Added docs for template access vie RT API

neon/real-time-api/tutorials/index.md

@@ -101,7 +101,7 @@
 
 ```python
 from datetime import datetime
 import matplotlib.pyplot as plt
 import cv2
 from pupil_labs.realtime_api.simple import discover_one_device
 
@@ -118,8 +118,8 @@
 print(f"For the left eye x, y, z: {gaze_sample.optical_axis_left_x}, {gaze_sample.optical_axis_left_y}, {gaze_sample.optical_axis_left_z} and for the right eye x, y, z: {gaze_sample.optical_axis_right_x}, {gaze_sample.optical_axis_right_y}, {gaze_sample.optical_axis_right_z}.")
 
 scene_image_rgb = cv2.cvtColor(scene_sample.bgr_pixels, cv2.COLOR_BGR2RGB)
 plt.imshow(scene_image_rgb)
 plt.scatter(gaze_sample.x, gaze_sample.y, s=200, facecolors='none', edgecolors='r')
 ```
 The output data would look as follows:
 ```
@@ -147,7 +147,7 @@
 
 imu_sample = device.receive_imu_datum()
 
 dt = datetime.fromtimestamp(imu_sample.timestamp_unix_seconds)
 print(f"This IMU sample was recorded at {dt}")
 
 print(f"It contains the following data:")
@@ -175,7 +175,7 @@
 
 ## Camera Calibration
 
 You can receive camera calibration parameters using the [`get_calibration`](https://pupil-labs-realtime-api.readthedocs.io/en/stable/api/simple.html#pupil_labs.realtime_api.simple.Device.get_calibration) method. Especially the scene camera matrix and distortion coefficients are useful for undistorting the scene video.
 
 ```python
 from pupil_labs.realtime_api.simple import discover_one_device
@@ -199,12 +199,71 @@
 print(calibration["left_distortion_coefficients"][0])
 ```
 
+## Template Data
+You can access the response data entered into the template questionnaire on the phone and also set those responses remotely.
+
+Using the [`get_template`](https://pupil-labs-realtime-api.readthedocs.io/en/stable/api/simple.html#pupil_labs.realtime_api.simple.Device.get_template) method, you can receive the definition of the template containing all questions and sections.
+
+```python
+template = device.get_template()
+fstring = "{i.id}\t{i.title}\t{i.widget_type} \t{i.choices}"
+print("\n".join(fstring.format(i=i) for i in template.items))
+```
+```
+e3b94cc7-dce4-4781-a818-f769574c31d2    Section 1       SECTION_HEADER  []
+a54e85aa-5474-42f8-90c0-19f40e9ca825    Question 1      TEXT            []
+59c01ff9-972e-42c7-8b6f-5ef4e11df5d8    Section 2       SECTION_HEADER  []
+3c7d620f-9f98-4556-92dd-b66df329999c    Question 2      PARAGRAPH       []
+6169276c-91f4-4ef9-8e03-45759ff61477    Question 3      CHECKBOX_LIST   ['a', 'b', 'c']
+33059b82-63b7-4c4e-9bab-a27f7724bd1e    Question 4      RADIO_LIST      ['1', '2', '3']
+```
+
+Using the [`get_template_data`](https://pupil-labs-realtime-api.readthedocs.io/en/stable/api/simple.html#pupil_labs.realtime_api.simple.Device.get_template_data) method, you can receive the responses currently saved in the template.
+
+```python
+data = device.get_template_data()
+print("\n".join(f"{k}\t{v}" for k, v in data.items()))
+```
+```
+6169276c-91f4-4ef9-8e03-45759ff61477    ['a']
+3c7d620f-9f98-4556-92dd-b66df329999c    An example paragraph.
+a54e85aa-5474-42f8-90c0-19f40e9ca825    An example short text.
+33059b82-63b7-4c4e-9bab-a27f7724bd1e    ['1']
+```
+
+Using the [`post_template_data`](https://pupil-labs-realtime-api.readthedocs.io/en/stable/api/simple.html#pupil_labs.realtime_api.simple.Device.post_template_data) method, you can set the template responses remotely.
+
+```python
+questionnaire = {
+    "6169276c-91f4-4ef9-8e03-45759ff61477": "b",
+    "3c7d620f-9f98-4556-92dd-b66df329999c": "A different paragraph.",
+    "a54e85aa-5474-42f8-90c0-19f40e9ca825": "Another short text.",
+    "33059b82-63b7-4c4e-9bab-a27f7724bd1e": "3",
+}
+device.post_template_data(questionnaire)
+```
+
+You can also retrieve individual questions by their ID using the [`get_question_by_id`](https://pupil-labs-realtime-api.readthedocs.io/en/stable/api/models.html#pupil_labs.realtime_api.models.Template.get_question_by_id) method and check the validity of a response using the [`validate_answer`]( https://pupil-labs-realtime-api.readthedocs.io/en/stable/api/models.html#pupil_labs.realtime_api.models.TemplateItem.validate_answer) method.
+
+```python
+question = template.get_question_by_id("6169276c-91f4-4ef9-8e03-45759ff61477")
+question.validate_answer(["invalid_option"])
+```
+```
+pupil_labs/realtime_api/models.py", line 346, in validate_answer
+    raise InvalidTemplateAnswersError(self, answers, errors)
+pupil_labs.realtime_api.models.InvalidTemplateAnswersError: Question 3 (6169276c-91f4-4ef9-8e03-45759ff61477) validation errors:
+   location: ('6169276c-91f4-4ef9-8e03-45759ff61477', 0)
+     input: invalid_option
+     message: Value error, 'invalid_option' is not a valid choice from: ['a', 'b', 'c']
+```
+
 ## Troubleshooting
 
 If you are having trouble connecting to your Neon device via the real-time API, consider the following points:
 
 1. Make sure the Neon Companion app and the device you are using to access the API are connected to the same local network.
 1. For discovery the local network must allow MDNS and UDP traffic. In large public networks this may be prohibited for security reasons.
 
    - You may still be able to connect to Neon using its IP address. You can find the IP address in the WiFi settings of the phone. Once you have it, you can connect like this: