(.NET Core C#) Lookup Google Drive Folder ID Given a Folder Path

Demonstrates how to find the Google Drive folder ID given a Folder Path.

This example demonstrates that we cannot simply query by folder name. (We can if every folder name is unique, but if not...) For example, imagine we have the following directory structure on Google Drive:

/AAWorkArea
/AAWorkArea/FolderA
/AAWorkArea/FolderB
/Folder2
/Folder2/FolderA

There are two directories named "FolderA". One is contained within AAWorkArea, and one is contained within "Folder2". To say it differently: One has the parent "AAWorkArea" and the other's parent is "Folder2".

To find the id of "/AAWorkArea/FolderA", we need to first find the id for "AAWorkArea", and then find the id for the folder with name="FolderA" and with AAWorkArea's id in FolderA's parents.

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bool success = true;

// It requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

// This example uses a previously obtained access token having permission for the 
// Google Drive scope.

Chilkat.AuthGoogle gAuth = new Chilkat.AuthGoogle();
gAuth.AccessToken = "GOOGLE-DRIVE-ACCESS-TOKEN";

Chilkat.Rest rest = new Chilkat.Rest();

// Connect using TLS.
bool bAutoReconnect = true;
success = rest.Connect("www.googleapis.com",443,true,bAutoReconnect);

// Provide the authentication credentials (i.e. the access token)
rest.SetAuthGoogle(gAuth);

Chilkat.JsonObject json = new Chilkat.JsonObject();
json.EmitCompact = false;

// Get the AAWorkArea folder that is in the Google Drive root.
rest.AddQueryParam("q","'root' in parents and name='AAWorkArea'");
string jsonResponse = rest.FullRequestNoBody("GET","/drive/v3/files");
if (rest.LastMethodSuccess != true) {
    Debug.WriteLine(rest.LastErrorText);
    return;
}

json.Load(jsonResponse);
Debug.WriteLine(json.Emit());
Debug.WriteLine("name: " + json.StringOf("files[0].name"));
Debug.WriteLine("id: " + json.StringOf("files[0].id"));
Debug.WriteLine("mimeType: " + json.StringOf("files[0].mimeType"));
Debug.WriteLine("-");

rest.ClearAllQueryParams();

// Now that we know the ID for the AAWorkarea directory, get the id for the FolderA having AAWorkArea as the parent.
Chilkat.StringBuilder sbQuery = new Chilkat.StringBuilder();
sbQuery.Append("name = 'FolderA' and '");
sbQuery.Append(json.StringOf("files[0].id"));
sbQuery.Append("' in parents");
rest.AddQueryParamSb("q",sbQuery);

jsonResponse = rest.FullRequestNoBody("GET","/drive/v3/files");
if (rest.LastMethodSuccess != true) {
    Debug.WriteLine(rest.LastErrorText);
    return;
}

json.Load(jsonResponse);
Debug.WriteLine(json.Emit());
Debug.WriteLine("name: " + json.StringOf("files[0].name"));
Debug.WriteLine("id: " + json.StringOf("files[0].id"));
Debug.WriteLine("mimeType: " + json.StringOf("files[0].mimeType"));
Debug.WriteLine("-");