Caching Selected Text Element With Google Doc Apps Script

Update: This is a better way of asking the following question. Is there an Id like attribute for an Element in a Document which I can use to reach that element at a later time. Let

Solution 1:

One direct way is to add a bookmark, which is not dependent on subsequent document changes. It has a disadvantage: a bookmark is visible for everyone...

More interesting way is to add a named range with a unique name. Sample code is below:

function setNamedParagraph() {
  var doc = DocumentApp.getActiveDocument();
  // Suppose you want to remember namely the third paragraph (currently)
  var par = doc.getBody().getParagraphs()[2];
  Logger.log(par.getText());
  var rng = doc.newRange().addElement(par);
  doc.addNamedRange("My Unique Paragraph", rng);
}


function getParagraphByName() {
  var doc = DocumentApp.getActiveDocument();
  var rng = doc.getNamedRanges("My Unique Paragraph")[0];
  if (rng) {
    var par = rng.getRange().getRangeElements()[0].getElement().asParagraph();
    Logger.log(par.getText());
  } else {
    Logger.log("Deleted!");
  }
}

The first function "marks" the third paragraph as named range. The second one takes this paragraph by the range name despite subsequent document changes. Really here we need to consider the exception, when our "unique paragraph" was deleted.

Solution 2:

Not sure if cache is the best approach. Cache is volatile, so it might happen that the cached value doesn't exist anymore. Probably PropertiesService is a better choice.