Extract functions

client/src/utils/jsonPathUtils.ts

@@ -0,0 +1,152 @@
+import { JsonValue } from "../components/DynamicJsonForm";
+
+export type JsonObject = { [key: string]: JsonValue };
+
+/**
+ * Updates a value at a specific path in a nested JSON structure
+ * @param obj The original JSON value
+ * @param path Array of keys/indices representing the path to the value
+ * @param value The new value to set
+ * @returns A new JSON value with the updated path
+ */
+export function updateValueAtPath(
+  obj: JsonValue, 
+  path: string[], 
+  value: JsonValue
+): JsonValue {
+  if (path.length === 0) return value;
+
+  // Initialize if null/undefined
+  if (obj === null || obj === undefined) {
+    obj = !isNaN(Number(path[0])) ? [] : {};
+  }
+
+  // Handle arrays
+  if (Array.isArray(obj)) {
+    return updateArray(obj, path, value);
+  } 
+  // Handle objects
+  else if (typeof obj === "object" && obj !== null) {
+    return updateObject(obj as JsonObject, path, value);
+  } 
+  // Cannot update primitives
+  else {
+    console.error(
+      `Cannot update path ${path.join(".")} in non-object/array value:`,
+      obj
+    );
+    return obj;
+  }
+}
+
+/**
+ * Updates an array at a specific path
+ */
+function updateArray(
+  array: JsonValue[], 
+  path: string[], 
+  value: JsonValue
+): JsonValue[] {
+  const [index, ...restPath] = path;
+  const arrayIndex = Number(index);
+
+  // Validate array index
+  if (isNaN(arrayIndex)) {
+    console.error(`Invalid array index: ${index}`);
+    return array;
+  }
+
+  // Check array bounds
+  if (arrayIndex < 0) {
+    console.error(`Array index out of bounds: ${arrayIndex} < 0`);
+    return array;
+  }
+
+  const newArray = [...array];
+
+  if (restPath.length === 0) {
+    newArray[arrayIndex] = value;
+  } else {
+    // Ensure index position exists
+    if (arrayIndex >= array.length) {
+      console.warn(`Extending array to index ${arrayIndex}`);
+      newArray.length = arrayIndex + 1;
+      newArray.fill(null, array.length, arrayIndex);
+    }
+    newArray[arrayIndex] = updateValueAtPath(
+      newArray[arrayIndex],
+      restPath,
+      value
+    );
+  }
+  return newArray;
+}
+
+/**
+ * Updates an object at a specific path
+ */
+function updateObject(
+  obj: JsonObject, 
+  path: string[], 
+  value: JsonValue
+): JsonObject {
+  const [key, ...restPath] = path;
+
+  // Validate object key
+  if (typeof key !== "string") {
+    console.error(`Invalid object key: ${key}`);
+    return obj;
+  }
+
+  const newObj = { ...obj };
+
+  if (restPath.length === 0) {
+    newObj[key] = value;
+  } else {
+    // Ensure key exists
+    if (!(key in newObj)) {
+      console.warn(`Creating new key in object: ${key}`);
+      newObj[key] = {};
+    }
+    newObj[key] = updateValueAtPath(newObj[key], restPath, value);
+  }
+  return newObj;
+}
+
+/**
+ * Gets a value at a specific path in a nested JSON structure
+ * @param obj The JSON value to traverse
+ * @param path Array of keys/indices representing the path to the value
+ * @param defaultValue Value to return if path doesn't exist
+ * @returns The value at the path, or defaultValue if not found
+ */
+export function getValueAtPath(
+  obj: JsonValue, 
+  path: string[], 
+  defaultValue: JsonValue = null
+): JsonValue {
+  if (path.length === 0) return obj;
+  
+  const [first, ...rest] = path;
+  
+  if (obj === null || obj === undefined) {
+    return defaultValue;
+  }
+  
+  if (Array.isArray(obj)) {
+    const index = Number(first);
+    if (isNaN(index) || index < 0 || index >= obj.length) {
+      return defaultValue;
+    }
+    return getValueAtPath(obj[index], rest, defaultValue);
+  }
+  
+  if (typeof obj === "object" && obj !== null) {
+    if (!(first in obj)) {
+      return defaultValue;
+    }
+    return getValueAtPath((obj as JsonObject)[first], rest, defaultValue);
+  }
+  
+  return defaultValue;
+}