Reorder XML Elements in Extendscript Indesign

Question

I want to reorder the following list of movies in such a way that movies of the version==3D should be placed before the ones in version==2D.

Input

<films>
  <film name="Foobar" version="2D"></film>
  <film name="Foobar" version="3D"></film>
  <film name="Foobaz" version="2D"></film>
  <film name="Foobaz" version="3D"></film>
</films>

Desired Output

<films>
  <film name="Foobar" version="3D"></film>
  <film name="Foobar" version="2D"></film>
  <film name="Foobaz" version="3D"></film>
  <film name="Foobaz" version="2D"></film>
</films>

I've fiddled around and ended up with the following code. Hopefully it understandable.

/***
 Extend Array prototype to have a indeOf function
 ***/
Array.prototype.indexOf = function(item) { 
    var index = 0, length = this.length;  
    for ( ; index < length; index++ ) {
        if ( this[index] == item )  
            return index;  
        }  
    return -1;  
};  


var xmlString = '\
<films>\
    <film name="Foobar" version="2D"></film>\
    <film name="Foobar" version="3D"></film>\
    <film name="Foobaz" version="2D"></film>\
    <film name="Foobaz" version="3D"></film>\
</films>';

var xml = new XML(xmlString);
var sortVersion = ['2D', '3D'];
var uniqueMovies = new Array();


for (var index = 0; index < xml.elements().length(); index++) {
    if (index == 0) continue;

    // Fetch meta data of previous movie
    var prevTitle = xml.elements()[index - 1].@name;
    var prevVersion = xml.elements()[index - 1].@version;
    var prevVersionIdx = sortVersion.indexOf(prevVersion);

    // Fetch meta data of current movie
    var curTitle = xml.elements()[index].@name;
    var curVersion = xml.elements()[index].@version;
    var curVersionIdx = sortVersion.indexOf(curVersion);

    // If both movie title matches verify which movie should be prioritized
    if (prevTitle == curTitle) {
      if (prevVersionIdx < curVersionIdx) { 
          // Movie prio movie before less prio movie
          xml.insertChildBefore(xml.elements()[index - 1], xml.elements()[index]);
          // And delete the next in index
          delete xml.elements()[index + 1];
      }
    }   
}

$.writeln("-----");
$.writeln("");
$.writeln(xml.elements().toString());
return xml

However when I run this script I end with the following result where nothing is changed at all although the both if condition are hit and the element on index[1] is added before index[0].

<films>
  <film name="Foobar" version="2D"/>
  <film name="Foobar" version="3D"/>
  <film name="Foobaz" version="2D"/>
  <film name="Foobaz" version="3D"/>
</films>

Does anyone have an idea what I am doing wrong here?

are you sure that the script finds a scenario where both of the if tests pass? — user1754036
What is the purpose of the if (prevTitle == curTitle) condition ? I also recommend that you edit your question to show your desired xml output. — RobC
This condition is to verify if I am in a sitatuion where I would need to analyse the sorting 3D before 2D. The input XML is already sorted by Titles, but no by version. — flazzarini
I think moving would be better than creating/inserting and deleting. See an example of moving in the accepted answer here: forums.adobe.com/thread/879586 — user1754036

RobC RobC · Accepted Answer · 2019-07-12T10:41:46

Consider the following approach instead:

script.jsx

/**
 * Extend Array prototype to have a indexOf function
 */
Array.prototype.indexOf = function(item) {
    var index = 0, length = this.length;
    for ( ; index < length; index++ ) {
        if ( this[index] == item )
            return index;
        }
    return -1;
};

var xmlString = '\
<films>\
  <film name="Foobar" version="2D"></film>\
  <film name="Foobar" version="3D"></film>\
  <film name="Foobaz" version="2D"></film>\
  <film name="Foobaz" version="3D"></film>\
  <film name="Foo" version="3D"></film>\
  <film name="Quux" version="2D"></film>\
  <film name="Quux" version="3D"></film>\
</films>';

var xml = new XML(xmlString);
var sortVersion = ['2D', '3D'];

// 1. Create a temporary XML object with a  matching `films` root element.
var tempXml = new XML('<' + xml.name() + '></' + xml.name() + '>');

for (var index = 0, max = xml.elements().length(); index < max; index++) {

  // Fetch meta data of previous movie
  var prevTitle = String(xml.elements()[index - 1].@name);
  var prevVersion = xml.elements()[index - 1].@version;
  var prevVersionIdx = sortVersion.indexOf(prevVersion);

  // Fetch meta data of current movie
  var curTitle = String(xml.elements()[index].@name);
  var curVersion = xml.elements()[index].@version;
  var curVersionIdx = sortVersion.indexOf(curVersion);

  // 2. Insert each XML element node from the original XML Object into
  // the temporary XML Object and position (i.e. sort) as neccessary.
  if (prevTitle === curTitle && prevVersion < curVersion) {
    tempXml.insertChildBefore(tempXml.elements()[index -1], xml.elements()[index])
  } else {
    // There's nothing to change (i.e. sort) so insert it as-is .
    tempXml.insertChildBefore(tempXml.elements()[index], xml.elements()[index])
  }
}

// 3. Overwrite original XML object's children with temporary (sorted) XML objects children.
xml.setChildren(tempXml.children());

// 4. Delete temporary XML object.
tempXml = undefined;


// Testing...
$.writeln(xml)
$.writeln('-----------------')
$.writeln(xml.elements().length())
$.writeln('-----------------')

Explanation:

Instead of attempting to manipulate (i.e. sort) the original XML Object the gist above does the following instead:

Creates another XML Object that contains a <films> root element only. This XML Object will be temporary.
During each turn of the for loop we;
- Insert a clone of each XML element node from the original XML Object into the temporary XML Object.
- Position (i.e. sort) each XML element node as necessary.
Overwrite the original XML objects child element nodes with child element nodes from the temporary/sorted XML Object.
Finally we delete the temporary XML Object (i.e. set it to undefined) as it's no longer required.

Result

The example gist above includes the following source XML:

<films>
  <film name="Foobar" version="2D"></film>
  <film name="Foobar" version="3D"></film>
  <film name="Foobaz" version="2D"></film>
  <film name="Foobaz" version="3D"></film>
  <film name="Foo" version="3D"></film>
  <film name="Quux" version="2D"></film>
  <film name="Quux" version="3D"></film>
</films>

which will be transformed to the following:

<films>
  <film name="Foobar" version="3D"/>
  <film name="Foobar" version="2D"/>
  <film name="Foobaz" version="3D"/>
  <film name="Foobaz" version="2D"/>
  <film name="Foo" version="3D"/>
  <film name="Quux" version="3D"/>
  <film name="Quux" version="2D"/>
</films>

Note: For more complex XML structures and transformation requirements than the example provided in your question, I'd consider utilizing XSLT instead. Given your current requirement a template like this one will achieve your desired result.

Reorder XML Elements in Extendscript Indesign

1 Answers