I have a PHP website and a SQL database. Users will be able to update this data with a mobile phone. I would like all users to receive these updates. How would I do this?
I could simply use ajax and a timer to have each client request updates at a given interval.
Is there a way to set a callback of sorts so that a service on the server calls a list of method instances? This would prevent unnecessary requests and transfer of data...
If you don't want to use a third-party solution like the one @Alexandre Martin suggested, you could use Server Sent Events. The flow is as follows:
dataproperty and update their local models.
See this introduction, with sample PHP implementation.