April 2003 - Zope-Announce

ANN: eGenix mxODBC Zope Database Adapter, Version 1.0.4
by M.-A. Lemburg 23 Apr '03

23 Apr '03

________________________________________________________________________ ANNOUNCEMENT EGENIX.COM mxODBC Zope Database Adapter Version 1.0.4 Available for Zope 2.3 - 2.6 on Windows, Linux and Solaris ________________________________________________________________________ INTRODUCTION The eGenix mxODBC Zope Database Adapter (Zope DA) allows you to easily connect your Zope installation to just about any database backend on the market today, giving you the reliability of the commercially supported eGenix.com product mxODBC and the flexibility of the ODBC standard as middle-tier architecture. Unlike Zope's ZODBC Zope DA, the mxODBC Zope DA works on Windows XP/NT/2000/98/95, Linux and Solaris using the same interface on all platforms. The mxODBC Zope DA implements thread-safe connection pooling and multiple physical connects per logical Zope connection. You can safely run Z SQL Methods in parallel, achieving a much better performance than ZODBC Zope DA or similar Zope database adapters under heavy load. This makes it ideal for deployment in Zope Clusters and Zope hosting environments where stability and high performance are a top priority. ________________________________________________________________________ FEATURES * Zope Level 3 Database Adapter: the mxODBC Zope DA is fully multi-threaded and can handle multiple connections to multiple databases. * Fully compatible to Z SQL Methods. * Drop-in compatible to the ZODBC DA: the mxODBC Zope DA provides the same interfaces as Zope's ZODBC DA to allow a smooth upgrade path from this simplistic adapater to the high performance mxODBC Zope DA. * Fully compatible to the Znolk SQL Wizard Product and other similar products relying on the common database schema access methods .tables() and .columns(). * Connection Pooling: physical database connections are pooled and kept open, to reduce the connection overhead to a minimum. This is especially important for high latency database connections and ones like Oracle which take a considerable amount of time to setup * Parallel Execution of Queries on a single logical connection: the mxODBC Zope DA can manage any number of physical connections on a single logical connection. This enables running truly parallel Z SQL Method queries -- a feature not available in other Zope DAs. * Robust Mode of Operation: connections which have timed out or go away due to network problems are automatically reconnected. * Cross-platform Connection Objects: The Zope DA will automatically choose the right platform specific ODBC manager for you. * Per Connection Adjustable ODBC Interface: mxODBC comes with many different subpackages to choose from on Unix. The Zope DA allows you to select these subpackages on a per-connection basis. * Per Connection Error Handling: you can tell each connection whether it should report ODBC warnings or not; furthermore all warnings and errors are made available as list .messages on the DatabaseConnection object. * Transaction safe automatic reconnect: when the DA finds that a connection has timed out, it automatically tries a reconnect and replays the transaction on the connection (unlike other DAs which break the transaction scheme by doing a reconnect without replay). * Built-in Schema Cache: this results in improved performance under heavy load. * Database Schema Access: all ODBC catalog methods are made available for much better database schema inquiry. The catalog methods allow building generic database interrogation or manipulation tools and facilitates writing database independent Zope products. ________________________________________________________________________ NEWS We have had a lot of positive user feedback about the mxODBC Zope Database Adapter 1.0.0. * Some users have reported problems with certain ODBC drivers which required adding work-arounds and special options to the adapter. The version 1.0.4 includes a whole set of connection options which make the mxODBC Zope DA even more compatible to ODBC drivers in the field. * We also added a few usability enhancements, e.g. the default for creating connections is now to create closed connections. This makes it much easier setting up and configuring the connection objects. * Due to popular demand we put a lot of work into getting the mxODBC Zope DA to work with the 0.61 release of the FreeTDS ODBC driver. This driver is typically used when connecting from Linux to MS SQL Server. * Connections to non-transactional data sources are now also possible using a special connection option. This allows direct read-only access to e.g. Access or Excel files on Windows. It also makes connections to MySQL 3.x possible. * Because the mxODBC Zope DA supports multiple result sets, we added an option to always fetch the last available result set. This is sometimes needed when moving from ZODBC DA to mxODBC Zope DA if you are working with stored procedures. * Last not least, the mxODBC Zope DA is now also available for the Solaris platform. In short: mxODBC Zope DA is moving to become the number one solution for integrating relational databases with Zope applications. ________________________________________________________________________ UPGRADING If you have already bought mxODBC Zope DA licenses, you can use these license for the updated version as well. There is no need to buy new licenses. The same is true for evaluation license users. ________________________________________________________________________ MORE INFORMATION For more information on the mxODBC Zope DA, licensing and download instructions, please visit our web-site: http://www.egenix.com/ ________________________________________________________________________ Thank you, -- Marc-Andre Lemburg eGenix.com Professional Python Software directly from the Source (#1, Apr 23 2003) >>> Python/Zope Products & Consulting ... http://www.egenix.com/ >>> mxODBC, mxDateTime, mxTextTools ... http://python.egenix.com/ ________________________________________________________________________ EuroPython 2003, Charleroi, Belgium: 62 days left

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Ape 0.6 and DBTab 1.2
by Shane Hathaway 21 Apr '03

21 Apr '03

Ape 0.6 and DBTab 1.2 are ready to download. http://hathaway.freezope.org/Software/Ape http://hathaway.freezope.org/Software/DBTab Ape, short for "Adaptable Persistence", is the new name for Adaptable Storage. Ape adapts Zope objects to storage on the filesystem, in relational databases, or practically anywhere else. It combines the advantages of transparent object persistence with arbitrary databases and formats. It is especially designed to work with ZODB, but can work independently of both Zope and ZODB. Some of the changes made since Adaptable Storage version 0.5: - Added the tutorial outline presented at PyCon 2003. The tutorial describes the overall design of Ape and begins to explain how to use it with your own software. - Added MySQL 4.0 support. - Changed naming conventions to fit Zope 3. - Improved generation and interpretation of filename extensions. - Fixed loading of ZClass instances. - Made object modification dates match file dates. - Many bugfixes. Version 1.2 of DBTab removes the optional dependency on AdaptableStorage, fixes a problem with the activity monitor, and lets you choose what kind of container to create when mounting for the first time. You should use DBTab 1.2 with Ape 0.6. Shane

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VarImage 2 Released
by Terry Hancock 14 Apr '03

14 Apr '03

The much-improved version 2 of VarImage ("Variable Image") is now available, including generative image support, chainable image operations, color map and transposition effects, and more! It also includes an extremely simple plugin mechanism, so it is now easy to add your own operators to extend VarImage. Download from: http://www.anansispaceworks.com/papers_html or: http://www.zope.org/Members/terry/VarImage More information about VarImage ... VarImage 2.0-beta VarImage means "variable image". It provides a way to make on-the-fly modifications to an image in Zope simply by referring to the correct URL. Starting in this version (version 2), VarImage also allows "component" images to be loaded into a sub-folder called "components". These may be composited onto the main image to provide generative image effects. Version 2 also includes experimental code for referrer-blocking (this means that you can keep remote sites from directly linking to your images). Syntax The URL-command is parsed as a chain of "operations" to be applied to the original image, separated by "." (period). Each operation is specified as an "operator", followed by zero or more "arguments", separated by "_". Arguments and operators must be composed of only letters and numbers ([A-Za-z0-9], note that "_" and "." are not legal because they are used as separators). Other than the fact that floating point values have to use "o" (the letter "o") instead of "." for the decimal point, this works well. Colors are represented by strings, usually as hexadecimal codes, with a prefix of "x" and 6 hexadecimal characters. Component images may be referred to by their unadorned Zope ID, so "myimage/components/mycomponent" is simply "mycomponent". Note that, to be useful, you have to use only letters and numbers in the name of components. Each operation is applied in sequence, to the result of the previous operation, and then the final result is returned. Examples If you have a VarImage "shinobu_jpg", you can get it in an exact size of 100x100 (regardless of the original aspect):: shinobu_jpg/s_100 or 100x50:: shinobu_jpg/s_100_50 or you can thumbnail it into a 70x50 space (the longer dimension will be determined by the specified limit, while the smaller is determine by the image aspect ratio -- i.e. the image will "fit" into the available 70x50 space):: shinobu_jpg/f_70_50 or you can set the horizontal or vertical dimensions:: shinobu_jpg/h_85 shinobu_jpg/v_100 (The above examples are converted from the Version 1 docs). You can also convert the image to PNG or GIF format:: shinobu_jpg/tn_100.png shinobu_jpg/tn_100_200.gif And do color effects, such as black-and-white:: shinobu_jpg/bw or color-multiplication:: shinobu_jpg/mult_x0e5f00.png shinobu_jpg/bw.R.gif Special Commands For a help page with a complete list of all currently understood operators, use:: shinobu_jpg/help If you need to clear the cache and start over for some reason (this is necessary a lot when you're writing a new plugin):: shinobu_jpg/clear_cache And you may set the "fovial" region of the image (used by the "tn" thumbnail operator to show the center-of-interest/fovial-extent):: shinobu_jpg/set_fovia?x=100&y=150&dx=30&dy=30 Or you can call this from Zope:: <dtml-call expr="shinobu_jpg.set_fovia( (100,150,30,30) )"> Calling VarImages After writing the above, I have discovered that what does *not* work is calling the image as:: <dtml-var expr="shinobu_jpg.f_100"> (Actually it will work *if* you had previously generated the image, but it will not regenerate after the cache expires, which can bite you!). However, you can do this instead:: <dtml-var expr="shinobu_jpg.restrictedTraverse('f_100')"> Not as pretty, I know, but it will correctly regenerate, and you still get the benefit of the Zope image tag generation (the image tag will have correct width and height specified, which is handy, since with the f ("fit") command, you don't know them in advance (you know only the maximum possible values). I do consider this a bug, but it's low priority because the workaround exists. How It Works VarImage inherits from Zope's Image and ObjectManager types, so it is an image that also acts as a folder. The folder contains a Temporary Folder named "cache". When you query for a modified image, it first checks to see if the cache already contains the image. If so, it returns that. Otherwise, it uses Python Imaging Library to generate the image (storing it in the cache of course). A couple of other cases are caught, too: most plugins will try to catch "do-nothing" cases and pass through without operating. If you request an image *while* it is being generated, the requesting thread will sleep until the generation is complete and then return the result. Temporary Folder uses a RAM storage method which will lose objects when they are not in use (I don't know what algorithm it actually uses, though I'm hoping it's some variant of "least recently used"), or whenever Zope is restarted (this is good). Thus the cached objects are never permanently added to Zope. Note that because each resized image gets a unique URL, front end caches (proxy or browser) can efficiently cache these images, thus further reducing regeneration to the minimum needed. Writing Plugins It is now trivial to add a plugin operator to VarImage, and you do not need any understanding of Zope to do this. You will need to understand how to manipulate and process images in Python. It is not strictly necessary to use Python Imaging Library, but that is what I have used for all the example plugins, as it is the best Python library available as of this writing. The next best option is probably libmagick for C, which has some Python wrappers defined for it --- however, the Python wrappers were very immature or in poor repair when I wrote this. I would certainly welcome contributed libmagick plugins, though! To create a new operator, you will create an image processing function with the following profile:: imio, imtype, xsz, ysz = your_function(imio, imtype, xsz, ysz, args) Where: imio -- is a StringIO (file-like) object containing the image data. imtype -- is the image MIME type (e.g. "image/jpeg"). xsz -- is the width of the image. ysz -- is the height of the image. args -- is a tuple of converted arguments from the URL. Then you will register it with the 'Operator' class constructor:: Operator('foo', your_function, 0, 4, (int, int, float, str)) This example will register your operator under the name 'foo', accepting 0 to 4 arguments, with the specified types. The arguments will be converted from strings to these types before being passed to your function, so you won't normally have to parse them unless you need something special (in which case, you use "str"). The plugin "pil_resize.py" was the first, and best documented, so I recommend you look at that one for comments and examples. Operators that use components, or need to access the image fovia information have some special requirements --- see "Operators/pil_composite.py" and "Operators/pil_fovia.py" for examples. The function and the registration should be in a single Python module, which you will put into the 'Operators' package within VarImage. That's it --- if your code works, you'll have a new VarImage operator defined. Be sure to provide a (structured-text) docstring in your function, as this will be included in the automatic documentation produced by the "help" method. Requirements Currently, you need Zope 2.5.1 or higher and Python 2.1.3 is recommended. You'll need Python Imaging Library 1.1.3 or higher for all the provided plugins to work. GIF support is spotty --- especially for transparency --- in P.I.L. 1.1.3 (which is what I developed against), though I have read that 1.1.4 may address this, and is due to come out soon as of this writing. You might want to try it. This in turn requires the zlib, PNG, and JPEG libraries. I had real problems getting P.I.L. to find the libraries if they are not installed in one of the canonical locations such as /usr/local, so here's a heads-up -- you'll have to edit the Makefile and Setup.in manually for it to work right. Hopefully that'll get fixed in a later version of P.I.L. Author and Licensing Terry Hancock wrote VarImage for Anansi Spaceworks. It may be redistributed under the terms of the Gnu Public License. The full text of the GPL is in the file LICENSE.txt in this distribution. -- Terry Hancock ( hancock at anansispaceworks.com ) Anansi Spaceworks http://www.anansispaceworks.com

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[ANN] No-more-ReadConflictError patch
by Dieter Maurer 11 Apr '03

11 Apr '03

This is version 0.2 of a patch which formerly was called "ReadCommitted" patch. For most storages, it prevents database read conflict errors by implementing the snapshot transaction isolation level: A transaction reads objects as they have been when the transaction started. More information and download: <http://www.dieter.handshake.de/pyprojects/zope> Dieter

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CMFPhoto 0.2 and CMFPhotoAlbum 0.2
by Magnus Heino 11 Apr '03

11 Apr '03

Hi. I have released new versions of CMFPhotoAlbum and CMFPhoto, get them from http://www.sf.net/projects/collective. Both products are packaged for usage with Plone, http://www.plone.org. CMFPhotoAlbum 0.2 - i18n fix - Background color in datetime exif field was broken in mozilla. CMFPhoto 0.2 - Photo size variants now callable by url ${photo_url}/variant/${variant}) - Tag method now uses a real url to call each variant instead of passing a request parameter. This solves caching problems. /Magnus Heino

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DirectoryStorage 1.1.0
by Toby Dickenson 11 Apr '03

11 Apr '03

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 I am pleased to announce the release of DirectoryStorage version 1.1.0. Q. What has changed since 1.0.0 ? A. Storage Replication! Efficiently and robustly keep an online backup copy of your storage up to date with the latest changes from the master. Q. Is that all ? A. A few minor bugs are fixed, so it is worth upgrading even if you dont want to use replication. Q. What has changed since the 1.1 alpha release ? A. Nothing Q. What is DirectoryStorage anyway ? A. An alternative ZODB storage that uses ordinary files and directories to store revisions of ZODB objects; one file per revision per object. It has a design focus on simplicity, scalability, and fault tolerance. More information: http://dirstorage.sourceforge.net/ Download: http://sourceforge.net/project/showfiles.php?group_id=53818&release_id=1522… - -- Toby Dickenson http://www.geminidataloggers.com/people/tdickenson -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.1 (GNU/Linux) iD8DBQE+lp5J99Pa/DbwZfsRAnt4AJ4gGCiKpuVbDRvMfCd5ZUygTADyigCgp09L ZIw/MgNRUdkP6fpqlhrwAjg= =xYte -----END PGP SIGNATURE-----

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ANN: reStructuredText backport for Zope 2.6 released
by Andreas Jung 09 Apr '03

09 Apr '03

I have just released the backport of reStructuredText for Zope 2.6. This release gives Zope 2.6 full access to the functionality of reST. You can download the packages from http://www.zope.org/Members/ajung/reStructuredText/ Installation: unpackl the archive in the top-level Zope directory. It will monkey-patch Zope to do the integration. There should not be any side-effects Documentation: see doc/RESTRUCTUREDTEXT.txt

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PloneChat released !
by Olivier DECKMYN - IngeniWeb 04 Apr '03

04 Apr '03

Hi all, Ingeniweb, leading french company for Zope hosting and engineering is proud to announce the availability of a new content type for Plone : PloneChat This project is fully Open-Source and hosted at SourceForge This product is a chat component, featuring : - No client-side nor server-side special technology : - Client side is 100% HTML, with no page reload ! - Server side is 100% Plone/Zope/Python code, no need for IRC server or whatever - Chat can be moderated or not moderated - Chat can be used to make moderated real-time interviews - Users can propose a chat - Chat isn't ZODB filler : chat is stored on filesystem : nopersistency problem in ZODB. - Support Workflows Download here: http://ingeniweb.sourceforge.net/ Have a nice chatting Week-End, -- Olivier DECKMYN - CTO INGENIWEB (TM) - SARL 50000 Euros - RC B 438 725 632 2 cours du 14 Juillet - 78300 Poissy France - +331 300 601 41 web : www.ingeniweb.com - « les Services Web Ingénieux » PGP : http://www.ingeniweb.com/keys/olivier.deckmyn

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[Ann] ZopeProfiler: high and low level timing statistics
by Dieter Maurer 02 Apr '03

02 Apr '03

ZopeProfiler provides profiling support for the development of Zope applications. It can derive both high and low level timing statistics (Zope object call and Python function call level, respectively). Unlike with the standard Zope profiling support, Zope runs normally in multi-threaded mode. Statistics gathering can be enabled/disabled dynamically via the ZopeProfiler object in the Control_Panel. This objects supports most features of Python's pstats.Stats timing analysis class and is much smarter than the standard Zope profiler. Should the features be insufficient, then statistics data can be saved to files and later analysed with Python's Stats class. More information and download: <http://www.dieter.handshake.de/pyprojects/zope> Dieter

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Zwiki 0.17 released
by Simon Michael 02 Apr '03

02 Apr '03

This release goes out to the people in Iraq. Summary: Simpler page ids, faster performance and better memory efficiency, new general-purpose page type including tracker and fit support, more robust parenting, skin improvements, preliminary stylesheet support, code cleanups, doctest no longer used. More information: http://zwiki.org/ReleaseNotes , http://zwiki.org/KnownIssues , http://zwiki.org Download: http://zwiki.org/releases/ZWiki-0.17.0.tgz or http://zope.org/Members/simon/ZWiki/ZWiki-0.17.0.tgz Best wishes, --Simon

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