Document generate_nested_nrel_forms in editConfig, rework editConfig documentation

Author: manisandro

src/configuration/ThemesConfiguration.md

@@ -199,7 +199,7 @@ The format of the theme definitions is as follows:
 | `"extraPrintParameters": "<&KEY=VALUE>",`       | Optional, additional query parameters to append to GetPrint request (requires QGIS Server >= 3.32.0). |
 | `"extraPrintLayers": ["<layername>", ...],`     | Optional, extra list of layers to mark as internal print layers, i.e. which are omitted from the QWC2 LayerTree. |
 | `"printLabelBlacklist": ["<LabelId>", ...]`     | Optional, list of composer label ids to not expose in the print dialog.          |
-| `"editConfig": "<editConfig.json>"`             | Optional, object or path to a filename containing the editing configuration for the theme, see [Editing](#editing). |
+| `"editConfig": {<editConfig>}     `             | Optional, object containing the editing configuration for the theme, see [Editing](#editing). |
 | `"snapping": {...},`                            | Optional, snapping configuration, see [Snapping](../topics/Snapping.md).         |
 | `"flags": ["<flag1>", "<flag2>", ...],`         | Optional, list of arbitrary flag names. The visibility of menu items, toolbar items and map buttons can be controlled based on the flags a theme declares. See [Plugin Configuration](ViewerConfiguration.md#plugin-configuration). |
 | `"config": {`                                   | Optional, per-theme configuration entries which override the global entries in `config.json`, see [Viewer Configuration](ViewerConfiguration.md).|

src/topics/Editing.md

@@ -63,7 +63,19 @@ In a manually created Qt-Designer Ui form, you can use key-value relations for c
 
 For `Autogenerated` and `Drag and Drop Designer` forms, configure the 1:N relation in QGIS Project → Properties → Relations. Note that the child table foreign key must refer to parent primary key.
 
-By default, a table widget similar to an attribute table will be generated to manage the relation values. If you set `generate_nested_nrel_forms` to `true` in the config generator config, the relation values will be displayed as a list of buttons which open the record in a nested form. The button label is chosen according to the following rules:
+By default, a table widget similar to an attribute table will be generated to manage the relation values. You can switch to a list of child entries which, when clicked, are displayed in a nested form by setting `generate_nested_nrel_forms` to `true` as follows:
+
+* In the toplevel `config` section of the `tenantConfig.json`. This will apply globally to all datasets.
+* In the `editConfig` section of a theme in `themesConfig.json` (see also [`editConfig`](#edit-config) below). This will then apply only to the respective dataset. Example:
+```
+    "editConfig": {
+            "<LayerId>": {
+                    "generate_nested_nrel_forms": true
+            }
+    }
+```
+
+The label of the entry in the child entry list is chosen according to the following rules:
 
 * The display name (Layer properties &rarr; Display &rarr; Display Name) of the referencing layer, if the expression is a single field name.
 * The primary key value of the referencing layer.
@@ -119,15 +131,8 @@ The `qwc-data-service` offers some basic functionality for logging mutations:
 
 *Note*: for these fields to be written, ensure the qgis project is also up-to-date, i.e. that contain the up-to-date table schemas. You can set the respective field types to hidden in the QGIS layer properties to avoid them showing up in the autogenerated edit forms.
 
-
-## Using a custom editing backend
-
-You can also use a custom editing backend instead of the `qwc-data-service` by following these steps:
-
-- Implement the custom editing interface, taking [default `EditingInterface.js`](https://github.com/qgis/qwc2/blob/master/utils/EditingInterface.js) as a template.
-- Enable the desired editing plugins in [`js/appConfig.js`](https://github.com/qgis/qwc2-demo-app/blob/master/js/appConfig.js), passing your custom editing interface to `Editing`, `AttributeTable` and `FeatureForm`.
-- Set up an editing backend.
-- If you are using the [`qwc-config-generator`](https://github.com/qwc-services/qwc-config-generator), the edit configuration will be automatically generated from the QGIS project. Otherwise, you need to write a custom `editConfig` in `themesConfig.json` as follows:
+## The theme `editConfig` block<a name="edit-config"></a>
+The [`qwc-config-generator`](https://github.com/qwc-services/qwc-config-generator). will automatically generate the `editConfig` for a theme in `themesConfig.json`. You can however also specify it manually, in which case the manually defined entries will be merged with the automatically generated entries. The structure of the `editConfig` block is as follows:
 
 | Entry                                | Description                                                   |
 |--------------------------------------|---------------------------------------------------------------|
@@ -136,7 +141,7 @@ You can also use a custom editing backend instead of the `qwc-data-service` by f
 | `⁣    "layerName": "<LayerName>",`    | The layer name to show in the selection combo box. |
 | `⁣    "editDataset": "<DatasetName>",`| The name of the edit dataset passed to the editing interface. |
 | `⁣    "geomType": "<GeomType>",`      | The geometry type, either `Point`, `LineString` or `Polygon`. |
-| `⁣    "displayField": "<FieldId>",`  | The ID of the field to use in the feature selection menu.     |
+| `⁣    "displayField": "<FieldId>",`   | The ID of the field to use in the feature selection menu.     |
 | `⁣    "permissions": {`               | A list of different write permissions to specify rights and buttons. |
 | `⁣      "creatable": <boolean>,`      | If `true`, `Draw` button will appear in Editing interface and `Add` button in Attribute Table. |
 | `⁣      "updatable": <boolean>,`      | If `true`, `Pick` button will appear in Editing interface.    |
@@ -151,9 +156,16 @@ You can also use a custom editing backend instead of the `qwc-data-service` by f
 | `⁣        ...`                        | For regular HTML input types, the ReactJS API name of any applicable [HTML input constraint](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/input), i.e. `maxLength` or `readOnly`. |
 | `⁣      }`                            |                                                               |
 | `⁣    }],`                            |                                                               |
-| `⁣    "form": "<PathToUiFile>",`      | Optional, a QtDesigner UI file.                               |
+| `⁣    "form": "<PathToUiFile>",`      | URL to a Qt Designed UI form (use `:/<path>` to specify a path below the `assets` folder).|
+| `⁣    "generate_nested_nrel_forms": <boolean>` | Optional: Tell the config-generator whether 1:N relations of this dataset should be displayed in nested forms. |
 | `⁣  }`                                |                                                               |
 | `}`                                  |                                                               |
 
-* If you specify just `fields`, a simple form is autogenerated based on the field definitions.
-* Alternatively you can specify the URL to a Qt Designer UI form in `form` (use `:/<path>` to specify a path below the `assets` folder).
+
+## Using a custom editing backend
+
+You can also use a custom editing backend instead of the `qwc-data-service` by following these steps:
+
+- Implement the custom editing interface, taking [default `EditingInterface.js`](https://github.com/qgis/qwc2/blob/master/utils/EditingInterface.js) as a template.
+- Enable the desired editing plugins in [`js/appConfig.js`](https://github.com/qgis/qwc2-demo-app/blob/master/js/appConfig.js), passing your custom editing interface to `Editing`, `AttributeTable` and `FeatureForm`.
+- Set up an editing backend.