/
tables.go
500 lines (426 loc) · 12.5 KB
/
tables.go
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package uos
import (
"fmt"
"math"
"math/rand"
"net/http"
"net/url"
"strconv"
"strings"
"gorm.io/gorm"
)
// TableData represents a table with rows and columns.
type TableData [][]interface{}
// TableSpec describes the interface every web application table must implement.
type TableSpec interface {
// Name returns the short name of the table. The table data is available at '/tables/<name>'.
Name() string
// ModelName returns the name of the underlying DB model. Can return "" to indicate a custom table.
// A returned model must be registered (using RegisterDBModels).
ModelName() string
// ResourceName is required if the table IsExpandable (see display properties). The detail rows
// content will be loaded as the specified resource.
ResourceName() string
// LoadData returns the table data according to the specified configuration.
LoadData(TableConfiguration) (TableData, error)
// ColumnInfo returns table column information for the selected columns.
ColumnInfo([]string) []TableColumn
// ColumnDefault returns list of default columns
ColumnDefault() []string
// Actions returns a set of actions related to the table and their contained items.
Actions() *TableActions
}
// TableDisplay describes the interface a web application table must implement to
// customize the table visualization
type TableDisplay interface {
// DisplaySettings returns custom table display settings
DisplaySettings() TableDisplayProperties
}
// TableDelete must be implemented by a web application form to support DELETE requests.
type TableSpecDelete interface {
// Delete removes the specified items from the database.
Delete(ids []uint) (*ResponseAction, error)
}
// TableAction describes a function that can be triggered for a table, e.g. item deletion.
type TableAction struct {
// (LineAwesome) icon of the action
Icon string
// button text
Text string
// button class
ButtonClass string
// hx-<method>
Method string
// action target, e.g. "/dialogs/..."
TargetURL string
// CSS selector for elements to include in the resulting request
Include string
// confirmation dialog title, empty: no confirmation required
ConfirmationTitle string
// confirmation dialog message
ConfirmationMessage string
}
// TableActionButton returns a table action element with the specified icon, text and button class.
func TableActionButton(icon, text, class string) TableAction {
return TableAction{
Icon: icon,
Text: text,
ButtonClass: class,
}
}
// Dialog extends the action to open the specified dialog
func (a TableAction) Dialog(target string) TableAction {
a.Method = "get"
a.TargetURL = fmt.Sprintf("/dialogs/%s", target)
return a
}
// Post adds a HTMX post action to the element
func (a TableAction) Post(target, include string) TableAction {
a.Method = "post"
a.TargetURL = target
a.Include = include
return a
}
// Confirmation asks for user permission before sending the action
func (a TableAction) Confirmation(title, message string) TableAction {
a.ConfirmationTitle = title
a.ConfirmationMessage = message
return a
}
type TableActions []TableAction
// TableHandler returns a handler for the "/tables/" route providing the specified tables.
// The handler can be activated using RegisterAppRequestHandlers.
func TableHandler(tables ...TableSpec) AppRequestHandlerMapping {
return AppRequestHandlerMapping{
Route: "/tables/",
Handler: getTableHandlerFunc(tables),
Options: AppRequestHandlerOptions{
NoSitemap: true,
},
}
}
func getTableHandlerFunc(tables []TableSpec) AppRequestHandler {
nameToSpec := map[string]TableSpec{}
for _, t := range tables {
nameToSpec[t.Name()] = t
Log.DebugContext("register table spec", LogContext{"name": t.Name()})
}
return func(w http.ResponseWriter, r *http.Request) {
// determine table
tableName := getElementName("tables", r.URL.Path)
Log.DebugContextR(
r, "handle table",
LogContext{
"name": tableName,
"method": r.Method,
},
)
tableSpec, ok := nameToSpec[tableName]
if !ok {
RespondNotFound(w)
return
}
// process request
switch r.Method {
case http.MethodGet:
renderTable(w, r, tableSpec, r.Form)
case http.MethodPost:
// does the table support DELETE method?
tableDelete, ok := tableSpec.(TableSpecDelete)
if !ok {
RespondNotImplemented(w)
return
}
// CSRF protection
if !IsCSRFtokenValid(r, r.Form.Get("csrf")) {
Log.DebugR(r, "CSRF token mismatch")
RespondBadRequest(w)
return
}
// extract IDs from request
ids := []uint{}
for key := range r.Form {
if strings.HasPrefix(key, "item-") {
if id, err := strconv.Atoi(key[5:]); err == nil && id >= 0 {
ids = append(ids, uint(id))
}
}
}
// forward to table handler
action, err := tableDelete.Delete(ids)
if err != nil {
handleFormError(w, r, "could not delete table items", err)
return
}
handleResponseAction(w, r, action)
default:
RespondNotImplemented(w)
}
}
}
// TableConfiguration describes a specific table view, e.g. a specific column selection,
// page or sort column.
type TableConfiguration struct {
// comma separated list of selected columns
Columns []string
// sort column
SortColumn string
// sort mode (ASC or DESC or empty)
SortMode string
// selected page
Page int
// number of rows to return
Rows int
}
func (c TableConfiguration) DBQuery() *gorm.DB {
dbQuery := DB
if len(c.Columns) > 0 {
dbQuery = dbQuery.Select(append([]string{"id"}, c.Columns...))
}
if c.SortColumn != "" {
dbQuery = dbQuery.Order(
strings.TrimSpace(
strings.Join([]string{c.SortColumn, c.SortMode}, " "),
),
)
}
// additionally order by id to get a deterministic sequence
dbQuery = dbQuery.Order("id")
return dbQuery.Limit(c.Rows).Offset((c.Page - 1) * c.Rows)
}
// LoadTable loads table data for the specified model.
func (c TableConfiguration) LoadTable(dest interface{}) error {
return c.DBQuery().Find(dest).Error
}
func newTableConfiguration(t TableSpec, form url.Values) TableConfiguration {
var (
columns = form.Get("cols")
sortColumn = form.Get("sort")
sortMode = ""
)
switch {
case strings.HasPrefix(sortColumn, "+"):
sortColumn = sortColumn[1:]
case strings.HasPrefix(sortColumn, "-"):
sortColumn = sortColumn[1:]
sortMode = "DESC"
}
config := TableConfiguration{
Columns: strings.Split(columns, ","),
SortColumn: sortColumn,
SortMode: sortMode,
Page: stringToInt(form.Get("page"), 1),
Rows: stringToInt(form.Get("rows"), 10),
}
if columns == "" {
config.Columns = t.ColumnDefault()
}
return config
}
func (c TableConfiguration) isValid() bool {
// at least one column must exist
if len(c.Columns) == 0 {
return false
}
// columns must not contain empty entries and trailing/leading whitespace
for _, col := range c.Columns {
if col == "" || strings.TrimSpace(col) != col {
return false
}
}
// sort column (if defined) must be included in columns list
if c.SortColumn != "" && len(c.Columns) > 0 && !contains(c.Columns, c.SortColumn) {
return false
}
// page and rows must be >= 1
if c.Page < 1 || c.Rows < 1 {
return false
}
// rows must be <= 200
if c.Rows > 200 {
return false
}
return true
}
// TableFormatFunc describes a table cell visualization function. The input parameter
// are the row id and a raw value read from the database. The returned value is visualized
// in the frontend. The return value can contain HTML.
type TableFormatFunc func(interface{}, interface{}) interface{}
// TableColumn describes properties of a table column.
type TableColumn struct {
// display name
DisplayName string
// table supports sorting by this column
IsSortable bool
// function to convert raw values to visualization (e.g. for formatting)
Format TableFormatFunc
// is current sortfield? (determined automatically)
IsSortField bool
// is sorted descending? (determined automatically)
IsSortDesc bool
// internal name (determined automatically)
Name string
}
// TableDisplayProperties describes basic table visualization properties.
// Default: all properties set to false.
type TableDisplayProperties struct {
// show as full element width
IsFullWidth bool
// highlight table rows on hover
IsHoverable bool
// emphasize every second row
IsStriped bool
// show table content as cards on small displays
IsMobileReady bool
// rows can be selected
IsSelectable bool
// rows can be expanded
IsExpandable bool
// last column contains buttons
HasRowActions bool
}
type tableRenderContext struct {
TableID string
Data TableData
DataResource string
Count int64
Config TableConfiguration
Columns []TableColumn
Display TableDisplayProperties
Actions *TableActions
HasActions bool
IsEmpty bool
IsLoading bool
ColumnWidth int
LastDataColumn int
TableBaseURL string
PageCount int
}
func newTableRenderContext(t TableSpec, form url.Values) (tableRenderContext, error) {
// get configuration from URL parameter
config := newTableConfiguration(t, form)
if !config.isValid() {
return tableRenderContext{}, ErrorTableInvalidRequest
}
// get column information
columns := t.ColumnInfo(config.Columns)
// table has model? -> extended column check
validColumns := dbColumns(t.ModelName())
if t.ModelName() != "" && len(config.Columns) > 1 {
for _, c := range config.Columns {
if !contains(validColumns, c) {
return tableRenderContext{}, ErrorTableInvalidRequest
}
}
}
// load data
data, err := t.LoadData(config)
if err != nil {
return tableRenderContext{}, err
}
count, err := dbEntryCount(t.ModelName())
if err != nil {
return tableRenderContext{}, err
}
// base initialization
context := tableRenderContext{
TableID: fmt.Sprintf("%s-%d", t.Name(), rand.Intn(999999)),
Data: data,
DataResource: t.ResourceName(),
Count: count,
Config: config,
Columns: columns,
Actions: t.Actions(),
}
// custom display settings available?
settingsProvider, ok := t.(TableDisplay)
if ok {
context.Display = settingsProvider.DisplaySettings()
}
// call formatting functions (if defined)
for i, row := range data {
for j, cell := range row {
if j == 0 {
// first entry contains ID - not shown in table
continue
}
if context.Display.HasRowActions && j == len(row)-1 {
// skip last entry - contains action infos, handled in template
continue
}
if columns[j-1].Format != nil {
data[i][j] = columns[j-1].Format(row[0], cell)
}
}
}
// evaluate some properties to simplify context handling in template
// .. any actions defined?
context.HasActions = context.Actions != nil && len(*context.Actions) > 0
// .. no data available?
context.IsEmpty = len(data) == 0
// .. determine number of columns for table message
context.ColumnWidth = len(context.Config.Columns)
if context.Display.IsSelectable {
context.ColumnWidth += 1
}
if context.Display.IsExpandable {
context.ColumnWidth += 1
}
if context.Display.HasRowActions {
context.ColumnWidth += 1
}
// .. determine index of last data column (exclude action buttons)
if !context.IsEmpty {
context.LastDataColumn = len(data[0])
if context.Display.HasRowActions {
context.LastDataColumn -= 1
}
}
// .. integrate sorting info in columns info
for i, c := range context.Config.Columns {
if c == context.Config.SortColumn {
context.Columns[i].IsSortField = true
context.Columns[i].IsSortDesc = context.Config.SortMode == "DESC"
}
context.Columns[i].Name = c
}
// .. initialize table base URL - direct interaction with HTML does not change
// nr of rows or selected columns and resets current page to the first one
context.TableBaseURL = fmt.Sprintf(
"/tables/%s?rows=%d&cols=%s",
t.Name(),
context.Config.Rows,
strings.Join(context.Config.Columns, ","),
)
// .. calculate overall page count
if count != -1 {
context.PageCount = int(math.Ceil(float64(count) / float64(context.Config.Rows)))
}
return context, nil
}
func renderTable(w http.ResponseWriter, r *http.Request, t TableSpec, form url.Values) {
context, err := newTableRenderContext(t, form)
if err != nil {
handleTableError(w, r, "could not create table render context", err)
return
}
err = renderInternalTemplate(w, r, "table", context)
if err != nil {
Log.ErrorContextR(
r, "could not render table",
LogContext{"name": t.Name(), "error": err},
)
RespondInternalServerError(w)
return
}
}
func handleTableError(w http.ResponseWriter, r *http.Request, message string, err error) {
switch err {
case ErrorTableInvalidRequest:
RespondBadRequest(w)
return
}
// all other cases: log error and respond
Log.ErrorObjR(r, message, err)
RespondInternalServerError(w)
}