I think it's best to use the built-in JSON creation code and keep the code as JsCmd as long as possible.
Here's a snippet that will place the JSON for all the Users in the page.
I'm including the whole project as well:
class HelloWorld {
def json: NodeSeq = Script(jsonForAll(User))
private def jsonForAll[T <: Mapper[T]](meta: MetaMapper[T]): JsCmd =
JsArray(meta.findAll.map(_.asJs) :_*)
}
If you have further questions, please update the project and mark the places
in the code where you have a question and we'll work from there.
Thanks,
David
On Mon, Apr 13, 2009 at 2:07 AM, Amit Kumar Verma <cdac.a...@gmail.com>wrote:
>
> Hi David,
>
> Thanks for ur replies, I just want to make a generic function which
> will take an object of mapper and returns the json string of the same.
>
> I have written only two function
> 1. This will be called by ajax call :
>
> def getJSONString(xhtml: Group):NodeSeq = {
> getJSONStringGeneric(TestGearLogin) // here 'TestGearLogin' is
> a mapper object
> }
>
> 2. function to make JSON string i.e
>
> def getJSONStringGeneric(anyObject :Any):NodeSeq = {
>
> var sJSONString = "{\"bindings\": [";
>
> anyObject match {
> case mm: MetaMapper[_] => // this line is giving error
> mm.findAll.map(userdetails => {
>
> var tempJSON = "";
>
> val ret = new StringBuilder
>
> ret.append("{")
> ret.append(userdetails.getSingleton.appendFieldToStrings
> (userdetails))
> ret.append("}")
>
> tempJSON = ret.toString();
>
> // some manipulation for making correct JSON
> tempJSON = tempJSON.replaceAll("\\{","\\{\"");
> tempJSON = tempJSON.replaceAll("\\}","\"\\}");
> tempJSON = tempJSON.replaceAll("=","\":\"");
> tempJSON = tempJSON.replaceAll("," , "\",\"");
> tempJSON += ",";
>
> sJSONString +=tempJSON
> });
> }
>
> sJSONString = sJSONString.substring(0,sJSONString.length-1); //
> for slicing the last comma
> sJSONString += "]}";
>
> Text(sJSONString);
> }
>
>
> I changed the code as you suggested but getting the error as I posted.
> Please advise.
>
> Thanks
> Amit Kumar Verma
>
>
> On Apr 10, 9:46 pm, David Pollak <feeder.of.the.be...@gmail.com>
> wrote:
> > I think the .asJs method on all Mapper instances should give you the
> object
> > in JavaScript representation.
> > If you can post an entire file, I can work on helping you if the above
> > doesn't work.
> >
> > On Thu, Apr 9, 2009 at 6:53 AM, Amit Kumar Verma <cdac.a...@gmail.com
> >wrote:
> >
> >
> >
> >
> >
> > > copied the the same code but getting this error
> >
> > > type arguments [_] do not conform to trait MetaMapper's type parameter
> > > bounds [A <: net.liftweb.mapper.Mapper[A]]
> > > TravelMerchantTest/src/main/
> > > scala/com/vtech/travelmerchant/snippet default.scala line 142
> > > 1239284830763 85593
> >
> > > Actually I am trying to make the JSON object using a mapper object. My
> > > function is this :
> >
> > > def getJSONStringGeneric(anyObject :Any):NodeSeq = {
> >
> > > //Console.println("anyObject.getClass ::::::::
> > > "+anyObject.getClass);
> >
> > > //Console.println("anyObject.getClass.getName ::::::::
> > > "+anyObject.getClass.getName);
> >
> > > //var objTemp = anyObject.asInstanceOf[MetaMapper
> > > [TestGearLogin]];
> >
> > > var sJSONString = "{\"bindings\": [";
> >
> > > anyObject match {
> > > case mm: MetaMapper[_] =>
> > > mm.findAll.map(
> > > (userdetails: Mapper[_]) =>{
> >
> > > var tempJSON = "";
> >
> > > val ret = new StringBuilder
> >
> > > ret.append("{")
> >
> > > ret.append(userdetails.getSingleton.appendFieldToStrings
> > > (userdetails))
> >
> > > ret.append("}")
> >
> > > // ret will be like
> > > {username=222,password=222,audit_dt=2009-04-06
> > > 00:00:00.0,login_pid=26}
> >
> > > tempJSON = ret.toString();
> >
> > > tempJSON = tempJSON.replaceAll("\\{","\\{\"");
> > > tempJSON = tempJSON.replaceAll("\\}","\"\\}");
> > > tempJSON = tempJSON.replaceAll("=","\":\"");
> > > tempJSON = tempJSON.replaceAll("," , "\",\"");
> > > tempJSON += ",";
> >
> > > sJSONString +=tempJSON
> > > }
> > > )
> > > }
> >
> > > sJSONString = sJSONString.substring(0,sJSONString.length-1); //
> > > for slicing the last comma
> > > sJSONString += "]}";
> >
> > > Text(sJSONString);
> > > }
> >
> > > but not getting a way of doing this. Please advise.
> >
> > > Thanks
> > > Amit Kumar Verma
> >
> > > On Apr 9, 6:14 pm, David Pollak <feeder.of.the.be...@gmail.com> wrote:
> > > > Howdy,
> > > > Scala is a static language, so the class for casting must be known at
> > > > compile time. It's not possible to construct a String at runtime and
> > > cast
> > > > an object into a class represented by that String.
> >
> > > > However, casting to a known class is easy in Scala... and it's done
> > > > primarily using pattern matching. The following code:
> >
> > > > def foo(in: Any) = in match {
> > > > case mm: MetaMapper[_] =>
> > > > mm.findAll.map(
> > > > (m: Mapper[_]) =>
> > > > m.asJs
> > > > )
> > > > case _ =>
> > > > }
> >
> > > > Does what I think you want. It takes an incoming instance, in and
> > > matches
> > > > it against being an instance of MetaMapper[_]. This means its some
> type
> > > of
> > > > MetaMapper (we don't know or care what the type parameter is). If it
> is
> > > a
> > > > MetaMapper, it's assigned to the mm variable. We can then call
> findAll
> > > on
> > > > that variable and we have a bunch of Mapper[_] instances. Note that
> I
> > > > explicitly called out the type of m in the function, but that line
> could
> > > be
> > > > re-written mm.findAll.map(m => m.asJs) because the compiler infers
> the
> > > type
> > > > of m.
> >
> > > > Does this help?
> >
> > > > Thanks,
> >
> > > > David
> >
> > > > On Thu, Apr 9, 2009 at 3:55 AM, Amit Kumar Verma <
> cdac.a...@gmail.com
> > > >wrote:
> >
> > > > > Hi All,
> >
> > > > > I am trying to type cast an scala object to its mapper object
> >
> > > > > 1 def getJSONString(anyObject :Object):NodeSeq = {
> >
> > > > > 2 var obj = anyObject.asInstanceOf[anyObject.getClass
> > > > > ().getName()];
> >
> > > > > 3 obj.findAll.map(userdetails => {
> > > > > // some code will go here
> > > > > }
> > > > > Text("any string")
> > > > > }
> >
> > > > > but i am getting erroe as "expected [ but found (" on line 2.
> >
> > > > > please help me to typecast the object to its mapper object.
> >
> > > > > Thanks
> > > > > Amit Kumar Verma
> >
> > > > --
> > > > Lift, the simply functional web frameworkhttp://liftweb.net
> > > > Beginning Scalahttp://www.apress.com/book/view/1430219890
> > > > Follow me:http://twitter.com/dpp
> > > > Git some:http://github.com/dpp
> >
> > --
> > Lift, the simply functional web frameworkhttp://liftweb.net
> > Beginning Scalahttp://www.apress.com/book/view/1430219890
> > Follow me:http://twitter.com/dpp
> > Git some:http://github.com/dpp
>
> >
>
--
Lift, the simply functional web framework http://liftweb.net
Beginning Scala http://www.apress.com/book/view/1430219890
Follow me: http://twitter.com/dpp
Git some: http://github.com/dpp
--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups
"Lift" group.
To post to this group, send email to liftweb@googlegroups.com
To unsubscribe from this group, send email to
liftweb+unsubscr...@googlegroups.com
For more options, visit this group at
http://groups.google.com/group/liftweb?hl=en
-~----------~----~----~----~------~----~------~--~---
json.tgz
Description: GNU Zip compressed data
