Krow

A small library for generating tables in ASCII or HTML formats, built with Kotlin's type-safe builders

Building Tables

Tables are built with Kotlin's type-safe builder syntax. You open a krow closure, and are then able to call the various methods and set properties that build your table. A complete example is shown below:

val table = krow {
    cell("col1", "row1") { content = "1-1" }
    cell("col1", "row2") { content = "1-2" }

    cell("col2", "row1") { content = "2-1" }
    cell("col2", "row2") { content = "2-2" }

    cell("col3", "row1") { content = "3-1" }
    cell("col3", "row2") { content = "3-2" }

    table {
        wrapTextAt = 30
        horizontalAlignment = HorizontalAlignment.CENTER
        verticalAlignment = VerticalAlignment.TOP
    }
}

A Table is build of Cells arranged in a 2D grid.

The cell() method accepts a pair of keys for column, row index. If either of these two keys do not exist, then the table will add a row or column accordingly, and then set the properties of that cell with the closure opened at that cell.

The row() method takes a key for a row, and applies the closure to all cells in that row. If the row does not exist, the table will add the row before applying the closure to all its cells. In the same way, you can use the column() to setup an entire column of cells.

the table() method applies the closure to every cell in the entire table.

You can also set the ordering of rows and columns with the columns(), and rows() methods, which each take a list of Strings as the names of the columns or rows to add. Other rows or columns may be added later with the above methods, but they will be added at the end or added in place if the column or row already exists. At this time, it is not possible to reorder columns or rows once they have been created, so if you need a specific order, set it before configuring any individual cells, columns, or rows.

Formatting Tables

Once a Table has been created like so:

val table = krow {
    ...
}

You can then print the Table in any format you wish. Krow ships with Formatters that render the table as an HTML table, or as an ASCII table for the command-line. Examples are shown below:

SingleBorder AsciiTable

┌──────┬──────┬──────┬──────┐
│      │ col1 │ col2 │ col3 │
├──────┼──────┼──────┼──────┤
│ row1 │ 1-1  │ 2-1  │ 3-1  │
├──────┼──────┼──────┼──────┤
│ row2 │ 1-2  │ 2-2  │ 3-2  │
└──────┴──────┴──────┴──────┘

DoubleBorder AsciiTable

╔══════╦══════╦══════╦══════╗
║      ║ col1 ║ col2 ║ col3 ║
╠══════╬══════╬══════╬══════╣
║ row1 ║ 1-1  ║ 2-1  ║ 3-1  ║
╠══════╬══════╬══════╬══════╣
║ row2 ║ 1-2  ║ 2-2  ║ 3-2  ║
╚══════╩══════╩══════╩══════╝

Crossing AsciiTable

+------+------+------+------+
|      | col1 | col2 | col3 |
+------+------+------+------+
| row1 | 1-1  | 2-1  | 3-1  |
+------+------+------+------+
| row2 | 1-2  | 2-2  | 3-2  |
+------+------+------+------+

HtmlTable

<table>
  <thead>
  <tr>
    <th></th>
    <th>col1</th>
    <th>col2</th>
    <th>col3</th>
  </tr>
  </thead>
  <tbody>
  <tr>
    <td>row1</td>
    <td>1-1</td>
    <td>2-1</td>
    <td>3-1</td>
  </tr>
  <tr>
    <td>row2</td>
    <td>1-2</td>
    <td>2-2</td>
    <td>3-2</td>
  </tr>
  </tbody>
</table>