9. A non-transitory computer-readable medium having computer executable instructions stored thereon that, in response to execution by one or more processors of a computing device, cause the computing device to perform actions for visually rendering a user interface component, the actions comprising: in a document containing a description of an application's view logic, inserting an XLink that points to view logic associated with the user interface component, wherein the XLink includes logic that defines a condition for activating the XLink, and wherein the inserted XLink provides the application with sufficient information to obtain the view logic associated with the user interface component without exposing information to a client computing device that would require a separate permission check to access data stored at a network file system; rendering the application's view logic without activating the XLink; in response to an executing application causing the condition for activating the XLink to be satisfied, obtaining the view logic associated with the user interface component; and using the logic obtained when the XLink is activated to render the user interface component.
9. A non-transitory computer-readable medium having computer executable instructions stored thereon that, in response to execution by one or more processors of a computing device, cause the computing device to perform actions for visually rendering a user interface component, the actions comprising: in a document containing a description of an application's view logic, inserting an XLink that points to view logic associated with the user interface component, wherein the XLink includes logic that defines a condition for activating the XLink, and wherein the inserted XLink provides the application with sufficient information to obtain the view logic associated with the user interface component without exposing information to a client computing device that would require a separate permission check to access data stored at a network file system; rendering the application's view logic without activating the XLink; in response to an executing application causing the condition for activating the XLink to be satisfied, obtaining the view logic associated with the user interface component; and using the logic obtained when the XLink is activated to render the user interface component. 11. The computer-readable medium as recited in claim 9 , wherein the XLink is inserted as an element in an XML document and provides a bidirectional link between two documents.