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Posted to dev@struts.apache.org by Alec Bau <Al...@msdw.com> on 2000/09/19 18:31:44 UTC
[REPOST] FormTag patch to work with ActionMapping
Since I didn't get any replies I'm reposing the patch to add a "path"
parameter to the FormTag (or make a new FormPathTag) so it's possible to
simply have:
<struts:form path="foo.do"/>
That eliminates a need to duplicate in JSP "name" and "type" param
values that are already retrieved from action.xml and stored in
respective ActionMapping.
I think it's a useful addition that allows for easier and cleaner JSP
coding, right? If yes are there any plans to include this addition?
Also another question I've already asked: Is it really so beneficial to
have "final" tag classes so it's impossible to extend them? Perfect
example is a proposed patch below.
Thanks,
Alec
-------- Original Message --------
Sorry for making few typos while cut and pasting in proposed FormTag
patch/extension. Here's correct code:
/** Process path param if present and use
* params from corresponding ActionMapping
*/
public int doStartTag() throws JspException {
if ((path != null) && (path.length () > 0)) {
setAction (mapping); // use is as form action
// Find ActionMapping pointed by the path
ActionMappings actmaps = (ActionMappings)
pageContext.getAttribute
(Action.MAPPINGS_KEY, PageContext.APPLICATION_SCOPE);
ActionMapping actmap = actmaps.findMapping (getMappingPath
(path));
if (actmap == null)
throw new JspException (messages.getMessage("common.io",
"FormTag: No ActionMapping found for form tag path
value: " + path));
// Override FormTag params with bean type and name extracted
from mapping
setType (actmap.getFormClass ());
setName (actmap.getFormAttribute ());
}
return super.doStartTag ();
}
/**
* Identify and return the action path component (from the path URI)
that
* we will use to select an ActionMapping. If no such
* path can be identified, return <code>null</code>.
*/
protected static String getMappingPath (String uri)
{
String path = new String (uri); // make a copy
// For extension matching, we want to strip the extension (if
any)
int slash = path.lastIndexOf ("/");
int period = path.lastIndexOf (".");
if ((period >= 0) && (period > slash))
path = path.substring (0, period);
// Add a leading "/" if missing
if (slash != 0)
path = "/" + path;
return (path);
}
Thanks,
Alec Bau
P.S. Craig, can we make tag classes non "final" so that extending them
will become possible?
Alec Bau wrote:
> I was wondering if it's mandatory to specify on a FormTag "name" and
> "type" parameters since in most
> cases "action" value is actually ActionMapping path that already
> contains all needed information from "action.xml".
>
> I suggest adding to the FormTag a "path" param that if present
> overrides/compliments "action", "type" and/or "name" params. Other
> solution is to define a new tag such as FormPathTag (i.e.
> <struts:pathform>) derived from current FormTag. In any case this will
> allow in a true MVC fashion to keep most technical non design
> information such as full bean class names and id's in a single place
> and not to replicate them through jsp pages. Also this makes FormTag
> extremely easy to explain and use with a single param such as:
>
> <struts:form path="foo.do"/>
>
> I've attached a patch that for brevity extends FormTag (now impossible
> since FormTag class is "final"). New tag's "path" param overrides
> "action", "type" and "name" params if present. Alternatively it's easy
> to check if any of above params are present and if not override them
> with values form ActionMapping.
>
> Corresponding new tag TLD entry should redefine "name" and "type"
> params as optional (or remove them along with "action" altogether)
> and add an optional (or mandatory if "action" and others are removed)
> "path" param.
>
> public class FormPathTag extends FormTag {
>
> /**
> * An URL which path should match according to ActionServlet rules
>
> * action mapping name from action.xml thus eliminating the need
> to specify
> * form tag bean name and type.
> * Supersedes action, type and name params if specified.
> */
> private String path = null;
>
> public String getPath() {
> return (this.path);
> }
>
> public void setPath(String path) {
> this.path = path;
> }
>
> /** Process path param if present and use
> * params from corresponding ActionMapping
> */
> public int doStartTag() throws JspException {
>
> if ((path == null) || (path.length () < 1)) return;
>
> setAction (mapping); // use is as form action
>
> // Find ActionMapping pointed by the path
> ActionMappings actmaps = (ActionMappings)
> pageContext.getAttribute
> (Action.MAPPINGS_KEY, PageContext.APPLICATION_SCOPE);
> ActionMapping actmap = actmaps.findMapping (getMappingPath
> (path));
> if (actmap == null)
> throw new JspException
> (messages.getMessage("common.io",
> "FormTag: No ActionMapping found for form tag path
> value: " + path));
>
> // Override FormTag params with bean type and name extracted
> from mapping
> setType (actmap.getFormClass ());
> setName (actmap.getFormAttribute ());
>
> super.doStartTag();
> }
>
> /**
> * Identify and return the action path component (from the path
> URI) that
> * we will use to select an ActionMapping. If no such
> * path can be identified, return <code>null</code>.
> */
> protected static String getMappingPath (String uri)
> {
> String path = new String (uri); // make a copy
>
> // For extension matching, we want to strip the extension (if
> any)
> int slash = path.lastIndexOf ("/");
> int period = path.lastIndexOf (".");
> if ((period >= 0) && (period > slash))
> path = path.substring (0, period);
>
> // Add a leading "/" if missing
> if (!path.startsWith ("/"))
> path = "/" + path;
>
> return (path);
> }
>
> public void release() {
> super.release();
> path = null;
> }
>
> }
>
Re: [REPOST] FormTag patch to work with ActionMapping
Posted by "Craig R. McClanahan" <Cr...@eng.sun.com>.
Alec,
I need to apologize to you and everyone else that I've seemingly ignored
lately -- an incredible number of urgent deadlines has nailed pretty
much every minute of my time over the last few weeks. Fortunately, I've
only got two tasks over the next few weeks -- get both Tomcat 4.0 and
Struts 1.0 ready for release in time for ApacheCon Europe (Oct 23-25).
So Struts will definitely be getting some attention.
On the particular patch you posted, I agree that this will simplify
things -- and, since the form tag has to know that path anyway, keeping
that attribute is the right thing to do. I'm going to incorporate this
change with support for the new configuration file format that we
discussed on the list recently. This has a slightly different twist
(because there will be a new list of form beans accessed by name, so
more than one action can share the same bean), but the same basic idea.
Craig
Alec Bau wrote:
> Since I didn't get any replies I'm reposing the patch to add a "path"
> parameter to the FormTag (or make a new FormPathTag) so it's possible
> to simply have:
>
> <struts:form path="foo.do"/>
>
> That eliminates a need to duplicate in JSP "name" and "type" param
> values that are already retrieved from action.xml and stored in
> respective ActionMapping.
>
> I think it's a useful addition that allows for easier and cleaner JSP
> coding, right? If yes are there any plans to include this addition?
>
> Also another question I've already asked: Is it really so beneficial
> to have "final" tag classes so it's impossible to extend them?
> Perfect example is a proposed patch below.
>
> Thanks,
> Alec
>
> -------- Original Message --------
>
> Sorry for making few typos while cut and pasting in proposed FormTag
> patch/extension. Here's correct code:
>
> /** Process path param if present and use
> * params from corresponding ActionMapping
> */
> public int doStartTag() throws JspException {
>
> if ((path != null) && (path.length () > 0)) {
> setAction (mapping); // use is as form action
>
> // Find ActionMapping pointed by the path
> ActionMappings actmaps = (ActionMappings)
> pageContext.getAttribute
> (Action.MAPPINGS_KEY, PageContext.APPLICATION_SCOPE);
> ActionMapping actmap = actmaps.findMapping (getMappingPath
> (path));
> if (actmap == null)
> throw new JspException
> (messages.getMessage("common.io",
> "FormTag: No ActionMapping found for form tag path
> value: " + path));
>
> // Override FormTag params with bean type and name
> extracted from mapping
> setType (actmap.getFormClass ());
> setName (actmap.getFormAttribute ());
> }
> return super.doStartTag ();
> }
>
> /**
> * Identify and return the action path component (from the path
> URI) that
> * we will use to select an ActionMapping. If no such
> * path can be identified, return <code>null</code>.
> */
> protected static String getMappingPath (String uri)
> {
> String path = new String (uri); // make a copy
>
> // For extension matching, we want to strip the extension (if
> any)
> int slash = path.lastIndexOf ("/");
> int period = path.lastIndexOf (".");
> if ((period >= 0) && (period > slash))
> path = path.substring (0, period);
>
> // Add a leading "/" if missing
> if (slash != 0)
> path = "/" + path;
>
> return (path);
> }
>
> Thanks,
> Alec Bau
>
> P.S. Craig, can we make tag classes non "final" so that extending them
> will become possible?
>
> Alec Bau wrote:
>
>> I was wondering if it's mandatory to specify on a FormTag "name" and
>> "type" parameters since in most
>> cases "action" value is actually ActionMapping path that already
>> contains all needed information from "action.xml".
>>
>> I suggest adding to the FormTag a "path" param that if present
>> overrides/compliments "action", "type" and/or "name" params. Other
>> solution is to define a new tag such as FormPathTag (i.e.
>> <struts:pathform>) derived from current FormTag. In any case this
>> will allow in a true MVC fashion to keep most technical non design
>> information such as full bean class names and id's in a single place
>> and not to replicate them through jsp pages. Also this makes
>> FormTag extremely easy to explain and use with a single param such
>> as:
>>
>> <struts:form path="foo.do"/>
>>
>> I've attached a patch that for brevity extends FormTag (now
>> impossible since FormTag class is "final"). New tag's "path" param
>> overrides "action", "type" and "name" params if present.
>> Alternatively it's easy to check if any of above params are present
>> and if not override them with values form ActionMapping.
>>
>> Corresponding new tag TLD entry should redefine "name" and "type"
>> params as optional (or remove them along with "action" altogether)
>> and add an optional (or mandatory if "action" and others are
>> removed) "path" param.
>>
>> public class FormPathTag extends FormTag {
>>
>> /**
>> * An URL which path should match according to ActionServlet
>> rules
>> * action mapping name from action.xml thus eliminating the need
>> to specify
>> * form tag bean name and type.
>> * Supersedes action, type and name params if specified.
>> */
>> private String path = null;
>>
>> public String getPath() {
>> return (this.path);
>> }
>>
>> public void setPath(String path) {
>> this.path = path;
>> }
>>
>> /** Process path param if present and use
>> * params from corresponding ActionMapping
>> */
>> public int doStartTag() throws JspException {
>>
>> if ((path == null) || (path.length () < 1)) return;
>>
>> setAction (mapping); // use is as form action
>>
>> // Find ActionMapping pointed by the path
>> ActionMappings actmaps = (ActionMappings)
>> pageContext.getAttribute
>> (Action.MAPPINGS_KEY,
>> PageContext.APPLICATION_SCOPE);
>> ActionMapping actmap = actmaps.findMapping (getMappingPath
>> (path));
>> if (actmap == null)
>> throw new JspException
>> (messages.getMessage("common.io",
>> "FormTag: No ActionMapping found for form tag path
>> value: " + path));
>>
>> // Override FormTag params with bean type and name extracted
>> from mapping
>> setType (actmap.getFormClass ());
>> setName (actmap.getFormAttribute ());
>>
>> super.doStartTag();
>> }
>>
>> /**
>> * Identify and return the action path component (from the path
>> URI) that
>> * we will use to select an ActionMapping. If no such
>> * path can be identified, return <code>null</code>.
>> */
>> protected static String getMappingPath (String uri)
>> {
>> String path = new String (uri); // make a copy
>>
>> // For extension matching, we want to strip the extension
>> (if any)
>> int slash = path.lastIndexOf ("/");
>> int period = path.lastIndexOf (".");
>> if ((period >= 0) && (period > slash))
>> path = path.substring (0, period);
>>
>> // Add a leading "/" if missing
>> if (!path.startsWith ("/"))
>> path = "/" + path;
>>
>> return (path);
>> }
>>
>> public void release() {
>> super.release();
>> path = null;
>> }
>>
>> }
>>
>
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