List.ConformToPageReader

ListInternal

Conforms a list to a page reader table format. Intended for internal use only.

Examples on this page use shared sample tables. View them to understand the input data before reading the examples below.

Syntax

List.ConformToPageReader(list as list, optional options as nullable record) as table

Parameters

NameTypeRequiredDescription
listlistYesThe list to conform to the page reader format.
optionsrecordNoAn optional record of options that control the page reader behavior.

Return Value

tableA table representing the list data conformed to the page reader format.

Remarks

List.ConformToPageReader is an internal-only function as stated in the official Microsoft documentation. It is part of the Power Query engine's internal pagination infrastructure, used to convert a list into the engine's internal page reader table format.

### Background

The Power Query engine uses a page reader pattern internally to handle streaming and pagination of large data sets. When data is loaded from sources that provide data in pages (such as REST APIs with paginated responses), the engine uses page readers to efficiently stream data without loading everything into memory at once.

List.ConformToPageReader adapts a plain M list to this internal page reader format, making it compatible with the engine's streaming infrastructure.

### Important

This function is not intended for use in user-written M queries. For pagination patterns in user code, use:

  • List.Generate to implement manual pagination loops.
  • Table.GenerateByPage (a common helper pattern) for page-by-page API consumption.
  • The Web.Contents function with appropriate pagination logic.

Examples

Example 1: Conceptual usage

let
    // List.ConformToPageReader is used internally by the Power Query engine
    // for pagination infrastructure. In user code, use List.Generate instead:
    Pages = List.Generate(
        () => [Page = 0, Data = GetPage(0)],
        each [Data] <> null,
        each [Page = [Page] + 1, Data = GetPage([Page] + 1)],
        each [Data]
    )
in
    Pages

Compatibility

Power BI Desktop Power BI Service Excel Desktop Excel Online Dataflows Fabric Notebooks