Cell formatter

README.md

@@ -1,13 +1,18 @@
 # uitable [![GoDoc](https://godoc.org/github.com/gosuri/uitable?status.svg)](https://godoc.org/github.com/gosuri/uitable) [![Build Status](https://travis-ci.org/gosuri/uitable.svg?branch=master)](https://travis-ci.org/gosuri/uitable)
 
-uitable is a go library for representing data as tables for terminal applications. It provides primitives for sizing and wrapping columns to improve readability.
+`uitable` is a go library for representing data as tables for terminal applications. It provides primitives for sizing and wrapping columns to improve readability. It also makes it possible to attach a formatter to each table cell, typically used to colorize terminal output.
 
 ## Example Usage
 
 Full source code for the example is available at [example/main.go](example/main.go)
 
 ```go
 table := uitable.New()
+table.CellFormatter = func(x, y int) uitable.Formatter {
+  if y == 0 { return headerFormat }
+  if x == 0 { return nameFormat }
+  return uitable.DefaultFormatter
+}
 table.MaxColWidth = 50
 
 table.AddRow("NAME", "BIRTHDAY", "BIO")
@@ -17,18 +22,37 @@ for _, hacker := range hackers {
 fmt.Println(table)
 ```
 
-Will render the data as:
-
-```sh
-NAME          BIRTHDAY          BIO
-Ada Lovelace  December 10, 1815 Ada was a British mathematician and writer, chi...
-Alan Turing   June 23, 1912     Alan was a British pioneering computer scientis...
-```
+Will render the data like:
+
+<table>
+  <tr>
+    <td><b>NAME</b></td>
+    <td><b>BIRTHDAY</b></td>
+    <td><b>BIO</b></td>
+  </tr>
+  <tr>
+    <td style="color: green">Ada Lovelace</td>
+    <td>December 10, 1815</td>
+    <td>Ada was a British mathematician and writer, chi...</td>
+  </tr>
+  <tr>
+    <td  style="color: green">Alan Turing</td>
+    <td>June 23, 1912</td>
+    <td>Alan was a British pioneering computer scientis...</td>
+  </tr>
+</tr>
+
+</table>
 
 For wrapping in two columns:
 
 ```go
 table = uitable.New()
+table.CellFormatter = func(x, y int) uitable.Formatter {
+  if x == 0 { return headerFormat }
+  if x == 1 && y%4 == 0 { return nameFormat }
+  return uitable.DefaultFormatter
+}
 table.MaxColWidth = 80
 table.Wrap = true // wrap columns
 
@@ -41,20 +65,34 @@ for _, hacker := range hackers {
 fmt.Println(table)
 ```
 
-Will render the data as:
-
-```
-Name:     Ada Lovelace
-Birthday: December 10, 1815
-Bio:      Ada was a British mathematician and writer, chiefly known for her work on
-          Charles Babbage's early mechanical general-purpose computer, the Analytical
-          Engine
-
-Name:     Alan Turing
-Birthday: June 23, 1912
-Bio:      Alan was a British pioneering computer scientist, mathematician, logician,
-          cryptanalyst and theoretical biologist
-```
+Will render the data like:
+
+<table align="top">
+  <tr>
+    <td><b>Name:</b><td>
+    <td style="color: green">Ada Lovelace</td>
+  </tr>
+  <tr>
+    <td><b>Birthday:</b><td>
+    <td>December 10, 1815</td>
+  </tr>
+  <tr>
+    <td><b>Bio:</b><td>
+    <td>Ada was a British mathematician and writer, chiefly known for her work on Charles Babbage's early mechanical general-purpose computer, the Analytical Engine</td>
+  </tr>
+  <tr>
+    <td><b>Name:</b><td>
+    <td style="color: green">Alan Turing</td>
+  </tr>
+  <tr>
+    <td><b>Birthday:</b><td>
+    <td>June 23, 1912</td>
+  </tr>
+  <tr>
+    <td><b>Bio:</b><td>
+    <td>Alan was a British pioneering computer scientist, mathematician, logician, cryptanalyst and theoretical biologist</td>
+  </tr>
+</table>
 
 ## Installation
 

example/main.go

@@ -3,7 +3,8 @@ package main
 import (
 	"fmt"
 
-	"github.com/gosuri/uitable"
+	"github.com/fatih/color"
+	"github.com/svenax/uitable"
 )
 
 type hacker struct {
@@ -15,8 +16,22 @@ var hackers = []hacker{
 	{"Alan Turing", "June 23, 1912", "Alan was a British pioneering computer scientist, mathematician, logician, cryptanalyst and theoretical biologist"},
 }
 
+var (
+	headerFormat = color.New(color.FgBlack, color.Bold).SprintFunc()
+	nameFormat   = color.New(color.FgGreen).SprintFunc()
+)
+
 func main() {
 	table := uitable.New()
+	table.CellFormatter = func(x, y int) uitable.Formatter {
+		if y == 0 {
+			return headerFormat
+		}
+		if x == 0 {
+			return nameFormat
+		}
+		return uitable.DefaultFormatter
+	}
 	table.MaxColWidth = 50
 
 	fmt.Println("==> List")
@@ -28,6 +43,15 @@ func main() {
 
 	fmt.Print("\n==> Details\n")
 	table = uitable.New()
+	table.CellFormatter = func(x, y int) uitable.Formatter {
+		if x == 0 {
+			return headerFormat
+		}
+		if x == 1 && y%4 == 0 {
+			return nameFormat
+		}
+		return uitable.DefaultFormatter
+	}
 	table.MaxColWidth = 80
 	table.Wrap = true
 	for _, hacker := range hackers {

table.go

@@ -11,8 +11,24 @@ import (
 	"github.com/mattn/go-runewidth"
 )
 
-// Separator is the default column seperator
-var Separator = "\t"
+// CellFormatter takes x and y cell coordinates and returns a function
+// used to format the content.
+type CellFormatter func(x, y int) Formatter
+
+// Formatter formats the content of a cell. The signature
+// is that of fmt.Sprint which is used as default.
+type Formatter func(s ...interface{}) string
+
+var (
+	// Separator is the default column seperator
+	Separator = "\t"
+
+	// DefaultFormatter is the default cell content formatter
+	DefaultFormatter = fmt.Sprint
+
+	// DefaultCellFormatter is the default cell formatting function
+	DefaultCellFormatter = func(x, y int) Formatter { return DefaultFormatter }
+)
 
 // Table represents a decorator that renders the data in formatted in a table
 type Table struct {
@@ -28,16 +44,20 @@ type Table struct {
 	// Separator is the seperator for columns in the table. Default is "\t"
 	Separator string
 
+	// CellFormatter is the function that selects formatting functions for each cell
+	CellFormatter CellFormatter
+
 	mtx        *sync.RWMutex
 	rightAlign map[int]bool
 }
 
 // New returns a new Table with default values
 func New() *Table {
 	return &Table{
-		Separator:  Separator,
-		mtx:        new(sync.RWMutex),
-		rightAlign: map[int]bool{},
+		Separator:     Separator,
+		CellFormatter: DefaultCellFormatter,
+		mtx:           new(sync.RWMutex),
+		rightAlign:    map[int]bool{},
 	}
 }
 
@@ -47,6 +67,7 @@ func (t *Table) AddRow(data ...interface{}) *Table {
 	defer t.mtx.Unlock()
 	r := NewRow(data...)
 	t.Rows = append(t.Rows, r)
+	r.setCellFormatter(len(t.Rows)-1, t.CellFormatter)
 	return t
 }
 
@@ -55,6 +76,7 @@ func (t *Table) Bytes() []byte {
 	return []byte(t.String())
 }
 
+// RightAlign sets the column at index col to be right aligned
 func (t *Table) RightAlign(col int) {
 	t.mtx.Lock()
 	t.rightAlign[col] = true
@@ -135,7 +157,7 @@ func (r *Row) String() string {
 	for x := 0; x < lc; x++ {
 		cells[x] = make([]*Cell, len(r.Cells))
 		for y := 0; y < len(r.Cells); y++ {
-			cells[x][y] = &Cell{Width: r.Cells[y].Width}
+			cells[x][y] = &Cell{Width: r.Cells[y].Width, Formatter: r.Cells[y].Formatter}
 		}
 	}
 
@@ -152,13 +174,20 @@ func (r *Row) String() string {
 	for x := range lines {
 		line := make([]string, len(cells[x]))
 		for y := range cells[x] {
-			line[y] = cells[x][y].String()
+			c := cells[x][y]
+			line[y] = c.Formatter(c.String())
 		}
 		lines[x] = strutil.Join(line, r.Separator)
 	}
 	return strutil.Join(lines, "\n")
 }
 
+func (r *Row) setCellFormatter(y int, cellFormatter CellFormatter) {
+	for x, c := range r.Cells {
+		c.Formatter = cellFormatter(x, y)
+	}
+}
+
 // Cell represents a column in a row
 type Cell struct {
 	// Width is the width of the cell
@@ -172,6 +201,8 @@ type Cell struct {
 
 	// Data is the cell data
 	Data interface{}
+
+	Formatter Formatter
 }
 
 // LineWidth returns the max width of all the lines in a cell
@@ -195,9 +226,8 @@ func (c *Cell) String() string {
 	if c.Width > 0 {
 		if c.Wrap && uint(len(s)) > c.Width {
 			return wordwrap.WrapString(s, c.Width)
-		} else {
-			return strutil.Resize(s, c.Width, c.RightAlign)
 		}
+		return strutil.Resize(s, c.Width, c.RightAlign)
 	}
 	return s
 }

table_test.go

@@ -29,6 +29,18 @@ func TestCell(t *testing.T) {
 	}
 }
 
+func TestFormatCell(t *testing.T) {
+	c := &Cell{
+		Data:      "foo bar",
+		Formatter: formatter,
+	}
+
+	got := c.Formatter(c.String())
+	if got != ">>foo bar<<" {
+		t.Fatal("need", ">>foo bar<<", "got", got)
+	}
+}
+
 func TestRow(t *testing.T) {
 	row := &Row{
 		Separator: "\t",
@@ -45,6 +57,22 @@ func TestRow(t *testing.T) {
 	}
 }
 
+func TestFormatRow(t *testing.T) {
+	row := &Row{
+		Separator: "\t",
+		Cells: []*Cell{
+			{Data: "foo", Width: 3, Wrap: true, Formatter: formatter},
+			{Data: "bar baz", Width: 3, Wrap: true, Formatter: formatter},
+		},
+	}
+	got := row.String()
+	need := ">>foo<<\t>>bar<<\n>>   <<\t>>baz<<"
+
+	if got != need {
+		t.Fatalf("need: %q | got: %q ", need, got)
+	}
+}
+
 func TestAlign(t *testing.T) {
 	table := New()
 	table.AddRow("foo", "bar baz")
@@ -79,3 +107,7 @@ func TestAddRow(t *testing.T) {
 		t.Fatal("want", 100, "got", len(table.Rows))
 	}
 }
+
+func formatter(s ...interface{}) string {
+	return ">>" + DefaultFormatter(s[0]) + "<<"
+}