added support for transpose()

AllMightySauron · Oct 6, 2021 · a51d62a · a51d62a
1 parent c81b81d
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diff --git a/README.md b/README.md
@@ -1315,6 +1315,55 @@ console.log(table.toString());
 | 3 | Jim  | 83 |
 +---+------+----+
 ```
+### Transposing
+
+#### instance.transpose()
+
+Transposes table by exchanging rows for columns.
+
+Example:
+
+```javascript
+const table = 
+    new AsciiTable3('Sample table')
+    .setHeading('Name', 'Age', 'Eye color')
+    .addRowMatrix([
+        ['John', 23, 'green'],
+        ['Mary', 16, 'brown'],
+        ['Rita', 47, 'blue'],
+        ['Peter', 8, 'brown']
+    ]);
+
+console.log(table.toString());
+```
+```
++-------------------------+
+|      Sample table       |
++-------+-----+-----------+
+| Name  | Age | Eye color |
++-------+-----+-----------+
+| John  |  23 | green     |
+| Mary  |  16 | brown     |
+| Rita  |  47 | blue      |
+| Peter |   8 | brown     |
++-------+-----+-----------+
+```
+
+```javascript
+// transpose table
+table.transpose();
+
+console.log(table.toString());
+```
+```
++------------------------------------------+
+|               Sample table               |
++-----------+-------+-------+------+-------+
+| Name      | John  | Mary  | Rita | Peter |
+| Age       |    23 |    16 |   47 |     8 |
+| Eye color | green | brown | blue | brown |
++-----------+-------+-------+------+-------+
+```
 
 ### Serialization
 

diff --git a/ascii-table3.js b/ascii-table3.js
@@ -238,9 +238,10 @@ class AsciiTable3 {
      * @static
      * @param {number} len Length of array.
      * @param {*} [value] The fill value (optional).
+     * @returns {*[]} Array filled with with desired value.
      */
     static arrayFill(len, value) {
-        var result = [];
+        const result = [];
 
         for (var i = 0; i < len; i++) {
             result.push(value);
@@ -546,13 +547,33 @@ class AsciiTable3 {
     }
 
     /**
-     * Table rows getter
+     * Table rows getter.
      * @returns {*[]} Array with row cell values (column array).
      */
     getRows() {
         return Array.from(this.rows);
     }
 
+    /**
+     * Sets cell value for this row and column combination.
+     * @param {number} row Desired row number (1-based index).
+     * @param {number} col Desired column number (1-based index).
+     * @param {*} value The cell value to set.
+     */
+    setCell(row, col, value) {
+        this.rows[row - 1][col - 1] = value;
+    }
+
+    /**
+     * Gets cell value for this row and column combination.
+     * @param {number} row Desired row number (1-based index).
+     * @param {number} col Desired column number (1-based index).
+     * @returns {*} The cell value.
+     */
+    getCell(row, col) {
+        return this.getRows()[row - 1][col - 1];
+    }
+
     /**
      * Sets the preset width for a given column rendering output.
      * @param {number} idx Column index to align (starts at 1).
@@ -814,6 +835,44 @@ class AsciiTable3 {
         return this.justify ? this.justify : false;
     }
 
+    /**
+     * Transposes table by exchanging rows for columns.
+     * @returns {AsciiTable3} The AsciiTable3 object instance.
+     */
+    transpose() {
+        // get number of data columns
+        const nCols = this.getHeading().length > 0 ? this.getHeading().length : this.getRows()[0].length;
+
+        // get number of data rows
+        const nRows = this.getRows().length;
+
+        // create new matrix with number of rows equal number of columns
+        const newMatrix = AsciiTable3.arrayFill(nCols);
+
+        // columns where data starts (depends on heading existence)
+        const dataStartCol = this.getHeading().length > 0 ? 1 : 0;
+
+        // loop over rows
+        for (var row = 0; row < newMatrix.length; row++) {
+            // column array for this row (number of rows + heading if needed)
+            newMatrix[row] = AsciiTable3.arrayFill(nRows + dataStartCol);
+
+            if (this.getHeading()) {
+                // setup first column with heading values
+                newMatrix[row][0] = this.getHeading()[row];
+            }
+
+            // loop over columns
+            for (var col = dataStartCol; col < newMatrix[0].length; col++) {
+                // fill row with column data values
+                newMatrix[row][col] = this.getCell(col + Math.abs(dataStartCol - 1), row + 1);
+            }
+        }
+
+        // new value
+        return new AsciiTable3(this.getTitle()).addRowMatrix(newMatrix);
+    }
+
     /**
      * Return the JSON representation of the table, this also allows us to call JSON.stringify on the instance.
      * @returns {string} The table JSON representation.

diff --git a/package.json b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "ascii-table3",
-  "version": "0.5.4",
+  "version": "0.6.0",
   "author": "João Simões <[email protected]> (https://github.com/AllMightySauron)",
   "description": "Javascript ASCII renderer for beautiful console-based tables",
   "repository": {

diff --git a/samples.js b/samples.js
@@ -19,7 +19,10 @@ const table =
 
 console.log(`base table:\n${table.toString()}`);
 
-// Example 2. cell margins
+// example 2. transpose
+console.log(`transpose table:\n${table.transpose().toString()}`);
+
+// Example 3. cell margins
 console.log ('>>>>>> example 2: cell margins');
 
 table.setCellMargin(0);
@@ -28,7 +31,7 @@ console.log(`cell margin = 0:\n${table.toString()}`);
 table.setCellMargin(2);
 console.log(`cell margin = 2:\n${table.toString()}`);
 
-// example 3. Test out styles
+// example 4. Test out styles
 console.log ('>>>>>> example 3: test out styles');
 
 table.setCellMargin(1);
@@ -39,7 +42,7 @@ table.getStyles().forEach(style => {
     console.log(`${style.name}:\n${table.toString()}`);
 });
 
-// example 4. column width
+// example 5. column width
 console.log ('>>>>>> example 4: column width');
 
 table.setStyle("ramac");
@@ -52,7 +55,7 @@ console.log(`name width = 6:\n${table.toString()}`);
 table.setWidths([10, 8, 12]);
 console.log(`multiple widths = [10, 8, 12]:\n${table.toString()}`);
 
-// example 5. adding a new style
+// example 6. adding a new style
 console.log ('>>>>>> example 5: adding a new style');
 
 const roundedStyle = {
@@ -77,27 +80,26 @@ table.addStyle(roundedStyle);
 table.setStyle("rounded");
 console.log(`rounded style:\n${table.toString()}`);
 
-// example 6. row data wrapping
+// example 7. row data wrapping
 console.log ('>>>>>> example 6: row data wrapping');
 table.clearRows();
 table.addRow('James Bond', 41, 'blue').addRow('Harry Potter', 18, 'brown').addRow('Scooby Doo', 23, 'brown').addRow('Mickey Mouse', 120, 'black');
 table.setWidth(1, 8).setWrapped(1);
 
 console.log(`data wrapping:\n${table.toString()}`);
 
-// example 7. justification (all columns of same width)
+// example 8. justification (all columns of same width)
 console.log ('>>>>>> example 7: justification (all columns of same width)');
 table.setWidths().setWrapped(1, false);
 table.setJustify();
 
 console.log(`justified:\n${table.toString()}`);
 
-// example 8. no title or heading
+// example 9. no title or heading
 console.log ('>>>>>> example 8: no title or heading');
 table.setJustify(false);
 table.setTitle();
 table.setHeading();
 
 table.setStyle('ramac');
 console.log(`no title/heading:\n${table.toString()}`);
-
diff --git a/test/ascii-table3.test.js b/test/ascii-table3.test.js
@@ -153,7 +153,7 @@ describe('Heading', () => {
     });
 });
 
-describe('DataRows', () => {
+describe('Data rows', () => {
     it ('addRow/getRows', () => {
         const aTable = new AsciiTable3('Dummy title')
             .setHeading('Title', 'Count', 'Rate (%)')
@@ -193,6 +193,37 @@ describe('DataRows', () => {
     });
 });
 
+describe('Cell values', () => {
+    it ('getCell', () => {
+        const aTable = new AsciiTable3('People')
+            .setHeading('Name', 'Age', 'Eye color')
+            .addRowMatrix([ 
+                ['John', 18, 'green'], 
+                ['Peter', 5, 'brown'],  
+                ['Mary', 40, 'blue'],
+                ['Timothy', 16, 'hazel'],
+             ]);
+
+        assert.strictEqual(aTable.getCell(1, 1), 'John');
+        assert.strictEqual(aTable.getCell(3, 2), 40);
+    });
+
+    it ('setCell', () => {
+        const aTable = new AsciiTable3('People')
+            .setHeading('Name', 'Age', 'Eye color')
+            .addRowMatrix([ 
+                ['John', 18, 'green'], 
+                ['Peter', 5, 'brown'],  
+                ['Mary', 40, 'blue'],
+                ['Timothy', 16, 'hazel'],
+             ]);
+
+        assert.strictEqual(aTable.getCell(3, 2), 40);
+        aTable.setCell(3, 2, 55);
+        assert.strictEqual(aTable.getCell(3, 2), 55);
+    });
+});
+
 describe('Sorting', () => {
    it ('sort', () => {
         const aTable = 
@@ -819,3 +850,83 @@ describe('Clearing data', () => {
         assert.strictEqual(aTable.isJustify(), false);
     });
 });
+
+describe('Transpose', () => {
+    it ('no heading', () => {
+        const aTable = new AsciiTable3('People')
+            .addRowMatrix([ 
+                ['John', 18, 'green'], 
+                ['Peter', 5, 'brown'],  
+                ['Mary', 40, 'blue'],
+                ['Timothy', 16, 'hazel'],
+             ]);
+
+        const newTable = aTable.transpose();
+
+        // same title
+        assert.strictEqual(newTable.getTitle(), aTable.getTitle());
+
+        // number of rows / columns
+        assert.strictEqual(newTable.getRows().length, aTable.getRows()[0].length);
+        assert.strictEqual(newTable.getRows()[0].length, aTable.getRows().length);
+
+        // test cell values
+        for (var row  = 0; row < newTable.getRows().length; row++) {
+            for (var col = 0; col < newTable.getRows()[0].length; col++) {
+                assert.strictEqual(newTable.getCell(row + 1, col + 1), aTable.getCell(col + 1, row + 1));
+            }
+        }
+    });
+
+    it ('heading', () => {
+        const aTable = new AsciiTable3('People')
+            .setHeading('Name', 'Age', 'Eye color')
+            .addRowMatrix([ 
+                ['John', 18, 'green'], 
+                ['Peter', 5, 'brown'],  
+                ['Mary', 40, 'blue'],
+                ['Timothy', 16, 'hazel'],
+             ]);
+
+        const newTable = aTable.transpose();
+
+        // same title
+        assert.strictEqual(newTable.getTitle(), aTable.getTitle());
+
+        // number of rows / columns
+        assert.strictEqual(newTable.getRows().length, aTable.getRows()[0].length);
+        assert.strictEqual(newTable.getRows()[0].length, aTable.getRows().length + 1); // extra column on new table for heading
+
+        // test original heading exists on first column of transposed matrix
+        for (var row = 0; row < newTable.getRows().length; row++) {
+            assert.strictEqual(newTable.getRows()[row][0], aTable.getHeading()[row]);
+        }
+
+         // test cell values
+         for (row  = 0; row < newTable.getRows().length; row++) {
+            for (var col = 1; col < newTable.getRows()[0].length; col++) {
+                assert.strictEqual(newTable.getCell(row + 1, col + 1), aTable.getCell(col, row + 1));
+            }
+        }
+    });
+
+    it ('heading (no data)', () => {
+        const aTable = new AsciiTable3('People')
+            .setHeading('Name', 'Age', 'Eye color');
+
+        const newTable = aTable.transpose();
+
+        // same title
+        assert.strictEqual(newTable.getTitle(), aTable.getTitle());
+
+        // number of rows / columns
+        assert.strictEqual(newTable.getRows().length, aTable.getHeading().length);
+        assert.strictEqual(newTable.getRows()[0].length, 1); // 1 column for heading
+
+        // test original heading exists on first column of transposed matrix
+        for (var row = 0; row < newTable.getRows().length; row++) {
+            assert.strictEqual(newTable.getRows()[row][0], aTable.getHeading()[row]);
+        }
+    });
+
+});