jrnl/jrnl/plugins/template.py
MinchinWeb cfadcd39ca Apply isort Mk II (#942)
* Apply isort!
2020-05-09 13:14:43 -07:00

139 lines
4.7 KiB
Python

import re
import yaml
VAR_RE = r"[_a-zA-Z][a-zA-Z0-9_]*"
EXPRESSION_RE = r"[\[\]():.a-zA-Z0-9_]*"
PRINT_RE = r"{{ *(.+?) *}}"
START_BLOCK_RE = r"{% *(if|for) +(.+?) *%}"
END_BLOCK_RE = r"{% *end(for|if) *%}"
FOR_RE = r"{{% *for +({varname}) +in +([^%]+) *%}}".format(varname=VAR_RE)
IF_RE = r"{% *if +(.+?) *%}"
BLOCK_RE = r"{% *block +(.+?) *%}((?:.|\n)+?){% *endblock *%}"
INCLUDE_RE = r"{% *include +(.+?) *%}"
class Template:
def __init__(self, template):
self.template = template
self.clean_template = None
self.blocks = {}
@classmethod
def from_file(cls, filename):
with open(filename) as f:
front_matter, body = f.read().strip("-\n").split("---", 2)
front_matter = yaml.load(front_matter, Loader=yaml.FullLoader)
template = cls(body)
template.__dict__.update(front_matter)
return template
def render(self, **vars):
if self.clean_template is None:
self._get_blocks()
return self._expand(self.clean_template, **vars)
def render_block(self, block, **vars):
if self.clean_template is None:
self._get_blocks()
return self._expand(self.blocks[block], **vars)
def _eval_context(self, vars):
import asteval
e = asteval.Interpreter(use_numpy=False, writer=None)
e.symtable.update(vars)
e.symtable["__last_iteration"] = vars.get("__last_iteration", False)
return e
def _get_blocks(self):
def s(match):
name, contents = match.groups()
self.blocks[name] = self._strip_single_nl(contents)
return ""
self.clean_template = re.sub(BLOCK_RE, s, self.template, flags=re.MULTILINE)
def _expand(self, template, **vars):
stack = sorted(
[
(m.start(), 1, m.groups()[0])
for m in re.finditer(START_BLOCK_RE, template)
]
+ [
(m.end(), -1, m.groups()[0])
for m in re.finditer(END_BLOCK_RE, template)
]
)
last_nesting, nesting = 0, 0
start = 0
result = ""
block_type = None
if not stack:
return self._expand_vars(template, **vars)
for pos, indent, typ in stack:
nesting += indent
if nesting == 1 and last_nesting == 0:
block_type = typ
result += self._expand_vars(template[start:pos], **vars)
start = pos
elif nesting == 0 and last_nesting == 1:
if block_type == "if":
result += self._expand_cond(template[start:pos], **vars)
elif block_type == "for":
result += self._expand_loops(template[start:pos], **vars)
elif block_type == "block":
result += self._save_block(template[start:pos], **vars)
start = pos
last_nesting = nesting
result += self._expand_vars(template[stack[-1][0] :], **vars)
return result
def _expand_vars(self, template, **vars):
safe_eval = self._eval_context(vars)
expanded = re.sub(
INCLUDE_RE, lambda m: self.render_block(m.groups()[0], **vars), template
)
return re.sub(PRINT_RE, lambda m: str(safe_eval(m.groups()[0])), expanded)
def _expand_cond(self, template, **vars):
start_block = re.search(IF_RE, template, re.M)
end_block = list(re.finditer(END_BLOCK_RE, template, re.M))[-1]
expression = start_block.groups()[0]
sub_template = self._strip_single_nl(
template[start_block.end() : end_block.start()]
)
safe_eval = self._eval_context(vars)
if safe_eval(expression):
return self._expand(sub_template)
return ""
def _strip_single_nl(self, template, strip_r=True):
if template[0] == "\n":
template = template[1:]
if strip_r and template[-1] == "\n":
template = template[:-1]
return template
def _expand_loops(self, template, **vars):
start_block = re.search(FOR_RE, template, re.M)
end_block = list(re.finditer(END_BLOCK_RE, template, re.M))[-1]
var_name, iterator = start_block.groups()
sub_template = self._strip_single_nl(
template[start_block.end() : end_block.start()], strip_r=False
)
safe_eval = self._eval_context(vars)
result = ""
items = safe_eval(iterator)
for idx, var in enumerate(items):
vars[var_name] = var
vars["__last_iteration"] = idx == len(items) - 1
result += self._expand(sub_template, **vars)
del vars[var_name]
return self._strip_single_nl(result)