NSWritingToolsCoordinator.Context
A data object that you use to share your custom view’s text with Writing Tools.
Declaration
class ContextMentioned in
Overview
At the start of every Writing Tools operation, you create one or more NSWritingToolsCoordinator.Context objects with a copy of the text you want Writing Tools to evaluate. Each Writing Tools operation starts with a call to the writingToolsCoordinator(_:requestsContextsFor:completion:) method of your NSWritingToolsCoordinator.Delegate object. Use the parameters of that method to determine how much of your view’s text to provide. For some operations, Writing Tools asks for all of your view’s text, but in others it asks for only a portion of the text. When Writing Tools finishes its evaluation, it reports changes back to your delegate relative to the context objects you provided.
When Writing Tools asks for your view’s text, create one or more NSWritingToolsCoordinator.Context objects with the requested content. If your view contains only one text storage object, create only one context object for the request. However, if you use multiple text storage objects to manage different parts of your view’s content, you might need to create multiple context objects. The actual number depends on how much of your text Writing Tools asks for. For example, when Writing Tools asks for all of your view’s content, you return one context object for each text storage object in your view. However, if Writing Tools asks for the current selection, and one text storage object contains all of the selected text, you create only one context object for the content.
Writing Tools uses your context objects as the starting point for its evaluations, and as a reference point for any changes. Because Writing Tools doesn’t know anything about your view or its content, it makes suggestions only relative to your context objects. It’s your responsibility to take those suggestions and incorporate them back into your view’s text storage. In some cases, you might need to store additional information to update your storage correctly. For example, you might need to store, and update as needed, the offset from the start of your document to the start of the text in your context object.
When Writing Tools asks for the currently selected text in your view, include some of the surrounding text in your context object as well. Supply a string that includes the selection and any text up to the nearest paragraph boundary. When creating your context object, specify a range value that represents the portion of that string that corresponds to the text selection. Providing some additional text in your context object can help Writing Tools improve its evaluation of your content. Writing Tools uses the resolvedRange property of your context object to indicate what text it considered.
If your context object includes text that you don’t want Writing Tools to evaluate, add the excludeFromWritingTools attribute to the corresponding characters of your NSAttributedString object. You might add this attribute if the text string includes a code listing or readonly content that you don’t want Writing Tools to change.