""" A templating engine for separation of code and HTML. The documentation of this templating engine is separated to two parts: 1. Description of the templating language. 2. Documentation of classes and API of this module that provides a Python implementation of the templating language. All the documentation can be found in 'doc' directory of the distribution tarball or at the homepage of the engine. Latest versions of this module are also available at that website. You can use and redistribute this module under conditions of the GNU General Public License that can be found either at [ http://www.gnu.org/ ] or in file "LICENSE" contained in the distribution tarball of this module. Copyright (c) 2001 Tomas Styblo, tripie@cpan.org @name htmltmpl @version 1.22 @author-name Tomas Styblo @author-email tripie@cpan.org @website http://htmltmpl.sourceforge.net/ @license-name GNU GPL @license-url http://www.gnu.org/licenses/gpl.html """ __version__ = 1.22 __author__ = "Tomas Styblo (tripie@cpan.org)" # All imported modules are part of the standard Python library. from types import * import re import os import os.path import pprint # only for debugging import sys import copy import cgi # for HTML escaping of variables import urllib # for URL escaping of variables import cPickle # for template compilation import gettext INCLUDE_DIR = "inc" # Total number of possible parameters. # Increment if adding a parameter to any statement. PARAMS_NUMBER = 3 # Relative positions of parameters in TemplateCompiler.tokenize(). PARAM_NAME = 1 PARAM_ESCAPE = 2 PARAM_GLOBAL = 3 PARAM_GETTEXT_STRING = 1 # Find a way to lock files. Currently implemented only for UNIX and windows. LOCKTYPE_FCNTL = 1 LOCKTYPE_MSVCRT = 2 LOCKTYPE = None try: import fcntl except: try: import msvcrt except: LOCKTYPE = None else: LOCKTYPE = LOCKTYPE_MSVCRT else: LOCKTYPE = LOCKTYPE_FCNTL LOCK_EX = 1 LOCK_SH = 2 LOCK_UN = 3 ############################################## # CLASS: TemplateManager # ############################################## class TemplateManager: """ Class that manages compilation and precompilation of templates. You should use this class whenever you work with templates that are stored in a file. The class can create a compiled template and transparently manage its precompilation. It also keeps the precompiled templates up-to-date by modification times comparisons. """ def __init__(self, include=1, max_include=5, precompile=1, comments=1, gettext=0, debug=0): """ Constructor. @header __init__(include=1, max_include=5, precompile=1, comments=1, gettext=0, debug=0) @param include Enable or disable included templates. This optional parameter can be used to enable or disable TMPL_INCLUDE inclusion of templates. Disabling of inclusion can improve performance a bit. The inclusion is enabled by default. @param max_include Maximum depth of nested inclusions. This optional parameter can be used to specify maximum depth of nested TMPL_INCLUDE inclusions. It defaults to 5. This setting prevents infinite recursive inclusions. @param precompile Enable or disable precompilation of templates. This optional parameter can be used to enable or disable creation and usage of precompiled templates. A precompiled template is saved to the same directory in which the main template file is located. You need write permissions to that directory. Precompilation provides a significant performance boost because it's not necessary to parse the templates over and over again. The boost is especially noticeable when templates that include other templates are used. Comparison of modification times of the main template and all included templates is used to ensure that the precompiled templates are up-to-date. Templates are also recompiled if the htmltmpl module is updated. The TemplateErrorexception is raised when the precompiled template cannot be saved. Precompilation is enabled by default. Precompilation is available only on UNIX and Windows platforms, because proper file locking which is necessary to ensure multitask safe behaviour is platform specific and is not implemented for other platforms. Attempts to enable precompilation on the other platforms result in raise of the TemplateError exception. @param comments Enable or disable template comments. This optional parameter can be used to enable or disable template comments. Disabling of the comments can improve performance a bit. Comments are enabled by default. @param gettext Enable or disable gettext support. @param debug Enable or disable debugging messages. This optional parameter is a flag that can be used to enable or disable debugging messages which are printed to the standard error output. The debugging messages are disabled by default. """ # Save the optional parameters. # These values are not modified by any method. self._include = include self._max_include = max_include self._precompile = precompile self._comments = comments self._gettext = gettext self._debug = debug # Find what module to use to lock files. # File locking is necessary for the 'precompile' feature to be # multitask/thread safe. Currently it works only on UNIX # and Windows. Anyone willing to implement it on Mac ? if precompile and not LOCKTYPE: raise TemplateError, "Template precompilation is not "\ "available on this platform." self.DEB("INIT DONE") def prepare(self, file): """ Preprocess, parse, tokenize and compile the template. If precompilation is enabled then this method tries to load a precompiled form of the template from the same directory in which the template source file is located. If it succeeds, then it compares modification times stored in the precompiled form to modification times of source files of the template, including source files of all templates included via the TMPL_INCLUDE statements. If any of the modification times differs, then the template is recompiled and the precompiled form updated. If precompilation is disabled, then this method parses and compiles the template. @header prepare(file) @return Compiled template. The methods returns an instance of the Template class which is a compiled form of the template. This instance can be used as input for the TemplateProcessor. @param file Path to the template file to prepare. The method looks for the template file in current directory if the parameter is a relative path. All included templates must be placed in subdirectory 'inc' of the directory in which the main template file is located. """ compiled = None if self._precompile: if self.is_precompiled(file): try: precompiled = self.load_precompiled(file) except PrecompiledError, template: print >> sys.stderr, "Htmltmpl: bad precompiled "\ "template '%s' removed" % template compiled = self.compile(file) self.save_precompiled(compiled) else: precompiled.debug(self._debug) compile_params = (self._include, self._max_include, self._comments, self._gettext) if precompiled.is_uptodate(compile_params): self.DEB("PRECOMPILED: UPTODATE") compiled = precompiled else: self.DEB("PRECOMPILED: NOT UPTODATE") compiled = self.update(precompiled) else: self.DEB("PRECOMPILED: NOT PRECOMPILED") compiled = self.compile(file) self.save_precompiled(compiled) else: self.DEB("PRECOMPILATION DISABLED") compiled = self.compile(file) return compiled def update(self, template): """ Update (recompile) a compiled template. This method recompiles a template compiled from a file. If precompilation is enabled then the precompiled form saved on disk is also updated. @header update(template) @return Recompiled template. It's ensured that the returned template is up-to-date. @param template A compiled template. This parameter should be an instance of the Template class, created either by the TemplateManager or by the TemplateCompiler. The instance must represent a template compiled from a file on disk. """ self.DEB("UPDATE") updated = self.compile(template.file()) if self._precompile: self.save_precompiled(updated) return updated ############################################## # PRIVATE METHODS # ############################################## def DEB(self, str): """ Print debugging message to stderr if debugging is enabled. @hidden """ if self._debug: print >> sys.stderr, str def lock_file(self, file, lock): """ Provide platform independent file locking. @hidden """ fd = file.fileno() if LOCKTYPE == LOCKTYPE_FCNTL: if lock == LOCK_SH: fcntl.flock(fd, fcntl.LOCK_SH) elif lock == LOCK_EX: fcntl.flock(fd, fcntl.LOCK_EX) elif lock == LOCK_UN: fcntl.flock(fd, fcntl.LOCK_UN) else: raise TemplateError, "BUG: bad lock in lock_file" elif LOCKTYPE == LOCKTYPE_MSVCRT: if lock == LOCK_SH: # msvcrt does not support shared locks :-( msvcrt.locking(fd, msvcrt.LK_LOCK, 1) elif lock == LOCK_EX: msvcrt.locking(fd, msvcrt.LK_LOCK, 1) elif lock == LOCK_UN: msvcrt.locking(fd, msvcrt.LK_UNLCK, 1) else: raise TemplateError, "BUG: bad lock in lock_file" else: raise TemplateError, "BUG: bad locktype in lock_file" def compile(self, file): """ Compile the template. @hidden """ return TemplateCompiler(self._include, self._max_include, self._comments, self._gettext, self._debug).compile(file) def is_precompiled(self, file): """ Return true if the template is already precompiled on the disk. This method doesn't check whether the compiled template is uptodate. @hidden """ filename = file + "c" # "template.tmplc" if os.path.isfile(filename): return 1 else: return 0 def load_precompiled(self, file): """ Load precompiled template from disk. Remove the precompiled template file and recompile it if the file contains corrupted or unpicklable data. @hidden """ filename = file + "c" # "template.tmplc" self.DEB("LOADING PRECOMPILED") try: remove_bad = 0 file = None try: file = open(filename, "rb") self.lock_file(file, LOCK_SH) precompiled = cPickle.load(file) except IOError, (errno, errstr): raise TemplateError, "IO error in load precompiled "\ "template '%s': (%d) %s"\ % (filename, errno, errstr) except cPickle.UnpicklingError: remove_bad = 1 raise PrecompiledError, filename except: remove_bad = 1 raise else: return precompiled finally: if file: self.lock_file(file, LOCK_UN) file.close() if remove_bad and os.path.isfile(filename): # X: We may lose the original exception here, raising OSError. os.remove(filename) def save_precompiled(self, template): """ Save compiled template to disk in precompiled form. Associated metadata is also saved. It includes: filename of the main template file, modification time of the main template file, modification times of all included templates and version of the htmltmpl module which compiled the template. The method removes a file which is saved only partially because of some error. @hidden """ filename = template.file() + "c" # creates "template.tmplc" # Check if we have write permission to the template's directory. template_dir = os.path.dirname(os.path.abspath(filename)) if not os.access(template_dir, os.W_OK): raise TemplateError, "Cannot save precompiled templates "\ "to '%s': write permission denied."\ % template_dir try: remove_bad = 0 file = None try: file = open(filename, "wb") # may truncate existing file self.lock_file(file, LOCK_EX) BINARY = 1 READABLE = 0 if self._debug: cPickle.dump(template, file, READABLE) else: cPickle.dump(template, file, BINARY) except IOError, (errno, errstr): remove_bad = 1 raise TemplateError, "IO error while saving precompiled "\ "template '%s': (%d) %s"\ % (filename, errno, errstr) except cPickle.PicklingError, error: remove_bad = 1 raise TemplateError, "Pickling error while saving "\ "precompiled template '%s': %s"\ % (filename, error) except: remove_bad = 1 raise else: self.DEB("SAVING PRECOMPILED") finally: if file: self.lock_file(file, LOCK_UN) file.close() if remove_bad and os.path.isfile(filename): # X: We may lose the original exception here, raising OSError. os.remove(filename) ############################################## # CLASS: TemplateProcessor # ############################################## class TemplateProcessor: """ Fill the template with data and process it. This class provides actual processing of a compiled template. Use it to set template variables and loops and then obtain result of the processing. """ def __init__(self, html_escape=1, magic_vars=1, global_vars=0, debug=0): """ Constructor. @header __init__(html_escape=1, magic_vars=1, global_vars=0, debug=0) @param html_escape Enable or disable HTML escaping of variables. This optional parameter is a flag that can be used to enable or disable automatic HTML escaping of variables. All variables are by default automatically HTML escaped. The escaping process substitutes HTML brackets, ampersands and double quotes with appropriate HTML entities. @param magic_vars Enable or disable loop magic variables. This parameter can be used to enable or disable "magic" context variables, that are automatically defined inside loops. Magic variables are enabled by default. Refer to the language specification for description of these magic variables. @param global_vars Globally activate global lookup of variables. This optional parameter is a flag that can be used to specify whether variables which cannot be found in the current scope should be automatically looked up in enclosing scopes. Automatic global lookup is disabled by default. Global lookup can be overriden on a per-variable basis by the GLOBAL parameter of a TMPL_VAR statement. @param debug Enable or disable debugging messages. """ self._html_escape = html_escape self._magic_vars = magic_vars self._global_vars = global_vars self._debug = debug # Data structure containing variables and loops set by the # application. Use debug=1, process some template and # then check stderr to see how the structure looks. # It's modified only by set() and reset() methods. self._vars = {} # Following variables are for multipart templates. self._current_part = 1 self._current_pos = 0 def set(self, var, value): """ Associate a value with top-level template variable or loop. A template identifier can represent either an ordinary variable (string) or a loop. To assign a value to a string identifier pass a scalar as the 'value' parameter. This scalar will be automatically converted to string. To assign a value to a loop identifier pass a list of mappings as the 'value' parameter. The engine iterates over this list and assigns values from the mappings to variables in a template loop block if a key in the mapping corresponds to a name of a variable in the loop block. The number of mappings contained in this list is equal to number of times the loop block is repeated in the output. @header set(var, value) @return No return value. @param var Name of template variable or loop. @param value The value to associate. """ # The correctness of character case is verified only for top-level # variables. if self.is_ordinary_var(value): # template top-level ordinary variable if not var.islower(): raise TemplateError, "Invalid variable name '%s'." % var elif type(value) == ListType: # template top-level loop if var != var.capitalize(): raise TemplateError, "Invalid loop name '%s'." % var else: raise TemplateError, "Value of toplevel variable '%s' must "\ "be either a scalar or a list." % var self._vars[var] = value self.DEB("VALUE SET: " + str(var)) def reset(self, keep_data=0): """ Reset the template data. This method resets the data contained in the template processor instance. The template processor instance can be used to process any number of templates, but this method must be called after a template is processed to reuse the instance, @header reset(keep_data=0) @return No return value. @param keep_data Do not reset the template data. Use this flag if you do not want the template data to be erased. This way you can reuse the data contained in the instance of the TemplateProcessor. """ self._current_part = 1 self._current_pos = 0 if not keep_data: self._vars.clear() self.DEB("RESET") def process(self, template, part=None): """ Process a compiled template. Return the result as string. This method actually processes a template and returns the result. @header process(template, part=None) @return Result of the processing as string. @param template A compiled template. Value of this parameter must be an instance of the Template class created either by the TemplateManager or by the TemplateCompiler. @param part The part of a multipart template to process. This parameter can be used only together with a multipart template. It specifies the number of the part to process. It must be greater than zero, because the parts are numbered from one. The parts must be processed in the right order. You cannot process a part which precedes an already processed part. If this parameter is not specified, then the whole template is processed, or all remaining parts are processed. """ self.DEB("APP INPUT:") if self._debug: pprint.pprint(self._vars, sys.stderr) if part != None and (part == 0 or part < self._current_part): raise TemplateError, "process() - invalid part number" # This flag means "jump behind the end of current statement" or # "skip the parameters of current statement". # Even parameters that actually are not present in the template # do appear in the list of tokens as empty items ! skip_params = 0 # Stack for enabling or disabling output in response to TMPL_IF, # TMPL_UNLESS, TMPL_ELSE and TMPL_LOOPs with no passes. output_control = [] ENABLE_OUTPUT = 1 DISABLE_OUTPUT = 0 # Stacks for data related to loops. loop_name = [] # name of a loop loop_pass = [] # current pass of a loop (counted from zero) loop_start = [] # index of loop start in token list loop_total = [] # total number of passes in a loop tokens = template.tokens() len_tokens = len(tokens) out = "" # buffer for processed output # Recover position at which we ended after processing of last part. i = self._current_pos # Process the list of tokens. while 1: if i == len_tokens: break if skip_params: # Skip the parameters following a statement. skip_params = 0 i += PARAMS_NUMBER continue token = tokens[i] if token.startswith("." escape = tokens[i + PARAM_ESCAPE] globalp = tokens[i + PARAM_GLOBAL] skip_params = 1 # If output of current block is not disabled then append # the substitued and escaped variable to the output. if DISABLE_OUTPUT not in output_control: value = str(self.find_value(var, loop_name, loop_pass, loop_total, globalp)) out += self.escape(value, escape) self.DEB("VAR: " + str(var)) elif token == "." skip_params = 1 # Find total number of passes in this loop. passtotal = self.find_value(var, loop_name, loop_pass, loop_total) if not passtotal: passtotal = 0 # Push data for this loop on the stack. loop_total.append(passtotal) loop_start.append(i) loop_pass.append(0) loop_name.append(var) # Disable output of loop block if the number of passes # in this loop is zero. if passtotal == 0: # This loop is empty. output_control.append(DISABLE_OUTPUT) self.DEB("LOOP: DISABLE: " + str(var)) else: output_control.append(ENABLE_OUTPUT) self.DEB("LOOP: FIRST PASS: %s TOTAL: %d"\ % (var, passtotal)) elif token == "." globalp = tokens[i + PARAM_GLOBAL] skip_params = 1 if self.find_value(var, loop_name, loop_pass, loop_total, globalp): output_control.append(ENABLE_OUTPUT) self.DEB("IF: ENABLE: " + str(var)) else: output_control.append(DISABLE_OUTPUT) self.DEB("IF: DISABLE: " + str(var)) elif token == "." globalp = tokens[i + PARAM_GLOBAL] skip_params = 1 if self.find_value(var, loop_name, loop_pass, loop_total, globalp): output_control.append(DISABLE_OUTPUT) self.DEB("UNLESS: DISABLE: " + str(var)) else: output_control.append(ENABLE_OUTPUT) self.DEB("UNLESS: ENABLE: " + str(var)) elif token == "." # If this loop was not disabled, then record the pass. if loop_total[-1] > 0: loop_pass[-1] += 1 if loop_pass[-1] == loop_total[-1]: # There are no more passes in this loop. Pop # the loop from stack. loop_pass.pop() loop_name.pop() loop_start.pop() loop_total.pop() output_control.pop() self.DEB("LOOP: END") else: # Jump to the beggining of this loop block # to process next pass of the loop. i = loop_start[-1] self.DEB("LOOP: NEXT PASS") elif token == "." output_control.pop() self.DEB("IF: END") elif token == "." output_control.pop() self.DEB("UNLESS: END") elif token == "." if output_control[-1] == DISABLE_OUTPUT: # Condition was false, activate the ELSE block. output_control[-1] = ENABLE_OUTPUT self.DEB("ELSE: ENABLE") elif output_control[-1] == ENABLE_OUTPUT: # Condition was true, deactivate the ELSE block. output_control[-1] = DISABLE_OUTPUT self.DEB("ELSE: DISABLE") else: raise TemplateError, "BUG: ELSE: INVALID FLAG" elif token == "

HTMLTMPL WARNING:
Cannot include template: %s


""" % filename self.DEB("CANNOT INCLUDE WARNING") elif token == "." % token elif DISABLE_OUTPUT not in output_control: # Raw textual template data. # If output of current block is not disabled, then # append template data to the output buffer. out += token i += 1 # end of the big while loop # Check whether all opening statements were closed. if loop_name: raise TemplateError, "Missing ." if output_control: raise TemplateError, "Missing or " return out ############################################## # PRIVATE METHODS # ############################################## def DEB(self, str): """ Print debugging message to stderr if debugging is enabled. @hidden """ if self._debug: print >> sys.stderr, str def find_value(self, var, loop_name, loop_pass, loop_total, global_override=None): """ Search the self._vars data structure to find variable var located in currently processed pass of a loop which is currently being processed. If the variable is an ordinary variable, then return it. If the variable is an identificator of a loop, then return the total number of times this loop will be executed. Return an empty string, if the variable is not found at all. @hidden """ # Search for the requested variable in magic vars if the name # of the variable starts with "__" and if we are inside a loop. if self._magic_vars and var.startswith("__") and loop_name: return self.magic_var(var, loop_pass[-1], loop_total[-1]) # Search for an ordinary variable or for a loop. # Recursively search in self._vars for the requested variable. scope = self._vars globals = [] for i in range(len(loop_name)): # If global lookup is on then push the value on the stack. if ((self._global_vars and global_override != "0") or \ global_override == "1") and scope.has_key(var) and \ self.is_ordinary_var(scope[var]): globals.append(scope[var]) # Descent deeper into the hierarchy. if scope.has_key(loop_name[i]) and scope[loop_name[i]]: scope = scope[loop_name[i]][loop_pass[i]] else: return "" if scope.has_key(var): # Value exists in current loop. if type(scope[var]) == ListType: # The requested value is a loop. # Return total number of its passes. return len(scope[var]) else: return scope[var] elif globals and \ ((self._global_vars and global_override != "0") or \ global_override == "1"): # Return globally looked up value. return globals.pop() else: # No value found. if var[0].isupper(): # This is a loop name. # Return zero, because the user wants to know number # of its passes. return 0 else: return "" def magic_var(self, var, loop_pass, loop_total): """ Resolve and return value of a magic variable. Raise an exception if the magic variable is not recognized. @hidden """ self.DEB("MAGIC: '%s', PASS: %d, TOTAL: %d"\ % (var, loop_pass, loop_total)) if var == "__FIRST__": if loop_pass == 0: return 1 else: return 0 elif var == "__LAST__": if loop_pass == loop_total - 1: return 1 else: return 0 elif var == "__INNER__": # If this is neither the first nor the last pass. if loop_pass != 0 and loop_pass != loop_total - 1: return 1 else: return 0 elif var == "__PASS__": # Magic variable __PASS__ counts passes from one. return loop_pass + 1 elif var == "__PASSTOTAL__": return loop_total elif var == "__ODD__": # Internally pass numbers stored in loop_pass are counted from # zero. But the template language presents them counted from one. # Therefore we must add one to the actual loop_pass value to get # the value we present to the user. if (loop_pass + 1) % 2 != 0: return 1 else: return 0 elif var.startswith("__EVERY__"): # Magic variable __EVERY__x is never true in first or last pass. if loop_pass != 0 and loop_pass != loop_total - 1: # Check if an integer follows the variable name. try: every = int(var[9:]) # nine is length of "__EVERY__" except ValueError: raise TemplateError, "Magic variable __EVERY__x: "\ "Invalid pass number." else: if not every: raise TemplateError, "Magic variable __EVERY__x: "\ "Pass number cannot be zero." elif (loop_pass + 1) % every == 0: self.DEB("MAGIC: EVERY: " + str(every)) return 1 else: return 0 else: return 0 else: raise TemplateError, "Invalid magic variable '%s'." % var def escape(self, str, override=""): """ Escape a string either by HTML escaping or by URL escaping. @hidden """ ESCAPE_QUOTES = 1 if (self._html_escape and override != "NONE" and override != "0" and \ override != "URL") or override == "HTML" or override == "1": return cgi.escape(str, ESCAPE_QUOTES) elif override == "URL": return urllib.quote_plus(str) else: return str def is_ordinary_var(self, var): """ Return true if var is a scalar. (not a reference to loop) @hidden """ if type(var) == StringType or type(var) == IntType or \ type(var) == LongType or type(var) == FloatType: return 1 else: return 0 ############################################## # CLASS: TemplateCompiler # ############################################## class TemplateCompiler: """ Preprocess, parse, tokenize and compile the template. This class parses the template and produces a 'compiled' form of it. This compiled form is an instance of the Template class. The compiled form is used as input for the TemplateProcessor which uses it to actually process the template. This class should be used direcly only when you need to compile a template from a string. If your template is in a file, then you should use the TemplateManager class which provides a higher level interface to this class and also can save the compiled template to disk in a precompiled form. """ def __init__(self, include=1, max_include=5, comments=1, gettext=0, debug=0): """ Constructor. @header __init__(include=1, max_include=5, comments=1, gettext=0, debug=0) @param include Enable or disable included templates. @param max_include Maximum depth of nested inclusions. @param comments Enable or disable template comments. @param gettext Enable or disable gettext support. @param debug Enable or disable debugging messages. """ self._include = include self._max_include = max_include self._comments = comments self._gettext = gettext self._debug = debug # This is a list of filenames of all included templates. # It's modified by the include_templates() method. self._include_files = [] # This is a counter of current inclusion depth. It's used to prevent # infinite recursive includes. self._include_level = 0 def compile(self, file): """ Compile template from a file. @header compile(file) @return Compiled template. The return value is an instance of the Template class. @param file Filename of the template. See the prepare() method of the TemplateManager class for exaplanation of this parameter. """ self.DEB("COMPILING FROM FILE: " + file) self._include_path = os.path.join(os.path.dirname(file), INCLUDE_DIR) tokens = self.parse(self.read(file)) compile_params = (self._include, self._max_include, self._comments, self._gettext) return Template(__version__, file, self._include_files, tokens, compile_params, self._debug) def compile_string(self, data): """ Compile template from a string. This method compiles a template from a string. The template cannot include any templates. TMPL_INCLUDE statements are turned into warnings. @header compile_string(data) @return Compiled template. The return value is an instance of the Template class. @param data String containing the template data. """ self.DEB("COMPILING FROM STRING") self._include = 0 tokens = self.parse(data) compile_params = (self._include, self._max_include, self._comments, self._gettext) return Template(__version__, None, None, tokens, compile_params, self._debug) ############################################## # PRIVATE METHODS # ############################################## def DEB(self, str): """ Print debugging message to stderr if debugging is enabled. @hidden """ if self._debug: print >> sys.stderr, str def read(self, filename): """ Read content of file and return it. Raise an error if a problem occurs. @hidden """ self.DEB("READING: " + filename) try: f = None try: f = open(filename, "r") data = f.read() except IOError, (errno, errstr): raise TemplateError, "IO error while reading template '%s': "\ "(%d) %s" % (filename, errno, errstr) else: return data finally: if f: f.close() def parse(self, template_data): """ Parse the template. This method is recursively called from within the include_templates() method. @return List of processing tokens. @hidden """ if self._comments: self.DEB("PREPROCESS: COMMENTS") template_data = self.remove_comments(template_data) tokens = self.tokenize(template_data) if self._include: self.DEB("PREPROCESS: INCLUDES") self.include_templates(tokens) return tokens def remove_comments(self, template_data): """ Remove comments from the template data. @hidden """ pattern = r"### .*" return re.sub(pattern, "", template_data) def include_templates(self, tokens): """ Process TMPL_INCLUDE statements. Use the include_level counter to prevent infinite recursion. Record paths to all included templates to self._include_files. @hidden """ i = 0 out = "" # buffer for output skip_params = 0 # Process the list of tokens. while 1: if i == len(tokens): break if skip_params: skip_params = 0 i += PARAMS_NUMBER continue token = tokens[i] if token == "." self._include_level += 1 if self._include_level > self._max_include: # Do not include the template. # Protection against infinite recursive includes. skip_params = 1 self.DEB("INCLUDE: LIMIT REACHED: " + filename) else: # Include the template. skip_params = 0 include_file = os.path.join(self._include_path, filename) self._include_files.append(include_file) include_data = self.read(include_file) include_tokens = self.parse(include_data) # Append the tokens from the included template to actual # position in the tokens list, replacing the TMPL_INCLUDE # token and its parameters. tokens[i:i+PARAMS_NUMBER+1] = include_tokens i = i + len(include_tokens) self.DEB("INCLUDED: " + filename) continue # Do not increment 'i' below. i += 1 # end of the main while loop if self._include_level > 0: self._include_level -= 1 return out def tokenize(self, template_data): """ Split the template into tokens separated by template statements. The statements itself and associated parameters are also separately included in the resulting list of tokens. Return list of the tokens. @hidden """ self.DEB("TOKENIZING TEMPLATE") # NOTE: The TWO double quotes in character class in the regexp below # are there only to prevent confusion of syntax highlighter in Emacs. pattern = r""" (?:^[ \t]+)? # eat spaces, tabs (opt.) (< (?:!--[ ])? # comment start + space (opt.) /?TMPL_[A-Z]+ # closing slash / (opt.) + statement [ a-zA-Z0-9""/.=:_\\-]* # this spans also comments ending (--) >) [%s]? # eat trailing newline (opt.) """ % os.linesep rc = re.compile(pattern, re.VERBOSE | re.MULTILINE) split = rc.split(template_data) tokens = [] for statement in split: if statement.startswith(" 0 and '=' not in params[0]: # implicit identifier name = params[0] del params[0] else: # explicit identifier as a 'NAME' parameter name = self.find_param("NAME", params) self.DEB("TOKENIZER: NAME: " + str(name)) return name def find_param(self, param, params): """ Extract value of parameter from a statement. @hidden """ for pair in params: name, value = pair.split("=") if not name or not value: raise TemplateError, "Syntax error in template." if name == param: if value[0] == '"': # The value is in double quotes. ret_value = value[1:-1] else: # The value is without double quotes. ret_value = value self.DEB("TOKENIZER: PARAM: '%s' => '%s'" % (param, ret_value)) return ret_value else: self.DEB("TOKENIZER: PARAM: '%s' => NOT DEFINED" % param) return None ############################################## # CLASS: Template # ############################################## class Template: """ This class represents a compiled template. This class provides storage and methods for the compiled template and associated metadata. It's serialized by pickle if we need to save the compiled template to disk in a precompiled form. You should never instantiate this class directly. Always use the TemplateManager or TemplateCompiler classes to create the instances of this class. The only method which you can directly use is the is_uptodate method. """ def __init__(self, version, file, include_files, tokens, compile_params, debug=0): """ Constructor. @hidden """ self._version = version self._file = file self._tokens = tokens self._compile_params = compile_params self._debug = debug self._mtime = None self._include_mtimes = {} if not file: self.DEB("TEMPLATE WAS COMPILED FROM A STRING") return # Save modifitcation time of the main template file. if os.path.isfile(file): self._mtime = os.path.getmtime(file) else: raise TemplateError, "Template: file does not exist: '%s'" % file # Save modificaton times of all included template files. for inc_file in include_files: if os.path.isfile(inc_file): self._include_mtimes[inc_file] = os.path.getmtime(inc_file) else: raise TemplateError, "Template: file does not exist: '%s'"\ % inc_file self.DEB("NEW TEMPLATE CREATED") def is_uptodate(self, compile_params=None): """ Check whether the compiled template is uptodate. Return true if this compiled template is uptodate. Return false, if the template source file was changed on the disk since it was compiled. Works by comparison of modification times. Also takes modification times of all included templates into account. @header is_uptodate(compile_params=None) @return True if the template is uptodate, false otherwise. @param compile_params Only for internal use. Do not use this optional parameter. It's intended only for internal use by the TemplateManager. """ if not self._file: self.DEB("TEMPLATE COMPILED FROM A STRING") return 0 if self._version != __version__: self.DEB("TEMPLATE: VERSION NOT UPTODATE") return 0 if compile_params != None and compile_params != self._compile_params: self.DEB("TEMPLATE: DIFFERENT COMPILATION PARAMS") return 0 # Check modification times of the main template and all included # templates. If the included template no longer exists, then # the problem will be resolved when the template is recompiled. # Main template file. if not (os.path.isfile(self._file) and \ self._mtime == os.path.getmtime(self._file)): self.DEB("TEMPLATE: NOT UPTODATE: " + self._file) return 0 # Included templates. for inc_file in self._include_mtimes.keys(): if not (os.path.isfile(inc_file) and \ self._include_mtimes[inc_file] == \ os.path.getmtime(inc_file)): self.DEB("TEMPLATE: NOT UPTODATE: " + inc_file) return 0 else: self.DEB("TEMPLATE: UPTODATE") return 1 def tokens(self): """ Get tokens of this template. @hidden """ return self._tokens def file(self): """ Get filename of the main file of this template. @hidden """ return self._file def debug(self, debug): """ Get debugging state. @hidden """ self._debug = debug ############################################## # PRIVATE METHODS # ############################################## def __getstate__(self): """ Used by pickle when the class is serialized. Remove the 'debug' attribute before serialization. @hidden """ dict = copy.copy(self.__dict__) del dict["_debug"] return dict def __setstate__(self, dict): """ Used by pickle when the class is unserialized. Add the 'debug' attribute. @hidden """ dict["_debug"] = 0 self.__dict__ = dict def DEB(self, str): """ Print debugging message to stderr. @hidden """ if self._debug: print >> sys.stderr, str ############################################## # EXCEPTIONS # ############################################## class TemplateError(Exception): """ Fatal exception. Raised on runtime or template syntax errors. This exception is raised when a runtime error occurs or when a syntax error in the template is found. It has one parameter which always is a string containing a description of the error. All potential IOError exceptions are handled by the module and are converted to TemplateError exceptions. That means you should catch the TemplateError exception if there is a possibility that for example the template file will not be accesssible. The exception can be raised by constructors or by any method of any class. The instance is no longer usable when this exception is raised. """ def __init__(self, error): """ Constructor. @hidden """ Exception.__init__(self, "Htmltmpl error: " + error) class PrecompiledError(Exception): """ This exception is _PRIVATE_ and non fatal. @hidden """ def __init__(self, template): """ Constructor. @hidden """ Exception.__init__(self, template)