Row Models

Depending on your needs, the grid can be configured with different row models. The row models differ in how the data is loaded. You can load all the data and hand it over to the grid (Client-side Row Model) or you can keep most of the data on the server and lazy-load based on what is currently visible to the user (Infinite, Viewport and Server-side Row Models).

The following is a summary of the different row models:

What row model you use is set as a grid property rowModelType. Set it to one of clientSide, infinite, viewport, serverSide. The default is clientSide.

When to Use

Which row model you use will depend on your application. Here are some quick rules of thumb:

• If using ag-Grid Free, use Client-side Row Model if you want to load all your data into the browser, or Infinite Row Model if you want to load it in blocks.
• If using ag-Grid Enterprise, use Client-side Row Model if you want to load all your data into the browser, or Server-side Row Model if you want to load it in blocks. Server-side Row Model is Infinite Row Model plus more. So if you are an ag-Grid Enterprise customer, you should prefer Server-side Row Model over Infinite Row Model.
• Don't use Viewport Row Model unless you understand what its advantages are and when you need them. We find many of our users use Viewport Row Model when they don't need to and end up with more complicated applications as a result.

Here are more detailed rules of thumb.

• If you are not sure, use default Client-side. The grid can handle massive (100k+) amounts of data. The grid will only render what's visible on the screen (40 rows approximately, depending on your screen size) even if you have thousands of rows returned from your server. You will not kill the grid with too much data - rather your browser will run out of memory before the grid gets into problems. So if you are unsure, go with Client-side row model first and only change if you need to. With Client-side, you get sorting, filtering, grouping, pivoting and aggregation all done for you by the grid. All of the examples in the documentation use the Client-side model unless specified otherwise.
• If you do not want to shift all the data from your server to your client, as the amount of data is too large to shift over the network or to extract from the underlying datasource, then use either infinite, server-side or viewport. Each one takes data from the server in different ways.
• Use Infinite or Server-side to bring back a list of data one block at a time from the server. As the user scrolls the grid will ask for more rows. Server-side has more features than Infinite and will allow row grouping, aggregation, lazy loading of groups and slice and dice of data.
• Use Viewport if you want the server to know exactly what the user is looking at. This is best when you have a large amount of changing data and want to push updates to the client when the server-side data changes. Knowing exactly what the user is looking at means you only have to push updates to the relevant users. All the row models can receive updates however only the Viewport row model provides the server with the information of the rows the users currently sees on screen without scrolling.

Row Model Comparisons

Below is a quick feature comparison of all the grids features across all four row models.

Deeper Understanding of Row Models

The grid follows an MVC pattern. Each data item is wrapped in a Row Node and then stored in the Row Model. The grid rendering engine is called Row Renderer and listens for changes to the row model and updates the DOM accordingly.

Below shows a simplified version of a class diagram showing the relationships between the major classes involved with the row models.

The following should be noted from the diagram:

• The grid has exactly one RowRenderer instance. The RowRenderer contains a reference to the PaginationProxy where it asks for the rows one at a time for rendering.
• The grid has exactly one PaginationProxy instance. The PaginationProxy will either a) do nothing if pagination is not active and just forward all requests to the Row Model or b) do pagination if pagination is active. The PaginationProxy has exactly one RowModel instance.
• You can configure the grid to use any of the provided Row Models - that's why RowModel is in italics, it means it's an interface, the concrete implementation is what you decide when configuring the grid. The RowModel contains a list of RowNodes. The RowModel may have a list of all the RowNodes (Client-side Row Model) or have a DataSource where it can lazy load RowNodes
• A RowNode has a reference to exactly one row data item (the client application provides the row data items). The RowNode has state information about the row item, such as whether it is selected and the height of it.
• When there is a change in state in the RowNodes, the RowModel fires a modelUpdated event which gets the RowRenderer to refresh. This happens for many reasons, or example the data is sorted, filtered, a group is opened, or the underlying data has changed.

Pagination

Pagination can be applied to any of the row model types. The documentation on each row model type covers pagination for that row model type.

Grid Datasource

The Client-side row model does not need a datasource. Infinite, Viewport and Server-side all use a datasource. The documentation on each row model type explains how to configure the datasource for the particular row model.