Merge pull request #32 from andreax79/master

Pass arguments to function as environment variable MO_ALLOW_FUNCTION_ARGUMENTS

README.md

@@ -41,7 +41,7 @@ There are a few ways you can install this tool.  How you install it depends on h
 You can install this file in `/usr/local/bin/` or `/usr/bin/` by simply downloading it, changing the permissions, then moving it to the right location.  Double check that your system's PATH includes the destination folder, otherwise users may have a hard time starting the command.
 
     # Download
-    curl -sSO https://raw.githubusercontent.com/tests-always-included/mo/master/mo
+    curl -sSL https://git.io/get-mo -o mo
 
     # Make executable
     chmod +x mo
@@ -58,7 +58,7 @@ You can install this file in `/usr/local/bin/` or `/usr/bin/` by simply download
 This is very similar to installing it globally but it does not require root privileges.  It is very important that your PATH includes the destination folder otherwise it won't work.  Some local folders that are typically used are `~/bin/` and `~/.local/bin/`.
 
     # Download
-    curl -sSO https://raw.githubusercontent.com/tests-always-included/mo/master/mo
+    curl -sSL https://git.io/get-mo -o mo
 
     # Make executable
     chmod +x mo
@@ -78,7 +78,7 @@ This is very similar to installing it globally but it does not require root priv
 Bash scripts can source `mo` to include the functionality in their own routines.  This usage typically would have `mo` saved to a `lib/` folder in an application and your other scripts would use `. lib/mo` to bring it into your project.
 
     # Download
-    curl -sSO https://raw.githubusercontent.com/tests-always-included/mo/master/mo
+    curl -sSL https://git.io/get-mo -o mo
 
     # Move into your project folder
     mv mo ~/projects/amazing-things/lib/
@@ -115,6 +115,8 @@ The result?  You get a list of the five elements in the array.  It is vital that
 
 There are more scripts available in the [demos directory](demo/) that could help illustrate how you would use this program.
 
+There are additional features that the program supports. Try using `mo --help` to see what is available.
+
 
 Concessions
 -----------

demo/function-args

@@ -0,0 +1,29 @@
+#!/bin/bash
+#
+# This sources a simple script with the env. variables needed for the template.
+
+cd "$(dirname "$0")" # Go to the script's directory
+source ../mo
+
+export NAME="Alex"
+export ARRAY=( AAA BBB CCC )
+
+# Include an external template
+INCLUDE() {
+    cat "$MO_FUNCTION_ARGS"
+}
+
+# Print section title
+TITLE() {
+    echo "+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+"
+    echo "$MO_FUNCTION_ARGS"
+    echo "+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+"
+}
+
+cat <<EOF | mo -u
+{{TITLE Part 1}}
+{{INCLUDE function-args-part1}}
+
+{{TITLE Part 2}}
+{{INCLUDE function-args-part2}}
+EOF

demo/function-args-part1

@@ -0,0 +1 @@
+Hello, my name is {{NAME}}.

demo/function-args-part2

@@ -0,0 +1,3 @@
+{{#ARRAY}}
+    * {{.}}
+{{/ARRAY}}

demo/function-for-advanced-looping

@@ -3,6 +3,9 @@
 cd "$(dirname "$0")" # Go to the script's directory
 
 EVERY_REPO() {
+    # The block contents come in through standard input. Capture it here.
+    content=$(cat)
+
     echo "# Starting EVERY_REPO"
 
     # Get list of repos
@@ -14,7 +17,7 @@ EVERY_REPO() {
         # It rewrites {{__REPO__.name}} into {{resque.name}}, for instance.
         # You can prefix your environment variables and do other things as well.
         
-        echo -n "$1" | sed "s/__REPO__/${REPO}/"
+        echo "$content" | sed "s/__REPO__/${REPO}/"
 
         echo "## Looped one time for repo: $REPO"
     done

demo/function-for-building-json

@@ -0,0 +1,39 @@
+#!/bin/bash
+
+cd "$(dirname "$0")" # Go to the script's directory
+
+# Detect if this is the first item and write a comma if it is.
+# Normally, I would track this using a variable, like so:
+#
+# COMMA_IF_NOT_FIRST_FLAG=false
+# COMMA_IF_NOT_FIRST() {
+#     $COMMA_IF_NOT_FIRST || echo ","
+#     COMMA_IF_NOT_FIRST_FLAG=true
+# }
+#
+# Since this function executes in a subshell, that approach will not work.
+# Instead, we peek inside mo and see what is being processed. If the variable
+# name in moParse() changes, this will need to get updated as well. An
+# alternate variable that is usable is context, but that is in moLoop() and is
+# two levels levels deep instead of just one.
+COMMA_IF_NOT_FIRST() {
+    [[ "${moCurrent#*.}" != "0" ]] && echo ","
+}
+
+# Create an array that will be embedded into the JSON. If you are manipulating
+# JSON, might I suggest you look at using jq? It's really good at processing
+# JSON.
+items=(
+    '{"position":"one","url":"1"}'
+    '{"position":"two","url":"2"}'
+    '{"position":"three","url":"3"}'
+)
+. ../mo
+cat <<EOF | mo
+{
+    {{#items}}
+    {{COMMA_IF_NOT_FIRST}}
+    {{.}}
+    {{/items}}
+}
+EOF

demo/function-for-foreach

@@ -0,0 +1,48 @@
+#!/usr/bin/env bash
+# Example for how #29 can get implemented.
+
+cd "$(dirname "$0")" # Go to the script's directory
+
+foreach() {
+    # Trying to use unique names
+    local foreachSourceName foreachIterator foreachEvalString foreachContent
+
+    foreachContent=$(cat)
+
+    if [[ "$2" != "as" && "$2" != "in" ]]; then
+        echo "Invalid foreach - bad format."
+    elif [[ "$(declare -p "$1")" != "declare -"[aA]* ]]; then
+        echo "$1 is not an array"
+    else
+        foreachSourceName="${1}[@]"
+
+        for foreachIterator in "${!foreachSourceName}"; do
+            foreachEvalString=$(declare -p "$foreachIterator")
+            foreachEvalString="declare -A $3=${foreachEvalString#*=}"
+            eval "$foreachEvalString"
+            echo "$foreachContent" | mo
+        done
+    fi
+}
+
+
+# The links are associative arrays
+declare -A resque hub rip
+resque=([name]=Resque [url]=http://example.com/resque)
+hub=([name]=Hub [url]=http://example.com/hub)
+rip=([name]=Rip [url]=http://example.com/rip)
+
+# This is a list of the link arrays
+links=(resque hub rip)
+
+# Source mo in order to work with arrays
+. ../mo
+
+# Process the template
+cat <<EOF | mo --allow-function-arguments
+Here are your links:
+{{#foreach links as link}}
+ * [{{link.name}}]({{link.url}})
+{{/foreach}}
+
+EOF

demo/important-file

@@ -2,13 +2,17 @@
 
 cd "$(dirname "$0")"/..
 
-date-string() { date; }
-wrapper() { echo -n "*** $1 ***"; }
+date-string() {
+    date
+}
+wrapper() {
+    echo -n "*** $(cat) ***"
+}
 
 export IP=127.0.0.1
 export ALLOWED_HOSTS=( 192.168.0.1 192.168.0.2 192.168.0.3 )
 
-. mo  # Keep in mind this script is executing in the parent directory
+. ./mo  # Keep in mind this script is executing in the parent directory
 cat <<EOF | mo
 # {{#wrapper}}OH SO IMPORTANT{{/wrapper}}
 # This file automatically generated at {{date-string}}

mo

@@ -11,12 +11,18 @@
 #/
 #/ Simple usage:
 #/
-#/    mo [--false] [--help] [--source=FILE] filenames...
+#/    mo [OPTIONS] filenames...
 #/
-#/ --fail-not-set - Fail upon expansion of an unset variable.
-#/ --false        - Treat the string "false" as empty for conditionals.
-#/ --help         - This message.
-#/ --source=FILE  - Load FILE into the environment before processing templates.
+#/ Options:
+#/
+#/    -u, --fail-not-set
+#/          - Fail upon expansion of an unset variable.
+#/    -e, --false
+#/          - Treat the string "false" as empty for conditionals.
+#/    -h, --help
+#/          - This message.
+#/    -s=FILE, --source=FILE
+#/          - Load FILE into the environment before processing templates.
 #
 # Mo is under a MIT style licence with an additional non-advertising clause.
 # See LICENSE.md for the full text.
@@ -29,13 +35,20 @@
 # Public: Template parser function.  Writes templates to stdout.
 #
 # $0             - Name of the mo file, used for getting the help message.
-# --fail-not-set - Fail upon expansion of an unset variable.  Default behavior
+# --allow-function-arguments
+#                - Permit functions in templates to be called with additional
+#                  arguments. This puts template data directly in to the path
+#                  of an eval statement. Use with caution. Not listed in the
+#                  help because it only makes sense when mo is sourced.
+# -u, --fail-not-set
+#                - Fail upon expansion of an unset variable.  Default behavior
 #                  is to silently ignore and expand into empty string.
-# --false        - Treat "false" as an empty value.  You may set the
+# -e, --false    - Treat "false" as an empty value.  You may set the
 #                  MO_FALSE_IS_EMPTY environment variable instead to a non-empty
 #                  value to enable this behavior.
-# --help         - Display a help message.
-# --source=FILE  - Source a file into the environment before processint
+# -h, --help     - Display a help message.
+# -s=FILE, --source=FILE
+#                - Source a file into the environment before processint
 #                  template files.
 # --             - Used to indicate the end of options.  You may optionally
 #                  use this when filenames may start with two hyphens.
@@ -43,6 +56,13 @@
 #
 # Mo uses the following environment variables:
 #
+# MO_ALLOW_FUNCTION_ARGUMENTS
+#                     - When set to a non-empty value, this allows functions
+#                       referenced in templates to receive additional
+#                       options and arguments. This puts the content from the
+#                       template directly into an eval statement. Use with
+#                       extreme care.
+# MO_FUNCTION_ARGS    - Arguments passed to the function
 # MO_FAIL_ON_UNSET    - When set to a non-empty value, expansion of an unset
 #                       env variable will be aborted with an error.
 # MO_FALSE_IS_EMPTY   - When set to a non-empty value, the string "false"
@@ -74,18 +94,27 @@ mo() (
                         exit 0
                         ;;
 
-                    --fail-not-set)
+                    --allow-function-arguments)
+                        # shellcheck disable=SC2030
+                        MO_ALLOW_FUNCTION_ARGUMENTS=true
+                        ;;
+
+                    -u | --fail-not-set)
                         # shellcheck disable=SC2030
                         MO_FAIL_ON_UNSET=true
                         ;;
 
-                    --false)
+                    -e | --false)
                         # shellcheck disable=SC2030
                         MO_FALSE_IS_EMPTY=true
                         ;;
 
-                    --source=*)
+                    -s=* | --source=*)
+                        if [[ "$arg" == --source=* ]]; then
                             f2source="${arg#--source=}"
+                        else
+                            f2source="${arg#-s=}"
+                        fi
 
                         if [[ -f "$f2source" ]]; then
                             # shellcheck disable=SC1090
@@ -115,6 +144,31 @@ mo() (
 )
 
 
+# Internal: Call a function.
+#
+# $1 - Function to call
+# $2 - Content to pass
+# $3 - Additional arguments as a single string
+#
+# This can be dangerous, especially if you are using tags like
+# {{someFunction ; rm -rf / }}
+#
+# Returns nothing.
+moCallFunction() {
+    local moArgs moFunctionArgs
+
+    moArgs=()
+    moTrimWhitespace moFunctionArgs "$3"
+
+    # shellcheck disable=SC2031
+    if [[ -n "${MO_ALLOW_FUNCTION_ARGUMENTS-}" ]]; then
+        moArgs=$3
+    fi
+
+    echo -n "$2" | MO_FUNCTION_ARGS="$moFunctionArgs" eval "$1" "$moArgs"
+}
+
+
 # Internal: Scan content until the right end tag is found.  Creates an array
 # with the following members:
 #
@@ -567,7 +621,7 @@ moLoop() {
 moParse() {
     # Keep naming variables mo* here to not overwrite needed variables
     # used in the string replacements
-    local moBlock moContent moCurrent moIsBeginning moNextIsBeginning moTag
+    local moArgs moBlock moContent moCurrent moIsBeginning moNextIsBeginning moTag
 
     moCurrent=$2
     moIsBeginning=$3
@@ -585,6 +639,13 @@ moParse() {
                 # Sets context
                 moStandaloneAllowed moContent "${moContent[@]}" "$moIsBeginning"
                 moTrimWhitespace moTag "${moTag:1}"
+                
+                # Split arguments from the tag name. Arguments are passed to
+                # functions.
+                moArgs=$moTag
+                moTag=${moTag%% *}
+                moTag=${moTag%%$'\t'*}
+                moArgs=${moArgs:${#moTag}}
                 moFindEndTag moBlock "$moContent" "$moTag"
                 moFullTagName moTag "$moCurrent" "$moTag"
 
@@ -593,7 +654,7 @@ moParse() {
                     if moIsFunction "$moTag"; then
                         #: Consider piping the output to moGetContent
                         #: so the lambda does not execute in a subshell?
-                        moContent=$($moTag "${moBlock[0]}")
+                        moContent=$(moCallFunction "$moTag" "${moBlock[0]}" "$moArgs")
                         moParse "$moContent" "$moCurrent" false
                         moContent="${moBlock[2]}"
                     elif moIsArray "$moTag"; then
@@ -658,11 +719,16 @@ moParse() {
                 moContent="${moTag:1}"'}}'"$moContent"
                 moSplit moContent "$moContent" '}}}'
                 moTrimWhitespace moTag "${moContent[0]}"
+                moArgs=$moTag
+                moTag=${moTag%% *}
+                moTag=${moTag%%$'\t'*}
+                moArgs=${moArgs:${#moTag}}
                 moFullTagName moTag "$moCurrent" "$moTag"
                 moContent=${moContent[1]}
 
                 # Now show the value
-                moShow "$moTag" "$moCurrent"
+                # Quote moArgs here, do not quote it later.
+                moShow "$moTag" "$moCurrent" "$moArgs"
                 ;;
 
             '&'*)
@@ -676,8 +742,14 @@ moParse() {
             *)
                 # Normal environment variable or function call
                 moStandaloneDenied moContent "${moContent[@]}"
+                moArgs=$moTag
+                moTag=${moTag%% *}
+                moTag=${moTag%%$'\t'*}
+                moArgs=${moArgs:${#moTag}}
                 moFullTagName moTag "$moCurrent" "$moTag"
-                moShow "$moTag" "$moCurrent"
+
+                # Quote moArgs here, do not quote it later.
+                moShow "$moTag" "$moCurrent" "$moArgs"
                 ;;
         esac
 
@@ -763,6 +835,7 @@ moPartial() {
 #
 # $1 - Name of environment variable or function
 # $2 - Current context
+# $3 - Arguments string if $1 is a function
 #
 # Returns nothing.
 moShow() {
@@ -770,22 +843,22 @@ moShow() {
     local moJoined moNameParts
 
     if moIsFunction "$1"; then
-        CONTENT=$($1 "")
+        CONTENT=$(moCallFunction "$1" "" "$3")
         moParse "$CONTENT" "$2" false
         return 0
     fi
 
     moSplit moNameParts "$1" "."
 
-    if [[ -z "${moNameParts[1]}" ]]; then
+    if [[ -z "${moNameParts[1]-}" ]]; then
         if moIsArray "$1"; then
             eval moJoin moJoined "," "\${$1[@]}"
             echo -n "$moJoined"
         else
             # shellcheck disable=SC2031
-            if [[ -z "$MO_FAIL_ON_UNSET" ]] || moTestVarSet "$1"; then
+            if moTestVarSet "$1"; then
                 echo -n "${!1}"
-            else
+            elif [[ -n "${MO_FAIL_ON_UNSET-}" ]]; then
                 echo "Env variable not set: $1" >&2
                 exit 1
             fi
@@ -972,11 +1045,14 @@ moTrimWhitespace() {
 # Returns nothing.
 moUsage() {
     grep '^#/' "${MO_ORIGINAL_COMMAND}" | cut -c 4-
+    echo ""
+    set | grep ^MO_VERSION=
 }
 
 
 # Save the original command's path for usage later
 MO_ORIGINAL_COMMAND="$(cd "${BASH_SOURCE[0]%/*}" || exit 1; pwd)/${BASH_SOURCE[0]##*/}"
+MO_VERSION="2.0.4"
 
 # If sourced, load all functions.
 # If executed, perform the actions as expected.

tests/function-args-read.env

@@ -0,0 +1,3 @@
+testArgs() {
+    echo "$MO_FUNCTION_ARGS"
+}

tests/function-args-read.expected

@@ -0,0 +1,4 @@
+No args: [] - done
+One arg: [one] - done
+Multiple arguments: [aa bb cc 'x' " ! {[_.|] - done
+Evil: [bla; cat /etc/issue] - done

tests/function-args-read.template

@@ -0,0 +1,4 @@
+No args: [{{testArgs}}] - done
+One arg: [{{testArgs one}}] - done
+Multiple arguments: [{{testArgs aa bb cc 'x' " ! {[_.| }}] - done
+Evil: [{{testArgs bla; cat /etc/issue}}] - done

tests/function-args.env

@@ -0,0 +1,13 @@
+name=Willy
+MO_ALLOW_FUNCTION_ARGUMENTS=true
+
+pipeTo() {
+    cat | "$1"
+}
+
+testArgs() {
+    printf "%d" "$#"
+
+    # Display all arguments
+    printf " %q" ${@+"$@"}
+}

tests/function-args.expected

@@ -0,0 +1,4 @@
+No args: 0 '' - done
+One arg: 1 one - done
+Getting name in a string: 1 The\ name\ is\ Willy - done
+Reverse this: edcba

tests/function-args.template

@@ -0,0 +1,4 @@
+No args: {{testArgs}} - done
+One arg: {{testArgs one}} - done
+Getting name in a string: {{testArgs "The name is $name"}} - done
+Reverse this: {{#pipeTo rev}}abcde{{/pipeTo}}

tests/function.env

@@ -1,5 +1,5 @@
 name=Willy
 wrapped() {
-    # The final newline is eaten by mo
-    echo "<b>$1</b>"
+    # This eats the newline in the content
+    echo "<b>$(cat)</b>"
 }

tests/function.expected

@@ -1,2 +1 @@
-<b>  Willy is awesome.
-</b>... this is the last line.
+<b>  Willy is awesome.</b>... this is the last line.