fix: pathExpressions from context are handled correctly

Closes #860

packages/form-js-viewer/src/features/expression-language/variableExtractionHelpers.js

@@ -17,6 +17,12 @@ export const getFlavouredFeelVariableNames = (feelString, feelFlavour = 'express
 
     if (node.name === 'PathExpression') {
 
+      // if the path is built on top of a context, we process that context and
+      // ignore the rest of the path expression, as it is not relevant for variable extraction
+      const pathRoot = _linearizePathExpression(node)[0];
+      if (pathRoot.name === 'Context') return _unfoldVariables(pathRoot);
+
+
       if (Object.keys(specialDepthAccessors).length === 0) {
         return depth === 0 ? [ _getVariableNameAtPathIndex(node, 0) ] : [ ];
       }
@@ -53,8 +59,8 @@ export const getFlavouredFeelVariableNames = (feelString, feelFlavour = 'express
  * @returns {string|null} The variable name at the specified index or null if index is out of bounds.
  */
 const _getVariableNameAtPathIndex = (root, index) => {
-  const accessors = _deconstructPathExpression(root);
-  return accessors[index] || null;
+  const nodes = _linearizePathExpression(root);
+  return nodes[index].variableName || null;
 };
 
 
@@ -65,18 +71,18 @@ const _getVariableNameAtPathIndex = (root, index) => {
  * @param {Object} node - The root node of the path expression tree.
  * @param {number} initialDepth - The depth at which the root node is located in the outer context.
  * @param {Object} specialDepthAccessors - Definitions of special keywords which represent more complex accesses of the outer context.
- * @returns {Set} - A set containing the extracted variable names.
+ * @returns {Set} - A set containing the extracted variable names, or null if the path expression is built on top of a context.
  */
 const _smartExtractVariableNames = (node, initialDepth, specialDepthAccessors) => {
 
   // depth info represents the previous (initialised as null) and current depth of the current accessor in the path expression
   // we track multiple of these to account for the fact that a path expression may be ambiguous due to special keywords
   let accessorDepthInfos = [ { previous: null, current: initialDepth - 1 } ];
   const extractedVariables = new Set();
-  const nodeAccessors = _deconstructPathExpression(node);
+  const pathNodes = _linearizePathExpression(node);
 
-  for (let i = 0; i < nodeAccessors.length; i++) {
-    const currentAccessor = nodeAccessors[i];
+  for (let i = 0; i < pathNodes.length; i++) {
+    const currentAccessor = pathNodes[i].variableName;
 
     if (currentAccessor in specialDepthAccessors) {
       const depthOffsets = specialDepthAccessors[currentAccessor];
@@ -115,21 +121,21 @@ const _smartExtractVariableNames = (node, initialDepth, specialDepthAccessors) =
  * Deconstructs a path expression tree into an array of components.
  *
  * @param {Object} root - The root node of the path expression tree.
- * @returns {Array<string>} An array of components in the path expression, in the correct order.
+ * @returns {Array<object>} An array of components in the path expression, in the correct order.
  */
-const _deconstructPathExpression = (root) => {
+const _linearizePathExpression = (root) => {
 
   let node = root;
   let parts = [];
 
   // Traverse the tree and collect path components
   while (node.name === 'PathExpression') {
-    parts.push(node.children[1].variableName);
+    parts.push(node.children[1]);
     node = node.children[0];
   }
 
   // Add the last component to the array
-  parts.push(node.variableName);
+  parts.push(node);
 
   // Reverse and return the array to get the correct order
   return parts.reverse();

packages/form-js-viewer/test/spec/complex-conditions.json

@@ -0,0 +1,16 @@
+{
+  "components": [
+    {
+      "label": "Complex display condition 1",
+      "type": "textarea",
+      "key": "c1",
+      "conditional": {
+        "hide": "={\nremainingAllowance: loanOptions.maxAllowance - loanOptions.currentlyUsed,\nrestAfterNewLoan: remainingAllowance - offeredAdditionalLoan\n        }.restAfterNewLoan < 0"
+      }
+    }
+  ],
+  "type": "default",
+  "id": "Form_0jn1poe",
+  "exporter": {},
+  "schemaVersion": 12
+}

packages/form-js-viewer/test/spec/features/expression-language/variableExtractionHelpers.spec.js

@@ -34,6 +34,8 @@ describe('getFlavouredFeelVariableNames', () => {
 
   expectVariables('ListInContextEntry', '{entry1: [variable1, variable2]}', [ 'variable1', 'variable2' ]);
 
+  expectVariables('ContextIntoPathExpression', '={ entry1: variable1 }.accessor1 < 0', [ 'variable1' ]);
+
   expectVariables('VariableInUnaryTest', 'variable1 in (variable2..variable3)', [ 'variable1', 'variable2', 'variable3' ]);
 
   expectVariables('ArrayAccessorSingleVariable', 'variable1[1]', [ 'variable1' ]);

packages/form-js-viewer/test/spec/util/GetSchemaVariables.spec.js

@@ -14,6 +14,7 @@ import descriptionsSchema from '../descriptions.json';
 import adornersSchema from '../appearance.json';
 import imagesSchema from '../images.json';
 import valuesExpressionSchema from '../valuesExpression.json';
+import complexConditionExpressionSchema from '../complex-conditions.json';
 import validateSchema from '../validate.json';
 import groupsSchema from '../groups.json';
 import shipsExampleSchema from '../ships-example.json';
@@ -194,6 +195,19 @@ describe('util/getSchemaVariables', () => {
   });
 
 
+  it('should include variables in complex conditions example', () => {
+
+    const variables = getSchemaVariables(complexConditionExpressionSchema);
+
+    expect(variables).to.eql([
+      'loanOptions',
+      'remainingAllowance',
+      'offeredAdditionalLoan',
+      'c1'
+    ]);
+  });
+
+
   it('should only include root keys in nested components, but all variable references', () => {
 
     const variables = getSchemaVariables(groupsSchema);