make master,v4,v5 compatible

filters.go

@@ -10,10 +10,9 @@ import (
 	"time"
 	"unicode/utf8"
 
-	"github.com/flosch/pongo2/v4"
-
 	"github.com/extemporalgenome/slug"
 	"github.com/flosch/go-humanize"
+	"github.com/flosch/pongo2"
 	"github.com/russross/blackfriday/v2"
 )
 

filters_test.go

@@ -4,9 +4,8 @@ import (
 	"testing"
 	"time"
 
-	. "gopkg.in/check.v1"
-
 	"github.com/flosch/pongo2"
+	. "gopkg.in/check.v1"
 )
 
 // Hook up gocheck into the "go test" runner.

go.mod

@@ -1,4 +1,4 @@
-module github.com/flosch/pongo2-addons
+module github.com/idc77/pongo2-addons
 
 go 1.14
 
@@ -6,10 +6,11 @@ require (
 	github.com/extemporalgenome/slug v0.0.0-20150414033109-0320c85e32e0
 	github.com/flosch/go-humanize v0.0.0-20140728123800-3ba51eabe506
 	github.com/flosch/pongo2 v0.0.0-20200529170236-5abacdfa4915
-	github.com/flosch/pongo2/v4 v4.0.2 // indirect
-	github.com/niemeyer/pretty v0.0.0-20200227124842-a10e7caefd8e // indirect
+	github.com/flosch/pongo2/v4 v4.0.2
+	github.com/flosch/pongo2/v5 v5.0.0
+	github.com/pmezard/go-difflib v1.0.0 // indirect
 	github.com/russross/blackfriday/v2 v2.0.1
 	github.com/shurcooL/sanitized_anchor_name v1.0.0 // indirect
-	golang.org/x/text v0.3.3 // indirect
-	gopkg.in/check.v1 v1.0.0-20200902074654-038fdea0a05b
+	golang.org/x/text v0.3.7 // indirect
+	gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c
 )

go.sum

@@ -6,20 +6,31 @@ github.com/flosch/pongo2 v0.0.0-20200529170236-5abacdfa4915 h1:rNVrewdFbSujcoKZi
 github.com/flosch/pongo2 v0.0.0-20200529170236-5abacdfa4915/go.mod h1:fB4mx6dzqFinCxIf3a7Mf5yLk+18Bia9mPAnuejcvDA=
 github.com/flosch/pongo2/v4 v4.0.2 h1:gv+5Pe3vaSVmiJvh/BZa82b7/00YUGm0PIyVVLop0Hw=
 github.com/flosch/pongo2/v4 v4.0.2/go.mod h1:B5ObFANs/36VwxxlgKpdchIJHMvHB562PW+BWPhwZD8=
+github.com/flosch/pongo2/v5 v5.0.0 h1:ZauMp+iPZzh2aI1QM2UwRb0lXD4BoFcvBuWqefkIuq0=
+github.com/flosch/pongo2/v5 v5.0.0/go.mod h1:6ysKu++8ANFXmc3x6uA6iVaS+PKUoDfdX3yPcv8TIzY=
+github.com/go-check/check v0.0.0-20180628173108-788fd7840127 h1:0gkP6mzaMqkmpcJYCFOLkIBwI7xFExG03bbkOkCvUPI=
 github.com/go-check/check v0.0.0-20180628173108-788fd7840127/go.mod h1:9ES+weclKsC9YodN5RgxqK/VD9HM9JsCSh7rNhMZE98=
 github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORNo=
+github.com/kr/pretty v0.2.1 h1:Fmg33tUaq4/8ym9TJN1x7sLJnHVwhP33CNkpYV/7rwI=
+github.com/kr/pretty v0.2.1/go.mod h1:ipq/a2n7PKx3OHsz4KJII5eveXtPO4qwEXGdVfWzfnI=
 github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
+github.com/kr/text v0.1.0 h1:45sCR5RtlFHMR4UwH9sdQ5TC8v0qDQCHnXt+kaKSTVE=
 github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
-github.com/niemeyer/pretty v0.0.0-20200227124842-a10e7caefd8e h1:fD57ERR4JtEqsWbfPhv4DMiApHyliiK5xCTNVSPiaAs=
 github.com/niemeyer/pretty v0.0.0-20200227124842-a10e7caefd8e/go.mod h1:zD1mROLANZcx1PVRCS0qkT7pwLkGfwJo4zjcN/Tysno=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/russross/blackfriday/v2 v2.0.1 h1:lPqVAte+HuHNfhJ/0LC98ESWRz8afy9tM/0RK8m9o+Q=
 github.com/russross/blackfriday/v2 v2.0.1/go.mod h1:+Rmxgy9KzJVeS9/2gXHxylqXiyQDYRxCVz55jmeOWTM=
+github.com/russross/blackfriday/v2 v2.1.0 h1:JIOH55/0cWyOuilr9/qlrm0BSXldqnqwMsf35Ld67mk=
+github.com/russross/blackfriday/v2 v2.1.0/go.mod h1:+Rmxgy9KzJVeS9/2gXHxylqXiyQDYRxCVz55jmeOWTM=
 github.com/shurcooL/sanitized_anchor_name v1.0.0 h1:PdmoCO6wvbs+7yrJyMORt4/BmY5IYyJwS/kOiWx8mHo=
 github.com/shurcooL/sanitized_anchor_name v1.0.0/go.mod h1:1NzhyTcUVG4SuEtjjoZeVRXNmyL/1OwPU0+IJeTBvfc=
 golang.org/x/text v0.3.3 h1:cokOdA+Jmi5PJGXLlLllQSgYigAEfHXJAERHVMaCc2k=
 golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
+golang.org/x/text v0.3.7 h1:olpwvP2KacW1ZWvsR7uQhoyTYvKAupfQrRGBFM352Gk=
+golang.org/x/text v0.3.7/go.mod h1:u+2+/6zg+i71rQMx5EYifcz6MCKuco9NR6JIITiCfzQ=
 golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
-gopkg.in/check.v1 v1.0.0-20200227125254-8fa46927fb4f h1:BLraFXnmrev5lT+xlilqcH8XK9/i0At2xKjWk4p6zsU=
-gopkg.in/check.v1 v1.0.0-20200227125254-8fa46927fb4f/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/check.v1 v1.0.0-20200902074654-038fdea0a05b/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c h1:Hei/4ADfdWqJk1ZMxUNpqntNwaWcugrBjAiHlqqRiVk=
+gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c/go.mod h1:JHkPIbrfpd72SG/EVd6muEfDQjcINNoR0C8j2r3qZ4Q=

v4/filters.go

@@ -0,0 +1,310 @@
+package pongo2addons
+
+import (
+	"bytes"
+	"errors"
+	"fmt"
+	"math/rand"
+	"regexp"
+	"strings"
+	"time"
+	"unicode/utf8"
+
+	"github.com/extemporalgenome/slug"
+	"github.com/flosch/go-humanize"
+	"github.com/flosch/pongo2/v4"
+	"github.com/russross/blackfriday/v2"
+)
+
+func init() {
+	rand.Seed(time.Now().UTC().UnixNano())
+
+	// Regulars
+	pongo2.RegisterFilter("slugify", filterSlugify)
+	pongo2.RegisterFilter("filesizeformat", filterFilesizeformat)
+	pongo2.RegisterFilter("truncatesentences", filterTruncatesentences)
+	pongo2.RegisterFilter("truncatesentences_html", filterTruncatesentencesHTML)
+	pongo2.RegisterFilter("random", filterRandom)
+
+	// Markup
+	pongo2.RegisterFilter("markdown", filterMarkdown)
+
+	// Humanize
+	pongo2.RegisterFilter("timeuntil", filterTimeuntilTimesince)
+	pongo2.RegisterFilter("timesince", filterTimeuntilTimesince)
+	pongo2.RegisterFilter("naturaltime", filterTimeuntilTimesince)
+	pongo2.RegisterFilter("naturalday", filterNaturalday)
+	pongo2.RegisterFilter("intcomma", filterIntcomma)
+	pongo2.RegisterFilter("ordinal", filterOrdinal)
+}
+
+func filterMarkdown(in *pongo2.Value, param *pongo2.Value) (*pongo2.Value, *pongo2.Error) {
+	return pongo2.AsSafeValue(string(blackfriday.Run([]byte(in.String())))), nil
+}
+
+func filterSlugify(in *pongo2.Value, param *pongo2.Value) (*pongo2.Value, *pongo2.Error) {
+	return pongo2.AsValue(slug.Slug(in.String())), nil
+}
+
+func filterFilesizeformat(in *pongo2.Value, param *pongo2.Value) (*pongo2.Value, *pongo2.Error) {
+	return pongo2.AsValue(humanize.IBytes(uint64(in.Integer()))), nil
+}
+
+var filterTruncatesentencesRe = regexp.MustCompile(`(?U:.*[\w]{3,}.*([\d][\.!?][\D]|[\D][\.!?][\s]|[\n$]))`)
+
+func filterTruncatesentences(in *pongo2.Value, param *pongo2.Value) (*pongo2.Value, *pongo2.Error) {
+	count := param.Integer()
+	if count <= 0 {
+		return pongo2.AsValue(""), nil
+	}
+	sentencens := filterTruncatesentencesRe.FindAllString(strings.TrimSpace(in.String()), -1)
+	return pongo2.AsValue(strings.TrimSpace(strings.Join(sentencens[:min(count, len(sentencens))], ""))), nil
+}
+
+// Taken from pongo2/filters_builtin.go
+func filterTruncateHTMLHelper(value string, newOutput *bytes.Buffer, cond func() bool, fn func(c rune, s int, idx int) int, finalize func()) {
+	vLen := len(value)
+	tagStack := make([]string, 0)
+	idx := 0
+
+	for idx < vLen && !cond() {
+		c, s := utf8.DecodeRuneInString(value[idx:])
+		if c == utf8.RuneError {
+			idx += s
+			continue
+		}
+
+		if c == '<' {
+			newOutput.WriteRune(c)
+			idx += s // consume "<"
+
+			if idx+1 < vLen {
+				if value[idx] == '/' {
+					// Close tag
+
+					newOutput.WriteString("/")
+
+					tag := ""
+					idx++ // consume "/"
+
+					for idx < vLen {
+						c2, size2 := utf8.DecodeRuneInString(value[idx:])
+						if c2 == utf8.RuneError {
+							idx += size2
+							continue
+						}
+
+						// End of tag found
+						if c2 == '>' {
+							idx++ // consume ">"
+							break
+						}
+						tag += string(c2)
+						idx += size2
+					}
+
+					if len(tagStack) > 0 {
+						// Ideally, the close tag is TOP of tag stack
+						// In malformed HTML, it must not be, so iterate through the stack and remove the tag
+						for i := len(tagStack) - 1; i >= 0; i-- {
+							if tagStack[i] == tag {
+								// Found the tag
+								tagStack[i] = tagStack[len(tagStack)-1]
+								tagStack = tagStack[:len(tagStack)-1]
+								break
+							}
+						}
+					}
+
+					newOutput.WriteString(tag)
+					newOutput.WriteString(">")
+				} else {
+					// Open tag
+
+					tag := ""
+
+					params := false
+					for idx < vLen {
+						c2, size2 := utf8.DecodeRuneInString(value[idx:])
+						if c2 == utf8.RuneError {
+							idx += size2
+							continue
+						}
+
+						newOutput.WriteRune(c2)
+
+						// End of tag found
+						if c2 == '>' {
+							idx++ // consume ">"
+							break
+						}
+
+						if !params {
+							if c2 == ' ' {
+								params = true
+							} else {
+								tag += string(c2)
+							}
+						}
+
+						idx += size2
+					}
+
+					// Add tag to stack
+					tagStack = append(tagStack, tag)
+				}
+			}
+		} else {
+			idx = fn(c, s, idx)
+		}
+	}
+
+	finalize()
+
+	for i := len(tagStack) - 1; i >= 0; i-- {
+		tag := tagStack[i]
+		// Close everything from the regular tag stack
+		newOutput.WriteString(fmt.Sprintf("</%s>", tag))
+	}
+}
+
+func filterTruncatesentencesHTML(in *pongo2.Value, param *pongo2.Value) (*pongo2.Value, *pongo2.Error) {
+	count := param.Integer()
+	if count <= 0 {
+		return pongo2.AsValue(""), nil
+	}
+
+	value := in.String()
+	newLen := max(param.Integer(), 0)
+
+	newOutput := bytes.NewBuffer(nil)
+
+	sentencefilter := 0
+
+	filterTruncateHTMLHelper(value, newOutput, func() bool {
+		return sentencefilter >= newLen
+	}, func(_ rune, _ int, idx int) int {
+		// Get next word
+		wordFound := false
+
+		for idx < len(value) {
+			c2, size2 := utf8.DecodeRuneInString(value[idx:])
+			if c2 == utf8.RuneError {
+				idx += size2
+				continue
+			}
+
+			if c2 == '<' {
+				// HTML tag start, don't consume it
+				return idx
+			}
+
+			newOutput.WriteRune(c2)
+			idx += size2
+
+			if (c2 == '.' && !(idx+1 < len(value) && value[idx+1] >= '0' && value[idx+1] <= '9')) ||
+				c2 == '!' || c2 == '?' || c2 == '\n' {
+				// Sentence ends here, stop capturing it now
+				break
+			} else {
+				wordFound = true
+			}
+		}
+
+		if wordFound {
+			sentencefilter++
+		}
+
+		return idx
+	}, func() {})
+
+	return pongo2.AsSafeValue(newOutput.String()), nil
+}
+
+func filterRandom(in *pongo2.Value, param *pongo2.Value) (*pongo2.Value, *pongo2.Error) {
+	if !in.CanSlice() {
+		return nil, &pongo2.Error{
+			Sender:    "filter:random",
+			OrigError: errors.New("input is not sliceable"),
+		}
+	}
+
+	if in.Len() <= 0 {
+		return nil, &pongo2.Error{
+			Sender:    "filter:random",
+			OrigError: errors.New("input slice is empty"),
+		}
+	}
+
+	return in.Index(rand.Intn(in.Len())), nil
+}
+
+func filterTimeuntilTimesince(in *pongo2.Value, param *pongo2.Value) (*pongo2.Value, *pongo2.Error) {
+	basetime, isTime := in.Interface().(time.Time)
+	if !isTime {
+		return nil, &pongo2.Error{
+			Sender:    "filter:timeuntil/timesince",
+			OrigError: errors.New("time-value is not a time.Time-instance"),
+		}
+	}
+	var paramtime time.Time
+	if !param.IsNil() {
+		paramtime, isTime = param.Interface().(time.Time)
+		if !isTime {
+			return nil, &pongo2.Error{
+				Sender:    "filter:timeuntil/timesince",
+				OrigError: errors.New("time-parameter is not a time.Time-instance"),
+			}
+		}
+	} else {
+		paramtime = time.Now()
+	}
+
+	return pongo2.AsValue(humanize.TimeDuration(basetime.Sub(paramtime))), nil
+}
+
+func filterIntcomma(in *pongo2.Value, param *pongo2.Value) (*pongo2.Value, *pongo2.Error) {
+	return pongo2.AsValue(humanize.Comma(int64(in.Integer()))), nil
+}
+
+func filterOrdinal(in *pongo2.Value, param *pongo2.Value) (*pongo2.Value, *pongo2.Error) {
+	return pongo2.AsValue(humanize.Ordinal(in.Integer())), nil
+}
+
+func filterNaturalday(in *pongo2.Value, param *pongo2.Value) (*pongo2.Value, *pongo2.Error) {
+	basetime, isTime := in.Interface().(time.Time)
+	if !isTime {
+		return nil, &pongo2.Error{
+			Sender:    "filter:naturalday",
+			OrigError: errors.New("naturalday-value is not a time.Time-instance"),
+		}
+	}
+
+	var referenceTime time.Time
+	if !param.IsNil() {
+		referenceTime, isTime = param.Interface().(time.Time)
+		if !isTime {
+			return nil, &pongo2.Error{
+				Sender:    "filter:naturalday",
+				OrigError: errors.New("naturalday-parameter is not a time.Time-instance"),
+			}
+		}
+	} else {
+		referenceTime = time.Now()
+	}
+
+	d := referenceTime.Sub(basetime) / time.Hour
+
+	switch {
+	case d >= 0 && d < 24:
+		// Today
+		return pongo2.AsValue("today"), nil
+	case d >= 24:
+		return pongo2.AsValue("yesterday"), nil
+	case d < 0 && d >= -24:
+		return pongo2.AsValue("tomorrow"), nil
+	}
+
+	// Default behaviour
+	return pongo2.ApplyFilter("naturaltime", in, param)
+}

v4/filters_test.go

@@ -0,0 +1,97 @@
+package pongo2addons
+
+import (
+	"testing"
+	"time"
+
+	"github.com/flosch/pongo2/v4"
+	. "gopkg.in/check.v1"
+)
+
+// Hook up gocheck into the "go test" runner.
+func Test(t *testing.T) {
+	TestingT(t)
+}
+
+// A wrapprt of pongo2.RenderTemplateString
+func getResult(s string, ctx pongo2.Context) string {
+	result, _ := pongo2.RenderTemplateString(s, ctx)
+	return result
+}
+
+type TestSuite1 struct{}
+
+var _ = Suite(&TestSuite1{})
+
+func (s *TestSuite1) TestFilters(c *C) {
+	// Markdown
+	c.Assert(getResult("{{ \"**test**\"|markdown }}", nil), Equals, "<p><strong>test</strong></p>\n")
+
+	// Slugify
+	c.Assert(getResult("{{ \"this is ä test!\"|slugify }}", nil), Equals, "this-is-a-test")
+
+	// Filesizeformat
+	c.Assert(getResult("{{ 123456789|filesizeformat }}", nil), Equals, "118MiB")
+
+	// Timesince/timeuntil
+	baseDate := time.Date(2014, time.February, 1, 8, 30, 00, 00, time.UTC)
+	futureDate := baseDate.Add(24*7*4*time.Hour + 2*time.Hour)
+	c.Assert(getResult("{{ future_date|timeuntil:base_date }}",
+		pongo2.Context{"base_date": baseDate, "future_date": futureDate}), Equals, "4 weeks from now")
+
+	baseDate = time.Date(2014, time.February, 1, 8, 30, 00, 00, time.UTC)
+	futureDate = baseDate.Add(2 * time.Hour)
+	c.Assert(getResult("{{ future_date|timeuntil:base_date }}",
+		pongo2.Context{"base_date": baseDate, "future_date": futureDate}), Equals, "2 hours from now")
+
+	baseDate = time.Date(2014, time.February, 1, 8, 30, 00, 00, time.UTC)
+	futureDate = baseDate.Add(2 * time.Hour)
+	c.Assert(getResult("{{ base_date|timesince:future_date }}",
+		pongo2.Context{"base_date": baseDate, "future_date": futureDate}), Equals, "2 hours ago")
+
+	// Natural time
+	baseDate = time.Date(2014, time.February, 1, 8, 30, 00, 00, time.UTC)
+	futureDate = baseDate.Add(4 * time.Second)
+	c.Assert(getResult("{{ base_date|naturaltime:future_date }}",
+		pongo2.Context{"base_date": baseDate, "future_date": futureDate}), Equals, "4 seconds ago")
+
+	// Naturalday
+	today := time.Date(2014, time.February, 1, 8, 30, 00, 00, time.UTC)
+	yesterday := today.Add(-24 * time.Hour)
+	tomorrow := today.Add(24 * time.Hour)
+	todayPlus3 := today.Add(3 * 24 * time.Hour)
+	c.Assert(getResult("{{ date|naturalday:today }}",
+		pongo2.Context{"date": today, "today": today}), Equals, "today")
+	c.Assert(getResult("{{ date|naturalday:today }}",
+		pongo2.Context{"date": yesterday, "today": today}), Equals, "yesterday")
+	c.Assert(getResult("{{ date|naturalday:today }}",
+		pongo2.Context{"date": tomorrow, "today": today}), Equals, "tomorrow")
+	c.Assert(getResult("{{ date|naturalday:today }}",
+		pongo2.Context{"date": todayPlus3, "today": today}), Equals, "3 days from now")
+
+	// Intcomma
+	c.Assert(getResult("{{ 123456789|intcomma }}", nil), Equals, "123,456,789")
+
+	// Ordinal
+	c.Assert(getResult("{{ 1|ordinal }} {{ 2|ordinal }} {{ 3|ordinal }} {{ 18241|ordinal }}", nil),
+		Equals, "1st 2nd 3rd 18241st")
+
+	// Truncatesentences
+	c.Assert(getResult("{{ text|truncatesentences:3|safe }}", pongo2.Context{
+		"text": `This is a first sentence with a 4.50 number. The second one is even more fun! Isn't it? Last sentence, okay.`}),
+		Equals, "This is a first sentence with a 4.50 number. The second one is even more fun! Isn't it?")
+
+	// Truncatesentences_html
+	c.Assert(getResult("{{ text|truncatesentences_html:2 }}", pongo2.Context{
+		"text": `<div class="test"><ul><li>This is a first sentence with a 4.50 number.</li><li>The second one is even more fun! Isn't it?</li><li>Last sentence, okay.</li></ul></div>`}),
+		Equals, `<div class="test"><ul><li>This is a first sentence with a 4.50 number.</li><li>The second one is even more fun!</li></ul></div>`)
+	c.Assert(getResult("{{ text|truncatesentences_html:3 }}", pongo2.Context{
+		"text": `<div class="test"><ul><li>This is a first sentence with a 4.50 number.</li><li>The second one is even more fun! Isn't it?</li><li>Last sentence, okay.</li></ul></div>`}),
+		Equals, `<div class="test"><ul><li>This is a first sentence with a 4.50 number.</li><li>The second one is even more fun! Isn't it?</li></ul></div>`)
+
+	// Random
+	c.Assert(getResult("{{ array|random }}",
+		pongo2.Context{"array": []int{42}}),
+		Equals, "42")
+
+}

v4/helpers.go

@@ -0,0 +1,15 @@
+package pongo2addons
+
+func max(a, b int) int {
+	if a > b {
+		return a
+	}
+	return b
+}
+
+func min(a, b int) int {
+	if a < b {
+		return a
+	}
+	return b
+}

v5/filters.go

@@ -0,0 +1,310 @@
+package pongo2addons
+
+import (
+	"bytes"
+	"errors"
+	"fmt"
+	"math/rand"
+	"regexp"
+	"strings"
+	"time"
+	"unicode/utf8"
+
+	"github.com/extemporalgenome/slug"
+	"github.com/flosch/go-humanize"
+	"github.com/flosch/pongo2/v5"
+	"github.com/russross/blackfriday/v2"
+)
+
+func init() {
+	rand.Seed(time.Now().UTC().UnixNano())
+
+	// Regulars
+	pongo2.RegisterFilter("slugify", filterSlugify)
+	pongo2.RegisterFilter("filesizeformat", filterFilesizeformat)
+	pongo2.RegisterFilter("truncatesentences", filterTruncatesentences)
+	pongo2.RegisterFilter("truncatesentences_html", filterTruncatesentencesHTML)
+	pongo2.RegisterFilter("random", filterRandom)
+
+	// Markup
+	pongo2.RegisterFilter("markdown", filterMarkdown)
+
+	// Humanize
+	pongo2.RegisterFilter("timeuntil", filterTimeuntilTimesince)
+	pongo2.RegisterFilter("timesince", filterTimeuntilTimesince)
+	pongo2.RegisterFilter("naturaltime", filterTimeuntilTimesince)
+	pongo2.RegisterFilter("naturalday", filterNaturalday)
+	pongo2.RegisterFilter("intcomma", filterIntcomma)
+	pongo2.RegisterFilter("ordinal", filterOrdinal)
+}
+
+func filterMarkdown(in *pongo2.Value, param *pongo2.Value) (*pongo2.Value, *pongo2.Error) {
+	return pongo2.AsSafeValue(string(blackfriday.Run([]byte(in.String())))), nil
+}
+
+func filterSlugify(in *pongo2.Value, param *pongo2.Value) (*pongo2.Value, *pongo2.Error) {
+	return pongo2.AsValue(slug.Slug(in.String())), nil
+}
+
+func filterFilesizeformat(in *pongo2.Value, param *pongo2.Value) (*pongo2.Value, *pongo2.Error) {
+	return pongo2.AsValue(humanize.IBytes(uint64(in.Integer()))), nil
+}
+
+var filterTruncatesentencesRe = regexp.MustCompile(`(?U:.*[\w]{3,}.*([\d][\.!?][\D]|[\D][\.!?][\s]|[\n$]))`)
+
+func filterTruncatesentences(in *pongo2.Value, param *pongo2.Value) (*pongo2.Value, *pongo2.Error) {
+	count := param.Integer()
+	if count <= 0 {
+		return pongo2.AsValue(""), nil
+	}
+	sentencens := filterTruncatesentencesRe.FindAllString(strings.TrimSpace(in.String()), -1)
+	return pongo2.AsValue(strings.TrimSpace(strings.Join(sentencens[:min(count, len(sentencens))], ""))), nil
+}
+
+// Taken from pongo2/filters_builtin.go
+func filterTruncateHTMLHelper(value string, newOutput *bytes.Buffer, cond func() bool, fn func(c rune, s int, idx int) int, finalize func()) {
+	vLen := len(value)
+	tagStack := make([]string, 0)
+	idx := 0
+
+	for idx < vLen && !cond() {
+		c, s := utf8.DecodeRuneInString(value[idx:])
+		if c == utf8.RuneError {
+			idx += s
+			continue
+		}
+
+		if c == '<' {
+			newOutput.WriteRune(c)
+			idx += s // consume "<"
+
+			if idx+1 < vLen {
+				if value[idx] == '/' {
+					// Close tag
+
+					newOutput.WriteString("/")
+
+					tag := ""
+					idx++ // consume "/"
+
+					for idx < vLen {
+						c2, size2 := utf8.DecodeRuneInString(value[idx:])
+						if c2 == utf8.RuneError {
+							idx += size2
+							continue
+						}
+
+						// End of tag found
+						if c2 == '>' {
+							idx++ // consume ">"
+							break
+						}
+						tag += string(c2)
+						idx += size2
+					}
+
+					if len(tagStack) > 0 {
+						// Ideally, the close tag is TOP of tag stack
+						// In malformed HTML, it must not be, so iterate through the stack and remove the tag
+						for i := len(tagStack) - 1; i >= 0; i-- {
+							if tagStack[i] == tag {
+								// Found the tag
+								tagStack[i] = tagStack[len(tagStack)-1]
+								tagStack = tagStack[:len(tagStack)-1]
+								break
+							}
+						}
+					}
+
+					newOutput.WriteString(tag)
+					newOutput.WriteString(">")
+				} else {
+					// Open tag
+
+					tag := ""
+
+					params := false
+					for idx < vLen {
+						c2, size2 := utf8.DecodeRuneInString(value[idx:])
+						if c2 == utf8.RuneError {
+							idx += size2
+							continue
+						}
+
+						newOutput.WriteRune(c2)
+
+						// End of tag found
+						if c2 == '>' {
+							idx++ // consume ">"
+							break
+						}
+
+						if !params {
+							if c2 == ' ' {
+								params = true
+							} else {
+								tag += string(c2)
+							}
+						}
+
+						idx += size2
+					}
+
+					// Add tag to stack
+					tagStack = append(tagStack, tag)
+				}
+			}
+		} else {
+			idx = fn(c, s, idx)
+		}
+	}
+
+	finalize()
+
+	for i := len(tagStack) - 1; i >= 0; i-- {
+		tag := tagStack[i]
+		// Close everything from the regular tag stack
+		newOutput.WriteString(fmt.Sprintf("</%s>", tag))
+	}
+}
+
+func filterTruncatesentencesHTML(in *pongo2.Value, param *pongo2.Value) (*pongo2.Value, *pongo2.Error) {
+	count := param.Integer()
+	if count <= 0 {
+		return pongo2.AsValue(""), nil
+	}
+
+	value := in.String()
+	newLen := max(param.Integer(), 0)
+
+	newOutput := bytes.NewBuffer(nil)
+
+	sentencefilter := 0
+
+	filterTruncateHTMLHelper(value, newOutput, func() bool {
+		return sentencefilter >= newLen
+	}, func(_ rune, _ int, idx int) int {
+		// Get next word
+		wordFound := false
+
+		for idx < len(value) {
+			c2, size2 := utf8.DecodeRuneInString(value[idx:])
+			if c2 == utf8.RuneError {
+				idx += size2
+				continue
+			}
+
+			if c2 == '<' {
+				// HTML tag start, don't consume it
+				return idx
+			}
+
+			newOutput.WriteRune(c2)
+			idx += size2
+
+			if (c2 == '.' && !(idx+1 < len(value) && value[idx+1] >= '0' && value[idx+1] <= '9')) ||
+				c2 == '!' || c2 == '?' || c2 == '\n' {
+				// Sentence ends here, stop capturing it now
+				break
+			} else {
+				wordFound = true
+			}
+		}
+
+		if wordFound {
+			sentencefilter++
+		}
+
+		return idx
+	}, func() {})
+
+	return pongo2.AsSafeValue(newOutput.String()), nil
+}
+
+func filterRandom(in *pongo2.Value, param *pongo2.Value) (*pongo2.Value, *pongo2.Error) {
+	if !in.CanSlice() {
+		return nil, &pongo2.Error{
+			Sender:    "filter:random",
+			OrigError: errors.New("input is not sliceable"),
+		}
+	}
+
+	if in.Len() <= 0 {
+		return nil, &pongo2.Error{
+			Sender:    "filter:random",
+			OrigError: errors.New("input slice is empty"),
+		}
+	}
+
+	return in.Index(rand.Intn(in.Len())), nil
+}
+
+func filterTimeuntilTimesince(in *pongo2.Value, param *pongo2.Value) (*pongo2.Value, *pongo2.Error) {
+	basetime, isTime := in.Interface().(time.Time)
+	if !isTime {
+		return nil, &pongo2.Error{
+			Sender:    "filter:timeuntil/timesince",
+			OrigError: errors.New("time-value is not a time.Time-instance"),
+		}
+	}
+	var paramtime time.Time
+	if !param.IsNil() {
+		paramtime, isTime = param.Interface().(time.Time)
+		if !isTime {
+			return nil, &pongo2.Error{
+				Sender:    "filter:timeuntil/timesince",
+				OrigError: errors.New("time-parameter is not a time.Time-instance"),
+			}
+		}
+	} else {
+		paramtime = time.Now()
+	}
+
+	return pongo2.AsValue(humanize.TimeDuration(basetime.Sub(paramtime))), nil
+}
+
+func filterIntcomma(in *pongo2.Value, param *pongo2.Value) (*pongo2.Value, *pongo2.Error) {
+	return pongo2.AsValue(humanize.Comma(int64(in.Integer()))), nil
+}
+
+func filterOrdinal(in *pongo2.Value, param *pongo2.Value) (*pongo2.Value, *pongo2.Error) {
+	return pongo2.AsValue(humanize.Ordinal(in.Integer())), nil
+}
+
+func filterNaturalday(in *pongo2.Value, param *pongo2.Value) (*pongo2.Value, *pongo2.Error) {
+	basetime, isTime := in.Interface().(time.Time)
+	if !isTime {
+		return nil, &pongo2.Error{
+			Sender:    "filter:naturalday",
+			OrigError: errors.New("naturalday-value is not a time.Time-instance"),
+		}
+	}
+
+	var referenceTime time.Time
+	if !param.IsNil() {
+		referenceTime, isTime = param.Interface().(time.Time)
+		if !isTime {
+			return nil, &pongo2.Error{
+				Sender:    "filter:naturalday",
+				OrigError: errors.New("naturalday-parameter is not a time.Time-instance"),
+			}
+		}
+	} else {
+		referenceTime = time.Now()
+	}
+
+	d := referenceTime.Sub(basetime) / time.Hour
+
+	switch {
+	case d >= 0 && d < 24:
+		// Today
+		return pongo2.AsValue("today"), nil
+	case d >= 24:
+		return pongo2.AsValue("yesterday"), nil
+	case d < 0 && d >= -24:
+		return pongo2.AsValue("tomorrow"), nil
+	}
+
+	// Default behaviour
+	return pongo2.ApplyFilter("naturaltime", in, param)
+}

v5/filters_test.go

@@ -0,0 +1,97 @@
+package pongo2addons
+
+import (
+	"testing"
+	"time"
+
+	"github.com/flosch/pongo2/v5"
+	. "gopkg.in/check.v1"
+)
+
+// Hook up gocheck into the "go test" runner.
+func Test(t *testing.T) {
+	TestingT(t)
+}
+
+// A wrapprt of pongo2.RenderTemplateString
+func getResult(s string, ctx pongo2.Context) string {
+	result, _ := pongo2.RenderTemplateString(s, ctx)
+	return result
+}
+
+type TestSuite1 struct{}
+
+var _ = Suite(&TestSuite1{})
+
+func (s *TestSuite1) TestFilters(c *C) {
+	// Markdown
+	c.Assert(getResult("{{ \"**test**\"|markdown }}", nil), Equals, "<p><strong>test</strong></p>\n")
+
+	// Slugify
+	c.Assert(getResult("{{ \"this is ä test!\"|slugify }}", nil), Equals, "this-is-a-test")
+
+	// Filesizeformat
+	c.Assert(getResult("{{ 123456789|filesizeformat }}", nil), Equals, "118MiB")
+
+	// Timesince/timeuntil
+	baseDate := time.Date(2014, time.February, 1, 8, 30, 00, 00, time.UTC)
+	futureDate := baseDate.Add(24*7*4*time.Hour + 2*time.Hour)
+	c.Assert(getResult("{{ future_date|timeuntil:base_date }}",
+		pongo2.Context{"base_date": baseDate, "future_date": futureDate}), Equals, "4 weeks from now")
+
+	baseDate = time.Date(2014, time.February, 1, 8, 30, 00, 00, time.UTC)
+	futureDate = baseDate.Add(2 * time.Hour)
+	c.Assert(getResult("{{ future_date|timeuntil:base_date }}",
+		pongo2.Context{"base_date": baseDate, "future_date": futureDate}), Equals, "2 hours from now")
+
+	baseDate = time.Date(2014, time.February, 1, 8, 30, 00, 00, time.UTC)
+	futureDate = baseDate.Add(2 * time.Hour)
+	c.Assert(getResult("{{ base_date|timesince:future_date }}",
+		pongo2.Context{"base_date": baseDate, "future_date": futureDate}), Equals, "2 hours ago")
+
+	// Natural time
+	baseDate = time.Date(2014, time.February, 1, 8, 30, 00, 00, time.UTC)
+	futureDate = baseDate.Add(4 * time.Second)
+	c.Assert(getResult("{{ base_date|naturaltime:future_date }}",
+		pongo2.Context{"base_date": baseDate, "future_date": futureDate}), Equals, "4 seconds ago")
+
+	// Naturalday
+	today := time.Date(2014, time.February, 1, 8, 30, 00, 00, time.UTC)
+	yesterday := today.Add(-24 * time.Hour)
+	tomorrow := today.Add(24 * time.Hour)
+	todayPlus3 := today.Add(3 * 24 * time.Hour)
+	c.Assert(getResult("{{ date|naturalday:today }}",
+		pongo2.Context{"date": today, "today": today}), Equals, "today")
+	c.Assert(getResult("{{ date|naturalday:today }}",
+		pongo2.Context{"date": yesterday, "today": today}), Equals, "yesterday")
+	c.Assert(getResult("{{ date|naturalday:today }}",
+		pongo2.Context{"date": tomorrow, "today": today}), Equals, "tomorrow")
+	c.Assert(getResult("{{ date|naturalday:today }}",
+		pongo2.Context{"date": todayPlus3, "today": today}), Equals, "3 days from now")
+
+	// Intcomma
+	c.Assert(getResult("{{ 123456789|intcomma }}", nil), Equals, "123,456,789")
+
+	// Ordinal
+	c.Assert(getResult("{{ 1|ordinal }} {{ 2|ordinal }} {{ 3|ordinal }} {{ 18241|ordinal }}", nil),
+		Equals, "1st 2nd 3rd 18241st")
+
+	// Truncatesentences
+	c.Assert(getResult("{{ text|truncatesentences:3|safe }}", pongo2.Context{
+		"text": `This is a first sentence with a 4.50 number. The second one is even more fun! Isn't it? Last sentence, okay.`}),
+		Equals, "This is a first sentence with a 4.50 number. The second one is even more fun! Isn't it?")
+
+	// Truncatesentences_html
+	c.Assert(getResult("{{ text|truncatesentences_html:2 }}", pongo2.Context{
+		"text": `<div class="test"><ul><li>This is a first sentence with a 4.50 number.</li><li>The second one is even more fun! Isn't it?</li><li>Last sentence, okay.</li></ul></div>`}),
+		Equals, `<div class="test"><ul><li>This is a first sentence with a 4.50 number.</li><li>The second one is even more fun!</li></ul></div>`)
+	c.Assert(getResult("{{ text|truncatesentences_html:3 }}", pongo2.Context{
+		"text": `<div class="test"><ul><li>This is a first sentence with a 4.50 number.</li><li>The second one is even more fun! Isn't it?</li><li>Last sentence, okay.</li></ul></div>`}),
+		Equals, `<div class="test"><ul><li>This is a first sentence with a 4.50 number.</li><li>The second one is even more fun! Isn't it?</li></ul></div>`)
+
+	// Random
+	c.Assert(getResult("{{ array|random }}",
+		pongo2.Context{"array": []int{42}}),
+		Equals, "42")
+
+}

v5/helpers.go

@@ -0,0 +1,15 @@
+package pongo2addons
+
+func max(a, b int) int {
+	if a > b {
+		return a
+	}
+	return b
+}
+
+func min(a, b int) int {
+	if a < b {
+		return a
+	}
+	return b
+}