set up simple dependency injection

Author: boweihan

src/hypercube/ArrayCube.js

@@ -0,0 +1,101 @@
+class ArrayCube {
+  /**
+   * Create an ArrayCube
+   * @param {Object} config
+   * @param {Array} config.dimensions
+   * @param {Array} config.members
+   */
+  constructor(config) {
+    this.config = {
+      dimensions: [],
+      members: [],
+      ...config,
+    };
+    this.cube = this.createNDimArray(config.dimensions);
+  }
+
+  /**
+   * helper to recursively create an n-dimensional array implementation of a cube
+   * @param {Array} dimensions
+   * @returns {Array} n-dimensional array cube
+   */
+  createCube(dimensions) {
+    var dim = dimensions[0];
+    var rest = dimensions.slice(1);
+    var cube = new Array();
+    for (var i = 0; i < dim; i++) {
+      cube[i] = createNDimArray(rest);
+    }
+    return cube;
+  }
+
+  /**
+   * helper to recursively retrieve an element from the cube
+   * @param {Array} indices
+   * @returns {Array} n-dimensional cube slice
+   */
+  getElement(indices) {
+    if (!indices || indices.length == 0) {
+      return this.cube;
+    } else {
+      return getElement(this.cube[indices[0]], indices.slice(1));
+    }
+  }
+
+  /**
+   * slice - analyze data for a single dimension
+   * example: what were the sales in June of last year?
+   */
+  slice(dimension, filter) {
+    let points = [];
+    let data = [];
+
+    const dimensionIndex = this.config.dimensions.indexOf(dimension);
+
+    if (dimensionIndex === -1) {
+      throw new TypeError('dimension not found', dimension);
+    }
+
+    this.points.forEach((point, i) => {
+      // Add slice if it matches given filter.
+      if (point[dimensionIndex] === filter) {
+        data.push(this.data[i]);
+        points.push(this.points[i]);
+      }
+    });
+
+    return new Table(Object.assign({}, structure, { points, data }));
+  }
+
+  /**
+   * dice - analyize data for more than one dimension
+   * example: what were our sales in June of last year in New York state?
+   */
+  dice() {}
+
+  /**
+   * drillUp - analyze data at most summarized level
+   * example: what were our sales last year?
+   */
+  drillUp() {}
+
+  /**
+   * drillDown - analyze data at most detailed level
+   * example: what were our sales last year?
+   */
+  drillDown() {}
+
+  /**
+   * rollUp - analyze summary information for one or more dimensions
+   * example: what were our monthly totals?
+   */
+  rollUp() {}
+
+  /**
+   * pivot - rotate data to provide alternative presentation
+   * example: what were our monthly totals for each product category?
+   */
+  pivot() {}
+}
+
+module.exports = ArrayCube;

src/hypercube/HyperCube.js

@@ -0,0 +1,22 @@
+const InputValidator = require('./InputValidator');
+
+/**
+ * Create a HyperCube with dependencies
+ * @param {Class} CubeImpl
+ */
+const HyperCube = CubeImpl => {
+  return class HyperCube {
+    /**
+     * Construct the HyperCube
+     * @param {Object} config
+     * @param {Array} config.dimensions
+     * @param {Array} config.members
+     */
+    constructor(config) {
+      InputValidator.validateConfig(config);
+      this.cube = new CubeImpl(config);
+    }
+  };
+};
+
+module.exports = HyperCube;

src/hypercube/InputValidator.js

@@ -0,0 +1,21 @@
+class InputValidator {
+  /**
+   * Validates cube constructor configuration
+   * @param {Object} config
+   * @param {Array} config.dimensions
+   * @param {Array} config.members
+   * @throws {Error} if no dimensions are specified
+   * @throws {Error} if no members are specified
+   */
+  static validateConfig(config) {
+    const { dimensions, members } = config;
+    if (!dimensions || dimensions.length === 0) {
+      throw new Error('Cannot construct ArrayCube without dimensions.');
+    }
+    if (!members || members.length === 0) {
+      throw new Error('Cannot construct ArrayCube without members.');
+    }
+  }
+}
+
+module.exports = InputValidator;

src/hypercube/index.js

@@ -1,77 +1,4 @@
-const { createNDimArray } = require('./util');
+const HyperCube = require('./HyperCube');
+const ArrayCube = require('./ArrayCube');
 
-class Hypercube {
-  /**
-   * Create a hypercube.
-   * @param {Object} config
-   * @param {Array} config.dimensions
-   * @param {Array} config.members
-   */
-  constructor(config) {
-    this.config = Object.assign(
-      {
-        dimensions: [],
-        members: [],
-      },
-      config,
-    );
-    this.cube = createNDimArray();
-  }
-
-  /**
-   * slice - analyze data for a single dimension
-   * example: what were the sales in June of last year?
-   */
-  slice(dimension, filter) {
-    let points = [];
-    let data = [];
-
-    const dimensionIndex = this.config.dimensions.indexOf(dimension);
-
-    if (dimensionIndex === -1) {
-      throw new TypeError('dimension not found', dimension);
-    }
-
-    this.points.forEach((point, i) => {
-      // Add slice if it matches given filter.
-      if (point[dimensionIndex] === filter) {
-        data.push(this.data[i]);
-        points.push(this.points[i]);
-      }
-    });
-
-    return new Table(Object.assign({}, structure, { points, data }));
-  }
-
-  /**
-   * dice - analyize data for more than one dimension
-   * example: what were our sales in June of last year in New York state?
-   */
-  dice() {}
-
-  /**
-   * drillUp - analyze data at most summarized level
-   * example: what were our sales last year?
-   */
-  drillUp() {}
-
-  /**
-   * drillDown - analyze data at most detailed level
-   * example: what were our sales last year?
-   */
-  drillDown() {}
-
-  /**
-   * rollUp - analyze summary information for one or more dimensions
-   * example: what were our monthly totals?
-   */
-  rollUp() {}
-
-  /**
-   * pivot - rotate data to provide alternative presentation
-   * example: what were our monthly totals for each product category?
-   */
-  pivot() {}
-}
-
-module.exports = Hypercube;
+module.exports = HyperCube(ArrayCube);