The View Data window allows you to see the attribute data behind each feature on a layer. As we revealed in the Building a Map with Layers article, each layer gets its data from a data source, and most vector-type layers use a data source that looks like a table. You can think of the data behind a layer as being similar to a spreadsheet or a database, with a row for each feature in the layer and a column for each attribute that a feature can have.

As an example, you might have a Shapefile layer of the United States. In this layer, each U.S. state would have one row, plus a variety of columns containing attributes like “Population”, “Postal Abbreviation”, “Date of Statehood”, and many more.

The GIS Editor's View Data window allows you to see all of these rows and columns in a tabular format. This is helpful when you want to style a layer based on its data or perform other operations based on this data. You can use the View Data window to see what kind of data your layer contains so that you know how to set up your operations accordingly.

You can open the View Data window in one of two ways:

1. By clicking the “View Data” button on the Home tab of the GIS Editor's ribbon bar.
2. By right-clicking on the layer you want to view in the Layer List, and then choosing “View Data” from the context menu.

Once the View Data windows is visible, it can be positioned anywhere you like, even on a different screen, and then remain open while you work with the GIS Editor's other tools.

Additionally, you can drag the View Data window near the edges of the GIS Editor's main window to dock it there. When the View Data window is docked, it will remain fixed in place and the GIS Editor's other interfaces will be resized to make room for it. In this way, even if your computer only has one screen, you can leave the View Data window open and continue to work with the GIS Editor simultaneously. When the View Data window is docked, you can use the window controls at the top right to close it, switch it to Auto-Hide mode, undock it or perform other operations.

The View Data window consists of a tabular layout in which you can see the attribute data for every feature in a layer. You can change the layer whose data you are viewing at any time; by default, the table will display the data for the layer that you have currently selected on the Layer List (or the layer you right-clicked, if you opened the View Data menu from a layer context menu). If no layer is selected, data for the bottommost layer will be shown.

At the top of the window is a series of controls that you can use to change what you are viewing, including filtering the table to a subset of features. The available controls include the following:

1. Layer being viewed. Clicking this control will open a dropdown menu from which you can choose any of the layers currently on your map.
2. Number of features selected vs. number of features in the layer. Selecting a feature (which is done by clicking on its row) will add it to the count of selected features.
3. Filter button. Clicking this will open a dialog from which you can put together a query for a specific subset of features. Applying the query will filter the list of rows in the View Data window. The Filter dialog works the same way as the Advanced Query from the GIS Editor's Find Features dialog.
4. Show All button. If you have filtered the View Data window's list of features, clicking this button will remove the filter and return to displaying all features in the layer.
5. Zoom to Selected Features button. If you have one or more features selected (highlighted in blue) in the View Data window, clicking this button will zoom the map to the combined extent of all selected features (i.e., the map will zoom in as far as it can while ensuring that all of the selected features are visible at once).
6. Show Only Selected Features checkbox. Checking this box will hide any feature from the View Data window that is not currently selected (highlighted in blue). If you have a layer with many hundreds or thousands of features, and you have several of them selected but are unable to see all of them at once, checking this box will group all of the selected features together in the data table so you can view them as a unit.

Each feature in your layer is represented by a row in the View Data table. At the far left of each row is a Zoom to Feature button that will zoom the map to the feature represented by that data row. For instance, you might have a row of data that represents the shape of a U.S. state. Clicking the Zoom to Feature button next to that row will zoom the map so the entire state is visible.

At the top of the data table is the header row, which lists the name of each attribute column. Clicking on any header will sort the table by that header; clicking it again will invert the sort direction.

To minimize processing time, layers that have a large number of features are loaded “on-the-fly” as you scroll the data table. Changing the table sort by clicking a header will necessarily load all of the data from the layer at once, which may take a few seconds. When this happens, a progress bar will be shown to give you an idea of how much time the sorting operation will take to complete.

The attribute data for a layer cannot be edited in the View Data window. To edit a layer's attribute data, you will need to use the Edit Data window on the Edit tab of the ribbon bar.