This git repo gives you a sample code to interact with ISABELA API. There are two sample codes:

• Built to Visual Studio Community and available in the master branch.
• Built to the linux and gcc compiler and available on the linux-gcc branch.

Install on Ubuntu

1. Download the code:

git clone https://github.com/jmSfernandes/SRC-Test.git

2. Checkout to the linux branch:

git checkout linux-gcc

3. Install all the missing libraries with apt-get (gcc,clang,libtool,autoconf,automake), see the instructions

4. Run the following commands in json-c path:

   sh autogen.sh
   ./configure
   make
   make install (need sudo)
   make check

5. Install libcurl:

   sudo apt-get install libcurl4-gnutls-dev

6. Add the library to the environment variables:

   export LD_RUN_PATH=/usr/local/lib
   export LD_LIBRARY_PATH=/usr/local/lib/

7. Compile the application using gcc:

   gcc main.c -o main -lcurl -ljson-c

If you want to run the code, with all the libraries already installed and pre-compiled, you need to install the Visual Studio Community 2013 (V120 Build tools).

If you want to create the example from scracth in another IDE, the following libraries need to be installed:

• The Libcurl C library;
• The JSON-C library;

The data is retrieved by invoking an HTTP GET, and a JSON array object is retrieved by the API (with the data from the students). The privacy server will act as an anonymisation server, protecting the privacy of the students. The clients that interact with the privacy server will be able to retrieve their own data (the student ID will act as a token that gives access to individual data). When retrieved other student's data, the proxy will anonymize the data to the clients.

1. Create a JSON object to store the JSON data

   struct json_object *jobj_array, *jobj_obj;

2. Get the student data from the ISABELA API

   jobj_array = get_student_data();

3. Get individual fields from the array of data (e.g., location)

   arraylen = json_object_array_length(jobj_array);
   for (i = 0; i < arraylen; i++) {
   	jobj_obj = json_object_array_get_idx(jobj_array, i);
   	jobj_object_location = json_object_object_get(jobj_obj, "location");
   	printf("location=%s\n", json_object_get_string(jobj_object_location));
   }

The fields available in the ISABELA API are:

• id: student ID code (check your ID in the ISABELA Android settings);
• activity: student activity (Exercise,Sleeping,Classes,Tilting,Walking,In vehicle,Unknown,Still);
• accelerometer: an array of values from the accelerometer, with the x,y,z values for several events, the t attribute corresponds to the timestamp of the event;
• ble: scan of the ble devices;
• bluetooth: scan of the bluetooth devices;
• gyroscope: scan of the gyroscope values, with the x,y,z values for several events, the t attribute corresponds to the timestamp of the event;
• location: student location (University, House, Other);
• callsduration: duration of calls made in the last 5 seconds;
• callsmade: number of calls made in the last 5 seconds;
• callsmissed: number of calls missed in the last 5 seconds;
• callsreceived: number of calls received in the last 5 seconds;
• department: name of the department (DEI);
• smsreceived: number of sms received in the last 5 seconds;
• smssent: number of sms sent in the last 5 seconds;
• wifi: scan of the available Access Points(APs), in the form of Json Object where the keys are the mac address of the APs and the values are the strength of the signal (RSSI);
• timestamp: datetime in the format of ISO8601 corresponding to the date and time at which the event was recorded;

To use this example from outside, the URL of the request need to be changed from the interal IP address to the DNS address (socialiteorion2.dei.uc.pt)

//From this:
   curl_easy_setopt(hnd, CURLOPT_URL, "http://10.3.4.75:9014/v2/entities?options=keyValues&type=student&limit=1000");
   
//To this:
   curl_easy_setopt(hnd, CURLOPT_URL, "http://socialiteorion2.dei.uc.pt:9014/v2/entities?options=keyValues&type=student&limit=1000");