developer documentation update

DEVELOPERS.md

@@ -19,7 +19,7 @@ JaLHyd offers **calculation modules** also called **Nub**s, that are each respon
 
 #### calculator type
 
-Each Nub must have a **calculator type**, that is an item of the `CalculatorType` enum. It is stored in `this._calcType` and must be defined in the Nub's constructor.
+Each Nub must have a **calculator type**, that is an item of the `CalculatorType` enum. It is stored in the `calcType` property and must be defined in the properties passed to the Nub `setProperties` method.
 
 #### calculated parameter
 
@@ -51,7 +51,7 @@ To be calculated, a Nub might require the results of one or more other Nubs. See
 
 Parameters are objects that represent the input/outputs of a Nub's equation. All the parameters of a given Nub must be grouped in an object derived from `ParamsEquation`, (ex: `CloisonsParams` for Nub `Cloisons`). Only one parameter at a time may be the **calculated parameter** of its Nub; its value is computed based on the fixed values of other parameters.
 
-A parameter is characterized by a **symbol** (ex: "Q"), a **definition domain** (from the `ParamDomainValue` enum, or a free interval), a **unit** (for display purposes only, ex: "m³/s"), an **initial value**, a **family** (see "Links" below), and a **visibility** (for display purposes only).
+A parameter is characterized by a **symbol** (ex: "Q"), a **definition domain** (from the `ParamDomainValue` enum, or a free interval), a **unit** (for display purposes only, ex: "m³/s"), an **initial value**, a **family** (see "Links" below), its **calculability**, a **mode** and a **visibility** (for display purposes only).
 
 #### calculability
 
@@ -103,7 +103,7 @@ Parameters are grouped into **families**, indicating that they may be linked to
 
 A **property** is an attribute of a Nub that is not numerical and/or accepts only values from a limited set. It is thus distinct from a **parameter**. Usually they are bound to enums, through `Session.enumFromProperty`. Example: "trigoOperation" in `Trigo` that only accepts items from `TrigoOperation` enum.
 
-Properties are stored in `this.properties`. Not all Nubs have properties. Those who do should set a default value for each property in their constructor, through a call to `this.properties.setPropValue()`.
+Properties are stored in `this._props_` and accessed by client code through `getPropValue`/`setPropValue` methods. Not all Nubs have properties. Those who do should set a default value for each property in their constructor, through a call to `this.setPropValue()`.
 
 Properties are **observable** objects: subscribing to a Nub's properties through `addObserver()` method guarantees to be informed of a property value change through the `update()` method of the `Observer` interface.
 
@@ -119,9 +119,9 @@ Otherwise, when no parameter is varying there is exactly one result element, and
 
 #### result elements
 
-A `ResultElement` is an object that contains a main calculated value `.vCalc`, optional additional calculated values stored as key-value pairs in `.values` (often referred to as "extra results"), and a calculation log concerning this calculation step only.
+A `ResultElement` is an object that contains a main calculated value `vCalc`, optional additional calculated values stored as key-value pairs in `values` (often referred to as "extra results"), and a calculation log concerning this calculation step only.
 
-A result element is `.ok` if it has a value and no error-level message.
+The result element state (returned by `ok` getter) is true if it has a value and no error-level message.
 
 #### families
 
@@ -129,13 +129,13 @@ Results families allow results to be linked to parameters of the same **family**
 
 ### Log
 
-A **log** is a collection of `Messages` objects used to inform about events during the calculation process.
+A **log** is a collection of `Message` objects used to inform about events during the calculation process.
 
-Every result element has a log, and the `Result` object has an additional `.globalLog`.
+Every result element has a log, and the `Result` object has an additional `globalLog`.
 
 #### messages
 
-A **message** is an object containing a `MessageCode` that describes the issue, along with optional key-value pairs stored in `.extraVars`. The message severity `INFO`, `WARNING` or `ERROR` is inferred from the message code string prefix.
+A **message** is an object containing a `MessageCode` that describes the issue, along with optional key-value pairs stored in `extraVars`. The message severity `INFO`, `WARNING` or `ERROR` is inferred from the message code string prefix.
 
 ### Links
 
@@ -215,7 +215,7 @@ Note the **mandatory** call to `this.addParamDefinition()` and getter method for
 
 #### Nub class
 
-In `addition.ts`, create and export a new class named `Addition`:
+In `addition.ts`, create and export a new class named `Addition` that extends Nub class:
 ```typescript
 import { CalculatorType } from "../compute-node";
 import { Nub } from "../nub";
@@ -361,6 +361,8 @@ export * from "./addition";
 export * from "./addition_params";
 ```
 
+Also add exports in `internal_modules.ts` for the new classes, as index.ts should not be used in JalHyd to avoid the "TypeError: Class extends value undefined is not a constructor or null" error (internal module pattern).
+
 ## Further considerations for adding more complex modules
 
 ### properties
@@ -371,7 +373,7 @@ If the module uses **properties**, one should add a default value in the Nub's c
 constructor(prms: TrigoParams, dbg: boolean = false) {
   …
   this._props.addObserver(this);
-  this.properties.setPropValue("trigoOperation", TrigoOperation.COS);
+  this.setPropValue("trigoOperation", TrigoOperation.COS);
 }
 ```
 
@@ -387,12 +389,12 @@ public update(sender: any, data: any) {
 }
 ```
 
-Update property-enum associations list in `src/app/formulaire/elements/select-field.ts` (example for operation property in Trigo module)
+Update property-enum associations list in `src/props.ts` (example for operation property in Trigo module)
 
 ```typescript
 public static enumFromProperty = {
   …
-  "trigoOperation": TrigoOperation
+  trigoOperation: TrigoOperation
 };
 ```
 
@@ -415,12 +417,12 @@ function setRandomTrigoOperation(sn: Trigo) {
 
 ### Nubs with children
 
-If a module has children, the `childrenType` attribute should be set in the Nub's constructor. This attribute is used for translation in GUIs, notably ngHyd. Example from `MacroRugoCompound`:
+If a module has children, the `intlType` attribute should be set in the Nub's constructor. This attribute is used for translation in GUIs, notably ngHyd. Example from `MacroRugoCompound`:
 
 ```typescript
 constructor(prms: MacrorugoCompoundParams, dbg: boolean = false) {
   …
-  this._childrenType = "MacroRugo";
+  this._intlType = "MacroRugo";
 ```
 
 When implementing parent's `Equation()` method, children should be calculated using `Calc()` and not `Equation()` or `Solve()`, so that their logs and results are properly attached to them.