GraphQL Pagination

The implementation of a GraphQL Service requires a certain structure to follow for Aurelia-Slickgrid to work correctly (it will fail if your GraphQL Schema is any different than what is shown below).

Implementation

For the implementation in your code, refer to the GraphQL Service section.

Without Cursor (recommended)

Pagination without cursor, this is the simplest implementation and is what we use on our side. The query can have any of the 3 arguments:

• first: integer representing how many rows of data to get from the start of dataset
• last: integer representing how many rows of data to get from the end of dataset
• offset: integer representing how many to skip

For example

  users (first:20, offset: 10) {
    totalCount
    nodes {
      name
      gender
    }
  }

With Cursor useCursor

Cursor Pagination is more generally used for real-time data scenarios. It usually reads sequentially from the head or tail of a list. It cannot navigate directly to the middle of a list. It conceptually treats the data similarly to a LinkedList as opposed to a Vector.

Pagination with cursor, the query can have any of the 4 arguments:

• first: integer representing how many rows of data to get from the start of dataset
• after: pull data starting at cursor "x", where "x" is the last item cursor
• last: integer representing how many rows of data to get from the end of dataset
• before: pull data before a cursor "x", where "x" is the last item cursor

For example

  users (first:20, after:"YXJyYXljb25uZWN0aW9uOjM=") {
    totalCount
    pageInfo {
      hasPreviousPage
      hasNextPage
      startCursor
      endCursor
    }
    edges {
      cursor
      node {
        name
        gender
      }
    }
  }

To retrieve subsequent data, the pageInfo.endCursor property should be used as part of the next query. eg:

users (first:20, after:"${pageInfo.endCursor}")

or when navigating backwards

users (last:20, before:"${pageInfo.startCursor}")

When using the paginationService, this is handled by calling setCursorPageInfo(pageInfo).

Also note the difference in behaviour between relay style pagination as it affects the returned pageInfo object. eg

relay pagination - Infinte scrolling appending data
  page1: {startCursor: A, endCursor: B }
  page2: {startCursor: A, endCursor: C }
  page3: {startCursor: A, endCursor: D }
  
non-relay pagination - Getting page chunks
  page1: {startCursor: A, endCursor: B }
  page2: {startCursor: B, endCursor: C }
  page3: {startCursor: C, endCursor: D }