How can I determine if a ListItem field already has a value?

[adamfisher]

This sounds simple and should be easy but for whatever reason SharePoint is a pain and any help would be appreciated. I'm trying to populate the hasProjectNumber boolean variable with true if that field already has a value in that SP column. I verified in the UI that there is a value for the folder I am currently debugging against. I just can't seem to get the existing value in that field?

foreach(IChange change in changes) {
  if (change is IChangeItem changeItem &&
    changeItem.IsPropertyAvailable < IChangeItem > (p => p.ListId) &&
    changeItem.IsPropertyAvailable < IChangeItem > (p => p.ItemId)) {

    IList ? list = await _sharePointContext.Web.Lists.GetByIdAsync(changeItem.ListId);

    IListItem item = await list.Items.GetByIdAsync(changeItem.ItemId,
      li => li.FieldValuesForEdit,
      li => li.File.QueryProperties(f => f.Name, f => f.ServerRelativeUrl),
      li => li.Folder.QueryProperties(f => f.Name, f => f.ServerRelativeUrl));

    bool alreadyHasProjectId = await item.FieldIsNotEmptyAsync("ProjectNumber");
	
	var hasProjectNumber = item.Values.ContainsKey("ProjectNumber") && !string.IsNullOrWhiteSpace(item["ProjectNumber"] as string);
	
	// hasProjectNumber is always false...
  }
}

Maybe it has something to do with how I am loading the item? I've tried setting up my query to include fields like in the doc example but that didn't change anything. I also should mention later in my code I am able to assign to that field and see the value reflected in SP UI so I know it is a valid field. I just can't get the existing value.

[adamfisher]

I've tried these variations too but they also produce errors or false:

// KeyNotFoundException
var hasProjectNumber = item["ProjectNumber"] != null;

// Always false
var hasProjectNumber = item.File.ListItemAllFields.Values.ContainsKey("ProjectNumber")
   || item.Folder.ListItemAllFields.Values.ContainsKey("ProjectNumber");

[jansenbe]

@adamfisher : the latter approach should work fine, we use it all the time in internal code. E.g. see below snippet from the Pages API code:

if (item.Values.ContainsKey(PageConstants.ClientSideApplicationId) && 
    item.Values[PageConstants.ClientSideApplicationId] != null && 
    item.Values[PageConstants.ClientSideApplicationId].ToString().Equals(PageConstants.SitePagesFeatureId, StringComparison.InvariantCultureIgnoreCase))
{
}

Think the issue is with how you load the IListItem, seems the fields you need were not loaded.

[adamfisher]

Thanks Bert but it looks like the only way I was able to get the properties to load was by using the All property when loading the item:

IListItem item = await list.Items.GetByIdAsync(changeItem.ItemId,
      li => li.All,
      li => li.File.QueryProperties(f => f.Name, f => f.ServerRelativeUrl),
      li => li.Folder.QueryProperties(f => f.Name, f => f.ServerRelativeUrl));

It didn't load it with any other combination of properties I tried to load. Not sure if that is a bug or just the way the API works but feels hacky. I also tried li => li.Values but that produces an error.