Help with targeting contentType with javascript

[frederickyocum]

Newbie with a problem with probably a obvious answer. I am having a little trouble in the script snippet below. In the for statement, the alert returns the contentType, so I know that I have an object selected and I can access the contentType enumeration. The switch statement (the real code where I want to process the selection depending on the contentType) returns nothing. This probably has a simple answer, I just don’t know it.

    for(var theCounter = 0; theCounter < app.selection.length ; theCounter++){

          var theThing = app.selection[theCounter].contentType;

          alert (theThing);

         switch(theThing){

          case 'GRAPHIC_TYPE' :

          alert("This is a graphic.");

          break;

         case 'TEXT_TYPE':

          alert("This is text");

          break;

       }  //End switch item checking

TIA

[SureshRaji · Accepted solution]

Hi

Try this:

for(var theCounter = 0; theCounter < app.selection.length ; theCounter++){
          var theThing = app.selection[theCounter].contentType;
          alert (theThing);
         switch(theThing.toString()){
          case 'GRAPHIC_TYPE':
          alert("This is a graphic.");
          break;
         case 'TEXT_TYPE':
          alert("This is text");
          break;
       }
   }

[frederickyocum]

Aaah, to (bloody) String! That did the trick.

The alert function simply converted the value to a string on the fly, so that it could be alerted, but the switch function did not know what I was talking about. So, enumerations are more than string values?

Thanks very much Sureshkumar

[Jongware]

(Re-typing again in Mozilla, Jive still suxx on IE9!)

frederickyocum wrote:

The alert function simply converted the value to a string on the fly, so that it could be alerted, but the switch function did not know what I was talking about. So, enumerations are more than string values?

They are in fact numbers: http://jongware.mit.edu/idcs6js/pe_ContentType.html -- although that doesn't imply you have to get used to writing

case 1735553140: ...

in your code, you can simply use

case ContentType.GRAPHIC_TYPE: ...

etc. The 'type' before the constant is required; unfortunately, the default toString function seems to forget to add it so your valiant "alert" try lead to nothing.

[frederickyocum]

Thanks Jongware.

This leaves me slightly confused because:

theThing is the contentType

In the switch statement I am asking for the contentType of the contentType am I not?

   var theThing = app.selection[theCounter].contentType;

   switch(theThing){

      case ContentType.GRAPHIC_TYPE : alert("This is a graphic.");

It works I just don’t know why.

[Jongware]

Don't get confused by the repetition of the phrase "contentType".

var theThing = app.selection[theCounter].contentType;

Here 'contentType' is just the name of the property. It could be called 'type' or 'content' or 'ct', or anything else. But its value is a member of the enumeration type "ContentType"; in this case, "ContentType.GRAPHIC_TYPE". This, as a single unit, is a variable with the constant value "1735553140", declared somewhere inside InDesign.

It is a common Javascript construct; you can define your own constants like this:

var myValue = { Test1:1, Test2:2 }
alert (myValue.Test1);

http://jongware.mit.edu/idcs6js/index_Enum%20Suite.html lists all default enumerations in InDesign (my favourite is NothingEnum, with just one member: NothingEnum.NOTHING; it bears the concise description "Nothing.", and its numerical value 1851876449 is, written out in ASCII, "nada").

[frederickyocum]

Thanks Jongware. I think I have got. As usual understanding comes with practice.