feat(chromium): support more units for paper size and margins

pkg/modules/api/formdata.go

@@ -2,6 +2,7 @@ package api
 
 import (
 	"fmt"
+	"math"
 	"net/http"
 	"os"
 	"path/filepath"
@@ -145,6 +146,91 @@ func (form *FormData) MandatoryDuration(key string, target *time.Duration) *Form
 	return form.mustMandatoryField(key, target)
 }
 
+// Inches binds a form field to a float64 variable. It populates an error
+// if the value cannot be computed back to inches.
+//
+//	var foo float64
+//
+//	ctx.FormData().Inches("foo", &foo, 2.0)
+func (form *FormData) Inches(key string, target *float64, defaultValue float64) *FormData {
+	form.inches(key, target)
+	if *target == -math.MaxFloat64 {
+		*target = defaultValue
+	}
+	return form
+}
+
+// MandatoryInches binds a form field to a float64 variable. It populates
+// an error if the value cannot be computed back to inches, is empty, or the
+// "key" does not exist.
+//
+//	var foo float64
+//
+//	ctx.FormData().MandatoryInches("foo", &foo)
+func (form *FormData) MandatoryInches(key string, target *float64) *FormData {
+	val, ok := form.values[key]
+	if !ok || val[0] == "" {
+		form.append(
+			fmt.Errorf("form field '%s' is required", key),
+		)
+		return form
+	}
+	return form.inches(key, target)
+}
+
+// inches tries to compute a string value to inches.
+func (form *FormData) inches(key string, target *float64) *FormData {
+	var value string
+	form.mustValue(key, &value, "")
+
+	if value == "" {
+		*target = -math.MaxFloat64
+		return form
+	}
+
+	for _, unit := range []string{"pt", "px", "in", "mm", "cm", "pc"} {
+		if !strings.HasSuffix(value, unit) {
+			continue
+		}
+
+		val, err := strconv.ParseFloat(strings.TrimSuffix(value, unit), 64)
+		if err != nil {
+			form.append(
+				fmt.Errorf("form field '%s' is invalid (got '%s', resulting to %w)", key, value, err),
+			)
+			return form
+		}
+
+		switch unit {
+		case "pt":
+			*target = val * (1.0 / 72.0)
+		case "px":
+			*target = val * (1.0 / 96.0)
+		case "in":
+			*target = val
+		case "mm":
+			*target = val * (1.0 / 25.4)
+		case "cm":
+			*target = val * (1.0 / 2.54)
+		case "pc":
+			*target = val * (1.0 / 6.0)
+		}
+
+		return form
+	}
+
+	val, err := strconv.ParseFloat(value, 64)
+	if err != nil {
+		form.append(
+			fmt.Errorf("form field '%s' is invalid (got '%s', resulting to %w)", key, value, err),
+		)
+		return form
+	}
+
+	*target = val
+	return form
+}
+
 // Custom helps to define a custom binding function for a form field.
 //
 //	var foo map[string]string

pkg/modules/api/formdata_test.go

@@ -3,6 +3,7 @@ package api
 import (
 	"encoding/json"
 	"errors"
+	"fmt"
 	"reflect"
 	"testing"
 	"time"
@@ -768,6 +769,333 @@ func TestFormData_MandatoryDuration(t *testing.T) {
 	}
 }
 
+func TestFormData_Inches(t *testing.T) {
+	for _, tc := range []struct {
+		scenario     string
+		form         *FormData
+		defaultValue float64
+		expect       float64
+		expectError  bool
+	}{
+		{
+			scenario:     "key does not exist, fallback to default zero value",
+			form:         &FormData{},
+			defaultValue: 0.0,
+			expect:       0.0,
+			expectError:  false,
+		},
+		{
+			scenario:     "key does not exist, fallback to default value",
+			form:         &FormData{},
+			defaultValue: 2.5,
+			expect:       2.5,
+			expectError:  false,
+		},
+		{
+			scenario: "key does exist, but empty value, fallback to default value",
+			form: &FormData{
+				values: map[string][]string{
+					"foo": {
+						"",
+					},
+				},
+			},
+			defaultValue: 0.0,
+			expect:       0.0,
+			expectError:  false,
+		},
+		{
+			scenario: "key does exist, value has a unit, but the rest is not float64 compatible",
+			form: &FormData{
+				values: map[string][]string{
+					"foo": {
+						"foomm",
+					},
+				},
+			},
+			defaultValue: 0.0,
+			expect:       0.0,
+			expectError:  true,
+		},
+		{
+			scenario: "key does exist, but value has no unit and is invalid",
+			form: &FormData{
+				values: map[string][]string{
+					"foo": {
+						"foo",
+					},
+				},
+			},
+			defaultValue: 0.0,
+			expect:       0.0,
+			expectError:  true,
+		},
+		{
+			scenario: "key does exist with a pt value",
+			form: &FormData{
+				values: map[string][]string{
+					"foo": {
+						"72pt",
+					},
+				},
+			},
+			defaultValue: 0.0,
+			expect:       1.0,
+			expectError:  false,
+		},
+		{
+			scenario: "key does exist with a px value",
+			form: &FormData{
+				values: map[string][]string{
+					"foo": {
+						"96px",
+					},
+				},
+			},
+			defaultValue: 0.0,
+			expect:       1.0,
+			expectError:  false,
+		},
+		{
+			scenario: "key does exist with an in value",
+			form: &FormData{
+				values: map[string][]string{
+					"foo": {
+						"1in",
+					},
+				},
+			},
+			defaultValue: 0.0,
+			expect:       1.0,
+			expectError:  false,
+		},
+		{
+			scenario: "key does exist with a mm value",
+			form: &FormData{
+				values: map[string][]string{
+					"foo": {
+						"25.4mm",
+					},
+				},
+			},
+			defaultValue: 0.0,
+			expect:       1.0,
+			expectError:  false,
+		},
+		{
+			scenario: "key does exist with a cm value",
+			form: &FormData{
+				values: map[string][]string{
+					"foo": {
+						"2.54cm",
+					},
+				},
+			},
+			defaultValue: 0.0,
+			expect:       1.0,
+			expectError:  false,
+		},
+		{
+			scenario: "key does exist with a pc value",
+			form: &FormData{
+				values: map[string][]string{
+					"foo": {
+						"6pc",
+					},
+				},
+			},
+			defaultValue: 0.0,
+			expect:       1.0,
+			expectError:  false,
+		},
+		{
+			scenario: "key does exist with no unit in the value",
+			form: &FormData{
+				values: map[string][]string{
+					"foo": {
+						"100",
+					},
+				},
+			},
+			defaultValue: 0.0,
+			expect:       100,
+			expectError:  false,
+		},
+	} {
+		t.Run(tc.scenario, func(t *testing.T) {
+			var actual float64
+
+			tc.form.Inches("foo", &actual, tc.defaultValue)
+
+			if fmt.Sprintf("%.1f", actual) != fmt.Sprintf("%.1f", tc.expect) {
+				t.Errorf("expected %.1f but got %.1f", tc.expect, actual)
+			}
+
+			if tc.expectError && tc.form.errors == nil {
+				t.Fatal("expected error but got none", tc.form.errors)
+			}
+
+			if !tc.expectError && tc.form.errors != nil {
+				t.Fatalf("expected no error but got: %v", tc.form.errors)
+			}
+		})
+	}
+}
+
+func TestFormData_MandatoryInches(t *testing.T) {
+	for _, tc := range []struct {
+		scenario    string
+		form        *FormData
+		expect      float64
+		expectError bool
+	}{
+		{
+			scenario:    "missing mandatory key",
+			form:        &FormData{},
+			expect:      0.0,
+			expectError: true,
+		},
+		{
+			scenario: "mandatory value is empty",
+			form: &FormData{
+				values: map[string][]string{
+					"foo": {
+						"",
+					},
+				},
+			},
+			expect:      0.0,
+			expectError: true,
+		},
+		{
+			scenario: "mandatory value has a unit, but the rest is not float64 compatible",
+			form: &FormData{
+				values: map[string][]string{
+					"foo": {
+						"foomm",
+					},
+				},
+			},
+			expect:      0.0,
+			expectError: true,
+		},
+		{
+			scenario: "mandatory value has no unit and is invalid",
+			form: &FormData{
+				values: map[string][]string{
+					"foo": {
+						"foo",
+					},
+				},
+			},
+			expect:      0.0,
+			expectError: true,
+		},
+		{
+			scenario: "a pt mandatory value",
+			form: &FormData{
+				values: map[string][]string{
+					"foo": {
+						"72pt",
+					},
+				},
+			},
+			expect:      1.0,
+			expectError: false,
+		},
+		{
+			scenario: "a px mandatory value",
+			form: &FormData{
+				values: map[string][]string{
+					"foo": {
+						"96px",
+					},
+				},
+			},
+			expect:      1.0,
+			expectError: false,
+		},
+		{
+			scenario: "an in mandatory value",
+			form: &FormData{
+				values: map[string][]string{
+					"foo": {
+						"1in",
+					},
+				},
+			},
+			expect:      1.0,
+			expectError: false,
+		},
+		{
+			scenario: "a mm mandatory value",
+			form: &FormData{
+				values: map[string][]string{
+					"foo": {
+						"25.4mm",
+					},
+				},
+			},
+			expect:      1.0,
+			expectError: false,
+		},
+		{
+			scenario: "a cm mandatory value",
+			form: &FormData{
+				values: map[string][]string{
+					"foo": {
+						"2.54cm",
+					},
+				},
+			},
+			expect:      1.0,
+			expectError: false,
+		},
+		{
+			scenario: "a pc mandatory value",
+			form: &FormData{
+				values: map[string][]string{
+					"foo": {
+						"6pc",
+					},
+				},
+			},
+			expect:      1.0,
+			expectError: false,
+		},
+		{
+			scenario: "no unit in the mandatory value",
+			form: &FormData{
+				values: map[string][]string{
+					"foo": {
+						"100",
+					},
+				},
+			},
+			expect:      100,
+			expectError: false,
+		},
+	} {
+		t.Run(tc.scenario, func(t *testing.T) {
+			var actual float64
+
+			tc.form.MandatoryInches("foo", &actual)
+
+			if fmt.Sprintf("%.1f", actual) != fmt.Sprintf("%.1f", tc.expect) {
+				t.Errorf("expected %.1f but got %.1f", tc.expect, actual)
+			}
+
+			if tc.expectError && tc.form.errors == nil {
+				t.Fatal("expected error but got none", tc.form.errors)
+			}
+
+			if !tc.expectError && tc.form.errors != nil {
+				t.Fatalf("expected no error but got: %v", tc.form.errors)
+			}
+		})
+	}
+}
+
 func TestFormData_Custom(t *testing.T) {
 	for _, tc := range []struct {
 		scenario     string

pkg/modules/chromium/routes.go

@@ -122,12 +122,12 @@ func FormDataChromiumPdfOptions(ctx *api.Context) (*api.FormData, PdfOptions) {
 		Bool("printBackground", &printBackground, defaultPdfOptions.PrintBackground).
 		Float64("scale", &scale, defaultPdfOptions.Scale).
 		Bool("singlePage", &singlePage, defaultPdfOptions.SinglePage).
-		Float64("paperWidth", &paperWidth, defaultPdfOptions.PaperWidth).
+		Inches("paperWidth", &paperWidth, defaultPdfOptions.PaperWidth).
-		Float64("paperHeight", &paperHeight, defaultPdfOptions.PaperHeight).
+		Inches("paperHeight", &paperHeight, defaultPdfOptions.PaperHeight).
-		Float64("marginTop", &marginTop, defaultPdfOptions.MarginTop).
+		Inches("marginTop", &marginTop, defaultPdfOptions.MarginTop).
-		Float64("marginBottom", &marginBottom, defaultPdfOptions.MarginBottom).
+		Inches("marginBottom", &marginBottom, defaultPdfOptions.MarginBottom).
-		Float64("marginLeft", &marginLeft, defaultPdfOptions.MarginLeft).
+		Inches("marginLeft", &marginLeft, defaultPdfOptions.MarginLeft).
-		Float64("marginRight", &marginRight, defaultPdfOptions.MarginRight).
+		Inches("marginRight", &marginRight, defaultPdfOptions.MarginRight).
 		String("nativePageRanges", &pageRanges, defaultPdfOptions.PageRanges).
 		Content("header.html", &headerTemplate, defaultPdfOptions.HeaderTemplate).
 		Content("footer.html", &footerTemplate, defaultPdfOptions.FooterTemplate).