Default startIndex value

src/FormCollection/Resources/assets/dist/controller.js

@@ -58,7 +58,7 @@ var _default = /*#__PURE__*/function (_Controller) {
     key: "connect",
     value: function connect() {
       this.controllerName = this.context.scope.identifier;
-      this.index = this.entryTargets.length - 1;
+      this.index = this.startIndexValue ? this.startIndexValue : this.entryTargets.length - 1;
 
       if (!this.prototypeNameValue) {
         this.prototypeNameValue = '__name__';
@@ -210,5 +210,6 @@ _defineProperty(_default, "values", {
   buttonAdd: String,
   buttonDelete: String,
   prototypeName: String,
-  prototype: String
+  prototype: String,
+  startIndex: Number
 });

src/FormCollection/Resources/assets/src/controller.js

@@ -13,7 +13,8 @@ export default class extends Controller {
         buttonAdd: String,
         buttonDelete: String,
         prototypeName: String,
-        prototype: String
+        prototype: String,
+        startIndex: Number
     };
 
     /**
@@ -30,7 +31,7 @@ export default class extends Controller {
 
     connect() {
         this.controllerName = this.context.scope.identifier;
-        this.index = this.entryTargets.length - 1;
+        this.index = this.startIndexValue ? this.startIndexValue : this.entryTargets.length - 1;
 
         if (!this.prototypeNameValue) {
             this.prototypeNameValue = '__name__';

src/FormCollection/Resources/views/form_theme_div.html.twig

@@ -24,12 +24,16 @@
     {% endif %}
     {%- set attr = attr|merge({('data-' ~ controllerName ~ '-target'): 'container' }) -%}
 
+    {% set indexKeys = data|keys %}
+    {% set startIndex = indexKeys|length == 0 ? 0 : max(indexKeys) %}
+
     <div data-controller="{{ dataController }}"
          data-{{ controllerName }}-allow-add-value="{{ allow_add|json_encode }}"
          data-{{ controllerName }}-allow-delete-value="{{ allow_delete|json_encode }}"
          data-{{ controllerName }}-button-add-value="{{ block('button_add')|e('html_attr') }}"
          data-{{ controllerName }}-button-delete-value="{{ block('button_delete')|e('html_attr') }}"
          data-{{ controllerName }}-prototype-name-value="{{ prototype_name }}"
+         data-{{ controllerName }}-start-index-value="{{ startIndex }}"
             {{ block('widget_container_attributes') }}
     >
         {%- if form is rootform -%}

src/FormCollection/Resources/views/form_theme_table.html.twig

@@ -27,12 +27,16 @@
         {%- set attr = attr|merge({'data-prototype': form_row(prototype, {'row_attr': prototype_attr}) }) -%}
     {% endif %}
 
+    {% set indexKeys = data|keys %}
+    {% set startIndex = indexKeys|length == 0 ? 0 : max(indexKeys) %}
+
     <div data-controller="{{ dataController }}"
          data-{{ controllerName }}-allow-add-value="{{ allow_add|json_encode }}"
          data-{{ controllerName }}-allow-delete-value="{{ allow_delete|json_encode }}"
          data-{{ controllerName }}-button-add-value="{{ block('button_add')|e('html_attr') }}"
          data-{{ controllerName }}-button-delete-value="{{ block('button_delete')|e('html_attr') }}"
          data-{{ controllerName }}-prototype-name-value="{{ prototype_name }}"
+         data-{{ controllerName }}-start-index-value="{{ startIndex }}"
             {{ block('widget_container_attributes') }}
     >
         <table>