""" This file contains the core methods for the Batch-command- and Batch-code-processors respectively. In short, these are two different ways to build a game world using a normal text-editor without having to do so 'on the fly' in-game. They also serve as an automatic backup so you can quickly recreate a world also after a server reset. The functions in this module is meant to form the backbone of a system called and accessed through game commands. The Batch-command processor is the simplest. It simply runs a list of in-game commands in sequence by reading them from a text file. The advantage of this is that the builder only need to remember the normal in-game commands. They are also executing with full permission checks etc, making it relatively safe for builders to use. The drawback is that in-game there is really a builder-character walking around building things, and it can be important to create rooms and objects in the right order, so the character can move between them. Also objects that affects players (such as mobs, dark rooms etc) will affect the building character too, requiring extra care to turn off/on. The Batch-code processor is a more advanced system that accepts full Python code, executing in chunks. The advantage of this is much more power; practically anything imaginable can be coded and handled using the batch-code processor. There is no in-game character that moves and that can be affected by what is being built - the database is populated on the fly. The drawback is safety and entry threshold - the code is executed as would any server code, without mud-specific permission checks and you have full access to modifying objects etc. You also need to know Python and Evennia's API. Hence it's recommended that the batch-code processor is limited only to superusers or highly trusted staff. Batch-command processor file syntax The batch-command processor accepts 'batchcommand files' e.g 'batch.ev', containing a sequence of valid evennia commands in a simple format. The engine runs each command in sequence, as if they had been run at the game prompt. This way entire game worlds can be created and planned offline; it is especially useful in order to create long room descriptions where a real offline text editor is often much better than any online text editor or prompt. Example of batch.ev file: ---------------------------- # batch file # all lines starting with # are comments; they also indicate # that a command definition is over. @create box # this comment ends the @create command. @set box/desc = A large box. Inside are some scattered piles of clothing. It seems the bottom of the box is a bit loose. # Again, this comment indicates the @set command is over. Note how # the description could be freely added. Excess whitespace on a line # is ignored. An empty line in the command definition is parsed as a \n # (so two empty lines becomes a new paragraph). @teleport #221 # (Assuming #221 is a warehouse or something.) # (remember, this comment ends the @teleport command! Don'f forget it) @drop box # Done, the box is in the warehouse! (this last comment is not necessary to # close the @drop command since it's the end of the file) ------------------------- An example batch file is game/gamesrc/commands/examples/batch_example.ev. Batch-code processor file syntax The Batch-code processor accepts full python modules (e.g. "batch.py") that looks identical to normal Python files with a few exceptions that allows them to the executed in blocks. This way of working assures a sequential execution of the file and allows for features like stepping from block to block (without executing those coming before), as well as automatic deletion of created objects etc. You can however also run a batch-code python file directly using Python (and can also be de). Code blocks are separated by python comments starting with special code words. #HEADER - this denotes commands global to the entire file, such as import statements and global variables. They will automatically be pasted at the top of all code blocks. Observe that changes to these variables made in one block is not preserved between blocks! #CODE [objname, objname, ...] - This designates a code block that will be executed like a stand-alone piece of code together with any #HEADER defined. s mark the (variable-)names of objects created in the code, and which may be auto-deleted by the processor if desired (such as when debugging the script). E.g., if the code contains the command myobj = create.create_object(...), you could put 'myobj' in the #CODE header regardless of what the created object is actually called in-game. The following variables are automatically made available for the script: caller - the object executing the script Example batch.py file ----------------------------------- #HEADER import traceback from django.config import settings from src.utils import create from game.gamesrc.typeclasses import basetypes GOLD = 10 #CODE obj, obj2 obj = create.create_object(basetypes.Object) obj2 = create.create_object(basetypes.Object) obj.location = caller.location obj.db.gold = GOLD caller.msg("The object was created!") #CODE script = create.create_script() """ import re import codecs from traceback import format_exc from django.conf import settings from django.core.management import setup_environ from src.utils import logger from src.utils import utils from game import settings as settings_module ENCODINGS = settings.ENCODINGS #------------------------------------------------------------ # Helper function #------------------------------------------------------------ def read_batchfile(pythonpath, file_ending='.py'): """ This reads the contents of a batch-file. Filename is considered to be the name of the batch file relative the directory specified in settings.py. file_ending specify which batchfile ending should be assumed (.ev or .py). """ # open the file if pythonpath and not (pythonpath.startswith('src.') or pythonpath.startswith('game.') or pythonpath.startswith('contrib.')): abspaths = [] for basepath in settings.BASE_BATCHPROCESS_PATHS: abspaths.append(utils.pypath_to_realpath("%s.%s" % (basepath, pythonpath), file_ending)) else: abspaths = [utils.pypath_to_realpath(pythonpath, file_ending)] fobj, lines, err = None, [], None for file_encoding in ENCODINGS: # try different encodings, in order load_errors = [] for abspath in abspaths: # try different paths, until we get a match try: # we read the file directly into unicode. fobj = codecs.open(abspath, 'r', encoding=file_encoding) except IOError: load_errors.append("Could not open batchfile '%s'." % abspath) continue break if not fobj: continue load_errors = [] err =None # We have successfully found and opened the file. Now actually # try to decode it using the given protocol. try: lines = fobj.readlines() except UnicodeDecodeError: # give the line of failure fobj.seek(0) try: lnum = 0 for lnum, line in enumerate(fobj): pass except UnicodeDecodeError, err: # lnum starts from 0, so we add +1 line, # besides the faulty line is never read # so we add another 1 (thus +2) to get # the actual line number seen in an editor. err.linenum = lnum + 2 fobj.close() # possibly try another encoding continue # if we get here, the encoding worked. Stop iteration. break if load_errors: logger.log_errmsg("\n".join(load_errors)) if err: return err else: return lines #------------------------------------------------------------ # # Batch-command processor # #------------------------------------------------------------ class BatchCommandProcessor(object): """ This class implements a batch-command processor. """ def parse_file(self, pythonpath): """ This parses the lines of a batchfile according to the following rules: 1) # at the beginning of a line marks the end of the command before it. It is also a comment and any number of # can exist on subsequent lines (but not inside comments). 2) Commands are placed alone at the beginning of a line and their arguments are considered to be everything following (on any number of lines) until the next comment line beginning with #. 3) Newlines are ignored in command definitions 4) A completely empty line in a command line definition is condered a newline (so two empty lines is a paragraph). 5) Excess spaces and indents inside arguments are stripped. """ #helper function def identify_line(line): """ Identifies the line type (comment, commanddef or empty) """ try: if line.strip()[0] == '#': return "comment" else: return "commanddef" except IndexError: return "empty" #read the indata, if possible. lines = read_batchfile(pythonpath, file_ending='.ev') #line = utils.to_unicode(line) if not lines: return None commands = [] curr_cmd = "" #purge all superfluous whitespace and newlines from lines reg1 = re.compile(r"\s+") lines = [reg1.sub(" ", l) for l in lines] #parse all command definitions into a list. for line in lines: typ = identify_line(line) if typ == "commanddef": curr_cmd += line elif typ == "empty" and curr_cmd: curr_cmd += "\r\n" else: #comment if curr_cmd: commands.append(curr_cmd.strip()) curr_cmd = "" if curr_cmd: commands.append(curr_cmd.strip()) #second round to clean up now merged line edges etc. reg2 = re.compile(r"[ \t\f\v]+") commands = [reg2.sub(" ", c) for c in commands] #remove eventual newline at the end of commands commands = [c.strip('\r\n') for c in commands] return commands #------------------------------------------------------------ # # Batch-code processor # #------------------------------------------------------------ class BatchCodeProcessor(object): """ This implements a batch-code processor """ def parse_file(self, pythonpath): """ This parses the lines of a batchfile according to the following rules: 1) Lines starting with #HEADER starts a header block (ends other blocks) 2) Lines starting with #CODE begins a code block (ends other blocks) 3) #CODE headers may be of the following form: #CODE (info) objname, objname2, ... 3) All lines outside blocks are stripped. 4) All excess whitespace beginning/ending a block is stripped. """ # helper function def parse_line(line): """ Identifies the line type: block command, comment, empty or normal code. """ line = line.strip() if line.startswith("#HEADER"): return ("header", "", "") elif line.startswith("#CODE"): # parse code command line = line.lstrip("#CODE").strip() objs = [] info = "" if line and '(' in line and ')' in line: # a code description lp = line.find('(') rp = line.find(')') info = line[lp:rp+1] line = line[rp+1:] if line: objs = [obj.strip() for obj in line.split(',')] return ("codeheader", info, objs) elif line.startswith('#'): return ('comment', "", "\n%s" % line) else: #normal line - return it with a line break. return ('line', "", "\n%s" % line) # read indata lines = read_batchfile(pythonpath, file_ending='.py') if not lines: return None # parse file into blocks header = "" codes = [] in_header = False in_code = False for line in lines: # parse line mode, info, line = parse_line(line) # try: # print "::", in_header, in_code, mode, line.strip() # except: # print "::", in_header, in_code, mode, line if mode == 'header': in_header = True in_code = False elif mode == 'codeheader': in_header = False in_code = True # the line is a list of object variable names # (or an empty list) at this point. codedict = {'objs':line, 'info':info, 'code':""} codes.append(codedict) elif mode == 'comment' and in_header: continue else: # another type of line (empty, comment or code) if line and in_header: header += line elif line and in_code: codes[-1]['code'] += line else: # not in a block (e.g. first in file). Ignore. continue # last, we merge the headers with all codes. for codedict in codes: codedict["code"] = "#CODE %s %s\n%s\n\n%s" % (codedict['info'], ", ".join(codedict["objs"]), header.strip(), codedict["code"].strip()) return codes def code_exec(self, codedict, extra_environ=None, debug=False): """ Execute a single code block, including imports and appending global vars extra_environ - dict with environment variables """ # define the execution environment environ = "setup_environ(settings_module)" environdict = {"setup_environ":setup_environ, "settings_module":settings_module} if extra_environ: for key, value in extra_environ.items(): environdict[key] = value # merge all into one block code = "%s\n%s" % (environ, codedict['code']) if debug: # try to delete marked objects for obj in codedict['objs']: code += "\ntry: %s.delete()\nexcept: pass" % obj # execute the block try: exec(code, environdict) except Exception: errlist = format_exc().split('\n') if len(errlist) > 4: errlist = errlist[4:] err = "\n".join(" %s" % line for line in errlist if line) if debug: # try to delete objects again. try: for obj in codedict['objs']: eval("%s.delete()" % obj, environdict) except Exception: pass return err return None BATCHCMD = BatchCommandProcessor() BATCHCODE = BatchCodeProcessor()