Ted Naleid

I’ve had problems since installing snow leopard with sharing my printer with my wife’s macbook pro.

Whenever she’d try to print, the job would say “On Hold: Authentication Required”. After some fiddling around I found a solution:

1. Go into System Preferences and go to the Print & Fax panel.
2. Right click on the printer and choose “Reset Printing System…”. This will remove all of your printers.
3. Hit the “+” and add the printer back, it should now be reset and have fixed whatever was fubar before.
4. Click on the “Sharing Preferences” button (or go to the “Sharing” System Preference panel)
5. Make sure that “Printer Sharing” is checked and that your printer’s name is also checked and that “Everyone” is set to “Can Print”
6. On the remote machine you want to remove the printer and add it back in through the System Preferences Print & Fax panel

(This is on 10.6.1, not sure if this works in 10.6.0 (where I first had the problem), you should update to the latest).

After doing all that, I was able to print from my remote computers without any problems or any issues around authentication.

I’ve just released a quick plugin that I put together tonight to help render markdown text as HTML within a grails application. It leverages the MarkdownJ library.

I’m a big fan of storing information in markdown format as it is easy to read, easy to write, and easy to transform. A number of big websites like stackoverflow.com support the entry and display of markdown text to help people format their questions and answers without having to remember to properly format HTML.

If you’re unfamiliar with Markdown there are a number of good references on it’s use.

The grails markdown plugin is a very basic plugin. Currently, it just wraps the markdown libarary with a single TagLib that lets you easily render html from a markdown string within your gsp pages.

To install it, just type:

grails install-plugin markdown

To use it in your gsp file:

<markdown:renderHtml>
The *four* cardinal directions are
 
- North
- South
- East
- West
</markdown:renderHtml>

renders the html:

<p>The <em>four</em> cardinal directions are</p>
<ul>
    <li>North</li>
    <li>South</li>
    <li>East</li>
    <li>West</li>
</ul>

Or you can use the “text” attribute of the taglib:

<markdown:renderHtml text="${post.body}"/>

See the Grails Markdown Wiki and source for more details.

I’ve spent some time over the last couple of weeks working on a Grails service that allows us to import new records into our MySQL database.

A number of interesting techniques have popped out of this that I think would be useful for others doing similar types of importing using GORM/Hibernate/MySQL. Read the rest of this article »

I’ve just switched hosting providers from slicehost to a reserved EC2 instance. I also upgraded from a really old version of wordpress to wordpress 2.8.4. I’ve been meaning to do this for a while now, but wanting to avoid yesterday’s worm prompted me to do it this weekend rather than next.

Let me know if you see any issues or broken links.

I’ve just released the latest version of the grails build-test-data plugin. This version has a couple of bugfixes that were reported by users. Including one with a nice patch including a test from Robert Fletcher (patches with tests are always appreciated).

For those that aren’t familiar with the plugin, it make creating testing data easy.

It automatically adapts to changes in your domain classes and makes your integration tests easier to write and much less fragile.

Resources

• Documentation on BitBucket
• Build-Test-Data Presentation

Overall, the plugin has been very stable for the past few releases and I’m thinking about just bumping the version up to 1.0 fairly soon. The plugin seems pretty feature complete when balanced with it’s ease of use. Most of the other features I’ve thought of would explode the complexity level of the plugin and defeat it’s purpose. Might be best to leave well enough alone for now :).

I had a hell of a time with the current grails release-plugin cycle (6 attempts before it finally went through). The grails release-plugin command uses an old version of svnkit that’s only compatible with svn 1.5. I’ve long since upgraded to 1.6 on my mac, though luckily I did it through macports and still had the old version available to activate (sudo port deactivate subversion && sudo port activate subversion @1.5.6_0).

I did some searching around to find out how to install an old version of subversion, but didn’t come up with anything after a quick google so I might be screwed after my wipe/reinstall for snow leopard next week till Grails patches things with svnkit 1.3.

I did open up a JIRA ticket for grails to upgrade to svnkit 1.3, and I was surprised that there wasn’t already a ticket open on it (and that trunk still had svnkit 1.2 in it).

This is a continuation of a sporadic set of blog posts about some practical uses for groovy metaprogramming.

Groovy Config DSL Overview

In Java, configuration is normally done with properties files. They’re kind of a pain because they’re inflexible, don’t allow executable code, and don’t easily provide a heirarchy.

Groovy greatly improves on Java by building in support for a simple configuration DSL using the ConfigSlurper. Read the rest of this article »

I gave a presentation tonight on the build-test-data grails plugin at the Groovy Users of Minnesota (GUM) meeting that was well received.

Lots of good questions from the people in attendance. Thanks to everyone for showing up.

Here’s a version of it on slideshow: Read the rest of this article »

A recent blog post, Cedric Beust asks about how to cleanly implement “soft asserts”. Soft asserts are test assertions that don’t “fail fast”. Instead, all of the assertion failures in the test method are collected and reported at the end of the test.

So far, the proposals in the comments look fairly clunky to me and include defining whole sets of new methods like “assertEqualsButContinue(“foo”, “foo”)”, chaning assertions together jQuery-style, or using lists to hold all of our assertions.

Wouldn’t it be a lot nicer if we could continue to use the same methods that we’re already using?

In groovy, enabling soft assertions is easy with a little closure magic. Read the rest of this article »

I’m currently working at a startup that’s small enough that we don’t have a dedicated DBA and I’ve been doing a lot of mysql maintenance work recently. I wanted a quick dashboard for which commands were currently running and how long they’ve been running for. Sort of like top but for mysql.

Combining the unix “watch” command with the mysql “show processlist” command gives me what I’m looking for. A quick, self-updating status of the current state of the database.

watch -n 5 --differences "mysql -u username -psekrit -e 'show processlist'"

Shows something like this:

Every 5.0s: mysql -n 5 -u username -psekrit -e 'show processlist'                                   Thu Jun 18 05:25:14 2009
 
Id      User    Host       db      Command Time    State         Info
3141    admin   localhost  mydb    Query   34978   freeing items SELECT id, type, active, email FROM user WHERE email
3146    admin   localhost  mydb    Sleep   0                     NULL       
24876   root    localhost  NULL    Query   0       NULL          show processlist

Where the “time” column is the number of seconds the query has been running, and Info holds the actual query (you can use “show full processlist” to see the full query).

Watch is a nice little linux util that runs a command every “n” seconds (it defaults to 2 seconds). If you use the –differences switch, it will highlight the differences between one update and another. I use watch for all kinds of monitoring activities, such as watching a directory to see a file grow in size as it gets transfered.

Here’s a quick shell function that you can add to your .bashrc/.bash_profile/.zshrc to use on arbitrary hosts:

function mysqltop() {
    MYSQL_OPTS=$@
    watch -n 5 --differences "mysql $MYSQL_OPTS -e 'show processlist'"
}

Then just pass in any creds/host info you need like a normal mysql command:

mysqltop -u ted -psekrit1 -h example.com -P 3307

If you’re on linux, you probably already have “watch” installed. If you’re on OSX, you probably don’t, but you can get it quickly through macports. Install macports, make sure “port” is in your path and run:

sudo port install watch

There is also a command called mytop that you can get which looks like the same thing, but prints out the processlist details with some nicer formatting and a little extra information. It’s in macports, but it has a number of dependencies including mysql so if you didn’t install mysql through macports, you might want to stick with what I have above or get it another way.

(EDIT: updated with bash function)

I’ve just released version 0.2.1 of the build-test-data grails plugin.

The build-test-data plugin makes creating integration test data easy. It decorates your domain objects with a “build” method that will create new domain instances and will automatically populate required fields with data and save it to the database. This enables you to create more maintainable tests where the data you create is targeted specifically at the situations you’re trying to test, without having to go through all of the ceremony of creating the rest of the object graph that you don’t care about.

// creates a new Book instance with all required fields 
// (like the Author that the book belongsTo) populated
def b = Book.build()

To learn more about the basics of the build-test-data plugin, see this blog post and check out the Basic Usage and Sample Code wiki pages.
Read the rest of this article »