Update README.md

README.md

@@ -22,12 +22,29 @@ It's fairly straight forward to use from an xcode project, following the standar
 
 A fit file is loaded using `let fitfile = FitFile(file: URL)` or `let fitfile = FitFile(data : Data)`
 
-The type FitMessageType represent the messages type (mesg_num in the sdk). You can access all the known messages with syntax like `FitMessageType.record`, `FitMessageType.session`, `FitMessageType.sport`, ...
-
 You can then use access function like `fitfile.messages(forMessageType: FitMessageType.session)` to get objects of type `FitMessage`
 
+The type `FitMessageType` represent the messages type (mesg_num in the sdk). You can access all the known messages with syntax like `FitMessageType.record`, `FitMessageType.session`, `FitMessageType.sport`, ...
+
 The function `message.interpretedFields()` provide access to the fields for the message as a dictionary of keys to `FitFieldValue` which can be either a date, a string, a double value, a double value with unit or a gps coordinate.
 
+Here is a full example:
+
+```swift
+var gps : [CLLocationCoordinate2D] = []
+var hr  : [Double] = []
+var ts  : [Date]   = []
+for message in fit_fast.messages(forMessageType: FitMessageType.record) {
+     if let one_gps = message.interpretedField(key: "position")?.coordinate,
+        let one_hr  = message.interpretedField(key: "heart_rate")?.valueUnit?.value,
+        let one_ts  = message.interpretedField(key: "timestamp")?.time {
+         gps.append( one_gps )
+         ts.append( one_ts)
+         hr.append( one_hr )
+     }
+}
+```
+
 ## Approach
 
 This code builds upon the example c code from the official SDK and integrate it into swift to generate a native object with an array of messages made of native swift dictionaries. It also adds support for developer fields.
@@ -39,6 +56,8 @@ There are two available approaches to parsing, determined by the `parsingType` a
 - `.fast` this method will only parse the fields defined as an example in the `Profile.xlsx` and therefore in `fit_example.h` from the sdk. This approach is the fastest as it relies on pre-defined static parsing of the fields.
 - `.generic` this method will blindly convert all the messages found in the files, interpreting as much as possible from the information in `Profile.xlsx` as possible, but also building information from unkonwn messages and types. This approach is a bit slower as tries to interpret each fields dynamically.
 
+All the required code is auto generated by running a python script `fitgenparser.py` that takes as input the `Profile.xlsx` from the sdk.
+
 ## Update for a new SDK
 
 When a new SDK is available, after download, use the `diffsdk.py` utility that will generate the diffs for [ksdiff](https://kaleidoscope.app) to merge the new code