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Posted to user@cayenne.apache.org by Andrus Adamchik <an...@objectstyle.org> on 2008/05/20 16:38:48 UTC
[POLL] loading XML configurations from filesystem
Wanted to check if anybody loads "cayenne.xml" and related Map and
Node XML files from locations other than default two: CLASSPATH and
WEB-INF/ ? More specifically:
1. anybody uses FileConfiguration?
2. anybody uses DefaultConfiguration (with 'addResourcePath' or
without) to directly reference file in the filesystem (vs. referencing
resources in classpath)?
3. anybody places DataMap / DataNode files in (jar) directories
outside of the directory where "cayenne.xml" is located?
I personally don't, as all these approaches lead to non-portable
applications that make unwarranted assumptions about the environment.
I think cases requiring to open cayenne.xml via the application UI are
special enough to warrant a custom configuration.
Some background. I am planning a rework of the config package to
include support for merging of multiple Cayenne projects into a single
"virtual project" in runtime (hence enabling multiple "persistent
units" in the app). So I am looking to simplify this task and stop
supporting edge cases that are not widely used, and also change the
basic algorithm of resolving files relative to cayenne.xml to ensure
they are actually relative to the URL within a JAR or class folder
where cayenne.xml is found (so that we can have multiple cayenne.xml
files and avoid conflicts when loading dependent XML files of those).
I think there is a lot of benefit in keeping the built-in choices of
file lookup down to just a few basic ones, and of course the users can
still write their own Configuration extensions to address non-standard
requirements.
Andrus
Re: [POLL] loading XML configurations from filesystem
Posted by Mike Kienenberger <mk...@gmail.com>.
I thought for sure that I used both 1. and 2., but upon reviewing my
various applications, everything now uses or subclasses
DefaultConfiguration and calls config.addClassPath().
On 5/20/08, Andrus Adamchik <an...@objectstyle.org> wrote:
> Wanted to check if anybody loads "cayenne.xml" and related Map and Node XML
> files from locations other than default two: CLASSPATH and WEB-INF/ ? More
> specifically:
>
> 1. anybody uses FileConfiguration?
> 2. anybody uses DefaultConfiguration (with 'addResourcePath' or without) to
> directly reference file in the filesystem (vs. referencing resources in
> classpath)?
> 3. anybody places DataMap / DataNode files in (jar) directories outside of
> the directory where "cayenne.xml" is located?
>
> I personally don't, as all these approaches lead to non-portable
> applications that make unwarranted assumptions about the environment. I
> think cases requiring to open cayenne.xml via the application UI are special
> enough to warrant a custom configuration.
>
> Some background. I am planning a rework of the config package to include
> support for merging of multiple Cayenne projects into a single "virtual
> project" in runtime (hence enabling multiple "persistent units" in the app).
> So I am looking to simplify this task and stop supporting edge cases that
> are not widely used, and also change the basic algorithm of resolving files
> relative to cayenne.xml to ensure they are actually relative to the URL
> within a JAR or class folder where cayenne.xml is found (so that we can have
> multiple cayenne.xml files and avoid conflicts when loading dependent XML
> files of those).
>
> I think there is a lot of benefit in keeping the built-in choices of file
> lookup down to just a few basic ones, and of course the users can still
> write their own Configuration extensions to address non-standard
> requirements.
>
> Andrus
>
>
>
Re: [POLL] loading XML configurations from filesystem
Posted by Andrus Adamchik <an...@objectstyle.org>.
Fair enough... I may have intentionally exaggerated the portability
claim and may argue about changing your specific setup (e.g. deploying
a full war or a jar to that single shared point of the server farm),
but I agree with you calling this the "ideal world", with real world
being all made of exceptions and edge cases.
As a practical matter I think we can support (1) and (2) in a multi-
cayenne.xml runtime (after all, files can be identified via URL's just
as well as jar components). And support (3) as well, detecting
conflicts on the fly and throwing an exception (2 DataMaps with the
same name located outside of any project roots, how do we merge them?)
So the refactoring I mentioned is not strictly necessary for things to
move forward. Although leaving them the way they are adds to the
Configuration hair ball... So it is very tempting to just leave it up
to the users to handle at least #3 by extending Configuration (per my
reply to Kevin, many cases of #3 would actually become obsolete).
Andrus
On May 20, 2008, at 7:22 PM, Philip Miller wrote:
> Portability means different things in different contexts.
>
> For example I might write an application which reads its config from a
> UNC file path (\\foo\bar\cayenne.xml). That application is portable to
> any environment which can see that path. It allows me to administer
> configuration of an indefinitely scalable server farm from a single
> point. That might be a desirable design feature in the context of my
> application.
>
> To answer your question I've used 1,2 and 3 at various times when it
> was
> appropriate to compromise on the ideal world solution.
>
> Phil
>
>
>> -----Original Message-----
>> From: Andrus Adamchik [mailto:andrus@objectstyle.org]
>> Sent: 20 May 2008 15:39
>> To: user@cayenne.apache.org
>> Subject: [POLL] loading XML configurations from filesystem
>>
>> Wanted to check if anybody loads "cayenne.xml" and related
>> Map and Node XML files from locations other than default two:
>> CLASSPATH and WEB-INF/ ? More specifically:
>>
>> 1. anybody uses FileConfiguration?
>> 2. anybody uses DefaultConfiguration (with 'addResourcePath' or
>> without) to directly reference file in the filesystem (vs.
>> referencing resources in classpath)?
>> 3. anybody places DataMap / DataNode files in (jar)
>> directories outside of the directory where "cayenne.xml" is located?
>>
>> I personally don't, as all these approaches lead to
>> non-portable applications that make unwarranted assumptions
>> about the environment.
>> I think cases requiring to open cayenne.xml via the
>> application UI are special enough to warrant a custom configuration.
>>
>> Some background. I am planning a rework of the config package
>> to include support for merging of multiple Cayenne projects
>> into a single "virtual project" in runtime (hence enabling
>> multiple "persistent units" in the app). So I am looking to
>> simplify this task and stop supporting edge cases that are
>> not widely used, and also change the basic algorithm of
>> resolving files relative to cayenne.xml to ensure they are
>> actually relative to the URL within a JAR or class folder
>> where cayenne.xml is found (so that we can have multiple
>> cayenne.xml files and avoid conflicts when loading dependent
>> XML files of those).
>>
>> I think there is a lot of benefit in keeping the built-in
>> choices of file lookup down to just a few basic ones, and of
>> course the users can still write their own Configuration
>> extensions to address non-standard requirements.
>>
>> Andrus
>>
>>
>>
>
> http://www.bbc.co.uk/
> This e-mail (and any attachments) is confidential and may contain
> personal views which are not the views of the BBC unless
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> If you have received it in error, please delete it from your system.
> Do not use, copy or disclose the information in any way nor act in
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> Further communication will signify your consent to this.
>
>
RE: [POLL] loading XML configurations from filesystem
Posted by Philip Miller <ph...@bbc.co.uk>.
Portability means different things in different contexts.
For example I might write an application which reads its config from a
UNC file path (\\foo\bar\cayenne.xml). That application is portable to
any environment which can see that path. It allows me to administer
configuration of an indefinitely scalable server farm from a single
point. That might be a desirable design feature in the context of my
application.
To answer your question I've used 1,2 and 3 at various times when it was
appropriate to compromise on the ideal world solution.
Phil
> -----Original Message-----
> From: Andrus Adamchik [mailto:andrus@objectstyle.org]
> Sent: 20 May 2008 15:39
> To: user@cayenne.apache.org
> Subject: [POLL] loading XML configurations from filesystem
>
> Wanted to check if anybody loads "cayenne.xml" and related
> Map and Node XML files from locations other than default two:
> CLASSPATH and WEB-INF/ ? More specifically:
>
> 1. anybody uses FileConfiguration?
> 2. anybody uses DefaultConfiguration (with 'addResourcePath' or
> without) to directly reference file in the filesystem (vs.
> referencing resources in classpath)?
> 3. anybody places DataMap / DataNode files in (jar)
> directories outside of the directory where "cayenne.xml" is located?
>
> I personally don't, as all these approaches lead to
> non-portable applications that make unwarranted assumptions
> about the environment.
> I think cases requiring to open cayenne.xml via the
> application UI are special enough to warrant a custom configuration.
>
> Some background. I am planning a rework of the config package
> to include support for merging of multiple Cayenne projects
> into a single "virtual project" in runtime (hence enabling
> multiple "persistent units" in the app). So I am looking to
> simplify this task and stop supporting edge cases that are
> not widely used, and also change the basic algorithm of
> resolving files relative to cayenne.xml to ensure they are
> actually relative to the URL within a JAR or class folder
> where cayenne.xml is found (so that we can have multiple
> cayenne.xml files and avoid conflicts when loading dependent
> XML files of those).
>
> I think there is a lot of benefit in keeping the built-in
> choices of file lookup down to just a few basic ones, and of
> course the users can still write their own Configuration
> extensions to address non-standard requirements.
>
> Andrus
>
>
>
http://www.bbc.co.uk/
This e-mail (and any attachments) is confidential and may contain personal views which are not the views of the BBC unless specifically stated.
If you have received it in error, please delete it from your system.
Do not use, copy or disclose the information in any way nor act in reliance on it and notify the sender immediately.
Please note that the BBC monitors e-mails sent or received.
Further communication will signify your consent to this.
Re: [POLL] loading XML configurations from filesystem
Posted by Kevin Menard <km...@servprise.com>.
Then +1 from me. One shortcoming of my approach is that the Modeler
auto-generates any missing DataNode, so if I want to manipulate my
DataMap, I have to remember to delete the generated DataNode or risk a
lot of confusion.
--
Kevin
On May 20, 2008, at 1:44 PM, Andrus Adamchik wrote:
>
> On May 20, 2008, at 8:33 PM, Kevin Menard wrote:
>
>> I have all of my Persistent objects in one module that bundles up
>> the DataMap. Each app that uses them provides its own DataNode.
>> It makes deployment to different environments really nice. It also
>> lets me swap out test and production DataNodes really simply.
>>
>> I'm not married to that one way of doing things, but I would like
>> to see that use case addressed somehow.
>
> Addressing it in a Modeler-friendly fashion is the whole point here.
> The idea is to get rid of workarounds like yours (or cdeploy Ant
> task). Here is a Wiki link to the raw design description of this
> feature:
>
> http://cwiki.apache.org/CAY/runtime-metadata-merging.html
>
> So you'll simply have multiple full Cayenne projects (one per module
> that define DataMaps, and one in the application that defines
> DataNodes and links DataMaps to them). Each project can be opened
> and manipulated in the modeler independently from each other. So it
> makes possible environment-agnostic "Cayenne libraries" (or
> "persistence units" in JPA speak) that can be combined with other
> such libraries and shared between the projects.
>
> Andrus
>
Re: [POLL] loading XML configurations from filesystem
Posted by Andrus Adamchik <an...@objectstyle.org>.
On May 20, 2008, at 8:33 PM, Kevin Menard wrote:
> I have all of my Persistent objects in one module that bundles up
> the DataMap. Each app that uses them provides its own DataNode. It
> makes deployment to different environments really nice. It also
> lets me swap out test and production DataNodes really simply.
>
> I'm not married to that one way of doing things, but I would like to
> see that use case addressed somehow.
Addressing it in a Modeler-friendly fashion is the whole point here.
The idea is to get rid of workarounds like yours (or cdeploy Ant
task). Here is a Wiki link to the raw design description of this
feature:
http://cwiki.apache.org/CAY/runtime-metadata-merging.html
So you'll simply have multiple full Cayenne projects (one per module
that define DataMaps, and one in the application that defines
DataNodes and links DataMaps to them). Each project can be opened and
manipulated in the modeler independently from each other. So it makes
possible environment-agnostic "Cayenne libraries" (or "persistence
units" in JPA speak) that can be combined with other such libraries
and shared between the projects.
Andrus
Re: [POLL] loading XML configurations from filesystem
Posted by Kevin Menard <km...@servprise.com>.
I use #3.
I have all of my Persistent objects in one module that bundles up the
DataMap. Each app that uses them provides its own DataNode. It makes
deployment to different environments really nice. It also lets me
swap out test and production DataNodes really simply.
I'm not married to that one way of doing things, but I would like to
see that use case addressed somehow.
--
Kevin
On May 20, 2008, at 10:38 AM, Andrus Adamchik wrote:
> Wanted to check if anybody loads "cayenne.xml" and related Map and
> Node XML files from locations other than default two: CLASSPATH and
> WEB-INF/ ? More specifically:
>
> 1. anybody uses FileConfiguration?
> 2. anybody uses DefaultConfiguration (with 'addResourcePath' or
> without) to directly reference file in the filesystem (vs.
> referencing resources in classpath)?
> 3. anybody places DataMap / DataNode files in (jar) directories
> outside of the directory where "cayenne.xml" is located?
Re: [POLL] loading XML configurations from filesystem
Posted by Fixe106 <fi...@ifrance.com>.
Hi
Like you, I load only from classpath and WEB-INF
best regards
Julien
Le Tue, 20 May 2008 16:38:48 +0200, Andrus Adamchik
<an...@objectstyle.org> a écrit:
> Wanted to check if anybody loads "cayenne.xml" and related Map and Node
> XML files from locations other than default two: CLASSPATH and WEB-INF/
> ? More specifically:
>
> 1. anybody uses FileConfiguration?
> 2. anybody uses DefaultConfiguration (with 'addResourcePath' or without)
> to directly reference file in the filesystem (vs. referencing resources
> in classpath)?
> 3. anybody places DataMap / DataNode files in (jar) directories outside
> of the directory where "cayenne.xml" is located?
>
> I personally don't, as all these approaches lead to non-portable
> applications that make unwarranted assumptions about the environment. I
> think cases requiring to open cayenne.xml via the application UI are
> special enough to warrant a custom configuration.
>
> Some background. I am planning a rework of the config package to include
> support for merging of multiple Cayenne projects into a single "virtual
> project" in runtime (hence enabling multiple "persistent units" in the
> app). So I am looking to simplify this task and stop supporting edge
> cases that are not widely used, and also change the basic algorithm of
> resolving files relative to cayenne.xml to ensure they are actually
> relative to the URL within a JAR or class folder where cayenne.xml is
> found (so that we can have multiple cayenne.xml files and avoid
> conflicts when loading dependent XML files of those).
>
> I think there is a lot of benefit in keeping the built-in choices of
> file lookup down to just a few basic ones, and of course the users can
> still write their own Configuration extensions to address non-standard
> requirements.
>
> Andrus
>
>
Re: [POLL] loading XML configurations from filesystem
Posted by Borut Bolčina <bo...@gmail.com>.
Hi,
I use this
Configuration conf;
if (pathWithConfigurationFiles != null) {
conf = new FileConfiguration("cayenne.xml");
// Cayenne configuration files can be found at this location
((FileConfiguration) conf).addFilesystemPath(new
File(pathWithConfigurationFiles));
Configuration.initializeSharedConfiguration(conf);
} else {
conf = Configuration.getSharedConfiguration();
}
boolean failed =
Configuration.getSharedConfiguration().getLoadStatus().hasFailures();
if (failed) {
String message = "Error initializing Cayenne Configuration";
logger.fatal(message);
System.exit(1);
}
-borut
2008/5/20 Andrus Adamchik <an...@objectstyle.org>:
> Wanted to check if anybody loads "cayenne.xml" and related Map and Node XML
> files from locations other than default two: CLASSPATH and WEB-INF/ ? More
> specifically:
>
> 1. anybody uses FileConfiguration?
> 2. anybody uses DefaultConfiguration (with 'addResourcePath' or without) to
> directly reference file in the filesystem (vs. referencing resources in
> classpath)?
> 3. anybody places DataMap / DataNode files in (jar) directories outside of
> the directory where "cayenne.xml" is located?
>
> I personally don't, as all these approaches lead to non-portable
> applications that make unwarranted assumptions about the environment. I
> think cases requiring to open cayenne.xml via the application UI are special
> enough to warrant a custom configuration.
>
> Some background. I am planning a rework of the config package to include
> support for merging of multiple Cayenne projects into a single "virtual
> project" in runtime (hence enabling multiple "persistent units" in the app).
> So I am looking to simplify this task and stop supporting edge cases that
> are not widely used, and also change the basic algorithm of resolving files
> relative to cayenne.xml to ensure they are actually relative to the URL
> within a JAR or class folder where cayenne.xml is found (so that we can have
> multiple cayenne.xml files and avoid conflicts when loading dependent XML
> files of those).
>
> I think there is a lot of benefit in keeping the built-in choices of file
> lookup down to just a few basic ones, and of course the users can still
> write their own Configuration extensions to address non-standard
> requirements.
>
> Andrus
>
>
>