add ability to have more methods available from within the templates

README.md

@@ -84,6 +84,7 @@ why [dotdrop](https://github.com/deadc0de6/dotdrop) rocks.
 * [Templating](#templating)
 
   * [Available variables](#available-variables)
+  * [Available methods](#available-methods)
   * [Dotdrop header](#dotdrop-header)
 
 * [Example](#example)
@@ -781,6 +782,22 @@ alias dotdrop='eval $(grep -v "^#" ~/dotfiles/.env) /usr/bin/dotdrop --cfg=~/dot
 The above aliases load all the variables from `~/dotfiles/.env`
 (while omitting lines starting with `#`) before calling dotdrop.
 
+## Available methods
+
+Beside jinja2 global functions
+(see [jinja2 global functions](http://jinja.pocoo.org/docs/2.10/templates/#list-of-global-functions)
+the following functions are available and can be used within the templates:
+
+* `exists(path)`: return true when path exists
+```
+{%@@ if exists('/dev/null') @@%}
+it does exist
+{%@@ endif @@%}
+```
+
+If you'd like a specific function to be available, either open an issue
+or do a PR.
+
 ## Dotdrop header
 
 Dotdrop is able to insert a header in the generated dotfiles. This allows

dotdrop/jhelpers.py

@@ -0,0 +1,13 @@
+"""
+author: deadc0de6 (https://github.com/deadc0de6)
+Copyright (c) 2018, deadc0de6
+
+jinja2 helper methods
+"""
+
+import os
+
+
+def exists(path):
+    '''return true when path exists'''
+    return os.path.exists(path)

dotdrop/templategen.py

@@ -11,6 +11,7 @@ from jinja2 import Environment, FileSystemLoader
 # local imports
 import dotdrop.utils as utils
 from dotdrop.logger import Logger
+import dotdrop.jhelpers as jhelpers
 
 BLOCK_START = '{%@@'
 BLOCK_END = '@@%}'
@@ -25,6 +26,7 @@ class Templategen:
     def __init__(self, profile, base='.', variables={}, debug=False):
         self.base = base.rstrip(os.sep)
         self.debug = debug
+        self.log = Logger()
         loader = FileSystemLoader(self.base)
         self.env = Environment(loader=loader,
                                trim_blocks=True, lstrip_blocks=True,
@@ -35,11 +37,14 @@ class Templategen:
                                variable_end_string=VAR_END,
                                comment_start_string=COMMENT_START,
                                comment_end_string=COMMENT_END)
-        self.env.globals['header'] = self._header
+        # adding variables
         self.env.globals['env'] = os.environ
         self.env.globals['profile'] = profile
         self.env.globals.update(variables)
-        self.log = Logger()
+        # adding header method
+        self.env.globals['header'] = self._header
+        # adding helper methods
+        self.env.globals['exists'] = jhelpers.exists
 
     def generate(self, src):
         if not os.path.exists(src):

tests-ng/jhelpers.sh

@@ -0,0 +1,102 @@
+#!/usr/bin/env bash
+# author: deadc0de6 (https://github.com/deadc0de6)
+# Copyright (c) 2017, deadc0de6
+#
+# test jinja2 helpers from jhelpers
+# returns 1 in case of error
+#
+
+# exit on first error
+set -e
+
+# all this crap to get current path
+rl="readlink -f"
+if ! ${rl} "${0}" >/dev/null 2>&1; then
+  rl="realpath"
+
+  if ! hash ${rl}; then
+    echo "\"${rl}\" not found !" && exit 1
+  fi
+fi
+cur=$(dirname "$(${rl} "${0}")")
+
+#hash dotdrop >/dev/null 2>&1
+#[ "$?" != "0" ] && echo "install dotdrop to run tests" && exit 1
+
+#echo "called with ${1}"
+
+# dotdrop path can be pass as argument
+ddpath="${cur}/../"
+[ "${1}" != "" ] && ddpath="${1}"
+[ ! -d ${ddpath} ] && echo "ddpath \"${ddpath}\" is not a directory" && exit 1
+
+export PYTHONPATH="${ddpath}:${PYTHONPATH}"
+bin="python3 -m dotdrop.dotdrop"
+
+echo "dotdrop path: ${ddpath}"
+echo "pythonpath: ${PYTHONPATH}"
+
+# get the helpers
+source ${cur}/helpers
+
+echo -e "\e[96m\e[1m==> RUNNING $(basename $BASH_SOURCE) <==\e[0m"
+
+################################################################
+# this is the test
+################################################################
+
+# the dotfile source
+tmps=`mktemp -d`
+mkdir -p ${tmps}/dotfiles
+# the dotfile destination
+tmpd=`mktemp -d`
+#echo "dotfile destination: ${tmpd}"
+
+# create the config file
+cfg="${tmps}/config.yaml"
+
+cat > ${cfg} << _EOF
+config:
+  backup: true
+  create: true
+  dotpath: dotfiles
+dotfiles:
+  f_abc:
+    dst: ${tmpd}/abc
+    src: abc
+profiles:
+  p1:
+    dotfiles:
+    - f_abc
+_EOF
+cat ${cfg}
+
+# create the dotfile
+echo "this is the test dotfile" > ${tmps}/dotfiles/abc
+
+# test exists
+echo "{%@@ if exists('/dev/null') @@%}" >> ${tmps}/dotfiles/abc
+echo "this should exist" >> ${tmps}/dotfiles/abc
+echo "{%@@ endif @@%}" >> ${tmps}/dotfiles/abc
+
+echo "{%@@ if exists('/dev/abcdef') @@%}" >> ${tmps}/dotfiles/abc
+echo "this should not exist" >> ${tmps}/dotfiles/abc
+echo "{%@@ endif @@%}" >> ${tmps}/dotfiles/abc
+
+cat ${tmps}/dotfiles/abc
+
+# install
+cd ${ddpath} | ${bin} install -f -c ${cfg} -p p1 -V
+
+cat ${tmpd}/abc
+
+grep '^this should exist' ${tmpd}/abc >/dev/null
+grep -v '^this should not exist' ${tmpd}/abc >/dev/null
+
+#cat ${tmpd}/abc
+
+## CLEANING
+rm -rf ${tmps} ${tmpd} ${scr}
+
+echo "OK"
+exit 0