"Will Glass-Husain" <[EMAIL PROTECTED]> writes:
Hm,
now that we are moving into the realm of loosely typed languages,
maybe we just want to sneak peek at e.g. Groovy, commons jexl or
commons el how they do it.
As it seems that e.g. JEXL has derived ideas from Velocity, maybe at
some point (2.0?) we could even drop our own code and plug it in.
Best regards
Henning
>yes! a related bug is that comparing items of two different classes gives
>an error (doesn't even return false).
>I think if both items are numbers the comparison should be numeric, of
>course. (integer 2 == double 2.0 even though the string representations are
>different). Otherwise, it'd be nice to compare on Strings.
>Is this in bugzilla? cough... I mean JIRA? It's a pretty easy fix.
>(ASTEquals if I remember from memory). Can we get away with this for the
>1.5 release or is that a backwards compatibility issue? (1.5 *must* stay
>backwards compatible). My first reaction is that this is ok. (since this
>wasn't even valid VTL before).
>WILL
>----- Original Message -----
>From: "Nathan Bubna" <[EMAIL PROTECTED]>
>To: "Velocity Users List" <[email protected]>;
><[EMAIL PROTECTED]>
>Sent: Friday, September 16, 2005 2:09 PM
>Subject: Re: Comparing strings
>All good discussion, Henning is, of course, right on.
>but all this reminds me of a closely related velocity wish-list item
>of mine: having == comparisons be done on the *rendered* value of the
>references, rather than the class value. in other words, i would
>like:
>#set( $two = 2 )
>#if( $two == '2' )
>to output this text!
>#end
>after all, putting "$two equals 2" in a template (leave off the #if)
>and rendering it will output "2 equals 2". why shouldn't things that
>will be rendered identically by VTL be treated as equal in #if
>statements? i think that is the most intuitive way to do comparisons
>in a template language where the focus is on the rendered output.
>perhaps it's time i put a page on the wiki for it, to perhaps build a
>little momentum/consensus for getting this in future versions.
>On 9/16/05, Henning P. Schmiedehausen <[EMAIL PROTECTED]> wrote:
>> "Steve O'Hara" <[EMAIL PROTECTED]> writes:
>>
>> >A while back I chastised someone for not using proper String comparison
>> >operators in their templates. I looked in the Velocity code and sure
>> >enough "==" operators are translated into equals. So I was looking a bit
>> >stupid.
>>
>> >Somebody challenged me to come up with a situation where the equality
>> >"==" operator doesn't work with Strings.
>> >Well, finally, I've just found an example in my code;
>>
>> > #if ($SummarySortField==$Field.getUdmFieldName())
>> > #if ($SummarySortField==${Field.getUdmFieldName()})
>> > #if ($SummarySortField.equalsIgnoreCase($Field.getUdmFieldName()))
>>
>> >I thought perhaps I was going mad before when I raised this and plenty
>> >of people on this list questioned me, but can anyone explain this?
>>
>> equalsIngoreCase != equals.
>>
>> In Java, equals != ==
>>
>> Look at this:
>>
>> public class Test {
>> public static void main(String [] argv) throws Exception {
>> String s1 = "foo";
>> String s2 = "foobar".substring(0,3);
>>
>> System.out.println(s1);
>> System.out.println(s2);
>> System.out.println(s1 == s2);
>> System.out.println(s1.equals(s2));
>> }
>>
>> }
>>
>> outputs
>>
>> foo
>> foo
>> false
>> true
>>
>> However, in Velocity:
>>
>> --- cut ---
>> import java.io.OutputStreamWriter;
>>
>> import org.apache.commons.lang.ObjectUtils;
>> import org.apache.velocity.Template;
>> import org.apache.velocity.VelocityContext;
>> import org.apache.velocity.app.Velocity;
>>
>> public class Demo {
>> public static void main(String[] args) {
>> try {
>> Velocity.init();
>>
>> VelocityContext vc = new VelocityContext();
>> String s1 = "foo";
>> String s2 = "foobar".substring(0,3);
>> vc.put("s1", s1);
>> vc.put("s2", s2);
>>
>> vc.put("s1info", ObjectUtils.appendIdentityToString(null,
>> s1).toString());
>> vc.put("s2info", ObjectUtils.appendIdentityToString(null,
>> s2).toString());
>>
>> Template template = Velocity.getTemplate("DemoTemplate.vm");
>> OutputStreamWriter osw = new OutputStreamWriter(System.out);
>>
>> template.merge(vc, osw);
>>
>> osw.flush();
>> osw.close();
>> } catch (Exception e) {
>> e.printStackTrace();
>> }
>> }
>> }
>> --- cut ---
>>
>> String1: ${s1}, Type is $s1.Class.Name
>> String2: ${s2}, Type is $s2.Class.Name
>>
>> String1 Info: ${s1info}
>> String2 Info: ${s2info}
>>
>> Equals:
>> #if ($s1.equals($s2))
>> True
>> #else
>> False
>> #end
>>
>> Compare:
>> #if ($s1 == $s2)
>> True
>> #else
>> False
>> #end
>>
>> --- cut ---
>>
>> produces:
>>
>> String1: foo, Type is java.lang.String
>> String2: foo, Type is java.lang.String
>>
>> String1 Info: [EMAIL PROTECTED]
>> String2 Info: [EMAIL PROTECTED]
>>
>> Equals:
>> True
>>
>> Compare:
>> True
>>
>> So Velocity == is not the same as Java == for Strings. It is the same
>> as equals().
>>
>> Best regards
>> Henning
>>
>>
>> --
>> Dipl.-Inf. (Univ.) Henning P. Schmiedehausen INTERMETA GmbH
>> [EMAIL PROTECTED] +49 9131 50 654 0 http://www.intermeta.de/
>>
>> RedHat Certified Engineer -- Jakarta Turbine Development -- hero for hire
>> Linux, Java, perl, Solaris -- Consulting, Training, Development
>>
>> 4 - 8 - 15 - 16 - 23 - 42
>>
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[EMAIL PROTECTED] +49 9131 50 654 0 http://www.intermeta.de/
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Linux, Java, perl, Solaris -- Consulting, Training, Development
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