Should we iterate over the output or the original list inside the sample code

[mvcsharepointdev]

I am reviewing this sample code:-

// Assume the fields where not yet loaded, so loading them with the list
var myList = context.Web.Lists.GetByTitle("My List", p => p.Title, 
                                                     p => p.Fields.QueryProperties(p => p.InternalName, 
                                                                                   p => p.FieldTypeKind, 
                                                                                   p => p.TypeAsString, 
                                                                                   p => p.Title));

// Build a query that only returns the Title field for the first 20 items where the Title field starts with "Item1"
string viewXml = @"<View>
                    <ViewFields>
                      <FieldRef Name='Title' />
                      <FieldRef Name='FileLeafRef' />
                    </ViewFields>
                    <Query>
                      <Where>
                        <BeginsWith>
                          <FieldRef Name='Title'/>
                          <Value Type='text'>![CDATA[Item1]]</Value>
                        </BeginsWith>
                      </Where>
                    </Query>
                    <OrderBy Override='TRUE'><FieldRef Name= 'ID' Ascending= 'FALSE' /></OrderBy>
                    <RowLimit Paged='TRUE'>20</RowLimit>
                   </View>";

// Load all the needed data using paged requests
bool paging = true;
string nextPage = null;
while (paging)
{
    var output = await pagesLibrary.LoadListDataAsStreamAsync(new RenderListDataOptions()
    {
        ViewXml = viewXml,
        RenderOptions = RenderListDataOptionsFlags.ListData,
        Paging = nextPage ?? null,
    }).ConfigureAwait(false);

    if (output.ContainsKey("NextHref"))
    {
        nextPage = output["NextHref"].ToString().Substring(1);
    }
    else
    {
        paging = false;
    }
}

// Iterate over the retrieved list items
foreach (var listItem in myList.Items.AsRequested())
{
    // Do something with the list item
}

but should we iterate over the output or over the myList.Items.AsRequested() inside the : -

foreach (var listItem in myList.Items.AsRequested())
{
    // Do something with the list item
}

as the output will hold all the paged values and not the myList.Items.AsRequested()? am i correct?

[jansenbe]

The paging loop will load all list items into memory and you can then iterate over the loaded items via foreach (var listItem in myList.Items.AsRequested())

[mvcsharepointdev]

@jansenbe so in this case what will the output variable contain exactly ?

[jansenbe]

Nothing relevant, only data to support the paging