如何避免 office-js 中的 context.loads() 过多

Question

I've read Michael Zlatkovsky's very excellent "Building Office Add-ins", and one of the things he says is attempt to avoid costly async calls to context.load() . He mentions that he would be hard pressed to find a scenario where he would need more than 2.

My question is this: If processing all the paragraphs in the entire document, I need to get at some very deeply nested elements (eg document.paragraphs.paragraph.listItem.siblingIndex ). If I start from the document, the only way I can see to do this is:

paragraphs =  context.document.body.paragraphs;
paragraphs.load("items");
await context.sync();
for (var i =0; i<paragraphs.items.length; i++){
      paragraphs.items[i].load("listItemOrNullObject");
}
await context.sync();

//.... Then iterate through every item in paragraph to load(siblingIndex)

await context.sync();

//finally am able to process stuff that requires properties from all nested levels

Is this the correct way to go about this? ie one sync() call for each nested level for which one needs properties? Seems like many async calls to sync() . Is this avoidable in any way? I would imagine this is a common use case.

Answer 1

You can load properties from deep levels by using forward slashes in the parameter that you pass to the load method. This technique lets you load nested levels with a single context.sync().

The following code is from the same book you mentioned gets the name property of all the columns in all the tables in all the worksheets:

Excel.run(async (context) => {
 workbook.load("worksheets/tables/columns/name");

 await context.sync();

 var secondColumnOfFirstTableOnThirdSheet =
  workbook
 .worksheets.items[2]
 .tables.items[0]
 .columns.items[1];

 console.log("The ridiculously-nested column name was " +
 secondColumnOfFirstTableOnThirdSheet.name);

}).catch(...);