diff -r a094eee9f862 -r b7fe69c6cb1c DebugClients/Python2/coverage/templite.py --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/DebugClients/Python2/coverage/templite.py Sat Sep 03 18:12:12 2016 +0200 @@ -0,0 +1,293 @@ +# Licensed under the Apache License: http://www.apache.org/licenses/LICENSE-2.0 +# For details: https://bitbucket.org/ned/coveragepy/src/default/NOTICE.txt + +"""A simple Python template renderer, for a nano-subset of Django syntax. + +For a detailed discussion of this code, see this chapter from 500 Lines: +http://aosabook.org/en/500L/a-template-engine.html + +""" + +# Coincidentally named the same as http://code.activestate.com/recipes/496702/ + +import re + +from coverage import env + + +class TempliteSyntaxError(ValueError): + """Raised when a template has a syntax error.""" + pass + + +class TempliteValueError(ValueError): + """Raised when an expression won't evaluate in a template.""" + pass + + +class CodeBuilder(object): + """Build source code conveniently.""" + + def __init__(self, indent=0): + self.code = [] + self.indent_level = indent + + def __str__(self): + return "".join(str(c) for c in self.code) + + def add_line(self, line): + """Add a line of source to the code. + + Indentation and newline will be added for you, don't provide them. + + """ + self.code.extend([" " * self.indent_level, line, "\n"]) + + def add_section(self): + """Add a section, a sub-CodeBuilder.""" + section = CodeBuilder(self.indent_level) + self.code.append(section) + return section + + INDENT_STEP = 4 # PEP8 says so! + + def indent(self): + """Increase the current indent for following lines.""" + self.indent_level += self.INDENT_STEP + + def dedent(self): + """Decrease the current indent for following lines.""" + self.indent_level -= self.INDENT_STEP + + def get_globals(self): + """Execute the code, and return a dict of globals it defines.""" + # A check that the caller really finished all the blocks they started. + assert self.indent_level == 0 + # Get the Python source as a single string. + python_source = str(self) + # Execute the source, defining globals, and return them. + global_namespace = {} + exec(python_source, global_namespace) + return global_namespace + + +class Templite(object): + """A simple template renderer, for a nano-subset of Django syntax. + + Supported constructs are extended variable access:: + + {{var.modifier.modifier|filter|filter}} + + loops:: + + {% for var in list %}...{% endfor %} + + and ifs:: + + {% if var %}...{% endif %} + + Comments are within curly-hash markers:: + + {# This will be ignored #} + + Any of these constructs can have a hypen at the end (`-}}`, `-%}`, `-#}`), + which will collapse the whitespace following the tag. + + Construct a Templite with the template text, then use `render` against a + dictionary context to create a finished string:: + + templite = Templite(''' + <h1>Hello {{name|upper}}!</h1> + {% for topic in topics %} + <p>You are interested in {{topic}}.</p> + {% endif %} + ''', + {'upper': str.upper}, + ) + text = templite.render({ + 'name': "Ned", + 'topics': ['Python', 'Geometry', 'Juggling'], + }) + + """ + def __init__(self, text, *contexts): + """Construct a Templite with the given `text`. + + `contexts` are dictionaries of values to use for future renderings. + These are good for filters and global values. + + """ + self.context = {} + for context in contexts: + self.context.update(context) + + self.all_vars = set() + self.loop_vars = set() + + # We construct a function in source form, then compile it and hold onto + # it, and execute it to render the template. + code = CodeBuilder() + + code.add_line("def render_function(context, do_dots):") + code.indent() + vars_code = code.add_section() + code.add_line("result = []") + code.add_line("append_result = result.append") + code.add_line("extend_result = result.extend") + if env.PY2: + code.add_line("to_str = unicode") + else: + code.add_line("to_str = str") + + buffered = [] + + def flush_output(): + """Force `buffered` to the code builder.""" + if len(buffered) == 1: + code.add_line("append_result(%s)" % buffered[0]) + elif len(buffered) > 1: + code.add_line("extend_result([%s])" % ", ".join(buffered)) + del buffered[:] + + ops_stack = [] + + # Split the text to form a list of tokens. + tokens = re.split(r"(?s)({{.*?}}|{%.*?%}|{#.*?#})", text) + + squash = False + + for token in tokens: + if token.startswith('{'): + start, end = 2, -2 + squash = (token[-3] == '-') + if squash: + end = -3 + + if token.startswith('{#'): + # Comment: ignore it and move on. + continue + elif token.startswith('{{'): + # An expression to evaluate. + expr = self._expr_code(token[start:end].strip()) + buffered.append("to_str(%s)" % expr) + elif token.startswith('{%'): + # Action tag: split into words and parse further. + flush_output() + + words = token[start:end].strip().split() + if words[0] == 'if': + # An if statement: evaluate the expression to determine if. + if len(words) != 2: + self._syntax_error("Don't understand if", token) + ops_stack.append('if') + code.add_line("if %s:" % self._expr_code(words[1])) + code.indent() + elif words[0] == 'for': + # A loop: iterate over expression result. + if len(words) != 4 or words[2] != 'in': + self._syntax_error("Don't understand for", token) + ops_stack.append('for') + self._variable(words[1], self.loop_vars) + code.add_line( + "for c_%s in %s:" % ( + words[1], + self._expr_code(words[3]) + ) + ) + code.indent() + elif words[0].startswith('end'): + # Endsomething. Pop the ops stack. + if len(words) != 1: + self._syntax_error("Don't understand end", token) + end_what = words[0][3:] + if not ops_stack: + self._syntax_error("Too many ends", token) + start_what = ops_stack.pop() + if start_what != end_what: + self._syntax_error("Mismatched end tag", end_what) + code.dedent() + else: + self._syntax_error("Don't understand tag", words[0]) + else: + # Literal content. If it isn't empty, output it. + if squash: + token = token.lstrip() + if token: + buffered.append(repr(token)) + + if ops_stack: + self._syntax_error("Unmatched action tag", ops_stack[-1]) + + flush_output() + + for var_name in self.all_vars - self.loop_vars: + vars_code.add_line("c_%s = context[%r]" % (var_name, var_name)) + + code.add_line('return "".join(result)') + code.dedent() + self._render_function = code.get_globals()['render_function'] + + def _expr_code(self, expr): + """Generate a Python expression for `expr`.""" + if "|" in expr: + pipes = expr.split("|") + code = self._expr_code(pipes[0]) + for func in pipes[1:]: + self._variable(func, self.all_vars) + code = "c_%s(%s)" % (func, code) + elif "." in expr: + dots = expr.split(".") + code = self._expr_code(dots[0]) + args = ", ".join(repr(d) for d in dots[1:]) + code = "do_dots(%s, %s)" % (code, args) + else: + self._variable(expr, self.all_vars) + code = "c_%s" % expr + return code + + def _syntax_error(self, msg, thing): + """Raise a syntax error using `msg`, and showing `thing`.""" + raise TempliteSyntaxError("%s: %r" % (msg, thing)) + + def _variable(self, name, vars_set): + """Track that `name` is used as a variable. + + Adds the name to `vars_set`, a set of variable names. + + Raises an syntax error if `name` is not a valid name. + + """ + if not re.match(r"[_a-zA-Z][_a-zA-Z0-9]*$", name): + self._syntax_error("Not a valid name", name) + vars_set.add(name) + + def render(self, context=None): + """Render this template by applying it to `context`. + + `context` is a dictionary of values to use in this rendering. + + """ + # Make the complete context we'll use. + render_context = dict(self.context) + if context: + render_context.update(context) + return self._render_function(render_context, self._do_dots) + + def _do_dots(self, value, *dots): + """Evaluate dotted expressions at run-time.""" + for dot in dots: + try: + value = getattr(value, dot) + except AttributeError: + try: + value = value[dot] + except (TypeError, KeyError): + raise TempliteValueError( + "Couldn't evaluate %r.%s" % (value, dot) + ) + if callable(value): + value = value() + return value + +# +# eflag: FileType = Python2