Hi Bob,
In the end, I ended up with a much more brutal low-tech approach that
involves updating the velocity model directly, it does one extra pass to try
to resolve embedded symbols. Here is the code...
...
protected String applyMapValuesToTemplate(String template,
Map<String,Object> mapValues) {
final String DELIMITER_PREFIX = "${";
final String DELIMITER_SUFFIX = "}";
for (String key : mapValues.keySet()) {
String matchKey = DELIMITER_PREFIX + key + DELIMITER_SUFFIX;
if (template.contains(matchKey)) {
template = template.replace(matchKey, (String)
mapValues.get(key));
}
}
return template;
}
....
// various calls to addModel including my Strings with embedded variable
....
for (String key : ((Map<String,Object>) getModel()).keySet()) {
String value = getModel().get(key).toString();
if (value.contains("${") &&
value.contains("}") &&
value.indexOf("${") <
value.indexOf("}")) {
value = applyMapValuesToTemplate(value, getModel());
getModel().put(key, value);
}
}
Cheers,
-G
__
--- == __/ t.O ==--
http://stacktrace.org/
On Tue, Jul 21, 2009 at 6:12 PM, Bob Schellink <[email protected]> wrote:
> Hi Garth,
>
> I've been wondering about this today. The most obvious solution is probably
> to use Java's MessageFormat and replace the property variables before adding
> them to the model. Off course MessageFormat doesn't support named
> parameters, only numeric ones. So you have to use:
>
> Intro=Hello {0}, welcome to the app
>
> Alternatively you might want to look at Velocity Renderable[1] interface.
> Its new in 1.6.
>
> Normally Velocity will invoke the toString() method of the variable it
> finds in the template. However if the variable implements Renderable,
> Velocity will invoke a callback method which allows you to manipulate the
> output as needed.
>
> I haven't used this Velocity feature yet but it seems quite powerful.
>
> Let us know what solution you end up using.
>
> kind regards
>
> bob
>
> [1]:
> http://velocity.apache.org/engine/devel/apidocs/org/apache/velocity/runtime/Renderable.html
>
>
> Garth Dahlstrom wrote:
>
>> Hi
>> I'm wondering if there is a recommended approach to replacing variables
>> that occur within other variables.
>>
>> I have text which I add to the model that comes from a properties file
>> that looks like:
>> Intro=Hello ${Name}, welcome to the application
>> Name=John
>>
>> I could break up intro into chunks in my template, but that will make
>> things slightly more difficult to maintain, particularily when I send it for
>> translation.
>>
>> So, is there a way to get model-variable subsitution to run a second time
>> or a way for me to change the to-be-rendered output to acomplish something
>> like this?
>>
>> Thanks,
>> -G
>>
>>
>
