add extendable join block, add xml fields first to fix extendables after sprite swapping

Author: CST1229

src/blocks/scratch3_operators.js

@@ -28,6 +28,7 @@ class Scratch3OperatorsBlocks {
             operator_not: this.not,
             operator_random: this.random,
             operator_join: this.join,
+            operator_join_extendable: this.joinExtendable,
             operator_letter_of: this.letterOf,
             operator_length: this.length,
             operator_contains: this.contains,
@@ -102,6 +103,15 @@ class Scratch3OperatorsBlocks {
         return Cast.toString(args.STRING1) + Cast.toString(args.STRING2);
     }
 
+    joinExtendable (args) {
+        let string = "";
+        const argCount = +args.STRINGS;
+        for (let i = 0; i < argCount; i++) {
+            string += Cast.toString(args["STRINGS_" + i + "_STRING"]);
+        }
+        return string;
+    }
+
     letterOf (args) {
         const index = Cast.toNumber(args.LETTER) - 1;
         const str = Cast.toString(args.STRING);

src/compiler/compat-blocks.js

@@ -36,6 +36,7 @@ const stacked = [
 const inputs = [
     'motion_xscroll',
     'motion_yscroll',
+    'operator_join_extendable',
     'sensing_loud',
     'sensing_loudness',
     'sensing_userid',

src/engine/blocks.js

@@ -1237,23 +1237,6 @@ class Blocks {
         if (block.mutation) {
             xmlString += this.mutationToXML(block.mutation);
         }
-        // Add any inputs on this block.
-        for (const input in block.inputs) {
-            if (!Object.prototype.hasOwnProperty.call(block.inputs, input)) continue;
-            const blockInput = block.inputs[input];
-            // Only encode a value tag if the value input is occupied.
-            if (blockInput.block || blockInput.shadow) {
-                xmlString += `<value name="${xmlEscape(blockInput.name)}">`;
-                if (blockInput.block) {
-                    xmlString += this.blockToXML(blockInput.block, comments);
-                }
-                if (blockInput.shadow && blockInput.shadow !== blockInput.block) {
-                    // Obscured shadow.
-                    xmlString += this.blockToXML(blockInput.shadow, comments);
-                }
-                xmlString += '</value>';
-            }
-        }
         // Add any fields on this block.
         for (const field in block.fields) {
             if (!Object.prototype.hasOwnProperty.call(block.fields, field)) continue;
@@ -1273,6 +1256,23 @@ class Blocks {
             }
             xmlString += `>${value}</field>`;
         }
+        // Add any inputs on this block.
+        for (const input in block.inputs) {
+            if (!Object.prototype.hasOwnProperty.call(block.inputs, input)) continue;
+            const blockInput = block.inputs[input];
+            // Only encode a value tag if the value input is occupied.
+            if (blockInput.block || blockInput.shadow) {
+                xmlString += `<value name="${xmlEscape(blockInput.name)}">`;
+                if (blockInput.block) {
+                    xmlString += this.blockToXML(blockInput.block, comments);
+                }
+                if (blockInput.shadow && blockInput.shadow !== blockInput.block) {
+                    // Obscured shadow.
+                    xmlString += this.blockToXML(blockInput.shadow, comments);
+                }
+                xmlString += '</value>';
+            }
+        }
         // Add blocks connected to the next connection.
         if (block.next) {
             xmlString += `<next>${this.blockToXML(block.next, comments)}</next>`;