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Posted to users@tapestry.apache.org by Kai Weber <ka...@glorybox.de> on 2009/06/11 15:38:13 UTC
Difference between prop: and ${...} in PageLink
Hi,
I am a Tapestry beginner. I am far from knowing all the internals. I use
the PageLink component in one of my as follows:
@Component(id="backLink",
parameters={
"page=${backLink}",
"context=backLinkContext",
"anchor=${prev.getUniqueIdentifier()}"})
private PageLink backLink;
My question is now
What does the ${...} do?
I fail to see what this means: If I replace
"context=prop:backLinkContext" with "context=${backLinkContext}" I get a
different link than expected. If I replace "page=prop:backLink" with
"page=${backLink}" I get no different link. Why?
Kai
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Re: Difference between prop: and ${...} in PageLink
Posted by Radek Terber <te...@b2bcentrum.cz>.
Hi all.
As I know from My experiments, ${ ... } converts each object to string,
in contrast to "prop:...", which returns object "as is". In page link,
this difference should not take an effect. But in parameters this is
significant ...
Kai Weber napsal(a):
> Hi,
>
> I am a Tapestry beginner. I am far from knowing all the internals. I
> use the PageLink component in one of my as follows:
>
> @Component(id="backLink",
> parameters={
> "page=${backLink}",
> "context=backLinkContext",
> "anchor=${prev.getUniqueIdentifier()}"})
> private PageLink backLink;
>
> My question is now
>
> What does the ${...} do?
>
> I fail to see what this means: If I replace
> "context=prop:backLinkContext" with "context=${backLinkContext}" I get
> a different link than expected. If I replace "page=prop:backLink" with
> "page=${backLink}" I get no different link. Why?
>
> Kai
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: users-unsubscribe@tapestry.apache.org
> For additional commands, e-mail: users-help@tapestry.apache.org
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Re: Difference between prop: and ${...} in PageLink
Posted by Howard Lewis Ship <hl...@gmail.com>.
On Thu, Jun 11, 2009 at 7:05 AM, Onno Scheffers <on...@piraya.nl> wrote:
> ${} is a shortcut to make it very easy to insert some property-value into
> your template without having to use a component for it. There are typically
> 3 ways to insert some content into your page:
>
> 1. The way you're using components, keeping most of the configuration in
> the
> Java class:
> <h1 t:id="title">Some title</h1>
>
> @Component(parameters = { "value=prop:myTitle" })
> private Output output;
>
>
> 2. Use and configure the component straight from within your template:
> <h1 t:type="Output" t:value="prop:myTitle">Some title</h1>
>
>
> 3. The easiest way is using the expansion:
> <h1>${myTitle}</h1>
>
You can also say ${message:my-key} to retrieve a localized key, or use any
other binding prefix.
>
>
> I use option 1 all the time. It makes refactoring much easier and keeps the
> templates clean for the designers. It takes more code though. This works
> for
> all components.
>
> Option 2 is typically great for quick prototyping but a lot of non-standard
> markup is added to the template which might confuse web-designers. It works
> for all components.
>
> Option 3 is a shortcut that makes it even easier to insert some property
> value directly into your page. It only works for inserting content
> retrieved
> from a property on your page.
>
> More information:
> http://tapestry.apache.org/tapestry5/guide/templates.html
>
>
> regards,
>
> Onno
>
>
> On Thu, Jun 11, 2009 at 3:38 PM, Kai Weber <ka...@glorybox.de> wrote:
>
> > Hi,
> >
> > I am a Tapestry beginner. I am far from knowing all the internals. I use
> > the PageLink component in one of my as follows:
> >
> > @Component(id="backLink",
> > parameters={
> > "page=${backLink}",
> > "context=backLinkContext",
> > "anchor=${prev.getUniqueIdentifier()}"})
> > private PageLink backLink;
> >
> > My question is now
> >
> > What does the ${...} do?
> >
> > I fail to see what this means: If I replace
> "context=prop:backLinkContext"
> > with "context=${backLinkContext}" I get a different link than expected.
> If I
> > replace "page=prop:backLink" with "page=${backLink}" I get no different
> > link. Why?
> >
> > Kai
> >
> > ---------------------------------------------------------------------
> > To unsubscribe, e-mail: users-unsubscribe@tapestry.apache.org
> > For additional commands, e-mail: users-help@tapestry.apache.org
> >
> >
>
--
Howard M. Lewis Ship
Creator of Apache Tapestry
Director of Open Source Technology at Formos
Re: Difference between prop: and ${...} in PageLink
Posted by Onno Scheffers <on...@piraya.nl>.
${} is a shortcut to make it very easy to insert some property-value into
your template without having to use a component for it. There are typically
3 ways to insert some content into your page:
1. The way you're using components, keeping most of the configuration in the
Java class:
<h1 t:id="title">Some title</h1>
@Component(parameters = { "value=prop:myTitle" })
private Output output;
2. Use and configure the component straight from within your template:
<h1 t:type="Output" t:value="prop:myTitle">Some title</h1>
3. The easiest way is using the expansion:
<h1>${myTitle}</h1>
I use option 1 all the time. It makes refactoring much easier and keeps the
templates clean for the designers. It takes more code though. This works for
all components.
Option 2 is typically great for quick prototyping but a lot of non-standard
markup is added to the template which might confuse web-designers. It works
for all components.
Option 3 is a shortcut that makes it even easier to insert some property
value directly into your page. It only works for inserting content retrieved
from a property on your page.
More information: http://tapestry.apache.org/tapestry5/guide/templates.html
regards,
Onno
On Thu, Jun 11, 2009 at 3:38 PM, Kai Weber <ka...@glorybox.de> wrote:
> Hi,
>
> I am a Tapestry beginner. I am far from knowing all the internals. I use
> the PageLink component in one of my as follows:
>
> @Component(id="backLink",
> parameters={
> "page=${backLink}",
> "context=backLinkContext",
> "anchor=${prev.getUniqueIdentifier()}"})
> private PageLink backLink;
>
> My question is now
>
> What does the ${...} do?
>
> I fail to see what this means: If I replace "context=prop:backLinkContext"
> with "context=${backLinkContext}" I get a different link than expected. If I
> replace "page=prop:backLink" with "page=${backLink}" I get no different
> link. Why?
>
> Kai
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: users-unsubscribe@tapestry.apache.org
> For additional commands, e-mail: users-help@tapestry.apache.org
>
>
Re: Difference between prop: and ${...} in PageLink
Posted by Howard Lewis Ship <hl...@gmail.com>.
${...} expansions evaluate the expression and convert it to a string.
Since the page parameter expects a string, that's OK.
Converting a context (an array or List to a string) is different than
passing the List, unchanged, as the context parameter.
Allowing ${...} expansions in attribute values was added for ordinary,
non-component, elements that want a little bit of dynamic behavior. For
components, use the prop: binding prefix. This is expecially important for
form components such as TextArea, as prop:somePageProperty is read/write
(the TextField can update the property when the form is submitted), whereas
${somePageProperty} is converted to a string and is read-only.
On Thu, Jun 11, 2009 at 6:38 AM, Kai Weber <ka...@glorybox.de> wrote:
> Hi,
>
> I am a Tapestry beginner. I am far from knowing all the internals. I use
> the PageLink component in one of my as follows:
>
> @Component(id="backLink",
> parameters={
> "page=${backLink}",
> "context=backLinkContext",
> "anchor=${prev.getUniqueIdentifier()}"})
> private PageLink backLink;
>
> My question is now
>
> What does the ${...} do?
>
> I fail to see what this means: If I replace "context=prop:backLinkContext"
> with "context=${backLinkContext}" I get a different link than expected. If I
> replace "page=prop:backLink" with "page=${backLink}" I get no different
> link. Why?
>
> Kai
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: users-unsubscribe@tapestry.apache.org
> For additional commands, e-mail: users-help@tapestry.apache.org
>
>
--
Howard M. Lewis Ship
Creator of Apache Tapestry
Director of Open Source Technology at Formos