Google App Engine

Recently I learned about Google’s App Engine and I must admit I am extremely impressed.  I am already have heard of at least two start ups that are deploying on it.

What it promises in terms of scalability and the amount it gives for free in terms of storage and bandwidth is impressive.  It is too bad it has not announced yet the terms when you begin to go over these limits.

I watched this tutorial on developing and deploying an application on Google App Engine.

My initial impressions were:

  • Python, hmmm…
  • Django, interesting…
  • this is not nearly as easy as Ruby on Rails

Still once has to believe this is going to help Python and its web framework, Django, in terms of momentum.

Jumping to different parts of a page using a dropdown

It is relatively simple to dynamically create a dropdown from which you can jump to different parts of a page using JavaScript and ATG DSPEL.

First create the dropdown.

<form name="jumpTo" action=".">
  <dspel:droplet name="/atg/dynamo/droplet/ForEach">
    <dspel:param name="array" param="categories"/>
    <dspel:setvalue param="category" paramvalue="element"/>
    <dspel:oparam name="outputStart">
      <select name="names">
    <dspel:oparam name="output">
      <dspel:getvalueof id="index" param="index"/>
      <c:set var="catShortName" value="cat${index}"/>
      <option value="<c:out value="${catShortName}"/>">
        <dspel:valueof param=""/>
    <dspel:oparam name="outputEnd">

Next create the button outside of the form for jumping to different parts of the page. I learned about the window.location.hash from this article. And I learned about how to access the selected value from the dropdown from this article.

 <input type="image" src="/img/buttons/update.gif"

Finally you create the name anchors throughout your document.

<dspel:droplet name="/atg/dynamo/droplet/ForEach">
  <dspel:param name="array" param="categories"/>
  <dspel:setvalue param="category" paramvalue="element"/>
  <dspel:oparam name="output">

    <%-- magazine category --%>
    <dspel:getvalueof id="index" param="index"/>
    <c:set var="catShortName" value="cat${index}"/>
    <a name="<c:out value="${catShortName}"/>"
       id="<c:out value="${catShortName}"/>">
      <dspel:valueof param=""/>


Gmail, SPF, and Broken Email Forwarding?

I read this article on Slashdot, Gmail, SPF, and Broken Email Forwarding?, which explains how email forwarding to Gmail and possibly other service providers may sometimes silently fail.

Background: Like many people, I have as my public facing Email address. When Email comes into my server, I forward it to But since my friend has published SPF (Sender Policy Framework) records that say only his server is allowed to send Emails for, gmail apparently rejects (silently buries actually!) the Email since it is forwarding through my server. Please note that this is exactly what SPF is designed to prevent — spammers from sending Emails with your address — but it breaks forwarding and has other problems.

I also do what the author above talks about, i.e. I forward the email for my various domains to my various Gmail accounts.  Hopefully this is not an issue, that no one who emails directly to my domain email addresses is using SPF.

One proposed solution by a Slashdot poster makes sense, use Google apps.  Fortunately this is available for free on Dreamhost, my web host, and is easy to set up.  I might try it later.

Is there another solution?

Yes, of course. Have all your email sent to Google in the first place! You don’t have to switch everything over to the Google app tool, you can just set MX records for your domain pointing to them, and collect it all (or forward it inside or outside Google.) It’s free (with a paid version available.) Check it out here Smart apps for email, documents, sites and more

How Facebook Stores Billions of Photos

Those guys at Facebook sure are smart. Here is an online presentation titled Needle in a Haystack: Efficient Storage of Billions of Photos.

Jason Sobel, the manager of infrastructure engineering at Facebook, … explains how Facebook efficiently stores ~6.5 billion images, in 4 or 5 sizes each, totaling ~30 billion files, and a total of 540 TB and serving 475,000 images per second at peak.

Slashdot | How Facebook Stores Billions of Photos

Stats on Dreamhost with WordPress

Analog: WWW logfile analysisOn my WordPress blogs hosted by Dreamhost to get stats I needed to add this to the .htaccess file.

# BEGIN Stats
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
RewriteCond %{REQUEST_URI} ^/(stats|failed_auth\.html).*$ [NC]
RewriteRule . - [L]
# END Stats

This is further explained in the Dreamhost Wiki page Making stats accessible with htaccess.

Dreamhost uses Analog to generate web statistics. Other recommended AWStats which seems more powerful. Maybe I’ll switch if I feel the need.

Google Doctype

Chris Weekly says Google Doctype looks like “a new, excellent resource for keeping up with webdev tips and tricks, browser compatibility issues, etc.”

Documenting the Open Web

Browse Google Doctype

Google Doctype is an open encyclopedia and reference library. Written by web developers, for web developers. It includes articles on web security, JavaScript DOM manipulation, CSS tips and tricks, and more. The reference section includes a growing library of test cases for checking cross-browser and cross-platform compatibility.

Google Doctype is 100% open.

  • Open source
  • Open content
  • Open to contributions from anyone

phpMyAdmin not starting

Today when I started up phpMyAdmin (version by going to http://localhost/phpMyAdmin I saw this error screen.

phpMyAdmin – Error

I googled around but could not find any solutions.

So I went and tried to install the latest version of phpMyAdmin, 2.11.5. When I tried to run setup I saw this error screen.

phpMyAdmin – Error

Cannot start session without errors, please check errors given in your PHP and/or webserver log file and configure your PHP installation properly.

Now that I had an error message to work with I googled around and found this post, Xampp phpMyAdmin Problem, which helped me diagnose the problem.

It turns out during one of my cleaning sessions I wiped out the session directory in, “C:\DOCUME~1\fkim\LOCALS~1\Temp\php\session.” After restoring it I ran into my next problem.

phpMyAdmin – Error

Cannot load mysql extension. Please check your PHP configuration. – Documentation

I upgraded to PHP 5.2.5 from 5.2.1 but that did not help. I installed the mbstring module but that did not help.

Finally I added the PHP extension directory to the path (I had already added the PHP directory to the path) and it finally worked! My path now includes the following two directories, E:\Program Files\PHP and E:\Program Files\PHP\ext.

Submitting an ATG Form Using a Text Link

It has always bedeviled me how to submit an ATG form using a text link. I have asked many people about this but no one seems to know. Finally with the help of ATG support I figured it out.

Below is a simple example of how to do it. The trick is the hidden submit input which triggers ATG to call the handleSubmit method of the form handler.

<%@ taglib uri="/dspTaglib" prefix="dsp"%>


  function submit(form) {

<dsp:form action="<%=request.getRequestURI()%>" method="post" name="testForm">

  Foo: <dsp:input type="text" bean=""/>

  <p><a href="javascript:submit(document.testForm)">Submit</a>

  <dsp:input type="hidden" bean="TestFormHandler.submit" value="Submit"/>



You can also invoke the JavaScript like this:

  <p><a href="#" onclick="submit(document.testForm); return false;">Submit</a>