semanticpool

Just found ProgramR, an AIML interpreter for Ruby. I think i’ll try it in the next weeks…

Second Life/Twitter application code available at the SL Developer’s Corner.

Just built a little Twitter / Second Life mashup using Ruby-on-Rails and LindenScript. Here is a little screenshot.

I will put the code on my new SL-weblog at http://sl-devcorner.blogspot.com in this week :)

http://weblog.rubyonrails.org/2007/3/14/rails-1-2-3-compatible-with-ruby-1-8-6-and-other-fixes

http://www.ruby-lang.org/en/news/2007/03/12/ruby-1-8-6-released/

If have played a little bit with Second Life and its ability to access external resources. Inspired by Matt Biddulph’s “flickr screen”, now i wanted to load xml data from an external source into the SL-world and display it on a nice looking screen. Because it is not possible — from my point of view — to display text directly on a SL-primitive, it was necessary to render the text in a first step to an image. I did this using a little RubyOnRails application which also loads and parses the xml-resource. Ok, now i show how i did this.
I used the REXML processor to work with the xml-data and RMagick to create the image. The xml-source is used is a little xml-file provided by LindenLabs which shows the land sales by resident for the last three month (http://secondlife.com/reports/marketplace_stats/2007-03-01/land_sales_by_residents.xml). The whole parsing is specific to this source.

# get the xml via http and read it into a variable and create a XML-Document after that
@content = Net::HTTP.get(URI.parse("
http://secondlife.com/reports/marketplace_stats/2007-03-01/land_sales_by_residents.xml"))
xmlDoc = REXML::Document.new(@content)

# get some attributes and select them with xpath
elRecords = REXML::XPath.first(xmlDoc, "records")
reportTitle = elRecords.attributes['report']
reportDate = elRecords.attributes['date']

# create a new image in the size you need. in my case it was 400 width and 200 height
f = Image.new(400,200) { self.background_color = "white" }# make some settings for the font
drawable = Magick::Draw.new
drawable.pointsize = 15.0
drawable.font_family = 'Helvetica'
drawable.fill = 'gray'
drawable.gravity = Magick::NorthWestGravity
drawable.font_weight = Magick::BoldWeight
drawable.annotate(f, 0, 0, 5, 4, "Second Life #{reportTitle} (#{reportDate})")
drawable.pointsize = 13.0
drawable.fill = 'black'
drawable.font_weight = Magick::NormalWeight

# set some position for the text i want to print
@startTopPos = 24

# go the records in the xml-document and print the values into the new image
REXML::XPath.each( xmlDoc, "records/record") do |element|
	element.elements.each("field") do |field|
		name = field.attributes['name']
		value = field.attributes['value']
		drawable.annotate(f, 0, 0, 5, @startTopPos, name)
		drawable.annotate(f, 0, 0, 250, @startTopPos, value)
		@startTopPos = @startTopPos + 15
	end
	@startTopPos = @startTopPos + 15
end

# write the image to the disk. i wasnt able to return it directly without saving. :(
f.write("result.png")
# return the image
createdImg = Magick::Image.read("result.png").first
@response.headers["Content-Type"] = "image/png"
@response.headers['Content-Disposition'] = %q{inline; filename="thepicture.png"}
render :text => createdImg.to_blob

This script returns the following image:

To put this image on an primitive i used the following linden script code:

touch_start(integer num_detected) {
    llSay(0, "trying..."); 

    if(llGetLandOwnerAt(llGetPos()) != llGetOwner()) {
        llSay(0,"Error: Cannot modify parcel media settings.");
    } 

    key video_texture = llList2Key(llParcelMediaQuery( [PARCEL_MEDIA_COMMAND_TEXTURE]), 0);

    if(video_texture == NULL_KEY)
    {
        video_texture = VIDEO_DEFAULT;
        llParcelMediaCommandList([PARCEL_MEDIA_COMMAND_TEXTURE, VIDEO_DEFAULT]);
    }
    llSetTexture(video_texture,ALL_SIDES);
    llParcelMediaCommandList([PARCEL_MEDIA_COMMAND_URL,"http://###URL###"]);
    llParcelMediaCommandList([PARCEL_MEDIA_COMMAND_PLAY]);
    llParcelMediaCommandList([PARCEL_MEDIA_COMMAND_AUTO_ALIGN,TRUE]);
}

###URL### has to be replaced with the URL of the Ruby-Script.

Note: To use this ParcelMedia-feature you have to allow streaming media i think in SL.

# gem update rails -y

(via: rubyonrailsblog.com)

Mongrel is a fast HTTP library and server for Ruby that is intended for hosting Ruby web applications of any kind using plain HTTP rather than FastCGI or SCGI. It is framework agnostic and already supports Ruby On Rails, Og+Nitro, Camping, and IOWA frameworks.

Ugo Cei has posted his experiences with Ruby handling Java code in 5 parts some month ago. Nice to read and very informative.

• Part I
• Part II
• Part III
• Part IV
• Part V

Call Java-Code from Ruby.

For example with RubyJavaBridge or YAJB.

JRuby is an 100% pure-Java implementation of the Ruby programming language.

A nice article regarding Ruby & Java can be found at javaworld.com: Ruby for the Java world.

Man lernt nie aus. Habe heute Morgen durch den lieben Schockwellenreiter von Grails erfahren. Das ist ein auf Java basierendes Framework für Rapid Web Application Development, ähnlich dem bekannten Ruby On Rails.
Wer mehr Information sehen und mehr Wissen erlangen möchte, sollte auf den Grails-Seiten stöbern.