Progress
1. Design for server side (updated)
To do it step by step, we first design the client side for one user who can register/monitor one variable/sensor.
The basic idea is that write new data to an XML file when it is available one the server side and return the file’s URL to the client.
2. Implementation
At current stage, logic in server side is not difficult. A program written by JSP, which is called by client, would do the following steps:
- Register a variable based on the parameters from client
- Write the new data to an XML file
- Return the URL of the file to the client
Discussion
1. Register multiple sensors for one user
The user first registers variable called A-var, the server can get the new coming data from some callback function. After that, he wants to register another variable B-var, is that true that we can obtain both data from the same function? There is a problem in register/unregister.
2. Register multiple sensors for multiple users
If multiple users register the same variable, which is better, the arrary or file? How to maintain the session?
Reference
- Bulletproof
- JSP : the complete reference, Hanna, Phil
- JavaScript bible, Goodman, Danny
