How to use nextLink and deltaLink

[maxklav]

I'm able to retrieve them with the SDK calling .Delta() before the .Get(), but how do I use them?

import (
	"context"

	msgraphsdk "github.com/microsoftgraph/msgraph-sdk-go"
	"github.com/microsoftgraph/msgraph-sdk-go/users"
)

func main() {
	ctx := context.Background()

	tokenCredential := "secret!"

	client, err := msgraphsdk.NewGraphServiceClientWithCredentials(tokenCredential, nil)
	if err != nil {
		return nil, err
	}

	params := &users.ItemMailFoldersDeltaRequestBuilderGetRequestConfiguration{
		QueryParameters: &users.ItemMailFoldersDeltaRequestBuilderGetQueryParameters{
			// nextLink somewhere here ?
		},
	}

	resp, err := client.Users().ByUserId(userID).MailFolders().Delta().Get(ctx, params)
	if err != nil {
		return nil, err
	}

	// How to use them
	nextLink := resp.GetOdataNextLink()
	deltaLink := resp.GetOdataDeltaLink()
}

How do we use the nextLink and deltaLink ?
Do I need to build a HTTP request with these links or can I just use the token from the link in the SDK ?
Is there code in the SDK that we can use to extract the skiptoken from the link ?
How can I use this token in client.Users().ByUserId(userID).MailFolders().Delta().Get(ctx, params) ?
Is it in the params ?

My ultimate goal is to use nextLink until I have a deltaLink and save the deltaLink for later use.

[baywet]

Thanks for using the Go SDK and for reaching out. The Go SDK now provides a page iterator that'll go through the next links automatically for you. Once your application has enumerated all the current changes, it needs to store the delta link that'll be provided and call the API again at a later time.

Unfortunately we haven't had time yet to document the use of the page iterator in our public docs (CC @jasonjoh ) but you can look at other languages for the time being to get a global understanding. (And maybe @rkodev can provide a snippet here).

You should also have a look at the delta queries concept page to get a better understanding of how delta queries work in general on Microsoft Graph.

[baywet]

it looks correct to me but I might be missing something @rkodev do you mind helping here please?

[maxklav]

Looks like Mail folders are supported for delta queries, so it should work

[luigi-fast]

Hello there,
I've tried to debug sdk code to figure out what's wrong with the delta link. I've found that each response received by the iterator is of type *users.ItemMailFoldersDeltaResponse and the last page (the one containing the delta link) is of type *models.BaseCollectionPaginationCountResponse. In the convertToPage method of page_iterator.go the response is casted to PageWithOdataDeltaLink but because the last page response is not of *users.ItemMailFoldersDeltaResponse type it fails and no deltaLink is returned by the iterator.

This is the first iteration:

I tried to hack the convertToPage method like this and it works perfectly.

This is the last iteration:

I've found another bug in base_collection_pagination_count_response.go, the method GetOdataNextLink look at the first level of the backingstore when it should look into backingstore/additionalData:

I hope this will help to fix the bug

[baywet]

I think there are multiple confusions in the last code example you've provided.

First off

req := client.Users().ByUserId(userID).MailFolders()

is not a delta endpoint but just the regular list endpoint, it will never return a delta link and should be instead

req := client.Users().ByUserId(userID).MailFolders().Delta()

(the request configuration and query parameters need to be updated accordingly)

Then, it's not models.CreateMailFolderCollectionResponseFromDiscriminatorValue that should be used for deserialization but users.CreateItemMailFoldersDeltaResponseFromDiscriminatorValue https://github.com/microsoftgraph/msgraph-sdk-go/blob/3280bd480cad4749ddd7c00a6310f74c3b3ce529/users/item_mail_folders_delta_response.go#L20C6-L20C62

Then it's not users.NewItemMailFoldersRequestBuilder that should be used but users.NewItemMailFoldersDeltaRequestBuilder

msgraph-sdk-go/users/item_mail_folders_delta_request_builder.go

Line 47 in 3280bd4

func NewItemMailFoldersDeltaRequestBuilder(rawUrl string, requestAdapter i2ae4187f7daee263371cb1c977df639813ab50ffa529013b7437480d1ec0158f.RequestAdapter)(*ItemMailFoldersDeltaRequestBuilder) {

This should solve the overall deserialization issues.

Lastly, I'd really like @rkodev to take over this discussion.

[luigi-fast]

Thanks a lot @baywet. The use of models.CreateMailFolderCollectionResponseFromDiscriminatorValue instead of users.CreateItemMailFoldersDeltaResponseFromDiscriminatorValue was the root of the problem :)
So it solves the issue

[jasonjoh]

We do document this in our public docs at the link you provided!

https://learn.microsoft.com/en-us/graph/sdks/paging?tabs=go

[baywet]

sorry, hadn't had my morning tea yet :)