TermUI.Widgets.LogViewer (TermUI v0.2.0)

View Source

LogViewer widget for displaying real-time logs with virtual scrolling.

LogViewer efficiently displays large log files (millions of lines) using virtual scrolling, with support for search, filtering, syntax highlighting, and bookmarking.

Usage

LogViewer.new(
  lines: log_lines,
  tail_mode: true,
  highlight_levels: true
)

Features

  • Virtual scrolling for efficient rendering of large datasets
  • Tail mode for live log monitoring
  • Search with regex support and match highlighting
  • Syntax highlighting for log levels and timestamps
  • Filtering by level, source, or pattern
  • Line bookmarking
  • Selection and copy functionality
  • Wrap/truncate toggle for long lines

Keyboard Controls

  • Up/Down: Move cursor
  • PageUp/PageDown: Scroll by page
  • Home/End: Jump to first/last line
  • /: Start search
  • n/N: Next/previous search match
  • f: Toggle filter mode
  • b: Toggle bookmark on current line
  • B: Jump to next bookmark
  • t: Toggle tail mode
  • w: Toggle wrap mode
  • Space: Start/extend selection
  • Escape: Clear search/filter/selection

Summary

Types

filter_spec()
log_entry()
log_level()
search_state()

Functions

add_line(state, line)

Adds a single log line to the viewer.

add_lines(state, new_lines)

Adds multiple log lines to the viewer.

clear(state)

Clears all log lines.

clear_filter(state)

Clears the current filter.

get_bookmarks(state)

Gets the list of bookmarked line indices.

get_search_matches(state)

Gets the current search matches.

get_selected_text(state)

Gets the currently selected text.

goto_line(state, line_num)

Jumps to a specific line number.

line_count(state)

Gets the total number of lines.

new(opts)

Creates new LogViewer widget props.

search(state, pattern)

Starts a search with the given pattern.

set_filter(state, filter)

Sets a filter on the log viewer.

tail_mode?(state)

Checks if tail mode is enabled.

visible_line_count(state)

Gets the number of visible lines (after filtering).

Types

filter_spec()

@type filter_spec() :: %{
  levels: [log_level()] | nil,
  source: String.t() | nil,
  pattern: Regex.t() | String.t() | nil,
  bookmarks_only: boolean()
}

log_entry()

@type log_entry() :: %{
  id: non_neg_integer(),
  timestamp: DateTime.t() | nil,
  level: log_level() | nil,
  source: String.t() | nil,
  message: String.t(),
  raw: String.t()
}

log_level()

@type log_level() ::
  :debug | :info | :notice | :warning | :error | :critical | :alert | :emergency

search_state()

@type search_state() :: %{
  pattern: Regex.t() | String.t(),
  matches: [non_neg_integer()],
  current_match: non_neg_integer(),
  highlight: boolean()
}

Functions

add_line(state, line)

@spec add_line(map(), String.t() | log_entry()) :: map()

Adds a single log line to the viewer.

add_lines(state, new_lines)

@spec add_lines(map(), [String.t() | log_entry()]) :: map()

Adds multiple log lines to the viewer.

clear(state)

@spec clear(map()) :: map()

Clears all log lines.

clear_filter(state)

@spec clear_filter(map()) :: map()

Clears the current filter.

get_bookmarks(state)

@spec get_bookmarks(map()) :: [non_neg_integer()]

Gets the list of bookmarked line indices.

get_search_matches(state)

@spec get_search_matches(map()) :: [non_neg_integer()]

Gets the current search matches.

get_selected_text(state)

@spec get_selected_text(map()) :: String.t()

Gets the currently selected text.

goto_line(state, line_num)

@spec goto_line(map(), non_neg_integer()) :: {:ok, map()}

Jumps to a specific line number.

line_count(state)

@spec line_count(map()) :: non_neg_integer()

Gets the total number of lines.

new(opts)

@spec new(keyword()) :: map()

Creates new LogViewer widget props.

Options

  • :lines - Initial log lines (strings or log entries)
  • :max_lines - Maximum lines to keep in buffer (default: 100_000)
  • :tail_mode - Auto-scroll to new lines (default: true)
  • :wrap_lines - Wrap long lines (default: false)
  • :show_line_numbers - Display line numbers (default: true)
  • :show_timestamps - Display timestamps column (default: false)
  • :show_levels - Display level column (default: true)
  • :highlight_levels - Color-code by level (default: true)
  • :on_select - Callback when lines are selected
  • :on_copy - Callback when copy is requested
  • :parser - Custom log parser function

search(state, pattern)

@spec search(map(), String.t()) :: map()

Starts a search with the given pattern.

set_filter(state, filter)

@spec set_filter(map(), filter_spec()) :: map()

Sets a filter on the log viewer.

tail_mode?(state)

@spec tail_mode?(map()) :: boolean()

Checks if tail mode is enabled.

visible_line_count(state)

@spec visible_line_count(map()) :: non_neg_integer()

Gets the number of visible lines (after filtering).