Merge branch '2017-2018' of https://github.com/hogeschool/Development-5…

… into 2017-2018

Lectures/Lecture2/practice.ipynb

@@ -378,7 +378,7 @@
     "- In short try to query at most once the database per problem without nested toList() calls\n",
     "\n",
     "\n",
-    "### Logging\n",
+    "### Logging (extra material)\n",
     "\n",
     "- To understand the process of translating LINQ queries into SQL and to understand if the atomic behaviour of the queries is maintained, the EF provides a decorator that logs the queries to a file\n",
     "\n",

Lectures/Lecture3/theory.ipynb

@@ -26,7 +26,7 @@
     "        - `PUT`\n",
     "        - `DELETE`\n",
     "    - A router, or routing rules, define which method is called by which URL, and what parts of the URL (if any) are parsed as parameters of the method\n",
-    "- All the API (methods) related to a single entity (for example `Student`) is usually put in a single class, but YMMV (_your mileage may vary_)\n",
+    "- All the API (methods) related to a single entity (for example `Student`) are usually put in a single class (in our example below, StudentApiController), but YMMV (_your mileage may vary_)\n",
     "- What methods do we add?\n",
     "    - A very common approach to structure data access is called REST\n",
     "        - REST means _representational state transfer_\n",
@@ -49,47 +49,52 @@
     "  [HttpGet]\n",
     "  public IActionResult GetAll()\n",
     "  {\n",
+    "    ...\n",
     "    return Ok(...);\n",
     "  }\n",
     "\n",
     "  [HttpGet(\"{id}\")]\n",
     "  public IActionResult GetById(int id)\n",
     "  {\n",
+    "    ...\n",
     "    return Ok(...);\n",
     "  }  \n",
     "\n",
     "  [HttpPost]\n",
     "  public IActionResult Create([FromBody] Student student)\n",
     "  {\n",
+    "    ...\n",
     "    return Ok(...);\n",
     "  }\n",
     "\n",
     "  [HttpPut]\n",
     "  public IActionResult Update([FromBody] Student modified_student)\n",
     "  {\n",
+    "    ...\n",
     "    return Ok(...);\n",
     "  }\n",
     "\n",
     "  [HttpDelete(\"{id}\")]\n",
     "  public IActionResult Delete(int id)\n",
     "  {\n",
+    "    ...\n",
     "    return Ok(...);\n",
     "  }\n",
     "}\n",
     "\n",
     "```\n",
     "\n",
-    "- The class above implements a RESTful interface on `xxx/students`\n",
-    "    - note that the router is just an attribute above the class\n",
-    "        - plus the argument to the attribute above each method\n",
-    "        - plus the null configuration `app.UseMvc(routes => {});` in `startup.cs`\n",
-    "    - An API call automatically transfers data via JSON, which is serialized and deserialized automatically (structural errors prevent completion of the call for type safety and security reasons)\n",
+    "- The class above implements a RESTful interface on `xxx/students`. In general, in .NET an application is RESTful if:\n",
+    "    - there is a class implementing the router attribute (`[Route(\"...\")]`)\n",
+    "    - there is a series of methods implementing get, post, put and delete operations\n",
+    "    - `startup.cs` contains `app.UseMvc(routes => {});` (null configuration), necessary to register the router to the services exposed by the server\n",
+    "- An API call automatically transfers data via JSON, which is serialized and deserialized automatically (structural errors prevent completion of the call for type safety and security reasons)\n",
     "- The body of the methods is just a combination of LINQ and regular code\n",
     "    - `Ok` denotes that we give a result back (the argument is the result, seralized to JSON)\n",
     "    - There are various methods such as `Ok` that we can give to signal errors, such as _not found_, _unauthorized_, and much more\n",
     "- Suppose now that we have a lot of students (hundreds of thousands)\n",
     "    - `GetAll` is a bit of an issue\n",
-    "    - A malicious attacker could cause a DDOS by simply spinning up a lot of requests\n",
+    "    - A malicious attacker could cause a DDOS (distributed denial of service) by simply spinning up a lot of requests\n",
     "    - Requests would all eventually fail because of timeout\n",
     "    - Our server would be quickly overwhelmed\n",
     "- The solution is pagination: we return a block of data (called _a page_), never bigger than a given amount of elements\n",
@@ -99,7 +104,7 @@
     "public IActionResult GetAll([FromQuery] int page_index, [FromQuery] int page_size)\n",
     "```\n",
     "\n",
-    "- `GetAll` will now return the elements from `page_index * page_size` to `page_index * page_size + page_size`\n",
+    "- `GetAll` will now return the elements from `page_index * page_size` to `page_index * page_size + page_size - 1`\n",
     "- We can impose a maximum cap for `page_size`, so that if the user asks for more than, say, 100 students, we still only give 100 back\n",
     "- `GetAll` will therefore return a JSON result looking like\n",
     "\n",
@@ -113,8 +118,8 @@
     "```\n",
     "\n",
     "- notice that the parameters `page_index` and `page_size` come from the query part of the URL itself\n",
+    "    - For example: `xxx/students?page_index=10&page_size=25`\n",
     "    - Everything after the `?` is the query\n",
-    "    - `xxx/students?page_index=10&page_size=25`\n",
     "\n",
     "- `GetAll` now contains basic filtering (basic because it is simply a range)\n",
     "- it is possible to add more parameters to perform extra filtering\n",