5. Searching for a Pattern

The searchcolumn subcommand was added in Tablelist version 5.3.  It is often used together with the -populatecommand configuration option, introduced in Tablelist version 5.4.  Here is a partly abbreviated version of the subcommand's description in the reference manual:

pathName searchcolumn columnIndex pattern ?options?

This subcommand searches the elements of the column given by columnIndex to see if one of them matches pattern.  If a match is found, the row index of the first matching element is returned as result (unless the option -all is specified).  If not, the return value is -1.  One or more of the following options may be specified to control the search:

-all Changes the result to be the list of all matching row indices, which will be in numeric order (or in reverse numeric order when used with the -backwards option).
 
-backwards The search will proceed backward through the given column's elements.
 
-check command Specifies an additional condition to be fulfilled by the matching elements. ...
 
-descend Search the elements of the specified column in all descendants of the tree node given by the -parent option. ...
 
-exact The matching element(s) must be identical to the literal string pattern.
 
-formatted Examine the formatted versions of the elements rather than the internal cell values.
 
-glob Treat pattern as a glob-style pattern and match it against the elements using the same rules as the  string match  command.
 
-nocase Causes comparisons to be handled in a case-insensitive manner.  Has no effect if combined with the -numeric option.
 
-not This option negates the sense of the match, ...
 
-numeric The elements are to be compared to pattern as integer or floating-point values, using the == comparison operator.  This option is only meaningful when used with -exact.
 
-parent nodeIndex  This option restricts the search to the children (or descendants, when used with -descend) of the tree node given by nodeIndex.  The default parent is root.
 
-regexp Treat pattern as a regular expression and match it against the elements using the rules described in the re_syntax reference page.
 
-start index The elements of the specified column are to be searched (forwards or backwards) starting at the row given by index. ...

If all matching style options -exact, -glob, and -regexp are omitted then the matching style defaults to -glob.  If more than one of them is specified, the last matching style given takes precedence.

Before examining the children (or descendants, when used with the -descend option) of a row whose children have not been inserted yet, the command specified as the value of the -populatecommand option (if any) is automatically concatenated with the name of the tablelist widget and the row index, and the resulting script is evaluated in the global scope.  This enables you to insert the children on demand, just before searching them for the specified pattern.

The following example is an extended version of the demo script dirViewer_tile.tcl.  The pop-up menu within the tablelist widget displaying the contents of a directory has a second command entry Search for Pattern..., which opens a dialog for entering the data needed for building the arguments to be passed to the searchcolumn subcommand:

proc displayContents dir {
    #
    # Create a scrolled tablelist widget with 3 dynamic-
    # width columns and interactive sort capability
    #
    set tf .tf
    ttk::frame $tf -class ScrollArea
    set tbl $tf.tbl
    set vsb $tf.vsb
    set hsb $tf.hsb
    tablelist::tablelist $tbl \
	-columns {0 "Name"	    left
		  0 "Size"	    right
		  0 "Date Modified" left} \
	-expandcommand expandCmd -collapsecommand collapseCmd \
	-xscrollcommand [list $hsb set] -yscrollcommand [list $vsb set] \
	-movablecolumns no -showseparators yes -height 18 -width 80 \
	-populatecommand populateCmd

    . . .

    #
    # Create a pop-up menu with 2 command entries; bind the script
    # associated with its first entry to the <Double-1> event, too
    #
    set menu .menu
    menu $menu -tearoff no
    foreach {label cmd} {"Display Contents" putContentsOfSelFolder
	"Search for Pattern..." openSearchDlgForSelFolder} {
	$menu add command -label $label -command [list $cmd $tbl]
    }
    set bodyTag [$tbl bodytag]
    bind $bodyTag <<Button3>>  [bind TablelistBody <Button-1>]
    bind $bodyTag <<Button3>> +[bind TablelistBody <ButtonRelease-1>]
    bind $bodyTag <<Button3>> +[list postPopupMenu %X %Y]
    bind $bodyTag <Double-1>   [list putContentsOfSelFolder $tbl]

    . . .

    #
    # Populate the tablelist with the contents of the given directory
    #
    $tbl sortbycolumn 0
    putContents $dir $tbl root
}

The procedure populateCmd, specified as the value of the -populatecommand configuration option, will be invoked automatically if (and only if) the searchcolumn subcommand has to examine the children of a tablelist item and these children are still unknown.  In the presence of the -descend subcommand option, this will be performed recursively  As described in the reference manual, the populateCmd procedure should just insert the children of the row in question, without expanding the node or changing its appearance in any other way.  In our example, these children correspond to the contents of the directory whose leaf name is displayed in the first cell of the specified row:

proc populateCmd {tbl row} {
    set dir [$tbl rowattrib $row pathName]
    putContents $dir $tbl $row
}

The procedure openSearchDlgForSelFolder, associated with the Search for Pattern... pop-up menu entry, creates a dialog window containing:

The procedure uses, among others, the mentry::dateTimeMentry command from the Mentry package for creating two multi-entry widgets that hold the modification date interval and the Wcb package for a strait-forward implementation of the text widget's read-only behavior:

proc openSearchDlgForSelFolder tbl {
    set row [$tbl curselection]
    set key [$tbl getkeys $row]
    set top .top$key
    if {[winfo exists $top]} {
	raise $top
	return ""
    }

    toplevel $top
    set dir [$tbl rowattrib $row pathName]
    wm title $top "Search in Directory \"[file nativename $dir]\""

    . . .

    #
    # "Modification Date" checkbuttons and mentry widgets
    #
    set lfLastModDateTime [ttk::labelframe $f.lfLastModDateTime -text \
			   "Modification Date"]
    set ::data($key-useMinDateTime) 0
    set ::data($key-useMaxDateTime) 0
    set ckMinDateTime [ttk::checkbutton $lfLastModDateTime.ckMinDateTime -text \
		       "After:" -variable data($key-useMinDateTime)]
    set meMinDateTime [mentry::dateTimeMentry \
		       $lfLastModDateTime.meMinDateTime YmdHM - : \
		       -justify center -background white]
    set ckMaxDateTime [ttk::checkbutton $lfLastModDateTime.ckMaxDateTime -text \
		       "Before:" -variable data($key-useMaxDateTime)]
    set meMaxDateTime [mentry::dateTimeMentry \
		       $lfLastModDateTime.meMaxDateTime YmdHM - : \
		       -justify center -background white]
    set maxClock [clock seconds]
    set minClock [expr {$maxClock - 24*60*60}]
    mentry::putClockVal $minClock $meMinDateTime
    mentry::putClockVal $maxClock $meMaxDateTime
    . . .

    #
    # "Find" and "Close" buttons
    #
    set fBtns [ttk::frame $f.fBtns]
    set bFind  [ttk::button $fBtns.bFind -text "Find" -default active \
		-command [list findPattern $tbl $key]]
    set bClose [ttk::button $fBtns.bClose -text "Close" -default normal \
		-command [list destroy $top]]
    . . .

    #
    # Readonly text widget displaying the search command
    #
    set tCmd [text $f.tCmd -background white -height 2 -width 70 -wrap word \
	      -highlightthickness 0 -insertwidth 0]
    wcb::callback $tCmd before insert cancelInput
    wcb::callback $tCmd before delete cancelInput
    proc cancelInput {w idx args} { wcb::cancel }
    set ::data($key-tCmd) $tCmd

    #
    # Scrollable tablelist widget displaying the search result
    #
    set fResult $f.fResult
    ttk::frame $fResult -class ScrollArea
    set resTbl $fResult.tbl
    set vsb $fResult.vsb
    set hsb $fResult.hsb
    tablelist::tablelist $resTbl \
	-columns {0 "Path"	    left
		  0 "Size"	    right
		  0 "Date Modified" left} \
	-xscrollcommand [list $hsb set] -yscrollcommand [list $vsb set] \
	-movablecolumns no -showseparators yes -height 12 -width 70

    . . .
}

The findPattern procedure associated with the Find button of the dialog described above builds the search command from the data entered by the user, evaluates it, and displays the data of the matching items in the search result tablelist widget :

proc findPattern {tbl key} {
    . . .

    #
    # Build, show, and evaluate the search command
    #
    set searchCmd [list $tbl searchcolumn 0 $::data($key-pattern) \
		   -parent k$key -all -formatted $::data($key-style)]
    if {$::data($key-descend)} {
	lappend searchCmd -descend
    }
    if {$::data($key-noCase)} {
	lappend searchCmd -nocase
    }
    if {$useMinDateTime || $useMaxDateTime} {
	set checkCmd [list checkDateTime $minDateTime $maxDateTime]
	lappend searchCmd -check $checkCmd
    }
    _$tCmd insert end $searchCmd
    update idletasks
    set rowList [eval $searchCmd]

    #
    # Populate the search result tablelist with the data of the matching items
    #
    foreach row $rowList {
	set item [$tbl get $row]
	foreach {name size dateTime} $item {}

	. . .
    }
}

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