Deep Thoughts by Robert Felty » wordpress

Multi-column balanced lists

robfelty — Thu, 18 Feb 2010 17:25:36 +0000

List with balanced columns

List with unbalanced columns

Recently I was working on a project where a client wanted a list of items to be displayed over multiple columns, and requested that the columns be balanced (as balanced as possible). It didn’t take me too long to figure out how to do this for 3 columns, but I knew that there was a more general solution, which did take me a little time to figure out. I am sharing my solution here for my future reference. Perhaps some one else will find it useful too. The solution is in php, though the general algorithm should apply to any language.

The intuition that led me to this solution was to examine unbalanced columns. Let’s look at the case of 5 columns with 56 items, as shown in the figures. It quickly becomes obvious that you need 12 items per column (ceil(56/5)). However, this yields columns of lengths 12, 12, 12, 12 and 8. If you decrease the number of total items to 55, then you have balanced columns of 11. If you increase the number of items to 60, you have balanced columns of 12. Thus, it is possible for the last column to have n-1 items less than the other columns, where n is the number of columns. The preferred output is to have columns of 12, 11, 11, 11, and 11. So what we are doing is shifting over elements from columns 2, 3, and 4 to column 5 (note that we are not messing with the order of the elements). We can always achieve the desired result by simply decreasing the number of items from some of the columns by 1. To determine which columns to decrease, we simply look at the difference in the number of elements per column in the unbalanced solution. In the case of 5 columns with 56 items, the last column would only have 8 items, which is 4 less than 12. So we should start reducing the number of items per column at the 2nd column ((5-4)+1). If we had 57 items total, we would start reducing at the 3rd column ((5-3)+1).

Here is the snippet of code which takes care of figuring this out:

$numCols = 5;

$numItems = 56;

$itemsPerCol = ceil($numItems / $numCols);

$adjustedItemsPerCol=$itemsPerCol;

$blank =$itemsPerCol - ($numItems % $itemsPerCol);

if ($blank!=$itemsPerCol && $blank >0) {

  $adjustedItemsPerCol--;

}

While we are looping over our array of items (or, in my example case, using a while loop), we check to see which column we are on, and if we are on the column where we start to decrease the number of items per column, then we switch $itemsPerCol to $adjustedItemsPerCol.

if ($colNum == ($numCols - $blank)) {

  $itemsPerCol=$adjustedItemsPerCol;

}

Feel free to look at this working example, along with the code for it. I have used the CSS float property to make the divs act like columns, and added some colors to help them stand out.

Wordpress 2.9 image changes

robfelty — Sat, 02 Jan 2010 22:58:48 +0000

Wordpress 2.9 has several new image enhancements. One of the biggest features is some basic image editing functionality. Another one is that you can now specify different alt text from the “caption” field. The “caption” field places a caption under the image. The “alt” text is used to describe the picture to non-seeing users (including search engines). This is a nice addition. However, I usually like my caption, alt text, and title text to be all the same, and I don’t like to have to enter it all manually or copy and paste. By default, wordpress will use an IPTC caption as its “description” field, which shows up in the title attribute of the image. This is nice, since I can add a caption in my image editing program of choice (Picasa) and then I don’t have to enter it again. Except for those pesky alt and caption fields, which are blank by default.

This is particularly important if I am uploading many pictures. So I wrote a little sql which will set the “caption” and “alt text” fields to be the same as the description. I already had this working for the “caption” field for quite some time, but getting it to work for the different alt text handling in 2.9 was a bit tricky, since I discovered that the alt text is not stored in wp_posts like the other fields. Instead it is stored in the wp_postmeta table, which is new in 2.9. Although it took me awhile to figure this out, the new table is a welcome addition. Now for each image you upload, wordpress stores meta information in this table, including the width and height, different sized versions of the file, the IPTC caption, some EXIF info and a few other goodies. This means that if you like to include EXIF info about your pictures, that doing so requires only a simple database lookup, instead of having to read the headers from the image, which should be considerably faster I would imagine.

Now for my little SQL which sets the “caption” and “alt text” to be the same as the description. I run this on my server after uploading pictures. It would be even better if I could figure out how to do this as a wordpress plugin.

-- First we set the image caption (post_excerpt) to be the same as the

-- description (post_content)

UPDATE wp_posts SET post_excerpt=post_content WHERE post_type='attachment' AND

date(post_date)=curdate();

-- Next we set the alternative text to be the same as the post_excerpt

INSERT INTO wp_postmeta (wp_postmeta.post_id, wp_postmeta.meta_value) SELECT

DISTINCT wp_posts.ID, wp_posts.post_excerpt FROM wp_posts, wp_postmeta WHERE

wp_posts.ID=wp_postmeta.post_id AND post_type='attachment' AND

date(post_date)=curdate();

-- This line sets the correct meta_key for the previous line, which doesn't

-- seem possible otherwise

UPDATE wp_postmeta SET meta_key='_wp_attachment_image_alt' WHERE meta_key IS

NULL;

Writing your own custom filters for postie

robfelty — Mon, 24 Aug 2009 19:00:03 +0000

In version 1.3.1 of postie, it is now easy to add custom filters to the content of your posts. Best of all, by using filters, you can easily write your own plugin, which will not be affected by upgrades to postie (as opposed to modifying the postie functions directly). There are two examples now included in version 1.3.1 of postie, in the filterPostie.php file. Here is how to write your own filter.

Copy the filterPostie.php into your plugins directory
Change the metadata at the top of the file, such as the author and plugin name
Modify the example functions to your liking, or create your own
Activate the plugin

A few more details. After modifying the headers, you might have something like the following:

/* Plugin Name: My own Postie Filter Plugin 

URI: http://mywebsite

Description: Adds a custom field to each post called postie 

Version: 0.1 Author: Joe Bloe 

Author URI: http://mywebsite.com 

*/

Just as with any filter for wordpress, you have 2 parts.

A function which receives an argument, makes some modifications (filtering) and returns a result
A function call to add this new function to the list of filters for a certain action

As you can see in the example file, I have created two functions, filter_title, and filter_content. After creating these functions, I then “hook” them into postie using the add_filter function.

add_filter('postie_post', 'filter_title'); 

add_filter('postie_post', 'filter_content');

Now lets create our new function to add a custom field

function add_custom_field($post) {

  //this function appends "(via postie)" to the title (subject)

  add_post_meta($post['ID'], 'postie', 'postie');

  return ($post);

}

Finally, we let wordpress know that this function should filter any post that is sent via postie

add_filter('postie_post', 'add_custom_field');

Currently our function is really not that useful, since the key and value of our custom field are the same. However, there is really very little limit to what we can do with filters. Perhaps a more useful function would be an auto- tagger. Suppose I often write about cooking, wordpress, and latex (which I do). But when I am posting via e-mail, I frequently forget to add tags. We could write a little filter function to read the body of the post, and automatically add tags depending on the content. Here is what it might look like:

function auto_tag($post) {  

  // this function automatically inserts tags for a post   

  $my_tags=array('cooking', 'latex', 'wordpress');   

  foreach ($my_tags as $my_tag) {     

    if (stripos($post['post_content'], $my_tag)!==false)       

      array_push($post['tags_input'], $my_tag);   

  }   

  return ($post); 

} 

add_filter('postie_post', 'auto_tag');

I’m sure that users will come up with many other interesting filters. If you develop any you would like to share, please post them on the postie forum

Blogging with LaTeX

robfelty — Tue, 18 Aug 2009 15:22:17 +0000

The first question on reader’s mind must be — why use LaTeX to blog?

Well, I have a pretty specific instance in mind, but I can imagine that others might be interested as well. This fall I am teaching a course on computational corpus linguistics at CU Boulder. I like to have some materials online for the students, such as the syllabus, course notes, etc. I thought about setting up a simple webpage, but then I decided instead to use wordpress, because it would give me extra functionality, such as auto-generating rss feeds, and with some plugins, would allow me to notify students via e-mail when I post lecture notes or slides, or homework tips. The one drawback I could see is that it would be hard to update the syllabus throughout the semester, as I tend to change the calendar some throughout the semester. Then I thought that maybe I could hack up a quick xml-rpc solution to the problem, and about an hour later, I had it done. All I needed was the Wordpress::API perl module from CPAN.

Now I have a handy little publish script which first compiles my syllabus as pdf, then compiles it as html using plasTeX. Then I run it through tidy for formatting and hack in a few more things. Then I update the syllabus page on the course blog via xml-rpc. Finally, I rsync the pdf to the server. And with the post-notification plugin for wordpress, students will get an e-mail when the syllabus is updated.

Here are the scripts:

publish

#!/bin/bash

# this script compiles a pdf version, an html version, and then copies it to my

# webserver

# compile as pdf

pdflatex syllabus && pdflatex syllabus

# compile as html

plastex  -c syllabus.cfg syllabus

# clean up code a bit

tidy --show-body-only true --ascii-chars true  -asxhtml --input-encoding utf8 --output-encoding ascii -wrap 0 -indent --tab-size 4 syllabus/index.html > syllabus/syllabus.tmp

# add in link to pdf version in the html version

cat pdflink syllabus/syllabus.tmp > syllabus/syllabus.html

# update the syllabus page via xml-rpc

./updateSyllabusPage.pl

# upload the newest version of the pdf

rsync -avzu syllabus.pdf robfelty.com:/var/www/html/robfelty/teaching/ling5200Fall2009/ling5200Fall2009-syllabus.pdf

updateSyllabusPage.pl

#!/usr/bin/perl -w

use WordPress::API;

# get new syllabus content

my $contentFile = 'syllabus/syllabus.html';

open(CONTENT, $contentFile);

# slurp in content

$content = do {local ( $/ );  };

my $w = WordPress::API->new({

   proxy => 'http://robfelty.com/teaching/ling5200Fall2009/xmlrpc.php',

   username => 'myusername',

   password => 'mypassword',

});

my $page = $w->page(3);

$page->description($content);

$page->save;

Finally, if you want to see how I customize content for pdf and html separately, you can check out the LaTeX source file

Postie 1.3.0 released

robfelty — Fri, 14 Aug 2009 18:10:59 +0000

After more than a month of fixing bugs and adding features, I have decided it is time to release Postie 1.3.0, the wordpress plugin which adds many features to post to your blog via e-mail. 1.3 offers many new features over the 1.2 line of postie, including better attachment handling, better language and character set support, and easier configuration. Here is a list of the new features and bug fixes from 1.3.beta to 1.3.0.

Features
- Added mpeg4 to default list of videotypes
- Added support for KOI8-R character set (cyrillic)
- Added support for iso-8859-2 character set (eastern european)
- Added option to include custom icons for attachments
- Added option to send confirmation message to sender
- Enhanced e-mails for unauthorized users
- Added option to send unauthorized e-mail back to sender
- Added option to only allow e-mails from a specified list of smtp
- Added option to use shortcode for embedding videos (works with the
- Better handling of comment authors (thanks to Petter for suggestion)
- Simplified message options (now includes an advanced options section)
- Added filter ability for post content
Bug fixes
- No longer including wp-config.php
- If tmpdir is not writable, try a different tmpdir
- More subject encoding fixes
- Updated image templates, which were causing problems for cron
- Fixed in text captions
- Fixed SQL problems when updating options
- Fixed name clashes with other plugins
- Fixed custom image field

I want to thank the many users who were willing to test out new features and bug fixes by trying out the development version. in particular, I want to thank Kyle and Hab at Abilene Christian University for offering me financial support to develop some additional features for their use of postie for a course at their university. I think that other postie users will enjoy some of these new features as well.

On blog navigation

robfelty — Fri, 24 Jul 2009 04:20:25 +0000

A few navigation choices after reading an article on a blog

I was recently debating with my friend Danny how people navigate sites, especially blogs. As the author of 3 plugins designed to enhance site navigation (collapsing archives, categories, and pages), I of course had my opinions, but what is really compelling is data. So I finally decided to modify my links on my site a bit in order to figure out more exactly how people are navigating my site. There are several different ways in which people can navigate to a particular page on my site.

external
- search
- social network (digg, reddit, friendfeed, etc.)
internal
- collapsing archives widget
- collpsing categorries widget
- collapsing pages widget
- category page
- archive page
- search
- index page link
- prev page link
- next page link

I added a ?nav query to each of these particular options, so that I could then find those values in the server logs. I wrote a little bash script which mostly does some grepping of the log. Here is the script, and the results for the last 12 hours or so. My plan is to collect about 30 days worth of data, and see what the data shows. I think the results will be informative.

#!/bin/bash

# calculate how people navigate my site

# first we filter out all spiders, any internal blog stuff, and requests from

# my own ip, and then pipe that to filter out page refreshes

grep -vEi '(Mediapartners-Google|bot|spider|crawler|slurp|scoutjet|httpunit|htmlparser|favicon|wp-cron.php|wp-content|wp-photos|wp-comments|feed|fail\.php|wp-login.php|POST|\/images|wp-includes|forum|71\.237\.102\.16)' experiment_log |grep -Ev '"GET (.*) .*\1' > nobots

# next we separate into internal and external referers

grep 'http://blog.robfelty.com' nobots > INTERNAL

grep -v 'http://blog.robfelty.com' nobots > EXTERNAL

EXTSEARCH=`grep -ciE '(yahoo|bing|google)' EXTERNAL`

SOCIAL=`grep -ciE '(fark|reddit|digg|slashdot|friendfeed|facebook|twitter)' EXTERNAL`

NOREFERER=`grep -c '"-"' EXTERNAL`

EXTREMAINING=`grep -viE '(yahoo|bing|google|fark|reddit|digg|slashdot|friendfeed|facebook|twitter)' EXTERNAL|grep -cv '"-"'`

COLLARCH=`grep -c '?nav=collapsing-archives' INTERNAL`

COLLCAT=`grep -c '?nav=collapsing-category' INTERNAL`

YEARLY=`grep -c '?nav=yearly' INTERNAL`

MONTHLY=`grep -c '?nav=monthly' INTERNAL`

CAT=`grep -c '?nav=category' INTERNAL`

COLLPAGE=`grep -c '?nav=collapsing-pages' INTERNAL`

SEARCH=`grep -c '?nav=search' INTERNAL`

INDEX=`grep -c '?nav=index' INTERNAL`

PREV=`grep -c '?nav=previous' INTERNAL`

NEXT=`grep -c '?nav=next' INTERNAL`

TOTAL=`wc -l nobots|cut -f1 -d ' '`

INTERNAL=`wc -l INTERNAL|cut -f1 -d ' '`

EXTERNAL=`wc -l EXTERNAL|cut -f1 -d ' '`

# Only firefox prefetches

PREFETCH=`grep -vE '\?nav=(collapsing-category|collapsing-archives|search|index|previous|next)' INTERNAL|grep -c 'Firefox'`

INTREMAINING=`grep -vE '\?nav=(collapsing-category|collapsing-archives|search|index|previous|next)' INTERNAL|grep -cv 'Firefox'`

echo "TOTAL PAGES = $TOTAL"

echo "  EXTERNAL= $EXTERNAL"

echo "    EXTSEARCH = $EXTSEARCH"

echo "    SOCIAL = $SOCIAL"

echo "    NOREFERER = $NOREFERER"

echo "    REMAINING = $EXTREMAINING"

echo "  INTERNAL= $INTERNAL"

echo "    COLLARCH = $COLLARCH"

echo "    YEARLY = $YEARLY"

echo "    MONTHLY = $MONTHLY"

echo "    COLLCAT = $COLLCAT"

echo "    CAT = $CAT"

echo "    COLLPAGE = $COLLPAGE"

echo "    SEARCH = $SEARCH"

echo "    INDEX = $INDEX"

echo "    PREV = $PREV"

echo "    NEXT = $NEXT"

echo "    PREFETCH = $PREFETCH"

echo "    REMAINING = $INTREMAINING"

TOTAL PAGES = 197
  EXTERNAL= 131
    EXTSEARCH = 51
    SOCIAL = 0
    NOREFERER = 43
    REMAINING = 37
  INTERNAL= 66
    COLLARCH = 3
    YEARLY = 0
    MONTHLY = 0
    COLLCAT = 4
    CAT = 0
    COLLPAGE = 0
    SEARCH = 1
    INDEX = 1
    PREV = 0
    NEXT = 0
    PREFETCH = 52
    REMAINING = 5

BBpress forums and wordpress plugin development versions

robfelty — Wed, 08 Jul 2009 19:40:12 +0000

Gentle reminders for forum users

I host a bbpress forum for each of my wordpress plugins, so that people can report bugs and ask for new features. Bbpress has many of the same features as wordpress, and it integrates very well with wordpress. It is also very fast, and as of version 1.0, now has the same admin interface as wordpress.

When people report bugs on the forum, I frequently try to fix them in the development version of the plugin, and ask them to test it, which requires downloading the development version from the wordpress.org site. Unfortunately, the development version is a bit hidden there, and I have gotten very tired of typing out the url in my replies, so I finally modified the topic.php file in my bbpress template to include a link to the development version (and a link to the faq too).

One downside of bbpress is that there is no documentation yet, so you have to search around for different functions in the code. I have done this several times now, so that it only took me about 20 minutes to figure out how to implement what I wanted. Here is the code I added (just before post_form())

$thisforum= bb_get_forum(get_forum_id(0));
$development='http://wordpress.org/extend/plugins/'.$thisforum->forum_slug.
'/download';
$faq='http://wordpress.org/extend/plugins/'.$thisforum->forum_slug.
'/faq';
?>

  Have you read the FAQ?

  Have you tried the latest development version (at the bottom)?

I then added the following css to my theme to make it stand out:

.alert {border:1px solid #999;

        background-color: #FBB;

        font-size:1.1.em;

        padding:.2em;

       }

wordpress 2.8 is out, and my plugins are ready

robfelty — Thu, 11 Jun 2009 13:13:04 +0000

As I mentioned a few months back, wordpress 2.8 has a completely new widget API, which means that I had to do quite a bit of work to get my widgetized plugins ready for 2.8. Fortunately, the new API is much better than the old style. I won’t guarantee that they are without bugs, which is why I am calling them beta. But they should all work with the defaults at any rate. They also have some new features, including several default style templates, which should make styling easier for most users. And for people who don’t like widgets, now you can enter all the options into your template manually, meaning you can use different options in different parts of your theme if you wish.

Also I will be on vacation for a few days, so I won’t be answering questions in the forum until Monday the 15th.

Releasing Postie 1.3.alpha, packed with new features

robfelty — Fri, 05 Jun 2009 18:59:52 +0000

Thanks to all the users who helped me test out the 1.3.testing version of postie, the wordpress plugin which allows you to post by e-mail. I now feel that it is stable enough to call it 1.3.alpha. There are probably still some bugs, but I think that the new features probably warrant giving it a try for most users. Here is a summary of the new features and fixes:

Now using default wordpress image and upload handling, which means:
- No more creating special directories for postie
- No more confusion about imagemagick
- Can now use the gallery feature of wordpress
- Attachments are now connected to posts in the database
- All image resizing uses wordpress’s default settings (under media)
Configuration, settings and documentation improvements
- Completely redesigned settings page (mostly thanks to Rainman)
- Reset configuration no longer deletes mailserver settings
- Now including help files and faq directly in settings page
More media features
- Automatically turn links to youtube into an embedded player
- Added option to embed audio files with custom templates
- Video options are now template based
- Image options are now solely template based, with several new default
  templates
Bug fixes
- Uploading images from vodafone phones should now work
- Correctly handling Windows-1252 encoding
- Correctly handling non-ascii characters in subject line

I still need your help! As I mentioned there are bound to be some bugs, and I would appreciate if you give me feedback in the postie forum. Several people have also provided localizations. That is a big help. Some of the current localizations now need some updating. If you are familiar with that, I would be grateful. A .pot file is included with the postie distribution.

I have mostly stopped development on the 1.2 branch of postie. I will be adding new updates to postie in the development version.

Below is a screenshot of the new options page for postie.

Screenshot of the new postie options page, showing the video and audio templates

2 new versions of postie released

robfelty — Sat, 16 May 2009 21:22:09 +0000

I would like to announce 2 new versions of my popular postie plugin for wordpress, which gives users advanced options for posting to their blog via e- mail.

The first new version is 1.2.2, which has some minor bug fixes and improvements over 1.2.1. I will continue to release several more 1.2 releases over the coming weeks with bug fixes.

The second new version is 1.3.testing, which is, as the name implies, under testing. The main new feature for the 1.3 line will be the use of wordpress’s built-in attachment uploading, and image handling. This may sound trivial at first, but it actually makes a big difference. Postie has been around since 2004. Over the last 5 years, wordpress has changed dramatically. Postie has gone through several different active maintainers, and several periods of neglect. During the times of neglect, postie got sorely out of date. I am working on bringing it back up to par with wordpress.

For example, Wordpress 2.5 introduced the gallery feature, which makes it very simply to make a nice thumbnail gallery of images in a post simply by using the shortcode . However, this depends on having a link between attachments and the post. Postie currently does not do this. In fact, postie <=1.2 uses its own custom upload directories, instead of the default wordpress directories. This makes postie more difficult to install and configure, and confusing to many users. Starting with 1.3.testing, this is no longer the case. Now postie uploads files into the default wordpress uploads directory (or whatever custom directory you have specified), and it links attachments to the post, which means you can use the gallery feature.

Postie used to have a bunch of different options for image handling, and did the image handling all itself, using either GD or imagemagick. Many users got confused by the imagemagick option. Starting with 1.3.testing, postie now lets wordpress handle resizing images — the same way it does when you would use the web-based post editor. This should simplify options dramatically, and hopefully cause much less confusion.

Also in the works, though not fully documented yet, will be the ability for postie to check multiple inboxes. This could be handy if for example, you have a multi-author blog, and you want some people’s posts to automatically be posted, while others be posted in draft form, and require approval.

I very much appreciate all the feedback I get from postie users in the postie forum, including feature requests, bug reports, praise and donations. I hope that the adventurous amongst you will take the time to download 1.3.testing and let me know what you think. As it is a testing version, I will be updating it on a fairly regular basis. Once I get some feedback from users, I will release an alpha version, and then a stable version in the next month or two.

Finally, I should mention that I posted this via postie, as well as this cooking post which shows off the gallery feature of wordpress.