You are viewing a plain text version of this content. The canonical link for it is here.
Posted to dev@struts.apache.org by Ernest Jones <ej...@netopia.com> on 2001/09/04 17:50:02 UTC
ActionMapping parameter
I wanted some feedback on a feature request before I submit it.
In the ActionMapping api you can only get one nameless config parameter
(public String getParameter()). I would find it useful if I could specify
any number of named parameters (public String getParameter(String key)).
The xml in the struts-config file could look like:
<action path="/myPath" type="com.mycompany.actions.DoSomething">
<parameter name="paramName" value="paramValue"/>
<parameter name="paramName2" value="paramValue2"/>
...
<forward name="success" path="/success.jsp" />
</action>
To maintain backwards compatability (if you really wanted to) you could keep
the old parameter attribute and function.
Thoughts? Comments?
Re: ActionMapping parameter
Posted by Ted Husted <hu...@apache.org>.
So far, we've had three suggestions about what to do about this:
1. Use named parameters instead of a single parameter (as just
mentioned)
2. Use parameter as the name of a property file or other resource where
the actual parameters are kept.
3. Add methods to ActionMappings to retrieve parameters as if parameter
were a query string.
So in the last case, you could set parameter to be something like
parameter="form=input+action=update"
and then retrieve it using methods like
String form = mapping.getParameter("form");
and still keep
String parameter = mapping.getParameter()
to retrieve the String as is (or maybe just the first parameter).
This has the virtue of being trival to implement, and jives with the way
Forwards have to be coded.
A quick and easy way to do this starting now, would be to use the
HttpUtils class
http://java.sun.com/j2ee/tutorial/api/javax/servlet/http/HttpUtils.html
and do something like
--
HashTable parameters =
HttpUtils.parseQueryString(mappings.getParameter());
String form = (String) parameters.get("form");
--
Anyone want to give a implementation of doing this within ActionMappings
a whirl? I'd be thinking we'd want all the same parameter methods from
ServletRequest
http://java.sun.com/j2ee/tutorial/api/javax/servlet/ServletRequest.html
Another idea would be to just implement getParameterMap() in
ActionMappings, since HttpUtils is deprecated in Servlet 2.3 ;-(, and
leave it at that.
-- Ted Husted, Husted dot Com, Fairport NY USA.
-- Custom Software ~ Technical Services.
-- Tel +1 716 737-3463
-- http://www.husted.com/about/struts/
Ernest Jones wrote:
>
> I wanted some feedback on a feature request before I submit it.
>
> In the ActionMapping api you can only get one nameless config parameter
> (public String getParameter()). I would find it useful if I could specify
> any number of named parameters (public String getParameter(String key)).
> The xml in the struts-config file could look like:
>
> <action path="/myPath" type="com.mycompany.actions.DoSomething">
> <parameter name="paramName" value="paramValue"/>
> <parameter name="paramName2" value="paramValue2"/>
> ...
> <forward name="success" path="/success.jsp" />
> </action>
>
> To maintain backwards compatability (if you really wanted to) you could keep
> the old parameter attribute and function.
>
> Thoughts? Comments?
Re: ActionMapping parameter
Posted by Ted Husted <hu...@apache.org>.
So far, on the DEV list, we've had three suggestions about what to do
about this:
1. Use named parameters instead of a single parameter (as just
mentioned)
2. Use parameter as the name of a property file or other resource where
the actual parameters are kept.
3. Add methods to ActionMappings to retrieve parameters as if parameter
were a query string.
So in the last case, you could set parameter to be something like
parameter="form=input+action=update"
and then retrieve it using methods like
String form = mapping.getParameter("form");
and still keep
String parameter = mapping.getParameter()
to retrieve the String as is (or maybe just the first parameter).
This has the virtue of being trival to implement, and jives with the way
Forwards have to be coded.
A quick and easy way to do this starting now, would be to use the
HttpUtils class
http://java.sun.com/j2ee/tutorial/api/javax/servlet/http/HttpUtils.html
and do something like
--
HashTable parameters =
HttpUtils.parseQueryString(mappings.getParameter());
String form = (String) parameters.get("form");
--
Anyone want to give a implementation of doing this within ActionMappings
a whirl? I'd be thinking we'd want all the same parameter methods from
ServletRequest
http://java.sun.com/j2ee/tutorial/api/javax/servlet/ServletRequest.html
Another idea would be to just implement getParameterMap() in
ActionMappings, since HttpUtils is deprecated in Servlet 2.3 ;-(, and
leave it at that.
-- Ted Husted, Husted dot Com, Fairport NY USA.
-- Custom Software ~ Technical Services.
-- Tel +1 716 737-3463
-- http://www.husted.com/about/struts/
Ernest Jones wrote:
>
> I wanted some feedback on a feature request before I submit it.
>
> In the ActionMapping api you can only get one nameless config parameter
> (public String getParameter()). I would find it useful if I could specify
> any number of named parameters (public String getParameter(String key)).
> The xml in the struts-config file could look like:
>
> <action path="/myPath" type="com.mycompany.actions.DoSomething">
> <parameter name="paramName" value="paramValue"/>
> <parameter name="paramName2" value="paramValue2"/>
> ...
> <forward name="success" path="/success.jsp" />
> </action>
>
> To maintain backwards compatability (if you really wanted to) you could keep
> the old parameter attribute and function.
>
> Thoughts? Comments?
Re: ActionMapping parameter
Posted by Ted Husted <hu...@apache.org>.
David Corbin wrote:
> I'm not saying it's a bad idea, but be very careful what road you start
> down. If you're not careful, you end up "programming" in xml, which can
> have its down sides....
I think we're already doing that ;-)
What's happening now is that people are embedding a lot of control-logic
into HTML forms in the form of hidden properties and such.
With better support for placing multiple parameters into the
ActionMapping, some of that won't be necessary, and more of the
control-flow programming can be centralized in the configuration file.
Personally, I'm thinking that the best way to handle multiple parameters
is as parameters, since this corresponds to what we already have to do
with global forwards. Otherwise we end up with two ways to do the same
thing, all in the same configuration file.
Meanwhile, to close the loop, we should also be able to specify the path
for an ActionForm with global and local forwards. This would make it
possible to "softcode" all of the system paths and parameters using
logical forwards from the configuration file.
I'm currently thinking about trying to extend the HTML form tag to allow
use of a FORWARD property as an alternative to the current ACTION
property. When this property is used, the tag would check the
application mappings for the specified logical name and use the mapped
URI for the ACTION property.
To permit use of local forwards, the tag could also check for an Action
Mapping object in the page, request, and session scopes. If found, the
instant mapping object could be used to check for a local and global
forwarding. If not found, the application mappings are used instead.
Again, the benefit of this change are that all URIs can be replaced with
logical forwards throughout a Struts application. It also allows the
target of a form to be changed at runtime from the Action. This would
makes many workflow patterns easier to achieve.
-- Ted Husted, Husted dot Com, Fairport NY USA.
-- Custom Software ~ Technical Services.
-- Tel +1 716 737-3463
-- http://www.husted.com/about/struts/
Re: ActionMapping parameter
Posted by Ernest Jones <ej...@netopia.com>.
Point well taken.
The intention is not to pull programming into the configuration file, only
to facilitate code re-use. Being able to pass in multiple name value pairs
into an action mapping allows the same Action class to be used in different
situations, servlet-contexts, etc. One may want to specify database urls,
jdbc class-names to use, file locations of resources, messages to log, and
who knows what else.
Alternative solutions include:
1. Using init-parameters on the ActionServlet
drawbacks:
--only one configuration possible of an Action per servlet-context
--naming conflicts have to be watched for.
2. Using a properties file
drawbacks:
--if the file location is hard coded, you have the same problem of only
one configuration possible of an Action per servlet-context
or (to get around that):
--if the property file is specified as the parameter value, you still have
to maintain x number of different configuration/property files.
3. Using some sort of delimited name, value specification as the parameter
value (sort of like cgi query strings)
drawbacks:
--the struts users have to do all the parameter parsing.
--its a more complicated, uglier solution for those writing the config
file. Xml provides a much simpler, cleaner solution with child elements.
----- Original Message -----
From: "David Corbin" <dc...@imperitek.com>
To: <st...@jakarta.apache.org>
Sent: Tuesday, September 04, 2001 11:49 AM
Subject: Re: ActionMapping parameter
> I'm not saying it's a bad idea, but be very careful what road you start
> down. If you're not careful, you end up "programming" in xml, which can
> have its down sides....
>
>
> ----- Original Message -----
> From: "Ernest Jones" <ej...@netopia.com>
> To: <st...@jakarta.apache.org>; <st...@jakarta.apache.org>
> Sent: Tuesday, September 04, 2001 11:50 AM
> Subject: ActionMapping parameter
>
>
> > I wanted some feedback on a feature request before I submit it.
> >
> > In the ActionMapping api you can only get one nameless config parameter
> > (public String getParameter()). I would find it useful if I could
specify
> > any number of named parameters (public String getParameter(String key)).
> > The xml in the struts-config file could look like:
> >
> > <action path="/myPath" type="com.mycompany.actions.DoSomething">
> > <parameter name="paramName" value="paramValue"/>
> > <parameter name="paramName2" value="paramValue2"/>
> > ...
> > <forward name="success" path="/success.jsp" />
> > </action>
> >
> > To maintain backwards compatability (if you really wanted to) you could
> keep
> > the old parameter attribute and function.
> >
> > Thoughts? Comments?
> >
> >
> >
> >
>
Re: ActionMapping parameter
Posted by Ted Husted <hu...@apache.org>.
David Corbin wrote:
> I'm not saying it's a bad idea, but be very careful what road you start
> down. If you're not careful, you end up "programming" in xml, which can
> have its down sides....
I think we're already doing that ;-)
What's happening now is that people are embedding a lot of control-logic
into HTML forms in the form of hidden properties and such.
With better support for placing multiple parameters into the
ActionMapping, some of that won't be necessary, and more of the
control-flow programming can be centralized in the configuration file.
Personally, I'm thinking that the best way to handle multiple parameters
is as parameters, since this corresponds to what we already have to do
with global forwards. Otherwise we end up with two ways to do the same
thing, all in the same configuration file.
Meanwhile, to close the loop, we should also be able to specify the path
for an ActionForm with global and local forwards. This would make it
possible to "softcode" all of the system paths and parameters using
logical forwards from the configuration file.
I'm currently thinking about trying to extend the HTML form tag to allow
use of a FORWARD property as an alternative to the current ACTION
property. When this property is used, the tag would check the
application mappings for the specified logical name and use the mapped
URI for the ACTION property.
To permit use of local forwards, the tag could also check for an Action
Mapping object in the page, request, and session scopes. If found, the
instant mapping object could be used to check for a local and global
forwarding. If not found, the application mappings are used instead.
Again, the benefit of this change are that all URIs can be replaced with
logical forwards throughout a Struts application. It also allows the
target of a form to be changed at runtime from the Action. This would
makes many workflow patterns easier to achieve.
-- Ted Husted, Husted dot Com, Fairport NY USA.
-- Custom Software ~ Technical Services.
-- Tel +1 716 737-3463
-- http://www.husted.com/about/struts/
Re: ActionMapping parameter
Posted by David Corbin <dc...@imperitek.com>.
I'm not saying it's a bad idea, but be very careful what road you start
down. If you're not careful, you end up "programming" in xml, which can
have its down sides....
----- Original Message -----
From: "Ernest Jones" <ej...@netopia.com>
To: <st...@jakarta.apache.org>; <st...@jakarta.apache.org>
Sent: Tuesday, September 04, 2001 11:50 AM
Subject: ActionMapping parameter
> I wanted some feedback on a feature request before I submit it.
>
> In the ActionMapping api you can only get one nameless config parameter
> (public String getParameter()). I would find it useful if I could specify
> any number of named parameters (public String getParameter(String key)).
> The xml in the struts-config file could look like:
>
> <action path="/myPath" type="com.mycompany.actions.DoSomething">
> <parameter name="paramName" value="paramValue"/>
> <parameter name="paramName2" value="paramValue2"/>
> ...
> <forward name="success" path="/success.jsp" />
> </action>
>
> To maintain backwards compatability (if you really wanted to) you could
keep
> the old parameter attribute and function.
>
> Thoughts? Comments?
>
>
>
>