Secure inter-module communication mechanism
Methods, apparatuses, and systems directed to facilitating secure, structured interactions between code modules executing within the context of a document processed by a user agent, such as a browser client, that implements a domain security model. In a particular implementation, a module connector script or object loaded into a base document discovers listener modules and sender modules corresponding to different origins or domains, and passes information between them. In this manner, a listener module may consume and use information from a sender module located on the same page simply by having an end-user add both modules to a web page without having to explicitly define any form of interconnection. For example, a photo module may access a user account at a remote photo sharing site, and provide one or more photos to a module that renders the photographs in a slide show.
1. A method comprising
receiving, at a first origin, a request for a web page from a user agent, wherein the user agent is operative to implement a domain security model disallowing interaction between content from different origins across inline frames;
accessing, responsive to the request for the web page, a data store to identify one or more module objects to be added to a structured document; and
transmitting, from the first origin, the structured document to the user agent, wherein the structured document comprises one or more module inline frame elements, wherein each module inline frame element is operative to cause the user agent to load a module document from a second origin within a module inline frame, wherein the module document comprises a messenger object and a module object of the one or more identified module objects;
wherein each messenger object is executable, within the context of the user agent, to
create, as a child element of the module inline frame element, a messenger inline frame element including a location attribute identifying the first origin and including a message queue;
add, responsive to a message sent by the module object of the module document, the message to the message queue; and
provide a new message detected in the message queue to the module object;
wherein the structured document further comprises a module connector object executable, within the context of the user agent, to
access message queues of one or more messenger inline frame elements to check for new messages; and
add, responsive to a new message, the new message to one or more message queues of corresponding messenger inline frame elements.
2. The method of claim 1 wherein the messenger object supports an application programming interface allowing the module object to register as a listener on a channel.
3. The method of claim 1 wherein the messenger object supports an application programming interface allowing the module object to register as a listener on a channel and declare a handler function for messages posted to the channel.
4. The method of claim 1 wherein the messenger object supports an application programming interface allowing the module object to post messages to a channel.
5. The method of claim 1 wherein the messenger object supports an application programming interface allowing the module object to register as a listener on a channel, and to post messages to a channel.
6. The method of claim 2 wherein the module connector object is operative to
selectively add, responsive to a new message posted to a channel, the new message to one or more message queues corresponding to messenger inline frame elements associated with module objects registered as listeners of the channel.
7. The method of claim 1 wherein the messenger object is further operative to expire messages previously added to the message queues of the messenger inline frame elements.
8. The method of claim 1 wherein the module connector object is further operative to expire messages previously added to the message queues of the location attributes of the messenger inline frame elements.
9. The method of claim 1 wherein the first origin and second origins are defined relative to a combination of a host name, port and protocol.
10. A method comprising
receiving, at a first origin, a request for a web page from a user agent, wherein the user agent is operative to implement a domain security model disallowing interaction between content from different origins across inline frames;
accessing, responsive to the request for the web page, a data store to identify one or more module objects to be added to a structured base document; and
transmitting, from the first origin, the structured base document to the user agent, wherein the structured base document comprises one or more module inline frame elements, wherein each module inline frame element is operative to cause the user agent to load a module document from a second origin within a module inline frame, wherein the module document comprises a messenger object and a module object of the one or more identified module objects;
wherein each messenger object is executable, within the context of the user agent, to
create, as a child element of the module inline frame element, a messenger inline frame element including a location attribute identifying the first origin and including a message queue;
support an application programming interface allowing the module object of the module document to register as a listener on a channel, declare a handler function for messages posted to the channel, and post messages to the channel;
add, responsive to a message sent by the module object, the message to the message queue; and
provide a new message detected in the message queue to the handler function of the module object;
wherein the base document further comprises a module connector object executable, within the context of the user agent, to
access message queues of one or more messenger inline frame elements to check for new messages; and
selectively add, responsive to a new message identifying a channel, the new message to the one or more message queues corresponding to respective messenger inline frame elements depending on the channel of the new message and the registered listeners on the channel.
11. A method comprising
receiving, at a first origin, a request for a web page from a user agent, wherein the user agent is operative to implement a domain security model disallowing interaction between content from different origins across inline frames;
accessing, responsive to the request for the web page, a data store to identify a first and a second module object to be added to a structured base document; and
transmitting, from the first origin, the structured base document to the user agent, wherein the structured base document comprises first and second module inline frame elements, wherein the first module inline frame element is operative to cause the user agent to load a first module document from a second origin within a first module inline frame, wherein the first module document comprises a first messenger object and the first module object, and wherein the second module inline frame element is operative to cause the user agent to load a second module document from a third origin within a second module inline frame, wherein the second module document comprises a second messenger object and the second module object;
wherein the first messenger object is executable, within the context of the user agent, to
create, as a child element of the first module inline frame element, a first messenger inline frame element including a first location attribute identifying the first origin and including a first message queue;
support an application programming interface allowing the first module object of the module document to register as a listener on a channel and declare a handler function for messages posted to the channel; and
provide a new message detected in the first message queue to the handler function of the module object;
wherein the second messenger object is executable, within the context of the user agent, to
create, as a child element of the second module inline frame element, a second messenger inline frame element including a second location attribute identifying the first origin and including a second message queue;
support an application programming interface allowing the second module object to post messages on the channel;
add, responsive to a message posted by the second module object, the message to the second message queue;
wherein the base document further comprises a module connector object executable, within the context of the user agent, to
access the second message queue to check for new messages; and
add, responsive to a new message identifying the channel, the new message to the first message queues.