spf13--cobra/bash_completionsV2.go
Marc Khouzam 15823e76b9 Print ActiveHelp for bash along other completions
In the bash shell we used to print ActiveHelp messages on every
tab-press. In the example below, notice the "Command help" line which is
ActiveHelp:

bash-5.1$ tanzu context u[tab]
Command help: Configure and manage contexts for the Tanzu CLI

bash-5.1$ tanzu context u[tab]
Command help: Configure and manage contexts for the Tanzu CLI

bash-5.1$ tanzu context u
unset  (Unset the active context so that it is not used by default.)
use    (Set the context to be used by default)
bash-5.1$ tanzu context u

Above, on the first [tab] press, only the ActiveHelp is printed.
On the second [tab] press, the ActiveHelp is printed again, followed
by a re-print of the command-line, followed by the completions choices.

The separation between ActiveHelp and completion choices makes the
ActiveHelp harder to see. Furthermore, I find the double printing of the
ActiveHelp string to look bad.

Note that for zsh, the UX is different and that ActiveHelp messages are
printed at the same time as the completion choices.

This commit aligns the UX for ActiveHelp in bash with the one for zsh:
if there are other completions to be shown, the ActiveHelp messages are
printed at the same time.

New behaviour:
1- ActiveHelp is no longer printed on the first [tab] press. This is
   better aligned with bash's standard approach.
2- ActiveHelp is printed on the second [tab] press, above the completion
   choices, with a `--` delimiter.
3- If there are no completion choices, the `--` delimiter is omitted.

This behaviour is the same as what is done for zsh (except that for zsh
the first [tab] press immediately shows completion choices).

Below is the above example, but using this commit.
Notice the more concise and easier to read completion output:

bash-5.1$ tanzu context u[tab][tab]
Command help: Configure and manage contexts for the Tanzu CLI
--
unset  (Unset the active context so that it is not used by default.)
use    (Set the context to be used by default)
bash-5.1$ tanzu context u

Signed-off-by: Marc Khouzam <marc.khouzam@gmail.com>
2023-11-23 09:47:28 -05:00

438 lines
15 KiB
Go

// Copyright 2013-2023 The Cobra Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package cobra
import (
"bytes"
"fmt"
"io"
"os"
)
func (c *Command) genBashCompletion(w io.Writer, includeDesc bool) error {
buf := new(bytes.Buffer)
genBashComp(buf, c.Name(), includeDesc)
_, err := buf.WriteTo(w)
return err
}
func genBashComp(buf io.StringWriter, name string, includeDesc bool) {
compCmd := ShellCompRequestCmd
if !includeDesc {
compCmd = ShellCompNoDescRequestCmd
}
WriteStringAndCheck(buf, fmt.Sprintf(`# bash completion V2 for %-36[1]s -*- shell-script -*-
__%[1]s_debug()
{
if [[ -n ${BASH_COMP_DEBUG_FILE-} ]]; then
echo "$*" >> "${BASH_COMP_DEBUG_FILE}"
fi
}
# Macs have bash3 for which the bash-completion package doesn't include
# _init_completion. This is a minimal version of that function.
__%[1]s_init_completion()
{
COMPREPLY=()
_get_comp_words_by_ref "$@" cur prev words cword
}
# This function calls the %[1]s program to obtain the completion
# results and the directive. It fills the 'out' and 'directive' vars.
__%[1]s_get_completion_results() {
local requestComp lastParam lastChar args
# Prepare the command to request completions for the program.
# Calling ${words[0]} instead of directly %[1]s allows handling aliases
args=("${words[@]:1}")
requestComp="${words[0]} %[2]s ${args[*]}"
lastParam=${words[$((${#words[@]}-1))]}
lastChar=${lastParam:$((${#lastParam}-1)):1}
__%[1]s_debug "lastParam ${lastParam}, lastChar ${lastChar}"
if [[ -z ${cur} && ${lastChar} != = ]]; then
# If the last parameter is complete (there is a space following it)
# We add an extra empty parameter so we can indicate this to the go method.
__%[1]s_debug "Adding extra empty parameter"
requestComp="${requestComp} ''"
fi
# When completing a flag with an = (e.g., %[1]s -n=<TAB>)
# bash focuses on the part after the =, so we need to remove
# the flag part from $cur
if [[ ${cur} == -*=* ]]; then
cur="${cur#*=}"
fi
__%[1]s_debug "Calling ${requestComp}"
# Use eval to handle any environment variables and such
out=$(eval "${requestComp}" 2>/dev/null)
# Extract the directive integer at the very end of the output following a colon (:)
directive=${out##*:}
# Remove the directive
out=${out%%:*}
if [[ ${directive} == "${out}" ]]; then
# There is not directive specified
directive=0
fi
__%[1]s_debug "The completion directive is: ${directive}"
__%[1]s_debug "The completions are: ${out}"
}
__%[1]s_process_completion_results() {
local shellCompDirectiveError=%[3]d
local shellCompDirectiveNoSpace=%[4]d
local shellCompDirectiveNoFileComp=%[5]d
local shellCompDirectiveFilterFileExt=%[6]d
local shellCompDirectiveFilterDirs=%[7]d
local shellCompDirectiveKeepOrder=%[8]d
if (((directive & shellCompDirectiveError) != 0)); then
# Error code. No completion.
__%[1]s_debug "Received error from custom completion go code"
return
else
if (((directive & shellCompDirectiveNoSpace) != 0)); then
if [[ $(type -t compopt) == builtin ]]; then
__%[1]s_debug "Activating no space"
compopt -o nospace
else
__%[1]s_debug "No space directive not supported in this version of bash"
fi
fi
if (((directive & shellCompDirectiveKeepOrder) != 0)); then
if [[ $(type -t compopt) == builtin ]]; then
# no sort isn't supported for bash less than < 4.4
if [[ ${BASH_VERSINFO[0]} -lt 4 || ( ${BASH_VERSINFO[0]} -eq 4 && ${BASH_VERSINFO[1]} -lt 4 ) ]]; then
__%[1]s_debug "No sort directive not supported in this version of bash"
else
__%[1]s_debug "Activating keep order"
compopt -o nosort
fi
else
__%[1]s_debug "No sort directive not supported in this version of bash"
fi
fi
if (((directive & shellCompDirectiveNoFileComp) != 0)); then
if [[ $(type -t compopt) == builtin ]]; then
__%[1]s_debug "Activating no file completion"
compopt +o default
else
__%[1]s_debug "No file completion directive not supported in this version of bash"
fi
fi
fi
# Separate activeHelp from normal completions
local completions=()
local activeHelp=()
__%[1]s_extract_activeHelp
if (((directive & shellCompDirectiveFilterFileExt) != 0)); then
# File extension filtering
local fullFilter filter filteringCmd
# Do not use quotes around the $completions variable or else newline
# characters will be kept.
for filter in ${completions[*]}; do
fullFilter+="$filter|"
done
filteringCmd="_filedir $fullFilter"
__%[1]s_debug "File filtering command: $filteringCmd"
$filteringCmd
elif (((directive & shellCompDirectiveFilterDirs) != 0)); then
# File completion for directories only
local subdir
subdir=${completions[0]}
if [[ -n $subdir ]]; then
__%[1]s_debug "Listing directories in $subdir"
pushd "$subdir" >/dev/null 2>&1 && _filedir -d && popd >/dev/null 2>&1 || return
else
__%[1]s_debug "Listing directories in ."
_filedir -d
fi
else
__%[1]s_handle_completion_types
fi
__%[1]s_handle_special_char "$cur" :
__%[1]s_handle_special_char "$cur" =
# Print the activeHelp statements before we finish
__%[1]s_handle_activeHelp
}
__%[1]s_handle_activeHelp() {
# Print the activeHelp statements
if ((${#activeHelp[*]} != 0)); then
# Only print ActiveHelp on the second TAB press
if [ $COMP_TYPE -eq 63 ]; then
printf "\n"
printf "%%s\n" "${activeHelp[@]}"
if ((${#COMPREPLY[*]} == 0)); then
# When there are no completion choices from the program, file completion
# may kick in if the program has not disabled it; in such a case, we want
# to know if any files will match what the user typed, so that we know if
# there will be completions presented, so that we know how to handle ActiveHelp.
# To find out, we actually trigger the file completion ourselves;
# the call to _filedir will fill COMPREPLY if files match.
if (((directive & shellCompDirectiveNoFileComp) == 0)); then
__%[1]s_debug "Listing files"
_filedir
fi
fi
if ((${#COMPREPLY[*]} != 0)); then
# If there are completion choices to be shown, print a delimiter.
# Re-printing the command-line will automatically be done
# by the shell when it prints the completion choices.
printf -- "--"
else
# When there are no completion choices at all, we need
# to re-print the command-line since the shell will
# not be doing it itself.
__%[1]s_reprint_commandLine
fi
elif [ $COMP_TYPE -eq 37 ] || [ $COMP_TYPE -eq 42 ]; then
# For completion type: menu-complete/menu-complete-backward and insert-completions
# the completions are immediately inserted into the command-line, so we first
# print the activeHelp message and reprint the command-line since the shell won't.
printf "\n"
printf "%%s\n" "${activeHelp[@]}"
__%[1]s_reprint_commandLine
fi
fi
}
__%[1]s_reprint_commandLine() {
# The prompt format is only available from bash 4.4.
# We test if it is available before using it.
if (x=${PS1@P}) 2> /dev/null; then
printf "%%s" "${PS1@P}${COMP_LINE[@]}"
else
# Can't print the prompt. Just print the
# text the user had typed, it is workable enough.
printf "%%s" "${COMP_LINE[@]}"
fi
}
# Separate activeHelp lines from real completions.
# Fills the $activeHelp and $completions arrays.
__%[1]s_extract_activeHelp() {
local activeHelpMarker="%[9]s"
local endIndex=${#activeHelpMarker}
while IFS='' read -r comp; do
if [[ ${comp:0:endIndex} == $activeHelpMarker ]]; then
comp=${comp:endIndex}
__%[1]s_debug "ActiveHelp found: $comp"
if [[ -n $comp ]]; then
activeHelp+=("$comp")
fi
else
# Not an activeHelp line but a normal completion
completions+=("$comp")
fi
done <<<"${out}"
}
__%[1]s_handle_completion_types() {
__%[1]s_debug "__%[1]s_handle_completion_types: COMP_TYPE is $COMP_TYPE"
case $COMP_TYPE in
37|42)
# Type: menu-complete/menu-complete-backward and insert-completions
# If the user requested inserting one completion at a time, or all
# completions at once on the command-line we must remove the descriptions.
# https://github.com/spf13/cobra/issues/1508
local tab=$'\t' comp
while IFS='' read -r comp; do
[[ -z $comp ]] && continue
# Strip any description
comp=${comp%%%%$tab*}
# Only consider the completions that match
if [[ $comp == "$cur"* ]]; then
COMPREPLY+=("$comp")
fi
done < <(printf "%%s\n" "${completions[@]}")
;;
*)
# Type: complete (normal completion)
__%[1]s_handle_standard_completion_case
;;
esac
}
__%[1]s_handle_standard_completion_case() {
local tab=$'\t' comp
# Short circuit to optimize if we don't have descriptions
if [[ "${completions[*]}" != *$tab* ]]; then
IFS=$'\n' read -ra COMPREPLY -d '' < <(compgen -W "${completions[*]}" -- "$cur")
return 0
fi
local longest=0
local compline
# Look for the longest completion so that we can format things nicely
while IFS='' read -r compline; do
[[ -z $compline ]] && continue
# Strip any description before checking the length
comp=${compline%%%%$tab*}
# Only consider the completions that match
[[ $comp == "$cur"* ]] || continue
COMPREPLY+=("$compline")
if ((${#comp}>longest)); then
longest=${#comp}
fi
done < <(printf "%%s\n" "${completions[@]}")
# If there is a single completion left, remove the description text
if ((${#COMPREPLY[*]} == 1)); then
__%[1]s_debug "COMPREPLY[0]: ${COMPREPLY[0]}"
comp="${COMPREPLY[0]%%%%$tab*}"
__%[1]s_debug "Removed description from single completion, which is now: ${comp}"
COMPREPLY[0]=$comp
else # Format the descriptions
__%[1]s_format_comp_descriptions $longest
fi
}
__%[1]s_handle_special_char()
{
local comp="$1"
local char=$2
if [[ "$comp" == *${char}* && "$COMP_WORDBREAKS" == *${char}* ]]; then
local word=${comp%%"${comp##*${char}}"}
local idx=${#COMPREPLY[*]}
while ((--idx >= 0)); do
COMPREPLY[idx]=${COMPREPLY[idx]#"$word"}
done
fi
}
__%[1]s_format_comp_descriptions()
{
local tab=$'\t'
local comp desc maxdesclength
local longest=$1
local i ci
for ci in ${!COMPREPLY[*]}; do
comp=${COMPREPLY[ci]}
# Properly format the description string which follows a tab character if there is one
if [[ "$comp" == *$tab* ]]; then
__%[1]s_debug "Original comp: $comp"
desc=${comp#*$tab}
comp=${comp%%%%$tab*}
# $COLUMNS stores the current shell width.
# Remove an extra 4 because we add 2 spaces and 2 parentheses.
maxdesclength=$(( COLUMNS - longest - 4 ))
# Make sure we can fit a description of at least 8 characters
# if we are to align the descriptions.
if ((maxdesclength > 8)); then
# Add the proper number of spaces to align the descriptions
for ((i = ${#comp} ; i < longest ; i++)); do
comp+=" "
done
else
# Don't pad the descriptions so we can fit more text after the completion
maxdesclength=$(( COLUMNS - ${#comp} - 4 ))
fi
# If there is enough space for any description text,
# truncate the descriptions that are too long for the shell width
if ((maxdesclength > 0)); then
if ((${#desc} > maxdesclength)); then
desc=${desc:0:$(( maxdesclength - 1 ))}
desc+="…"
fi
comp+=" ($desc)"
fi
COMPREPLY[ci]=$comp
__%[1]s_debug "Final comp: $comp"
fi
done
}
__start_%[1]s()
{
local cur prev words cword split
COMPREPLY=()
# Call _init_completion from the bash-completion package
# to prepare the arguments properly
if declare -F _init_completion >/dev/null 2>&1; then
_init_completion -n =: || return
else
__%[1]s_init_completion -n =: || return
fi
__%[1]s_debug
__%[1]s_debug "========= starting completion logic =========="
__%[1]s_debug "cur is ${cur}, words[*] is ${words[*]}, #words[@] is ${#words[@]}, cword is $cword"
# The user could have moved the cursor backwards on the command-line.
# We need to trigger completion from the $cword location, so we need
# to truncate the command-line ($words) up to the $cword location.
words=("${words[@]:0:$cword+1}")
__%[1]s_debug "Truncated words[*]: ${words[*]},"
local out directive
__%[1]s_get_completion_results
__%[1]s_process_completion_results
}
if [[ $(type -t compopt) = "builtin" ]]; then
complete -o default -F __start_%[1]s %[1]s
else
complete -o default -o nospace -F __start_%[1]s %[1]s
fi
# ex: ts=4 sw=4 et filetype=sh
`, name, compCmd,
ShellCompDirectiveError, ShellCompDirectiveNoSpace, ShellCompDirectiveNoFileComp,
ShellCompDirectiveFilterFileExt, ShellCompDirectiveFilterDirs, ShellCompDirectiveKeepOrder,
activeHelpMarker))
}
// GenBashCompletionFileV2 generates Bash completion version 2.
func (c *Command) GenBashCompletionFileV2(filename string, includeDesc bool) error {
outFile, err := os.Create(filename)
if err != nil {
return err
}
defer outFile.Close()
return c.GenBashCompletionV2(outFile, includeDesc)
}
// GenBashCompletionV2 generates Bash completion file version 2
// and writes it to the passed writer.
func (c *Command) GenBashCompletionV2(w io.Writer, includeDesc bool) error {
return c.genBashCompletion(w, includeDesc)
}