Use HTMx to delete and restore invoice products

It is better that way because it works without JavaScript; if HTMx is
not available, it will just use regulars forms.

The problem is that most of the submit buttons where using formaction
to send the request to a different action, and only one button was the
“real” action.  Since i could not pass the formaction to
invoice-product-form template, i have changed the “default” action to
the one with “ancillary” functions.

I have to use a different action to remove for each product because i
can not pass the index to the backend without JavaScript: it only
depends on the button click, that already has a name for the action.
Thus, in a way, i have “merged” the action and the index in a single
name.

pkg/invoices.go

@@ -20,6 +20,8 @@ import (
 	"time"
 )
 
+const removedProductSuffix = ".removed"
+
 type InvoiceEntry struct {
 	Slug         string
 	Date         time.Time
@@ -553,16 +555,17 @@ func mustWriteInvoicesPdf(r *http.Request, slugs []string) []byte {
 }
 
 type invoiceForm struct {
-	locale        *Locale
-	company       *Company
-	Number        string
-	InvoiceStatus *SelectField
-	Customer      *SelectField
-	Date          *InputField
-	Notes         *InputField
-	PaymentMethod *SelectField
-	Tags          *TagsField
-	Products      []*invoiceProductForm
+	locale         *Locale
+	company        *Company
+	Number         string
+	InvoiceStatus  *SelectField
+	Customer       *SelectField
+	Date           *InputField
+	Notes          *InputField
+	PaymentMethod  *SelectField
+	Tags           *TagsField
+	Products       []*invoiceProductForm
+	RemovedProduct *invoiceProductForm
 }
 
 func newInvoiceForm(ctx context.Context, conn *Conn, locale *Locale, company *Company) *invoiceForm {
@@ -665,6 +668,25 @@ func (form *invoiceForm) Update() {
 	}
 }
 
+func (form *invoiceForm) RemoveProduct(index int) {
+	products := form.Products
+	form.Products = nil
+	for n, product := range products {
+		if n == index {
+			form.RemovedProduct = product
+		} else {
+			if n != len(form.Products) {
+				product.Index = len(form.Products)
+				product.Rename()
+			}
+			form.Products = append(form.Products, product)
+		}
+	}
+	if form.RemovedProduct != nil {
+		form.RemovedProduct.RenameWithSuffix(removedProductSuffix)
+	}
+}
+
 const selectProductBySlug = `
 		select ''
 		     , product_id
@@ -708,6 +730,23 @@ func (form *invoiceForm) mustAddProductsFromQuery(ctx context.Context, conn *Con
 	}
 }
 
+func (form *invoiceForm) InsertProduct(product *invoiceProductForm) {
+	replaced := false
+	for n, existing := range form.Products {
+		if existing.Quantity.Val == "" || existing.Quantity.Val == "0" {
+			product.Index = n
+			form.Products[n] = product
+			replaced = true
+			break
+		}
+	}
+	if !replaced {
+		product.Index = len(form.Products)
+		form.Products = append(form.Products, product)
+	}
+	product.Rename()
+}
+
 func (form *invoiceForm) MustFillFromDatabase(ctx context.Context, conn *Conn, slug string) bool {
 	var invoiceId int
 	selectedInvoiceStatus := form.InvoiceStatus.Selected
@@ -834,7 +873,9 @@ func newInvoiceProductForm(index int, company *Company, locale *Locale, taxOptio
 }
 
 func (form *invoiceProductForm) Rename() {
-	suffix := "." + strconv.Itoa(form.Index)
+	form.RenameWithSuffix("." + strconv.Itoa(form.Index))
+}
+func (form *invoiceProductForm) RenameWithSuffix(suffix string) {
 	form.InvoiceProductId.Name = "product.invoice_product_id" + suffix
 	form.ProductId.Name = "product.id" + suffix
 	form.Name.Name = "product.name" + suffix
@@ -1018,7 +1059,8 @@ func handleInvoiceAction(w http.ResponseWriter, r *http.Request, action string,
 		http.Error(w, err.Error(), http.StatusForbidden)
 		return
 	}
-	switch r.Form.Get("action") {
+	actionField := r.Form.Get("action")
+	switch actionField {
 	case "update":
 		form.Update()
 		w.WriteHeader(http.StatusOK)
@@ -1030,8 +1072,31 @@ func handleInvoiceAction(w http.ResponseWriter, r *http.Request, action string,
 		form.AddProducts(r.Context(), conn, r.Form["slug"])
 		w.WriteHeader(http.StatusOK)
 		renderForm(w, r, form)
+	case "restore-product":
+		restoredProduct := newInvoiceProductForm(0, company, locale, mustGetTaxOptions(r.Context(), conn, company))
+		restoredProduct.RenameWithSuffix(removedProductSuffix)
+		if err := restoredProduct.Parse(r); err != nil {
+			panic(err)
+		}
+		form.InsertProduct(restoredProduct)
+		form.Update()
+		w.WriteHeader(http.StatusOK)
+		renderForm(w, r, form)
 	default:
-		http.Error(w, gettext("Invalid action", locale), http.StatusBadRequest)
+		prefix := "remove-product."
+		if strings.HasPrefix(actionField, prefix) {
+			index, err := strconv.Atoi(actionField[len(prefix):])
+			if err != nil {
+				http.Error(w, gettext("Invalid action", locale), http.StatusBadRequest)
+			} else {
+				form.RemoveProduct(index)
+				form.Update()
+				w.WriteHeader(http.StatusOK)
+				renderForm(w, r, form)
+			}
+		} else {
+			http.Error(w, gettext("Invalid action", locale), http.StatusBadRequest)
+		}
 	}
 }
 

web/template/form.gohtml

@@ -145,13 +145,13 @@
 {{ define "invoice-product-form" -}}
     {{- /*gotype: dev.tandem.ws/tandem/numerus/pkg.invoiceProductForm*/ -}}
     <fieldset class="new-invoice-product"
-              x-data="{removeProduct() { $el.remove(); document.getElementById('recompute-button').click(); }}"
               data-hx-select="unset"
               data-hx-vals='{"index": {{ .Index }}}'
               data-hx-include="[name='product.quantity.{{ .Index }}']"
     >
-        <button x-cloak type="button" class="icon delete-product"
-                @click="removeProduct()"
+        <button type="submit" class="icon delete-product"
+                formnovalidate
+                name="action" value="remove-product.{{ .Index }}"
                 aria-label="{{( gettext "Delete product from invoice" )}}"
         ><i class="ri-delete-back-2-line"></i></button>
         {{ template "hidden-field" .InvoiceProductId }}

web/template/invoices/edit.gohtml

@@ -17,18 +17,38 @@
     {{- /*gotype: dev.tandem.ws/tandem/numerus/pkg.editInvoicePage*/ -}}
     <section id="invoice-dialog-content" data-hx-target="main">
         <h2>{{ printf (pgettext "Edit Invoice “%s”" "title") .Number }}</h2>
-        <form method="POST" action="{{ companyURI "/invoices/" }}{{ .Slug }}" data-hx-boost="true">
+        <form method="POST" action="{{ companyURI "/invoices/" }}{{ .Slug }}/edit" data-hx-boost="true">
             {{ csrfToken }}
 
             {{ with .Form -}}
-            <div class="invoice-data">
-                {{ template "select-field" .Customer }}
-                {{ template "hidden-field" .Date }}
-                {{ template "tags-field" .Tags }}
-                {{ template "select-field" .PaymentMethod }}
-                {{ template "select-field" .InvoiceStatus }}
-                {{ template "input-field" .Notes }}
-            </div>
+                {{ if .RemovedProduct -}}
+                    <div role="alert">
+                        {{ with .RemovedProduct -}}
+                            <p>{{printf (gettext "Product “%s” removed") .Name}}</p>
+                            <button type="submit"
+                                    formnovalidate
+                                    name="action" value="restore-product"
+                            >{{( pgettext "Undo" "action" )}}</button>
+                            {{ template "hidden-field" .InvoiceProductId }}
+                            {{ template "hidden-field" .ProductId }}
+                            {{ template "hidden-field" .Name }}
+                            {{ template "hidden-field" .Price }}
+                            {{ template "hidden-field" .Quantity }}
+                            {{ template "hidden-field" .Discount }}
+                            {{ template "hidden-field" .Description }}
+                            {{ template "hidden-select-field" .Tax }}
+                        {{- end }}
+                    </div>
+                {{- end }}
+
+                <div class="invoice-data">
+                    {{ template "select-field" .Customer }}
+                    {{ template "hidden-field" .Date }}
+                    {{ template "tags-field" .Tags }}
+                    {{ template "select-field" .PaymentMethod }}
+                    {{ template "select-field" .InvoiceStatus }}
+                    {{ template "input-field" .Notes }}
+                </div>
 
                 {{- range $product := .Products }}
                     {{ template "invoice-product-form" . }}
@@ -55,18 +75,19 @@
             </table>
 
             <fieldset class="button-bar">
-                <button formnovalidate formaction="{{ companyURI "/invoices" }}/{{ .Slug }}/edit"
+                <button formnovalidate
                         name="action" value="select-products"
                         data-hx-get="{{ companyURI "/invoices/product-form" }}"
                         data-hx-target="#invoice-summary" data-hx-swap="beforebegin"
                         data-hx-select="unset"
                         data-hx-vals="js:{index: document.querySelectorAll('.new-invoice-product').length}"
                         type="submit">{{( pgettext "Add products" "action" )}}</button>
-                <button formnovalidate formaction="{{ companyURI "/invoices" }}/{{ .Slug }}/edit"
+                <button formnovalidate
                         id="recompute-button"
                         name="action" value="update"
                         type="submit">{{( pgettext "Update" "action" )}}</button>
                 <button class="primary" name="_method" value="PUT"
+                        formaction="{{ companyURI "/invoices" }}/{{ .Slug }}"
                         type="submit">{{( pgettext "Save" "action" )}}</button>
             </fieldset>
 

web/template/invoices/new.gohtml

@@ -17,18 +17,38 @@
     {{- /*gotype: dev.tandem.ws/tandem/numerus/pkg.newInvoicePage*/ -}}
     <section id="invoice-dialog-content" data-hx-target="main">
         <h2>{{(pgettext "New Invoice" "title")}}</h2>
-        <form method="POST" action="{{ companyURI "/invoices" }}" data-hx-boost="true">
+        <form method="POST" action="{{ companyURI "/invoices/new" }}" data-hx-boost="true">
             {{ csrfToken }}
 
             {{ with .Form -}}
-            <div class="invoice-data">
-                {{ template "hidden-select-field" .InvoiceStatus }}
-                {{ template "select-field" .Customer }}
-                {{ template "input-field" .Date }}
-                {{ template "tags-field" .Tags }}
-                {{ template "select-field" .PaymentMethod }}
-                {{ template "input-field" .Notes }}
-            </div>
+                {{ if .RemovedProduct -}}
+                    <div role="alert">
+                        {{ with .RemovedProduct -}}
+                            <p>{{printf (gettext "Product “%s” removed") .Name}}</p>
+                            <button type="submit"
+                                    formnovalidate
+                                    name="action" value="restore-product"
+                            >{{( pgettext "Undo" "action" )}}</button>
+                            {{ template "hidden-field" .InvoiceProductId }}
+                            {{ template "hidden-field" .ProductId }}
+                            {{ template "hidden-field" .Name }}
+                            {{ template "hidden-field" .Price }}
+                            {{ template "hidden-field" .Quantity }}
+                            {{ template "hidden-field" .Discount }}
+                            {{ template "hidden-field" .Description }}
+                            {{ template "hidden-select-field" .Tax }}
+                        {{- end }}
+                    </div>
+                {{- end }}
+
+                <div class="invoice-data">
+                    {{ template "hidden-select-field" .InvoiceStatus }}
+                    {{ template "select-field" .Customer }}
+                    {{ template "input-field" .Date }}
+                    {{ template "tags-field" .Tags }}
+                    {{ template "select-field" .PaymentMethod }}
+                    {{ template "input-field" .Notes }}
+                </div>
                 {{- range $product := .Products }}
                     {{ template "invoice-product-form" . }}
                 {{- end }}
@@ -54,18 +74,19 @@
             </table>
 
             <fieldset class="button-bar">
-                <button formnovalidate formaction="{{ companyURI "/invoices/new" }}"
+                <button formnovalidate
                         name="action" value="select-products"
                         data-hx-get="{{ companyURI "/invoices/product-form" }}"
                         data-hx-target="#invoice-summary" data-hx-swap="beforebegin"
                         data-hx-select="unset"
                         data-hx-vals="js:{index: document.querySelectorAll('.new-invoice-product').length}"
                         type="submit">{{( pgettext "Add products" "action" )}}</button>
-                <button formnovalidate formaction="{{ companyURI "/invoices/new" }}"
+                <button formnovalidate
                         id="recompute-button"
                         name="action" value="update"
                         type="submit">{{( pgettext "Update" "action" )}}</button>
                 <button class="primary" name="action" value="add"
+                        formaction="{{ companyURI "/invoices" }}"
                         type="submit">{{( pgettext "Save" "action" )}}</button>
             </fieldset>
         </form>