To get the selected range of user selection :
// Run a batch operation against the Word object model.
Word.run(function (context) {
var range = context.document.getSelection(); // Create a range proxy object for the current selection.
context.load(range);
// Synchronize the document state by executing the queued commands,and return a promise to indicate task completion.
return context.sync().then(function () {
if (range.isEmpty) //Check if the selection is empty
{
return;
}
var html = range.getHtml();
return context.sync().then(function () {
var htmlVal = html.value; //Get the selected text in HTML
});
});
});
To set in the selected range of user:
// Run a batch operation against the Word object model.
Word.run(function (context) {
var range = context.document.getSelection();// Create a range proxy object for the current selection.
range.clear();
range.delete();
// Synchronize the document state by executing the queued commands, and return a promise to indicate task completion.
return context.sync().then(function () {
range.styleBuiltIn = "Normal";
range.insertText("your text"); // Queue a command to insert the encrypted text instead the current text
});
})
So if you have somehow already the 'range' you don't need to get it.
** If you don't want to take user selection and want to change just some part on document you could achieve it with paragraph selection , you could find more information about paragraph object and what you could do with this here:
https://dev.office.com/reference/add-ins/word/paragraph
good luck
