# Advanced Editing Tools

## Comment/Uncomment

The Comment and Uncomment commands, available from the Tools menu allow you to add or remove comment markers to the selection, or the current line if no text is selected, if comments are supported by the format of the text you are editing.

The rules for how commenting is done are defined in the syntax definitions, so if syntax highlighting is not used, commenting/uncommenting is not possible.

Some formats define single line comment markers, some multiline markers and some both. If multiline markers are not available, commenting out a selection that does not fully include its last line is not possible.

If a single line marker is available, commenting single lines is preferred where applicable, as this helps to avoid problems with nested comments.

When removing comment markers, no uncommented text should be selected. When removing multiline comment markers from a selection, any whitespace outside the comment markers is ignored.

To place comment markers, use the Tools Comment menu item or the related keyboard shortcut sequence, default is &Ctrl;D.

To remove comment markers, use the Tools Uncomment menu item or the related keyboard shortcut, default is &Ctrl;&Shift;D.

## The Editor Component Command Line

Kate's editor component has an internal command line, allowing you to perform various actions from a minimal GUI. The command line is a text entry in the bottom of the editor area, to show it select View Switch to Command Line or use the shortcut (default is F7). The editor provides a set of commands as documented below, and additional commands can be provided by plugins.

To execute a command, type the comand then press the return key. The command line will indicate wether it succeded and possibly display a message. If you entered the command line by pressing F7 it will automatically hide after a few seconds. To clear the message and enter a new command, press F7 again.

The command line has a built-in help system, issue the command `help` to get started. To see a list of all available commands issue `help list`, to view help for a specific command, do `help `command``.

The command line has a built in history, so you can reuse commands already typed. To navigate the history, use the Up and Down keys. When showing historical commands, the argument part of the command will be selected, allowing you to easily overwrite the arguments.

### Standard Command Line Commands

#### Commands for Configuring the Editor

These commands are provided by the editor component, and allows you to configure the active document and view only. This is handy if you want to use a setting different from the default settings, for example for indentation.

#### Argument types

BOOLEAN

- This is used with commands that turns things on or off. Legal values are `on`, `off`, `true`, `false`, `1` or `0`

INTEGER

- An integer number

STRING

- A string

    set-tab-widthINTEGER width

- Sets the tab width to the number `width`

    set-indent-widthINTEGER width

- Sets the indentation width to the number `width`. Used only if you are indenting with spaces.

    set-word-wrap-columnINTEGER width

- Sets the line width for hard wrapping to `width`. This is used if you are having your text wrapped automatically.

    set-icon-borderBOOLEAN enable

- Sets the visibility of the icon border.

    set-folding-markersBOOLEAN enable

- Sets the visibility of the folding markers pane.

    set-line-numbersBOOLEAN enable

- Sets the visibility of the line numbers pane.

    set-replace-tabsBOOLEAN enable

- If enabled, tabs are replaced with spaces as you type.

    set-remove-trailing-spaceBOOLEAN enable

- If enabled, trailing whitespace are removed whenever the cursor leaves a line.

    set-show-tabsBOOLEAN enable

- If enabled, TAB characters and trailing whitespace will be visualized by a small dot.

    set-indent-spacesBOOLEAN enable

- If enabled, the editor will indent with `indent-width` spaces for each indentation level, rather than with one TAB character.

    set-mixed-indentBOOLEAN enable

- If enabled, kate will use a mix of TAB and spaces for indentation. Each indentation level will be `indent-width` wide, and more indentation levels will be optimized to use as many TAB characters as possible.

  When executed, this command will additionally set space indentation enabled, and if the indent width is unspecified it will be set to half of the `tab-width` for the document at the time of execution.

    set-word-wrapBOOLEAN
    enable

- Enables dynamic word wrap according to `enable`

    set-replace-tabs-saveBOOLEAN enable

- When enabled, tabs will be replaced with whitespace whenever the document is saved.

    set-remove-trailing-space-saveBOOLEAN enable

- When enabled, trailing space will be removed from each line whenever the document is saved.

    set-indent-modename

- Sets the autoindentation mode to `name`. If `name` is not known, the mode is set to 'none'. Valid modes are 'cstyle', 'csands', 'xml', 'python', 'varindent' and 'none'.

    set-highlighthighlight

- Sets the syntax highlighting system for the document. The argument must be a valid highlight name, as seen in the Tools Highlighting menu. This command provides an autocompletion list for its argument.

#### Commands for editing

These commands modify the current document.

    indent

- Indents the selected lines or the current line.

    unindent

- Unindents the selected lines or current line.

    cleanindent

- Cleans up the indentation of the selected lines or current line according to the indentation settings in the document.

    comment

- Inserts comment markers to make the selection or selected lines or current line a comment according to the text format as defined by the syntax highlight definition for the document.

    uncomment

- Removes comment markers from the selection or selected lines or current line according to the text format as defined by the syntax highlight definition for the document.

    kill-line

- Deletes the current line.

    replacepatternreplacement

- Replaces text matching `pattern` with `replacement`. If you want to include whitespace in the `pattern`, you must quote both the `pattern` and `replacement` with single or double quotes. If the arguments are unquoted, the first word is used as `pattern` and the rest for `replacement`. If `replacement` is empty, each occurrence of `pattern` is removed.

  You can set flags to configure the search by adding a colon, followed by one or more letters each representing a configuration, giving the form `replace:options pattern replacement`. Available options are:

  `b`

- Search backwards.

`c`

- Search from cursor position.

`e`

- Search in the selection only.

`r`

- Do regular expression search. If set, you may use `\N` where N is a number to represent captures in the replacement string.

`s`

- Do case sensitive search.

`p`

- Prompt for permission to replace the next occurence.

`w`

- Match whole words only.

    dateformat

- Inserts a date/time string as defined by the specified `format`, or the format yyyy-MM-dd hh:mm:ss if none is specified. The following translations are done when interpreting `format`:

  `d` | The day as number without a leading zero (1-31).
  `dd` | The day as number with a leading zero (01-31).
  `ddd` | The abbreviated localized day name (e.g. 'Mon'..'Sun').
  `dddd` | The long localized day name (e.g. 'Monday'..'Sunday').
  `M` | The month as number without a leading zero (1-12).
  `MM` | The month as number with a leading zero (01-12).
  `MMM` | The abbreviated localized month name (e.g. 'Jan'..'Dec').
  `yy` | The year as two digit number (00-99).
  `yyyy` | The year as four digit number (1752-8000).
  `h` | The hour without a leading zero (0..23 or 1..12 if AM/PM display).
  `hh` | The hour with a leading zero (00..23 or 01..12 if AM/PM display).
  `m` | The minute without a leading zero (0..59).
  `mm` | The minute with a leading zero (00..59).
  `s` | The second without a leading zero (0..59).
  `ss` | The second with a leading zero (00..59).
  `z` | The milliseconds without leading zeroes (0..999).
  `zzz` | The milliseconds with leading zeroes (000..999).
  `AP` | Use AM/PM display. AP will be replaced by either "AM" or "PM".
  `ap` | Use am/pm display. ap will be replaced by either "am" or "pm".

    charidentifier

- This command allows you to insert literal characters by their numerical identifier, in decimal, octal or hexadecimal form. To use it launch the Editing Command dialog and type `char: [number]` in the entry box, then hit OK.

  ##### `char` examples

  Input: `char:234`

  Output: `ê`

  Input: `char:0x1234`

  Output: `ሴ`

`s///[ig]` `%s///[ig]`

- This command does a sed-like search/replace operation on the current line, or on the whole file (`%s///`).

  In short, the text is searched for text matching the search pattern, the regular expression between the first and the second slash, and when a match is found, the matching part of the text is replaced with the expression between the middle and last part of the string. Parentheses in the search pattern create back references, that is the command remembers which part of the match matched in the parentheses; these strings can be reused in the replace pattern, referred to as `\1` for the first set of parentheses, `\2` for the second and so on.

  To search for a literal `(` or `)`, you need to escape it using a backslash character: `\(\)`

  If you put an `i` at the end of the expression, the matching will be case insensitive. If you put a `g` at the end, all occurrences of the pattern will be replaced, otherwise only the first occurrence is replaced.

  ##### Replacing text in the current line

  Your friendly compiler just stopped, telling you that the class `myClass` mentioned in line 3902 in your source file is not defined.

  "Buckle!" you think, it is of course `MyClass`. You go to line 3902, and instead of trying to find the word in the text, you launch the Editing Command Dialog, enter `s/myclass/MyClass/i`, hit the OK button, save the file and compile – successfully without the error.

  ##### Replacing text in the whole file

  Imagine that you have a file, in which you mention a Miss Jensen several times, when someone comes in and tells you that she just got married to Mr Jones. You want, of course, to replace each and every occurrence of Miss Jensen with Ms Jones.

  Enter the command line and issue the command `%s/Miss Jensen/Ms Jones/` and hit return, you are done.

  ##### A More Advanced Example

  This example makes use of back references as well as a character class (if you do not know what that is, please refer to the related documentation mentioned below).

  Suppose you have the following line:

      void MyClass::DoStringOps( String      &foo, String &bar String *p, int  &a, int &b )

  Now you realize that this is not nice code, and decide that you want to use the `const` keyword for all address of arguments, those characterized by the & operator in front of the argument name. You would also like to simplify the white space, so that there is only 1 whitespace character between each word.

  Launch the Editing Command Dialog, and enter: `s/\s+(\w+)\s+(&)/ const \1 \2/g` and hit the OK button. The `g` at the end of the expression makes the regular expression recompile for each match to save the backreferences.

  Output: `void MyClass::DoStringOps( const String &foo, const String &bar String *p, const int &a, const int &b )`

  Mission completed! Now, what happened? Well, we looked for some white space (`\s+`) followed by one or more alphabetic characters (`\w+`) followed by some more whitespace (`\s+`) followed by an ampersand, and in the process saved the alphabetic chunk and the ampersand for reuse in the replace operation. Then we replaced the matching part of our line with one whitespace followed by const followed by one whitespace followed by our saved alphabetical chunk (`\1`) followed by one whitespace followed by our saved ampersand (`\2`)

  Now in some cases the alphabetical chunk was String, in some int, so using the character class `\w` and the `+` quantifier proved a valuable asset.

#### Commands for navigation

    gotoINT line

- This command navigates to the specified line.

    findpattern

- This command navigates to the first occurrence of `pattern` according to the configuration. Following occurrences can be found using Edit Find Next (the default shortcut is F3).

  The find command can be configured by appending a colon followed by one or more options, the form is `find:options pattern`. The following options are supported:

  `b`

- Search backwards.

`c`

- Search from cursor position.

`e`

- Search in the selection only.

`r`

- Do regular expression search. If set, you may use `\N` where N is a number to represent captures in the replacement string.

`s`

- Do case sensitive search.

`w`

- Match whole words only.

    ifindpattern

- This command provides as-you-type searching. You can configure the behavior of the search by appending a colon followed by one or more options, like this: `ifind:options pattern`. Allowed options are

  `b`

- Search backwards.

`r`

- Do regular expression search.

`s`

- Do case sensitive search.

`c`

- Search from cursor position.

## Using Code Folding

Code folding allows you to hide parts of a document in the editor, making it easier to overview large documents. In &kate; the foldable regions are calculated using rules defined in the syntax highlight definitions, and therefore it is only available in some formats - typically program source code, XML markup and similar. Most highlight definitions supporting code folding also lets you manually define foldable regions, typically using the `BEGIN` and `END` keywords.

To use the code folding feature, activate the folding markers using View Show Folding Markers menu item if they are not already visible. The Folding Markers Pane in the left side of the screen displays a graphical view of the foldable regions, with +/- signs to indicate the possible operation on a given region: a - means that the region is expanded, clicking the - will collapse the region and a + will be displayed instead.

Four commands are provided to manipulate the state of folding regions, see the menu documentation.

If you do not want to use the code folding feature, you can disable the Show folding markers (if available) option in the Appearance page of the editor configuration

## Scripting the editor component with Javascript

### Introduction

Starting with version 2.5, the &kate; editor component supports scripting with ECMA script, also known as JavaScript.

Scripts can be used through the built in command line only. The requirements is that the script is placed in a folder where &kate; can find it, along with an optional .desktop file that defines the related properties. The valid folder are named `katepart/scripts` in the &kde; data folders. You can find the data folders by running the command `kde-config `--path` `data`` You will usually have at least a system and a personal data folder. Of course scripts in the system data folder are available to all users on the system, while those in the personal folder are available for you only.

This feature is experimental and will most likely change during future development.

We know that many of you will be disappointed because you can't add your scripts to the menu or assign shortcuts to them. Sorry, sometime in the future that will likely be possible.

It is also not possible to pass any arguments to your scripts yet. Be patient, and that may be added in the bright future ;)

### The Kate JavaScript API

Here is listed the complete set of functions and properties available in the `document` and `view` objects. In addition you can of course use all the standard objects such as `Math`, `String` `Regex` and so forth.

When a script is run, the `document` object is the current document, and the `view` object is the current view.

The types of arguments are of course not used in JavaScript at this time, they are there solely to indicate what sort of value the funcitons expect.

### Global Functions

`debug( ``string``) [function]`

- ### parameters

  - `string` the string to output

  Outputs the string to STDERR using `kdDebug()`. A dedicated output area is used for the output, which will be prefixed `Kate (KJS Scripts):`

### The `document` API

`document.attribute( ``line`` , ``column`` ); [function]`

- ### Parameters

  - `uint line` The line of the position for which to find the attribute.

  - `uint column` The column of the position for which to find the attribute.

  Returns the numeric ID of the attribute for the document position [`line`,`column`]. The attribute represents the visual appearance or style of the text, and is also used to calculate the syntax highlight for a specific part of the text in mixed formats like HTML or PHP.

`document.canBreakAt( `Char c`, `uint attribute` ); [function]`

- ### Parameters

  - `c` The character to test

  - `attribute` The attribute at the position of `c`.

  Returns whether it is allowed to break the line at a character c with attribute attribute. The result is decided by querying the highlight owning attribute for which characters allow breaking the line.

`document.canComment( `uint start_attribute`, `uint end_attribute` ); [function]`

- ### Parameters

  - `start_attribute` The attribute at the start of the range to turn into a comment.

  - `end_attribute` The attribute at end of the range to turn into a comment.

  Returns whether start_attribute and end_attribute belongs to the same syntax highlight system. If they do, it is sane.

  #### using canComment

      if ( document.canComment( document.attribute(1,0), document.attribute(5,0) ) ) {
          // 1,0 and 5,0 belongs to the same syntax highlighting system
      }

`document.clear(); [function]`

- Clears the document.

`document.commentStart( `uint attribute` ); [function]`

- ### Parameters

  - `attribute` The attribute of the text for which to get the commentStart string.

  Returns the string required to start a multiline comment for a text with attribute, or an empty string if multiline comments are not supported for that text.

`document.commentMarker( `uint attribute` ); [function]`

- ### Parameters

  - `attribute` The attribute of the text for which to get the commentMarker string

  Returns the string used to mark the rest of the line as a comment for a text with attribute or an empty string if single line comments are not supported for that text.

`document.commentEnd( `uint attribute` ); [function]`

- ### Parameters

  - `attribute` The attribute of the text for which to get the commentEnd string

  Returns the string required to end a multiline comment for a text with attribute, or an empty string if multiline comments are not supported for that text.

`document.editBegin(); [function]`

- Start an editing group. All actions done until the call of editEnd() will be grouped as one undo-action.

`document.editEnd(); [function]`

- Finish an editing group.

`document.highlightMode; [property:read only]`

- The name of the document's highlight mode, such as JavaScript or C++. If no syntax highlight mode is set for the document, the value is None. Notice that you need to use the English name in cases where it differs from the translated one.

`document.indentMode; [property:read only]`

- The name of the document indent mode, such as `normal` or `cstyle`. Remember that if no indent mode is set, the value is `none`.

`document.indentWidth; [property:read only]`

- The indentation width set for the document. This is used if space indenting is enabled.

`document.insertLine( `uint line`, `string text` ); [function]`

- ### Parameters

  - `line` document line number

  - `text` text to insert

  Inserts a new line with the text `text` at the line `line`.

`document.insertText( `uint line`, `uint column`, `string text` ); [function]`

- ### Parameters

  - `line` the line number

  - `column` the column

  - `text` the text which is to be inserted

  Inserts the text `text` in line `line` and column `column`.

document.length(); [function]

- Returns the document's size in bytes.

`document.lines(); [function]`

- Returns the number of lines in the document.

document.mixedIndent; [property:read only]

- A boolean telling whether the mixed-indent setting is enabled for the document. If so, indentation is optimized to contain a mix of tab characters and spaces like used by the Emacs editor.

document.removeLine( `uint line` ); [function]

- ### Parameters

  - `line` line number

  Removes the document line line.

`document.removeText( `uint startLine`, `uint startColumn`, `uint endLine`, `uint endColumn` ); [function]`

- ### Parameters

  - `startLine` specifies the beginning line

  - `startColumn` specifies the beginning column

  - `endLine` specifies the ending line

  - `endColumn` specifies the ending column

  Removes the text range from line `startLine` and column `startColumn` up to line `endLine` and column `endColumn`.

`document.setText( `string text` ); [function]`

- ### Parameters

  - `text` document text

  Sets the entire document content to `text`.

`document.spaceIndent; [property:read only]`

- A boolean telling whether space-indent is enabled for the document. If so, the document is indented with indentWidth spaces pr level, otherwise indentation is one tab character pr. level.

`document.textFull(); [function]`

- Returns the full document text. If the text spans over multiple lines the linefeed character is `\n`.

`document.textLine( uint line ); [function]`

- ### Parameters

  - `line` the line

  Returns the text of line `line`.

`document.textRange( `uint startLine`, `uint startColumn`, `uint endLine`, `uint endColumn` ); [function]`

- ### Parameters

  - `startLine` specifies the beginning line

  - `startColumn` specifies the beginning column

  - `endLine` specifies the ending line

  - `endColumn` specifies the ending column

  Returns the specified text range. If the range spans over multiple lines the linefeed character is `\n`.

### The `view` API

`view.clearSelection(); [function]`

- Deselects all text.

`view.cursorColumn(); [function]`

- Returns the current cursor column (TAB characters are expanded).

`view.cursorColumnReal(); [function]`

- Returns the current real cursor column (TAB characters counts one).

`view.cursorLine(); [function]`

- Returns the current cursor line.

`view.hasSelection(); [function]`

- Returns `true` if the view contains selected text, otherwise `false`.

`view.removeSelectedText(); [function]`

- Removes the selected text, if the view has a selection.

`view.selectAll(); [function]`

- Selects all text.

`view.selection(); [function]`

- Returns the selected text. If the selection spans over multiple lines the linefeed character is `\n`.

`view.selectionEndColumn; [property:read only]`

- Returns the ending column of the selection.

`view.selectionEndLine; [property:read only]`

- Returns the ending line of the selection.

`view.selectionStartColumn; [property:read only]`

- Returns the starting column of the selection.

`view.selectionStartLine; [property:read only]`

- Returns the starting line of the selection.

`view.setCursorPosition( `uint line`, `uint column` ); [function]`

- ### Parameters

  - `line` Specifies the line for the cursor.

  - `column` Specifies the column for the cursor.

  Sets the input cursor position in the view to [`line`, `col`]. This sets the cursor position by visual means, that is the a TAB character counts up to `tabwidth` depending on the position inside the line. The cursor position is made visible. Both line and column are zero-based.

`view.setCursorPositionReal( `uint line`, `uint column` ); [function]`

- ### Parameters

  - `line` Specifies the line for the cursor.

  - `column` Specifies the column for the cursor.

  Sets the input cursor position to [`line`, `col`]. This sets the string position, that is a TAB character counts for 1. The cursor position is made visible. Both line and column are zero-based.

`view.setSelection( `uint startLine`, `uint startColumn`, `uint endLine`, `uint endColumn` ); [function]`

- ### Parameters

  - `startLine` specifies the beginning line

  - `startColumn` specifies the beginning column

  - `endLine` specifies the ending line

  - `endColumn` specifies the ending column

  Sets a selection from line `startLine` and column `startColumn` up to line `endLine` and column `endColumn`.

#### A sample script

As an example we will create a small script that uppercases the selection. It is obvious that we first need to check whether a selection exists, if so we get the text, change the case and then replace it with the new one. An implementation could look like this:

    if ( view.hasSelection() )
    {
      // uppercase selection
      column = view.selectionStartColumn;
      line = view.selectionStartLine;

      selection = view.selection().toUpperCase();

      document.editBegin();
      view.removeSelectedText();
      document.insertText( line, column, selection );
      document.editEnd();
    }

To group this action together so that they will be reverted by a single activation of Undo we encapsulate the lines

    view.removeSelectedText()

and

    document.insertText()

with a

    document.editBegin()

and

    document.editEnd()

.

#### A sample `.desktop` file

Here is a sample .desktop file that accompanies the above script.

    # Example of a .desktop file
    [Desktop Entry]
    Encoding=UTF-8
    Name=Kate Part JavaScript Uppercase
    Comment=Script to uppercase the selection
    X-Kate-Command=uppercase-selection
    X-Kate-Help=<p>Usage: <code>uppercase-selection</code></p>

As you can see you can define the Encoding, set a Name, a Comment, a help text using X-Kate-Help and the command line name via X-Kate-Command. The entries Name, Comment and X-Kate-Help are automatically translated into other languages by the KDE translation teams, if the files are in KDE's SVN repository.

#### Putting it togeather

&kate; will search the script folders (see above) for `*.js` files. For every file it checks whether there is a corresponding `.desktop` file, like for uppercase.js it would look for uppercase.desktop.

If a `.desktop` file can not be found the script will be registered in katepart's command line with the filename without the ending .js, so in our example this would be `uppercase`. If the command-name is fine and you don't need the extra features a `.desktop` file provides you do not need a `.desktop` file at all.

If a `.desktop` file exists katepart will read the name under which the script will be registered from the .desktop-entry X-Kate-Command, for example X-Kate-Command=uppercase-selection.