How to insert a paragraph object in listItem preserving the formating of each word of the paragraph? - google-apps-script

Question

Following the documentation sample, I'm trying to create a function that search for a numerated list in a google document and, if it finds it, adds a new item to the list. My code works well (thanks to #Serge insas for previous help) with strings, but not with paragraphs objects. I know I could get the paragraph text and add it to listItem, but then I lose the formating. Is there a way to insert a paragraph preserving all it's formating? (I know I could use var newElement = child.getParent().insertListItem(childIndex, elementContent.getText()) do insert text without words formating)
Here the code:
function test() {
var targetDocId = "1A02VhxOWLUIdl8LTV1tt2S1yASDbOq77VbsUpxPa6vk";
var targetDoc = DocumentApp.openById(targetDocId);
var body = targetDoc.getBody();
var elementContent = targetDoc.getChild(2); // a paragraph with its formating
var childIndex = 0;
for (var p= 0; p< targetDoc.getNumChildren(); p++) {
var child = targetDoc.getChild(p);
if (child.getType() == DocumentApp.ElementType.LIST_ITEM){
while(child.getType() == DocumentApp.ElementType.LIST_ITEM){
child = targetDoc.getChild(p)
Logger.log("child = " + child.getText())
childIndex = body.getChildIndex(child);
Logger.log(childIndex)
p++
}
child = targetDoc.getChild(p-2);
var listId = child.getListId();
if (child.getText() == '') {
childIndex = childIndex -1;
}
Logger.log(childIndex)
var newElement = child.getParent().insertListItem(childIndex, elementContent);
newElement.setListId(child);
var lastEmptyItem = targetDoc.getChild(childIndex +1).removeFromParent();
break;
}
Here a screen shot of my targetDoc (note the second item, Paragraph):

Answer 1

I know this question is old, but I've come up with a solution and will leave here for anyone that may need it. It is not complete, as I have yet to find a way to copy any Inline Drawing and Equation to a new element...
Anyways, here is my code, it will work well if the paragraph you want to convert to a list item only has text and Inline Images.
function parToList() {
var doc = DocumentApp.getActiveDocument();
var body = doc.getBody();
//gets the paragraph at index 1 on body -> can be changed to what you want
var par = body.getChild(1);
var childs = [];
for (var i = 0; i<par.getNumChildren(); i++) {
var child = par.getChild(0);
childs.push(child);
child.removeFromParent();
};
par.removeFromParent();
//puts the list item on index 1 of body -> can be changed to the wanted position
var li = body.insertListItem(1, "");
childs.reverse();
for (var j in childs) {
var liChild = childs[j];
var childType = liChild.getType();
if (childType == DocumentApp.ElementType.EQUATION) {
//still need to find a way to append an equation
} else if (childType == DocumentApp.ElementType.INLINE_DRAWING) {
//still need to find a way to append an inlineDrawing
} else if (childType == DocumentApp.ElementType.INLINE_IMAGE) {
li.appendInlineImage(liChild);
} else if (childType == DocumentApp.ElementType.TEXT) {
li.appendText(liChild);
};
};
};
Cheers