feat(examples): add avl_pager reverse option, update userbook (#3297)

<!-- please provide a detailed description of the changes made in this
pull request. -->

## Description

This PR adds the reverse option in the avl_pager package, and updates
the rendering in the `r/demo/userbook` realm.

<details><summary>Contributors' checklist...</summary>

- [x] Added new tests, or not needed, or not feasible
- [x] Provided an example (e.g. screenshot) to aid review or the PR is
self-explanatory
- [x] Updated the official documentation or not needed
- [x] No breaking changes were made, or a `BREAKING CHANGE: xxx` message
was included in the description
- [x] Added references to related issues and PRs
- [x] Provided any useful hints for running manual tests
</details>

examples/gno.land/p/demo/avl/pager/pager.gno

@@ -15,6 +15,7 @@ type Pager struct {
 	PageQueryParam  string
 	SizeQueryParam  string
 	DefaultPageSize int
+	Reversed        bool
 }
 
 // Page represents a single page of results.
@@ -36,12 +37,13 @@ type Item struct {
 }
 
 // NewPager creates a new Pager with default values.
-func NewPager(tree *avl.Tree, defaultPageSize int) *Pager {
+func NewPager(tree *avl.Tree, defaultPageSize int, reversed bool) *Pager {
 	return &Pager{
 		Tree:            tree,
 		PageQueryParam:  "page",
 		SizeQueryParam:  "size",
 		DefaultPageSize: defaultPageSize,
+		Reversed:        reversed,
 	}
 }
 
@@ -86,10 +88,18 @@ func (p *Pager) GetPageWithSize(pageNumber, pageSize int) *Page {
 	}
 
 	items := []Item{}
-	p.Tree.ReverseIterateByOffset(startIndex, endIndex-startIndex, func(key string, value interface{}) bool {
-		items = append(items, Item{Key: key, Value: value})
-		return false
-	})
+
+	if p.Reversed {
+		p.Tree.IterateByOffset(startIndex, endIndex-startIndex, func(key string, value interface{}) bool {
+			items = append(items, Item{Key: key, Value: value})
+			return false
+		})
+	} else {
+		p.Tree.ReverseIterateByOffset(startIndex, endIndex-startIndex, func(key string, value interface{}) bool {
+			items = append(items, Item{Key: key, Value: value})
+			return false
+		})
+	}
 
 	page.Items = items
 	page.PageNumber = pageNumber
@@ -115,8 +125,8 @@ func (p *Pager) GetPageByPath(rawURL string) (*Page, error) {
 	return p.GetPageWithSize(pageNumber, pageSize), nil
 }
 
-// UI generates the Markdown UI for the page selector.
-func (p *Page) Selector() string {
+// Picker generates the Markdown UI for the page Picker
+func (p *Page) Picker() string {
 	pageNumber := p.PageNumber
 	pageNumber = max(pageNumber, 1)
 

examples/gno.land/p/demo/avl/pager/pager_test.gno

@@ -18,34 +18,67 @@ func TestPager_GetPage(t *testing.T) {
 	tree.Set("d", 4)
 	tree.Set("e", 5)
 
-	// Create a new pager.
-	pager := NewPager(tree, 10)
+	t.Run("normal ordering", func(t *testing.T) {
+		// Create a new pager.
+		pager := NewPager(tree, 10, false)
+
+		// Define test cases.
+		tests := []struct {
+			pageNumber int
+			pageSize   int
+			expected   []Item
+		}{
+			{1, 2, []Item{{Key: "a", Value: 1}, {Key: "b", Value: 2}}},
+			{2, 2, []Item{{Key: "c", Value: 3}, {Key: "d", Value: 4}}},
+			{3, 2, []Item{{Key: "e", Value: 5}}},
+			{1, 3, []Item{{Key: "a", Value: 1}, {Key: "b", Value: 2}, {Key: "c", Value: 3}}},
+			{2, 3, []Item{{Key: "d", Value: 4}, {Key: "e", Value: 5}}},
+			{1, 5, []Item{{Key: "a", Value: 1}, {Key: "b", Value: 2}, {Key: "c", Value: 3}, {Key: "d", Value: 4}, {Key: "e", Value: 5}}},
+			{2, 5, []Item{}},
+		}
 
-	// Define test cases.
-	tests := []struct {
-		pageNumber int
-		pageSize   int
-		expected   []Item
-	}{
-		{1, 2, []Item{{Key: "a", Value: 1}, {Key: "b", Value: 2}}},
-		{2, 2, []Item{{Key: "c", Value: 3}, {Key: "d", Value: 4}}},
-		{3, 2, []Item{{Key: "e", Value: 5}}},
-		{1, 3, []Item{{Key: "a", Value: 1}, {Key: "b", Value: 2}, {Key: "c", Value: 3}}},
-		{2, 3, []Item{{Key: "d", Value: 4}, {Key: "e", Value: 5}}},
-		{1, 5, []Item{{Key: "a", Value: 1}, {Key: "b", Value: 2}, {Key: "c", Value: 3}, {Key: "d", Value: 4}, {Key: "e", Value: 5}}},
-		{2, 5, []Item{}},
-	}
+		for _, tt := range tests {
+			page := pager.GetPageWithSize(tt.pageNumber, tt.pageSize)
 
-	for _, tt := range tests {
-		page := pager.GetPageWithSize(tt.pageNumber, tt.pageSize)
+			uassert.Equal(t, len(tt.expected), len(page.Items))
 
-		uassert.Equal(t, len(tt.expected), len(page.Items))
+			for i, item := range page.Items {
+				uassert.Equal(t, tt.expected[i].Key, item.Key)
+				uassert.Equal(t, tt.expected[i].Value, item.Value)
+			}
+		}
+	})
+
+	t.Run("reversed ordering", func(t *testing.T) {
+		// Create a new pager.
+		pager := NewPager(tree, 10, true)
+
+		// Define test cases.
+		tests := []struct {
+			pageNumber int
+			pageSize   int
+			expected   []Item
+		}{
+			{1, 2, []Item{{Key: "e", Value: 5}, {Key: "d", Value: 4}}},
+			{2, 2, []Item{{Key: "c", Value: 3}, {Key: "b", Value: 2}}},
+			{3, 2, []Item{{Key: "a", Value: 1}}},
+			{1, 3, []Item{{Key: "e", Value: 5}, {Key: "d", Value: 4}, {Key: "c", Value: 3}}},
+			{2, 3, []Item{{Key: "b", Value: 2}, {Key: "a", Value: 1}}},
+			{1, 5, []Item{{Key: "e", Value: 5}, {Key: "d", Value: 4}, {Key: "c", Value: 3}, {Key: "b", Value: 2}, {Key: "a", Value: 1}}},
+			{2, 5, []Item{}},
+		}
 
-		for i, item := range page.Items {
-			uassert.Equal(t, tt.expected[i].Key, item.Key)
-			uassert.Equal(t, tt.expected[i].Value, item.Value)
+		for _, tt := range tests {
+			page := pager.GetPageWithSize(tt.pageNumber, tt.pageSize)
+
+			uassert.Equal(t, len(tt.expected), len(page.Items))
+
+			for i, item := range page.Items {
+				uassert.Equal(t, tt.expected[i].Key, item.Key)
+				uassert.Equal(t, tt.expected[i].Value, item.Value)
+			}
 		}
-	}
+	})
 }
 
 func TestPager_GetPageByPath(t *testing.T) {
@@ -56,7 +89,7 @@ func TestPager_GetPageByPath(t *testing.T) {
 	}
 
 	// Create a new pager.
-	pager := NewPager(tree, 10)
+	pager := NewPager(tree, 10, false)
 
 	// Define test cases.
 	tests := []struct {
@@ -80,7 +113,7 @@ func TestPager_GetPageByPath(t *testing.T) {
 	}
 }
 
-func TestPage_Selector(t *testing.T) {
+func TestPage_Picker(t *testing.T) {
 	// Create a new AVL tree and populate it with some key-value pairs.
 	tree := avl.NewTree()
 	tree.Set("a", 1)
@@ -90,7 +123,7 @@ func TestPage_Selector(t *testing.T) {
 	tree.Set("e", 5)
 
 	// Create a new pager.
-	pager := NewPager(tree, 10)
+	pager := NewPager(tree, 10, false)
 
 	// Define test cases.
 	tests := []struct {
@@ -106,7 +139,7 @@ func TestPage_Selector(t *testing.T) {
 	for _, tt := range tests {
 		page := pager.GetPageWithSize(tt.pageNumber, tt.pageSize)
 
-		ui := page.Selector()
+		ui := page.Picker()
 		uassert.Equal(t, tt.expected, ui)
 	}
 }
@@ -119,7 +152,7 @@ func TestPager_UI_WithManyPages(t *testing.T) {
 	}
 
 	// Create a new pager.
-	pager := NewPager(tree, 10)
+	pager := NewPager(tree, 10, false)
 
 	// Define test cases for a large number of pages.
 	tests := []struct {
@@ -145,7 +178,7 @@ func TestPager_UI_WithManyPages(t *testing.T) {
 	for _, tt := range tests {
 		page := pager.GetPageWithSize(tt.pageNumber, tt.pageSize)
 
-		ui := page.Selector()
+		ui := page.Picker()
 		uassert.Equal(t, tt.expected, ui)
 	}
 }
@@ -160,7 +193,7 @@ func TestPager_ParseQuery(t *testing.T) {
 	tree.Set("e", 5)
 
 	// Create a new pager.
-	pager := NewPager(tree, 10)
+	pager := NewPager(tree, 10, false)
 
 	// Define test cases.
 	tests := []struct {

examples/gno.land/p/demo/avl/pager/z_filetest.gno

@@ -16,7 +16,7 @@ func main() {
 	}
 
 	// Create a new pager.
-	pager := pager.NewPager(tree, 7)
+	pager := pager.NewPager(tree, 7, false)
 
 	for pn := -1; pn < 8; pn++ {
 		page := pager.GetPage(pn)
@@ -25,7 +25,7 @@ func main() {
 		for idx, item := range page.Items {
 			println(ufmt.Sprintf("- idx=%d key=%s value=%d", idx, item.Key, item.Value))
 		}
-		println(page.Selector())
+		println(page.Picker())
 		println()
 	}
 }

examples/gno.land/r/demo/userbook/render.gno

@@ -2,50 +2,39 @@
 package userbook
 
 import (
-	"sort"
 	"strconv"
 
+	"gno.land/r/demo/users"
+
 	"gno.land/p/demo/avl/pager"
 	"gno.land/p/demo/ufmt"
 	"gno.land/p/moul/txlink"
 )
 
+const usersLink = "/r/demo/users"
+
 func Render(path string) string {
-	p := pager.NewPager(signupsTree, 2)
+	p := pager.NewPager(signupsTree, 20, true)
 	page := p.MustGetPageByPath(path)
 
 	out := "# Welcome to UserBook!\n\n"
 
 	out += ufmt.Sprintf("## [Click here to sign up!](%s)\n\n", txlink.Call("SignUp"))
 	out += "---\n\n"
 
-	var sorted sortedSignups
 	for _, item := range page.Items {
-		sorted = append(sorted, item.Value.(*Signup))
-	}
+		signup := item.Value.(*Signup)
+		user := signup.address.String()
 
-	sort.Sort(sorted)
+		if data := users.GetUserByAddress(signup.address); data != nil {
+			user = ufmt.Sprintf("[%s](%s:%s)", data.Name, usersLink, data.Name)
+		}
 
-	for _, item := range sorted {
-		out += ufmt.Sprintf("- **User #%d - %s - signed up on %s**\n\n", item.ordinal, item.address.String(), item.timestamp.Format("02-01-2006 15:04:05"))
+		out += ufmt.Sprintf("- **User #%d - %s - signed up on %s**\n\n", signup.ordinal, user, signup.timestamp.Format("January 2 2006, 03:04:04 PM"))
 	}
 
 	out += "---\n\n"
 	out += "**Page " + strconv.Itoa(page.PageNumber) + " of " + strconv.Itoa(page.TotalPages) + "**\n\n"
-	out += page.Selector() // Repeat selector for ease of navigation
+	out += page.Picker()
 	return out
 }
-
-type sortedSignups []*Signup
-
-func (s sortedSignups) Swap(i, j int) {
-	s[i], s[j] = s[j], s[i]
-}
-
-func (s sortedSignups) Len() int {
-	return len(s)
-}
-
-func (s sortedSignups) Less(i, j int) bool {
-	return s[i].timestamp.Before(s[j].timestamp)
-}

examples/gno.land/r/demo/userbook/userbook.gno

@@ -6,6 +6,7 @@ import (
 	"time"
 
 	"gno.land/p/demo/avl"
+	"gno.land/p/demo/seqid"
 	"gno.land/p/demo/ufmt"
 )
 
@@ -15,7 +16,11 @@ type Signup struct {
 	timestamp time.Time
 }
 
-var signupsTree = avl.NewTree()
+var (
+	signupsTree = avl.NewTree()
+	tracker     = avl.NewTree()
+	idCounter   seqid.ID
+)
 
 const signUpEvent = "SignUp"
 
@@ -28,19 +33,22 @@ func SignUp() string {
 	caller := std.PrevRealm().Addr()
 
 	// Check if the user is already signed up
-	if _, exists := signupsTree.Get(caller.String()); exists {
-		panic(caller + " is already signed up!")
+	if _, exists := tracker.Get(caller.String()); exists {
+		panic(caller.String() + " is already signed up!")
 	}
 
 	now := time.Now()
+
 	// Sign up the user
-	signupsTree.Set(caller.String(), &Signup{
-		std.PrevRealm().Addr(),
+	signupsTree.Set(idCounter.Next().String(), &Signup{
+		caller,
 		signupsTree.Size(),
 		now,
 	})
 
-	std.Emit(signUpEvent, "SignedUpAccount", caller.String())
+	tracker.Set(caller.String(), struct{}{})
+
+	std.Emit(signUpEvent, "account", caller.String())
 
 	return ufmt.Sprintf("%s added to userbook! Timestamp: %s", caller.String(), now.Format(time.RFC822Z))
 }

examples/gno.land/r/demo/users/users.gno

@@ -328,14 +328,14 @@ func Render(fullPath string) string {
 func renderHome(path string) string {
 	doc := ""
 
-	page := pager.NewPager(&name2User, 50).MustGetPageByPath(path)
+	page := pager.NewPager(&name2User, 50, false).MustGetPageByPath(path)
 
 	for _, item := range page.Items {
 		user := item.Value.(*users.User)
 		doc += " * [" + user.Name + "](/r/demo/users:" + user.Name + ")\n"
 	}
 	doc += "\n"
-	doc += page.Selector()
+	doc += page.Picker()
 	return doc
 }
 

examples/gno.land/r/docs/avl_pager/avl_pager.gno

@@ -22,19 +22,19 @@ func init() {
 // Render paginated content based on the given URL path.
 // URL format: `...?page=<page>&size=<size>` (default is page 1 and size 10).
 func Render(path string) string {
-	p := pager.NewPager(tree, 10) // Default page size is 10
+	p := pager.NewPager(tree, 10, false) // Default page size is 10
 	page := p.MustGetPageByPath(path)
 
 	// Header and pagination info
 	result := "# Paginated Items\n"
 	result += "Page " + strconv.Itoa(page.PageNumber) + " of " + strconv.Itoa(page.TotalPages) + "\n\n"
-	result += page.Selector() + "\n\n"
+	result += page.Picker() + "\n\n"
 
 	// Display items on the current page
 	for _, item := range page.Items {
 		result += "- " + item.Key + ": " + item.Value.(string) + "\n"
 	}
 
-	result += "\n" + page.Selector() // Repeat selector for ease of navigation
+	result += "\n" + page.Picker() // Repeat page picker for ease of navigation
 	return result
 }

examples/gno.land/r/leon/hof/render.gno

@@ -38,7 +38,7 @@ func (e Exhibition) Render(path string, dashboard bool) string {
 
 	out += "<div class='columns-2'>\n\n"
 
-	page := pager.NewPager(e.itemsSorted, pageSize).MustGetPageByPath(path)
+	page := pager.NewPager(e.itemsSorted, pageSize, false).MustGetPageByPath(path)
 
 	for i := len(page.Items) - 1; i >= 0; i-- {
 		item := page.Items[i]
@@ -52,7 +52,7 @@ func (e Exhibition) Render(path string, dashboard bool) string {
 
 	out += "</div><!-- /columns-2 -->\n\n"
 
-	out += page.Selector()
+	out += page.Picker()
 
 	return out
 }