table_column_base.go

package control

import (
	"bytes"
	"context"
	"fmt"
	"github.com/goradd/gengen/pkg/maps"
	"github.com/goradd/goradd/pkg/base"
	"github.com/goradd/goradd/pkg/html"
	"github.com/goradd/goradd/pkg/page"
	html2 "html"
	"strconv"
)

type SortDirection int

const (
	NotSortable    = SortDirection(0)
	SortAscending  = SortDirection(1)
	SortDescending = SortDirection(-1)
	NotSorted      = SortDirection(-100)
)

// SortButtonHtmlGetter is the injected function for getting the html for sort buttons in the column header.
// The default uses FontAwesome to draw the buttons, which means the css for FontAwesome must be loaded
// into the web page. You can change what html is loaded by setting this function.
var SortButtonHtmlGetter func(SortDirection) string

// ColumnI defines the interface that all columns must support. Most of these functions are provided by the
// default behavior of the ColumnBase class.
type ColumnI interface {
	ID() string
	SetID(string) ColumnI
	setParentTable(TableI)
	ParentTable() TableI
	Title() string
	SetTitle(string) ColumnI
	Span() int
	SetSpan(int) ColumnI
	IsHidden() bool
	SetHidden(bool) ColumnI
	DrawColumnTag(ctx context.Context, buf *bytes.Buffer)
	DrawFooterCell(ctx context.Context, row int, col int, count int, buf *bytes.Buffer)
	DrawCell(ctx context.Context, row int, col int, data interface{}, buf *bytes.Buffer)
	CellText(ctx context.Context, row int, col int, data interface{}) string
	HeaderCellHtml(ctx context.Context, row int, col int) string
	FooterCellHtml(ctx context.Context, row int, col int) string
	HeaderAttributes(row int, col int) *html.Attributes
	FooterAttributes(row int, col int) *html.Attributes
	ColTagAttributes() *html.Attributes
	UpdateFormValues(ctx *page.Context)
	AddActions(ctrl page.ControlI)
	Action(ctx context.Context, params page.ActionParams)
	SetHeaderTexter(s CellTexter) ColumnI
	SetCellTexter(s CellTexter) ColumnI
	SetFooterTexter(s CellTexter) ColumnI
	SetCellStyler(s html.Attributer)
	IsSortable() bool
	SortDirection() SortDirection
	SetSortDirection(SortDirection) ColumnI
	Sortable() ColumnI
	SetIsHtml(columnIsHtml bool) ColumnI
	PreRender()
	MarshalState(m maps.Setter)
	UnmarshalState(m maps.Loader)
}

// CellTexter defines the interface for a structure that provides the content of a table cell.
type CellTexter interface {
	CellText(ctx context.Context, col ColumnI, rowNum int, colNum int, data interface{}) string
}

// ColumnBase is the base implementation of all table columns
type ColumnBase struct {
	base.Base
	id               string
	parentTable      TableI
	title            string
	*html.Attributes // These are attributes that will appear on the cell
	headerAttributes *html.Attributes
	footerAttributes *html.Attributes
	colTagAttributes *html.Attributes
	span             int
	renderAsHeader   bool
	isHtml           bool
	cellTexter       CellTexter
	cellStyler       html.Attributer // for individually styling cells
	headerTexter     CellTexter
	footerTexter     CellTexter
	isHidden         bool
	sortDirection    SortDirection
}

func (c *ColumnBase) Init(self ColumnI) {
	c.Base.Init(self)
	c.span = 1
	c.Attributes = html.NewAttributes()
}

func (c *ColumnBase) this() ColumnI {
	return c.Self.(ColumnI)
}

// ID returns the id of the column
func (c *ColumnBase) ID() string {
	return c.id
}

// SetID sets the id of the column. If you are going to provide your own id, do this as the first thing after you create
// a table, or the new id might not propagate through the system correctly. Note that the id in html will have the table
// id prepended to it. This is required so that actions can be routed to a column.
func (c *ColumnBase) SetID(id string) ColumnI {
	c.id = id
	return c.this()
}

func (c *ColumnBase) setParentTable(t TableI) {
	c.parentTable = t
}

// ParentTable returns the table that is the parent of the column
func (c *ColumnBase) ParentTable() TableI {
	return c.parentTable
}

// Title returns the title text that will appear in the header of the column
func (c *ColumnBase) Title() string {
	return c.title
}

// SetTitle sets the title of the column. It returns a column reference for chaining.
func (c *ColumnBase) SetTitle(title string) ColumnI {
	c.title = title
	return c.this()
}

// Span returns the number of columns this column will span.
func (c *ColumnBase) Span() int {
	return c.span
}

// SetSpan sets the span indicated in the column tag of the column. This is used to create colgroup tags.
func (c *ColumnBase) SetSpan(span int) ColumnI {
	c.span = span
	return c.this()
}

// SetRenderAsHeader will cause the entire column to be output with th instead of td cells.
func (c *ColumnBase) SetRenderAsHeader(r bool) {
	c.renderAsHeader = r
}

// SetIsHtml will cause the cell to treat the text it receives as html rather than raw text it should escape.
// Use this with extreme caution. Do not display unescaped text that might come from user input, as it could
// open you up to XSS attacks.
func (c *ColumnBase) SetIsHtml(columnIsHtml bool) ColumnI {
	c.isHtml = columnIsHtml
	return c.this()
}

// SetCellStyler sets the CellStyler for the body cells.
func (c *ColumnBase) SetCellStyler(s html.Attributer) {
	c.cellStyler = s
}

// SetCellTexter sets the CellTexter for getting the content of each body cell.
func (c *ColumnBase) SetCellTexter(s CellTexter) ColumnI {
	c.cellTexter = s
	return c.this()
}

// CellTexter returns the cell texter.
func (c *ColumnBase) CellTexter() CellTexter {
	return c.cellTexter
}

// SetHeaderTexter sets the CellTexter that gets the text for header cells.
func (c *ColumnBase) SetHeaderTexter(s CellTexter) ColumnI {
	c.headerTexter = s
	return c.this()
}

// SetFooterTexter sets the CellTexter that gets the text for footer cells.
func (c *ColumnBase) SetFooterTexter(s CellTexter) ColumnI {
	c.footerTexter = s
	return c.this()
}

// IsHidden returns true if the column is hidden.
func (c *ColumnBase) IsHidden() bool {
	return c.isHidden
}

// SetHidden hides the column without removing it completely from the table.
func (c *ColumnBase) SetHidden(h bool) ColumnI {
	c.isHidden = h
	return c.this()
}

// HeaderAttributes returns the attributes to use on the header cell.
func (c *ColumnBase) HeaderAttributes(row int, col int) *html.Attributes {
	if c.headerAttributes == nil {
		c.headerAttributes = html.NewAttributes()
		c.headerAttributes.Set("scope", "col")
	}
	return c.headerAttributes
}

// FooterAttributes returns the attributes to use for the footer cell.
func (c *ColumnBase) FooterAttributes(row int, col int) *html.Attributes {
	if c.footerAttributes == nil {
		c.footerAttributes = html.NewAttributes()
	}
	return c.footerAttributes
}

// ColTagAttributes specifies attributes that will appear in the table tag. Note that you have to turn on table
// tags in the table object as well for these to appear.
func (c *ColumnBase) ColTagAttributes() *html.Attributes {
	if c.colTagAttributes == nil {
		c.colTagAttributes = html.NewAttributes()
	}
	return c.colTagAttributes
}

// DrawColumnTag draws the column tag if one was requested.
func (c *ColumnBase) DrawColumnTag(ctx context.Context, buf *bytes.Buffer) {
	if c.isHidden {
		return
	}
	a := c.this().ColTagAttributes()
	if c.id != "" {
		a.Set("id", c.this().ParentTable().ID() + "_" + c.id) // so that actions can get routed to a column
	}
	if c.span != 1 {
		a.Set("span", strconv.Itoa(c.span))
	}
	buf.WriteString(html.RenderTag("col", a, ""))
}

// HeaderCellHtml returns the text of the indicated header cell. The default will call into the headerTexter if it
// is provided, or just return the Label value. This function can also be overridden by embedding the ColumnBase object
// into another object.
func (c *ColumnBase) HeaderCellHtml(ctx context.Context, row int, col int) (h string) {
	if c.headerTexter != nil {
		h = c.headerTexter.CellText(ctx, c.this(), row, col, nil)
	} else {
		h = html2.EscapeString(c.title)
	}

	if c.IsSortable() {
		h = c.RenderSortButton(h)
	}
	return
}

// DrawFooterCell will draw the footer cells html into the given buffer.
func (c *ColumnBase) DrawFooterCell(ctx context.Context, row int, col int, count int, buf *bytes.Buffer) {
	if c.isHidden {
		return
	}
	cellHtml := c.this().FooterCellHtml(ctx, row, col)

	a := c.this().FooterAttributes(row, col)
	buf.WriteString(html.RenderTag("td", a, cellHtml))
}

// FooterCellHtml returns the html to use in the given footer cell.
func (c *ColumnBase) FooterCellHtml(ctx context.Context, row int, col int) string {
	if c.footerTexter != nil {
		return c.footerTexter.CellText(ctx, c.this(), row, col, nil) // careful, this does not get escaped
	}

	return ""
}

// DrawCell is the default cell drawing function.
func (c *ColumnBase) DrawCell(ctx context.Context, row int, col int, data interface{}, buf *bytes.Buffer) {
	if c.isHidden {
		return
	}

	cellHtml := c.this().CellText(ctx, row, col, data)
	if !c.isHtml {
		cellHtml = html2.EscapeString(cellHtml)
	}
	a := c.CellAttributes(ctx, row, col, data)

	buf.WriteString(html.RenderTag("td", a, cellHtml))
}

// CellText returns the text in the cell. It will use the CellTexter if one was provided.
func (c *ColumnBase) CellText(ctx context.Context, row int, col int, data interface{}) string {
	if c.cellTexter != nil {
		return c.cellTexter.CellText(ctx, c.this(), row, col, data)
	}
	return ""
}

// CellAttributes returns the attributes of the cell. Column implementations should call this base version first before
// customizing more. It will use the CellStyler if one was provided.
func (c *ColumnBase) CellAttributes(ctx context.Context, row int, col int, data interface{}) *html.Attributes {
	if c.cellStyler != nil {
		return c.cellStyler.Attributes(ctx, row, col, data)
	}
	return nil
}

// Sortable indicates that the column should be drawn with sort indicators.
func (c *ColumnBase) Sortable() ColumnI {
	c.sortDirection = NotSorted
	return c.this()
}

// IsSortable indicates whether the column is sortable, and has a sort indicator in the head.
func (c *ColumnBase) IsSortable() bool {
	return c.sortDirection != NotSortable
}

// UpdateFormValues is called by the system whenever values are sent by client controls.
// This default version does nothing. Columns that need to record information (checkbox columns for example), should
// implement this.
func (c *ColumnBase) UpdateFormValues(ctx *page.Context) {}

func (c *ColumnBase) AddActions(ctrl page.ControlI) {}

// Do a table action that is directed at this table
// Column implementations can implement this method to receive private actions that they have added using AddActions
func (c *ColumnBase) Action(ctx context.Context, params page.ActionParams) {}

func (c *ColumnBase) RenderSortButton(labelHtml string) string {
	if SortButtonHtmlGetter != nil {
		labelHtml += SortButtonHtmlGetter(c.sortDirection)
	}
	switch c.sortDirection {
	case NotSorted:
		labelHtml += ` <i class="fa fa-sort fa-lg"></i>`
	case SortAscending:
		labelHtml +=  ` <i class="fa fa-sort-asc fa-lg"></i>`
	case SortDescending:
		labelHtml +=  ` <i class="fa fa-sort-desc fa-lg"></i>`
	}

	return fmt.Sprintf(`<button onclick="$j('#%s').trigger('grsort', '%s'); return false;">%s</button>`, c.parentTable.ID(), c.ID(), labelHtml)
}

// SortDirection returns the current sort direction.
func (c *ColumnBase) SortDirection() SortDirection {
	return c.sortDirection
}

// SetSortDirection is used internally to set the sort direction indicator.
func (c *ColumnBase) SetSortDirection(d SortDirection) ColumnI {
	c.sortDirection = d
	return c.this()
}

// PreRender is called just before the table is redrawn.
func (c *ColumnBase) PreRender() {}

// MarshalState is an internal function to save the state of the control.
func (c *ColumnBase) MarshalState(m maps.Setter) {}

// UnmarshalState is an internal function to restore the state of the control.
func (c *ColumnBase) UnmarshalState(m maps.Loader) {}