web notes - a blog

This datatype was a lot of fun to build.

The objective was to allow people to upload Camtasia .zip files (videos) into eZ publish.

The strategy was to extend the eZBinaryFileType. When the attribute content is requested, the code checks to see if the .zip file data has been extracted and prepared for use. If it hasn’t, the .zip file is extracted and the HTML is filtered to retain only the tags necessary to deliver the video. The filtering includes updates to the paths in the HTML.

The display template assembles the URL of the HTML file and then uses an include call to bring it into the display.

One of the most interesting things I learned was how to use the PHP ZipArchive class (http://us.php.net/manual/en/class.ziparchive.php).

Nutshell explanation:

Make these changes to allow rounded image corners under eZ publish.

All .gifs and .pngs will have their corners rounded.
No .jpgs will have their corners rounded, unless you use the rounded aliases below, which force the output type to .png.

ez/settings/override/image.ini.append.php settings

<?php /* #?ini charset="utf-8"?

[AliasSettings]
AliasList[]=rounded-small
AliasList[]=rounded-medium
AliasList[]=rounded-large

[rounded-small]
MIMEType=image/png
Reference=small

[rounded-medium]
MIMEType=image/png
Reference=medium

[rounded-large]
MIMEType=image/png
Reference=large

[ImageMagick]
IsEnabled=true
ExecutablePath=/usr/local/bin
Executable=convert
ExecutableUnix=convert

# This line causes ALL images to have their corners rounded.  Only .gifs and .pngs will display with rounded corners, .jpgs
# will display with sharp corners, because they don't support transparency.  If a .jpg image is uploaded, the display class
# must be set to one of the above for the rounded corner version to display.
#
# The PostParameters settings must also be applied before the destination file name, modify /var/www/html/ez/lib/ezimage/classes/ezimageshellhandler.php
#
# Thanks to: http://www.imagemagick.org/Usage/thumbnails/#rounded
PostParameters=\( +clone -threshold -1 -draw "fill black polygon 0,0 0,10 10,0 fill white circle 10,10 10,0" \( +clone -flip \) -compose Multiply -composite \( +clone -flop \) -compose Multiply -composite \) +matte -compose CopyOpacity -composite

*/ ?>

/var/www/html/ez/lib/ezimage/classes/ezimageshellhandler.php

        if ( $filters !== false )
        {
            foreach ( $filters as $filterData )
            {
                $argumentList[] = $this->textForFilter( $filterData );
            }
        }

        /* Move PostParameters up before the destination file is named */
        if ( $this->PostParameters )
            $argumentList[] = $this->PostParameters;

        $destinationURL = $destinationMimeData['url'];

… same file … to help you see the command being executed …

file_put_contents('/tmp/eZ.out',$systemString."\n",FILE_APPEND);
system( $systemString, $returnCode );

Link is to a page that has daily dynamically generated background tile images, with a gradient overlay.

A fun way to make a site more interesting, especially for those with limited design skills. :)

Sometimes, code doesn’t do what it is supposed to, or what you expect. This is particularly common with open source code you didn’t write.

You can’t change the basic code architecture or data structures.

Key techniques to adapt and recover with javascript are instanceof and typeof. This allows you to test if an object or property has been created or assigned, and what type it is, then you can use it properly. Often, the best way to find out what types are being used is FireBug.

Take the time to look for examples in the code, so you don’t have to figure it all out from scratch. Usually, modifications to open source code involve code similar to that which is already in there, for example reassigning values.

Using objects with javascript, under IE requires attention to commas.

If you have an AJAX application that won’t load, and the error message is difficult to match up with the code, or not descriptive, one of the best things to check is the objects for trailing commas.

The code below will run fine in FF, but will not load in IE, because of the trailing comma after the second object in the array.

object={"object":"value","array":[{"v":"one"},{"v":"two"},]};

Be sure to check any JSON data sent back from the server, as well as that which is assigned or dynamically generated in javascript.

Brute force debugging with alert statements may be helpful.