. The code I used is very simple and here's an example of it with some real data:

import rpy

def calcular_curva(concentracoes = [], resultados = []):
    rpy.set_default_mode(rpy.NO_CONVERSION)
    linear_model = rpy.r.lm(rpy.r("y ~ x"), data = rpy.r.data_frame(x = concentracoes, y = resultados))
    rpy.set_default_mode(rpy.BASIC_CONVERSION)
    r2 = rpy.r.summary(linear_model)['r.squared']
    b = linear_model.as_py()['coefficients']['x']
    a = linear_model.as_py()['coefficients']['(Intercept)']
    return dict(a = a, b = b, r2 = r2)

def plotar_curva(concentracoes = [], resultados = [], nome = "", arquivo = ""):
    linear_model = rpy.r.lm(rpy.r("y ~ x"), data = rpy.r.data_frame(x = concentracoes, y = resultados))
    gradient = linear_model['coefficients']['x']
    yintercept= linear_model['coefficients']['(Intercept)']
    rpy.r.png(arquivo, width=400, height=350)
    rpy.r.plot(x = concentracoes, y = resultados, xlab = "Concentrações", ylab = "Resultados",
               main = nome)
    rpy.r.abline(a = yintercept, b = gradient, col = "red")
    rpy.r.dev_off()

conc1 = [0.15, 0.30, 0.45, 0.90, 1.80, 3.00]
res1 = [1591.52,  2814.94,  3401.72,  8688.14,  15231.72,  19490.96]

conc2 = [0.3, 0.6, 0.9, 1.8, 3.6, 6.0]
res2 = [4850.10, 8372.14, 10353.47, 26153.44, 40808.95, 58253.38]

conc3 = [0.1, 0.2, 0.3, 0.6, 1.2, 2.0]
res3 = [324.60, 749.26, 1110.53, 1499.41, 4218.34, 4836.81]

conc4 = [100, 200, 300, 600, 1200, 2000]
res4 = [2362.24, 4537.41, 5983.17, 8830.44, 23481.62, 16654.07]

acido_hipurico = calcular_curva(conc1, res1)
acido_metil_hipurico = calcular_curva(conc2, res2)
acido_mandelico = calcular_curva(conc3, res3)
acido_fenilglioxilico = calcular_curva(conc4, res4)

print "Ácido Hipúrico:", acido_hipurico
print "Ácido Metil Hipúrico:", acido_metil_hipurico
print "Ácido Mandélico:", acido_mandelico
print "Ácido Fenilglioxílico:", acido_fenilglioxilico

plotar_curva(conc1, res1, "Ácido Hipúrico", "acido_hipurico.png")
plotar_curva(conc2, res2, "Ácido Metil Hipúrico", "acido_metil_hipurico.png")
plotar_curva(conc3, res3, "Ácido Mandélico", "acido_mandelico.png")
plotar_curva(conc4, res4, "Ácido Fenilglioxílico", "acido_fenilglioxilico.png")

Here I have four calibration courves for four different exams. One of them even has expurious data, so that we can test and see how to deal with that. This is raw data read from their equipment and I just changed it to be python lists. ;-)

The answer pops out instantly (R is very fast!) and the graphics too. I'm saving them to files, so that I can load them with my web interface and display this right after they've entered all concentrations (concentracoes) and the results they've read from the equipament (resultados).

This was my first experience with R and rpy, and this was the first snippet of code I've written with it and this is why this is very raw. :-) Oh! I haven't translated the code from portuguese just to show that R works perfectly with accents.

reStructuredText

2006-03-08T01:55:00.000-03:00

reStructuredText

I'm always missing this documentation! :-) So, here it is a link to it. Now, for some redundancy, I'm also adding it to my del.icio.us account. ;-)

Just a curiosity...

2006-03-06T16:16:00.000-03:00

Have you noticed that all of my browser screenshots have two tabs open on Orkut? :-)

My girlfriend is an Orkut addicted so I always have her and mine scrapbooks open here... :-)

Creating a new website for us!

2006-03-06T16:08:00.000-03:00

It's been sometime since we created G2C Tech's website and we're now creating a new one. From Juliano's mouth (my brother and partner): "This site looks like crap! Why did it look good 3 years ago?"

And he's right... In 3 years web has evolved a lot, but our website never had too many things or was too polluted. I've always liked simple things, but G2C Tech's website could be a lot better even by the time we first published it...

Anyway, it shold be replaced soon. A new website is coming and we'll have a more modern look and feel. :-)

Just to save it for the future, here's how it looks like now:

There are 10 CSS errors there. All related to some bells and whistles that were available under Internet Explorer (Juliano's a Windows user, and he's our webdesigner...). :-)

I'm starting to get sentimental about it. Three and a half years now, with this website. :-) Bye, bye, old site! :-) Soon there'll be a new look for you. ;-)

Zope.org - TutorialPart1

2006-03-06T16:02:00.000-03:00

Zope.org - TutorialPart1

This is a valuable tutorial for beginners on Zope Page Templates. It serves as a nice "quickstart" guide as well (or something to remember you the syntax of things after a long time since you've last used it ;-))

Criando Formulários no Zope/Plone utilizando o banco de dados MySQL — fabiorizzo.com - PZP Rocks!!!

2006-03-06T16:00:00.000-03:00

Criando Formulários no Zope/Plone utilizando o banco de dados MySQL

Simple yet objective website for creating forms within Plone and making them interact with a RDBMS database.

This is in Brazilian Portuguese as you might have guessed from the title...

Showing RDBMS query results on a Plone site

2006-03-06T15:09:00.000-03:00

I always forget how to do that and always lose one morning looking for it in Google & cia.

So, here it is the recipe.

To create a new page template that will appear in Plone, you have to get into ZMI (Zope Management Interface), get into the place where you want your page to be and create a new Page Template. Then, on the new page, you must be sure to have the bold parts there, so that we can inherit the site layout:

<html metal:use-macro="here/main_template/macros/master">
<head>
<title content="template/title">The title</title>
</head>
<body>
<div slot="main">

</div>
</body>
</html>

Now we can fill the main slot with our contents. For this example, the query will return three fields from our table: id, field1 and field2. Will create an hyperlink from this first page to the second page where we will be showing some details for this specific selected record.

After editing the above template, our code will look like this:

<html metal:use-macro="here/main_template/macros/master">
<head>
<title content="template/title">The title</title>
</head>
<body>
<div slot="main">
<ul repeat="result context/my_zsql_method">
<li><a attributes="href string:show?id=${result/id}" content="string:${result/field1} - ${result/field2}"></a>&tt;/li>
</ul>
</div>
</body>
</html>

As for my_zsql_method, it is a standard SQL query, and looks like thid:

SELECT id, field1, field2 FROM table WHERE condition ORDER BY field1;

Note that the names "selected" are the variable names we use in our Template.

To capture the 'id' sent to the second page, to perform a kind of 'drill-down' view, you can capture it as 'request/id' or 'request.id', the later for Python code.

And here it is, how to perform a query and show its results in a Plone website.

Musings from Mars � Ajax/DHTML Library Scorecard:How Cross Platform Are They?

2006-03-06T09:14:00.000-03:00

Musings from Mars � Ajax/DHTML Library Scorecard:How Cross Platform Are They?

A very interesting history background for what is becoming web2.0 and what are the risks it is facing.

I agree with the OS-agnostic worriness, and I also believe the it is developer's fault that IE is so dominant. Most of these developers doesn't know anything about security, logic or even programming: they simply point to components, click, drag them together and say "that's it! if it works for me, then it should work for everyone that matters". When you send them a bug report or suggest supporting more browsers they simply say: "it can't be done, you browser answer for less than X % of all access to our website and the cost of changing the code isnt' worth it". As if they knew how to change the code...

Once I even sent a patch to the website and the guy "Wow! Just this to make it compatible? Thanks! I didn't knew that!". I started another (unsent) message asking: "If you didn't knew that, how did you say that costs were prohibitive?"...

At least here in Brasil it is a problem with some government and bank websites. For the bank you can try fighting by sending them suggestions all the time, making them use more human resources in their offices by going there to do operations that could be done through Internet -- and saying all the time to your manager that their website still doesn't support your browser / OS and ask for them to fix it -- and things like that. For government we don't have much to do since it usually is something you're forced by law to use. You can pester them as well, but it is harder...

Anyway, everytime you see a website that doesn't work, try sending the "webmaster" (who isn't a master of anything but a bunch of drag and drop tools, usually) a complaint. If he answers with the statistics of access, question him: "Isn't it because your website doesn't work? For example, you won't ever get my 'hit' again...".

If one cares for one thing, he/she should fight for it. I stop buying from some sites if I can't complete the process. And I let their webmaster / public relations know that.

Making Zope + Plone access a PostgreSQL database

2006-03-06T02:23:00.000-03:00

This has always bothered me... Every time I have to work with that something makes me sigh and puts me down. Dunno why, but I believe that the fact that it is very hard to get it right, it is very hard to get it producing what I want, etc.

Now, I have to make some simple things but here is that feeling again... And I thought I'd be free from it. :-(

It is late in the night, maybe I should sleep (damned insomnia!)...

Lost afternoon

2006-03-06T02:07:00.000-03:00

This afternoon -- actually yesterday, since it is already March 6th --, my brother got some visit here. It was an ex-colleague from his company and she had problems with her computer. So, there came the girl and her aunt.

The aunt was comfortably "dismissed" by then and left on the TV room, watching it (by the way, we have something like 50 channels and I still don't know why some people prefer the silly Sunday afternoon programs on open TV instead of the less-silly-but-still-silly programs on cable...) and both them went to the office to fix her computer.

I was just hearing things, waiting to see if he needed some help and called me, but everything went fine and he fixed it by himself.

One thing that amazed me was when he said "You had more than 40 viruses here." I just smiled and remembered that it is going to be 9 years since I don't use Windows at home in July and 7 years that I don't use it to work in December. ;-)

I'm blessed :-)

Super Fast development!

2006-03-06T01:55:00.000-03:00

I liked it! I've sent a patch yesterday removing an annoying thing at CalendarDatePicker template: it used a button tag instead of an input tag with type button. The difference? The button tag made the calendar pop up whenever one pressed ENTER while filling the form. The later sends the form, as expected. ;-)

But what I liked? The speed of the accepting and applying the patch. In fact, I had to dig TurboGears Trac to see what became of the tickect, since I didn't remember if I had sent it and I didn't remember seeing it being closed. ;-)

TurboGears, faster than your eyes can see! :-)

Continuing Intermittent Incoherency � Comet: Low Latency Data for the Browser

2006-03-06T01:42:00.000-03:00

Continuing Intermittent Incoherency � Comet: Low Latency Data for the Browser

This is something that people working with web apps should keep an eye on. It is an alternativa to AJAX where instead of making the client pull information from the server we make the server push information to the client.

Starting some docs on using Subversion

2006-03-05T14:51:00.000-03:00

I've written some documents about using CVS and best practices with it. But for something like 3 years now I've been using Subversion for my own projects and I think it would be interesting to share how I am working and what I think is an interesting method to work.

Wait and see. ;-) Either a bunch of posts will appear os a link to somewhere. I'm planning on doing the first version in Brazilian Portuguese for a friend of mine that is willing to switch from CVS to Subversion but later there will be an English version.

Status letters for 'svn status'

2006-03-05T14:42:00.000-03:00

L       some_dir            # svn left a lock in the .svn area of some_dir
M       bar.c               # the content in bar.c has local modifications
M       baz.c               # baz.c has property but no content modifications
X       3rd_party           # dir is part of an externals definition
?       foo.o               # svn doesn't manage foo.o
!       some_dir            # svn manages this, but it's missing or incomplete
~       qux                 # versioned as file/dir/link, but type has changed
I       .screenrc           # svn doesn't manage this, and is set to ignore it
A  +    moved_dir           # added with history of where it came from
M  +    moved_dir/README    # added with history and has local modifications
D       stuff/fish.c        # file is scheduled for deletion
A       stuff/loot/bloo.h   # file is scheduled for addition
C       stuff/loot/lump.c   # file has textual conflicts from an update
C       stuff/loot/glub.c   # file has property conflicts from an update
R       xyz.c               # file is scheduled for replacement
 S     stuff/squawk        # file or dir has been switched to a branch
   K   dog.jpg             # file is locked locally; lock-token present
   O   cat.jpg             # file is locked in the repository by other user
   B   bird.jpg            # file is locked locally, but lock has been broken
   T   fish.jpg            # file is locked locally, but lock has been stolen

Curiosity about Subversion status letters on update

2006-03-05T13:48:00.000-03:00

I've been curious about the meaning of letters when we do 'svn up' on a working copy and I've also tried finding out but it was buried too deep in the manual. :-) I've finally found it and so that I don't forget it, I'm posting it here. My main concern was with 'G' status, since I always end up with some local changes to projects to make them suit better my needs. :-) Anyway, here are the status letters for Subversion 1.2 from the manual:

U foo
File foo was Updated (received changes from the server).
A foo
File or directory foo was Added to your working copy.
D foo
File or directory foo was Deleted from your working copy.
R foo
File or directory foo was Replaced in your working copy; that is, foo was deleted, and a new item with the same name was added. While they may have the same name, the repository considers them to be distinct objects with distinct histories.
G foo
File foo received new changes from the repository, but your local copy of the file had your modifications. Either the changes did not intersect, or the changes were exactly the same as your local modifications, so Subversion has successfully merGed the repository's changes into the file without a problem.
C foo
File foo received Conflicting changes from the server. The changes from the server directly overlap your own changes to the file. No need to panic, though. This overlap needs to be resolved by a human (you); we discuss this situation later in this chapter.

Apache versus Pound

2006-03-03T09:15:00.000-03:00

I was "benchmarking" (actually "feeling") the time it takes to load a page using both Pound and Apache. The difference is amazing. Apache is something like 10x faster than Pound.

I believe that is because Apache does some caching while Pound doesn't. In my case, I'm trying the setup I described before, just replacing Pound by Apache and vice-versa. My contents are still on TurboGears and Zope.

This makes it much better using Apache on my case... Too bad, since I really liked Pound and its simplicity, but I need to deliver the best performance I can since their link isn't all that big and we plan on having a bit of traffic before upgrading it.

Application Deployment

2006-03-03T01:05:00.000-03:00

I've just deployed the application at the production server and wanted to make a small deployment diagram.

The idea is allowing any kind of client connecting to the application and corporative website. Pound is an HTTP / HTTPS proxy that is in front of my TurboGears application or Zope website. The idea is letting it decide where should packages be sent and saving server resources from running Apache.

TurboGears is using PostgreSQL as its RDBMS, and Zope will be consulting some data from PostgreSQL to complement information that should be more static at the website.

This is a simple structure but it is a very effective one. It is really nice seeing all this working and seeing that it all required very little configuration. Tomorrow, at the client, it will pass for its first heavy test. I'm confident that it will perform better than the client was expecting.

One more step done!

2006-03-02T23:45:00.000-03:00

OK. I finally finished the last thing I had to do for now. It is working and I just need to polish some things before the first delivery (actually, it is already running at the production server).

Here it is a screenshot of the page that allows associating clients with price lists. These are a few of my clients and I used them for testing the application so this table has nothing to do with reality.

One thing I have to say: it is a fast interface, very efficient and the mix of Zope + Plone for the website with TurboGears for this application made it easy to maintain a consistent layout.

In fact, this is one of the things that attracted me the most to this solution: the easiness to skin and reuse layouts.

(Not) Seeing the Obvious

2006-03-02T22:21:00.000-03:00

Sometimes we get blinded and try solving problems the hardest way. I was creating a view and later looking for information on how to do something that I needed because of the view when I already had planned one of the tables with the information I was needing.

I really should stop more and read my own code (I'm lucky that I decided changing my model before spending too much time with this new view... ;-)

Debugging Kid templates

2006-03-02T21:29:00.000-03:00

So far the worst part of development is when something goes wrong and you have to debug kid templates...

They aren't easily debuggable and even the Python code you can generate with kidc isn't always helpful.

Things get a bit worse with unhelpful error messages or messages referencing internal structures that have the minimum possibility of being the problem cause... Anyway, doing experimentation with Python using print et al. is good enough since kid allows using almost everything Python have within its templates...

But, it is still a PITA.

Finishing something that was hard to rework

2006-03-02T18:00:00.000-03:00

I used to have part of my application working in a recursive manner, where I relied on the name of the widget -- and I was overriding it at display-time -- to find out to what analysis I was referring to while inserting their cost in the database. Then, there were some changes in TurboGears that made this stop and I had to rework my application to make it work again.

My first idea was creating the fields I needed with JavaScript, but then I took some time to think and I saw that this was not the best approach to what I wanted.

Then, I have changed the application layout so that it was more clear that I was willing the user to fill in prices for each analysis and that I was processing them individually.

As a benefit, I could again use widgets, validators, error_handling and even use my custom "tg_flash" function when something worked or not.

My next step is to abstract the error handling I used here so that I can convert it into a decorator and make it an alternative error handler, as I do with standard error_handling system.

I believe that I might have some complaints if there are too many analysis in some category due to the size of the page, but lets make things work first.

Oh, yes... Another problem is that the error handling system isn't smart enough -- and I believe it doesn't have enough resources -- to put the error message on the form that was submitted instead of putting it in every form... Another minor problem I'll handle later.

The good thing is: another feature is back and the code got smaller.

Quick tips

2006-03-02T13:49:00.000-03:00

Quick tips on ipython

Here are some interesting tips on using ipython more efficiently. I really like it, and it proves to be a huge time-saver when dealing with more complex structures or figuring out how something works.

ipython is also a huge helper to optimize algorithms ;-)

My biggest TurboGears project

2006-03-02T13:00:00.000-03:00

I've started with a big project for a client of mine. And I got a lot of the development of TurboGears what has delayed my delivery considerably. On the other hand, two weeks ago, I've factored out more than 1K LOC from my code because of the use of widgets and decorators.

It is really a more productive environment, but you have to resist the temptation to try all the new and exciting stuff ;-)

On the other hand, this one project can be used in a lot of other clients and I believe it will be the main part of several other that I have in mind.

Starting a blog

2006-03-02T12:43:00.000-03:00

OK, I finally decided to start a blog... I hope I can keep on updating it and that I don't leave it out there as a bunch of lost and lose text...

This first post is here more for getting the feeling and seeing how things will look like when published.