1 #!/usr/bin/env python 2 3 """ 4 Resources for use with WebStack. 5 6 Copyright (C) 2005, 2006, 2007 Paul Boddie <paul@boddie.org.uk> 7 8 This program is free software; you can redistribute it and/or modify it under 9 the terms of the GNU Lesser General Public License as published by the Free 10 Software Foundation; either version 3 of the License, or (at your option) any 11 later version. 12 13 This program is distributed in the hope that it will be useful, but WITHOUT 14 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS 15 FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more 16 details. 17 18 You should have received a copy of the GNU Lesser General Public License along 19 with this program. If not, see <http://www.gnu.org/licenses/>. 20 """ 21 22 import WebStack.Generic 23 import XSLForms.Fields 24 import XSLForms.Prepare 25 import XSLForms.Output 26 import XSLForms.Utils 27 import XSLForms.Resources.Common 28 from XSLTools import XSLOutput 29 import os 30 31 class XSLFormsResource(XSLForms.Resources.Common.CommonResource): 32 33 """ 34 A generic XSLForms resource for use with WebStack. 35 36 When overriding this class, define the following attributes appropriately: 37 38 * template_resources - a dictionary mapping output identifiers to 39 (template_filename, output_filename) tuples, 40 indicating the template and stylesheet filenames 41 to be employed 42 43 * in_page_resources - a dictionary mapping fragment identifiers to 44 (output_identifier, output_filename, 45 node_identifier) tuples, indicating the output 46 identifier for which the fragment applies, the 47 stylesheet filename to be employed, along with 48 the node identifier used in the original 49 template and output documents to mark a region 50 of those documents as the fragment to be updated 51 upon "in-page" requests 52 53 * init_resources - a dictionary mapping initialiser/input 54 identifiers to (template_filename, 55 input_filename) tuples, indicating the template 56 and initialiser/input stylesheet filenames to be 57 employed 58 59 * transform_resources - a dictionary mapping transform identifiers to 60 lists of stylesheet filenames for use with the 61 transformation methods 62 63 * document_resources - a dictionary mapping document identifiers to 64 single filenames for use as source documents or 65 as references with the transformation methods 66 67 * resource_dir - the absolute path of the directory in which 68 stylesheet resources are to reside 69 70 All filenames shall be simple leafnames for files residing in the resource's 71 special resource directory 'resource_dir'. 72 73 The following attributes may also be specified: 74 75 * path_encoding - the assumed encoding of characters in request 76 paths 77 78 * encoding - the assumed encoding of characters in request 79 bodies 80 81 To provide actual functionality to resources, either override the 82 'respond_to_form' method and write the code for obtaining input, 83 initialising documents, creating output, and so on in that method, or 84 provide implementations for the following methods: 85 86 * select_activity - sets the activity name which will be used by the 87 default implementations of the other methods 88 89 * create_document - creates or obtains a document for the resource's 90 activity (need not be overridden) 91 92 * respond_to_input - application logic relying on any input from the 93 request, including submitted document 94 information 95 96 * init_document - initialises the document according to the 97 'init_resources' attribute described above (need 98 not be overridden) 99 100 * respond_to_document - application logic relying on any information 101 from the initialised document 102 103 * create_output - creates and sends final output to the user (need 104 not be overridden) 105 """ 106 107 path_encoding = "utf-8" 108 encoding = "utf-8" 109 template_resources = {} 110 in_page_resources = {} 111 init_resources = {} 112 transform_resources = {} 113 114 def clean_parameters(self, parameters): 115 116 """ 117 Workaround stray zero value characters from Konqueror in XMLHttpRequest 118 communications. 119 """ 120 121 for name, values in parameters.items(): 122 new_values = [] 123 for value in values: 124 if value.endswith("\x00"): 125 new_values.append(value[:-1]) 126 else: 127 new_values.append(value) 128 parameters[name] = new_values 129 130 def prepare_output(self, output_identifier): 131 132 """ 133 Prepare the output stylesheets using the given 'output_identifier' to 134 indicate which templates and stylesheets are to be employed in the 135 production of output from the resource. 136 137 The 'output_identifier' is used as a key to the 'template_resources' 138 dictionary attribute. 139 140 Return the full path to the output stylesheet for use with 'send_output' 141 or 'get_result'. 142 """ 143 144 template_path, output_path = prepare_output(self, output_identifier) 145 return output_path 146 147 def prepare_fragment(self, fragment_identifier): 148 149 """ 150 Prepare the output stylesheets for the given 'fragment_identifier', 151 indicating which templates and stylesheets are to be employed in the 152 production of output from the resource. 153 154 The 'fragment_identifier' is used as a key to the 'in_page_resources' 155 dictionary attribute which in turn obtains an 'output_identifier', which 156 is used as a key to the 'template_resources' dictionary attribute. 157 158 Return the full path to the output stylesheet for use with 'send_output' 159 or 'get_result'. 160 """ 161 162 template_path, fragment_path = prepare_fragment(self, fragment_identifier) 163 return fragment_path 164 165 def prepare_parameters(self, parameters): 166 167 """ 168 Prepare the stylesheet parameters from the given request 'parameters'. 169 This is most useful when preparing fragments for in-page update output. 170 """ 171 172 element_path = parameters.get("element-path", [""])[0] 173 if element_path: 174 return {"element-path" : element_path} 175 else: 176 return {} 177 178 def send_output(self, trans, stylesheet_filenames, document, stylesheet_parameters=None, 179 stylesheet_expressions=None, references=None): 180 181 """ 182 Send the output from the resource to the user employing the transaction 183 'trans', stylesheets having the given 'stylesheet_filenames', the 184 'document' upon which the output will be based, the optional parameters 185 as defined in the 'stylesheet_parameters' dictionary, the optional 186 expressions are defined in the 'stylesheet_expressions' dictionary, and 187 the optional 'references' to external documents. 188 """ 189 190 # Sanity check for the filenames list. 191 192 if isinstance(stylesheet_filenames, str) or isinstance(stylesheet_filenames, unicode): 193 raise ValueError, stylesheet_filenames 194 195 proc = XSLOutput.Processor(stylesheet_filenames, parameters=stylesheet_parameters, 196 expressions=stylesheet_expressions, references=references) 197 proc.send_output(trans.get_response_stream(), trans.get_response_stream_encoding(), 198 document) 199 200 def get_result(self, stylesheet_filenames, document, stylesheet_parameters=None, 201 stylesheet_expressions=None, references=None): 202 203 """ 204 Get the result of applying a transformation using stylesheets with the 205 given 'stylesheet_filenames', the 'document' upon which the result will 206 be based, the optional parameters as defined in the 207 'stylesheet_parameters' dictionary, the optional parameters as defined 208 in the 'stylesheet_parameters' dictionary and the optional 'references' 209 to external documents. 210 """ 211 212 # Sanity check for the filenames list. 213 214 if isinstance(stylesheet_filenames, str) or isinstance(stylesheet_filenames, unicode): 215 raise ValueError, stylesheet_filenames 216 217 proc = XSLOutput.Processor(stylesheet_filenames, parameters=stylesheet_parameters, 218 expressions=stylesheet_expressions, references=references) 219 return proc.get_result(document) 220 221 def prepare_initialiser(self, input_identifier, init_enumerations=1): 222 223 """ 224 Prepare an initialiser/input transformation using the given 225 'input_identifier'. The optional 'init_enumerations' (defaulting to 226 true) may be used to indicate whether enumerations are to be initialised 227 from external documents. 228 229 Return the full path to the input stylesheet for use with 'send_output' 230 or 'get_result'. 231 """ 232 233 template_path, input_path = prepare_initialiser(self, input_identifier, init_enumerations) 234 return input_path 235 236 def prepare_transform(self, transform_identifier): 237 238 """ 239 Prepare a transformation using the given 'transform_identifier'. 240 241 Return a list of full paths to the output stylesheets for use with 242 'send_output' or 'get_result'. 243 """ 244 245 filenames = self.transform_resources[transform_identifier] 246 247 # Sanity check for the filenames list. 248 249 if isinstance(filenames, str) or isinstance(filenames, unicode): 250 raise ValueError, filenames 251 252 paths = [] 253 for filename in filenames: 254 paths.append(os.path.abspath(os.path.join(self.resource_dir, filename))) 255 return paths 256 257 def get_in_page_resource(self, trans): 258 259 """ 260 Return the in-page resource being referred to in the given transaction 261 'trans'. 262 """ 263 264 if hasattr(self, "path_encoding"): 265 return trans.get_path_info(self.path_encoding).split("/")[-1] 266 else: 267 return trans.get_path_info().split("/")[-1] 268 269 def respond(self, trans): 270 271 """ 272 Respond to the request described by the given transaction 'trans'. 273 """ 274 275 # Only obtain field information according to the stated method. 276 277 content_type = trans.get_content_type() 278 method = trans.get_request_method() 279 in_page_resource = self.get_in_page_resource(trans) 280 281 # Handle typical request methods, processing request information. 282 283 if method == "GET": 284 285 # Get the fields from the request path (URL). 286 287 form = XSLForms.Fields.Form(encoding=None, values_are_lists=1) 288 parameters = trans.get_fields_from_path() 289 form.set_parameters(parameters) 290 291 elif method == "POST" and content_type.media_type == "application/x-www-form-urlencoded": 292 293 # Get the fields from the request body. 294 295 form = XSLForms.Fields.Form(encoding=None, values_are_lists=1) 296 if hasattr(self, "encoding"): 297 parameters = trans.get_fields_from_body(self.encoding) 298 else: 299 parameters = trans.get_fields_from_body() 300 301 # NOTE: Konqueror workaround. 302 self.clean_parameters(parameters) 303 304 form.set_parameters(parameters) 305 306 else: 307 308 # Initialise empty container. 309 310 form = XSLForms.Fields.Form(encoding=None, values_are_lists=1) 311 312 # Call an overridden method with the processed request information. 313 314 self.respond_to_form(trans, form) 315 316 def respond_to_form(self, trans, form): 317 318 """ 319 Respond to the request described by the given transaction 'trans', using 320 the given 'form' object to conveniently retrieve field (request 321 parameter) information and structured form information (as DOM-style XML 322 documents). 323 """ 324 325 self.select_activity(trans, form) 326 self.create_document(trans, form) 327 self.respond_to_input(trans, form) 328 self.init_document(trans, form) 329 self.respond_to_document(trans, form) 330 self.create_output(trans, form) 331 raise WebStack.Generic.EndOfResponse 332 333 # Modular methods for responding to requests. 334 335 def select_activity(self, trans, form): 336 337 """ 338 Using the given transaction 'trans' and 'form' information, select the 339 activity being performed and set the 'current_activity' attribute in the 340 transaction. 341 """ 342 343 pass 344 345 def create_document(self, trans, form): 346 347 """ 348 Using the given transaction 'trans' and 'form' information, create the 349 document involved in the current activity and set the 'current_document' 350 attribute in the transaction. 351 352 Return whether a new document was created. 353 """ 354 355 documents = form.get_documents() 356 activity = form.get_activity() 357 358 if documents.has_key(activity): 359 form.set_document(documents[activity]) 360 return 0 361 else: 362 form.set_document(form.new_instance(activity)) 363 return 1 364 365 def respond_to_input(self, trans, form): 366 367 """ 368 Using the given transaction 'trans' and 'form' information, perform the 369 parts of the current activity which rely on the information supplied in 370 the current document. 371 """ 372 373 pass 374 375 def init_document(self, trans, form, stylesheet_parameters=None, 376 stylesheet_expressions=None, references=None): 377 378 """ 379 Using the given transaction 'trans' and 'form' information, initialise 380 the current document. 381 """ 382 383 activity = form.get_activity() 384 385 # Transform, adding enumerations/ranges. 386 387 if self.init_resources.has_key(activity): 388 init_xsl = self.prepare_initialiser(activity) 389 form.set_document( 390 self.get_result( 391 [init_xsl], form.get_document(), stylesheet_parameters, 392 stylesheet_expressions, references 393 ) 394 ) 395 396 def respond_to_document(self, trans, form): 397 398 """ 399 Using the given transaction 'trans' and 'form' information, perform the 400 parts of the current activity which rely on a populated version of the 401 current document. 402 """ 403 404 pass 405 406 def create_output(self, trans, form, content_type=None, 407 stylesheet_parameters=None, stylesheet_expressions=None, references=None): 408 409 """ 410 Using the given transaction 'trans' and 'form' information, create the 411 output for the current activity using the previously set attributes in 412 the transaction. 413 """ 414 415 attributes = trans.get_attributes() 416 in_page_resource = self.get_in_page_resource(trans) 417 parameters = form.get_parameters() 418 419 # Start the response. 420 421 encoding = attributes.get("encoding") or self.encoding 422 content_type = content_type or WebStack.Generic.ContentType("application/xhtml+xml", encoding) 423 trans.set_content_type(content_type) 424 425 # Ensure that an output stylesheet exists. 426 427 stylesheet_parameters = stylesheet_parameters or {} 428 429 if in_page_resource in self.in_page_resources.keys(): 430 trans_xsl = self.prepare_fragment(in_page_resource) 431 stylesheet_parameters.update(self.prepare_parameters(parameters)) 432 else: 433 trans_xsl = self.prepare_output(form.get_activity()) 434 435 # Complete the response. 436 437 self.send_output(trans, [trans_xsl], form.get_document(), 438 stylesheet_parameters, stylesheet_expressions, references) 439 440 # General helper methods. 441 442 def add_elements(self, positions, *element_names): 443 444 """ 445 At the given 'positions', typically obtained as "selectors", add the 446 hierarchy of elements given in the 'element_names' parameters. 447 """ 448 449 XSLForms.Utils.add_elements(positions, *element_names) 450 451 def remove_elements(self, positions): 452 453 """ 454 Remove elements at the given 'positions', typically obtained as 455 "selectors". 456 """ 457 458 XSLForms.Utils.remove_elements(positions) 459 460 def prepare_output(self, output_identifier): 461 462 """ 463 Prepare the output stylesheet for the resource class or object 'self' 464 corresponding to the given 'output_identifier'. Return the template path 465 and the output stylesheet path in a 2-tuple. 466 """ 467 468 template_filename, output_filename = self.template_resources[output_identifier] 469 output_path = os.path.abspath(os.path.join(self.resource_dir, output_filename)) 470 template_path = os.path.abspath(os.path.join(self.resource_dir, template_filename)) 471 XSLForms.Prepare.ensure_stylesheet(template_path, output_path) 472 return template_path, output_path 473 474 def prepare_fragment(self, fragment_identifier): 475 476 """ 477 Prepare the output stylesheet for the resource class or object 'self' 478 corresponding to the given 'fragment_identifier'. Return the template path 479 and the output stylesheet path in a 2-tuple. 480 """ 481 482 output_identifier, fragment_filename, node_identifier = self.in_page_resources[fragment_identifier] 483 fragment_path = os.path.abspath(os.path.join(self.resource_dir, fragment_filename)) 484 template_filename, output_filename = self.template_resources[output_identifier] 485 template_path = os.path.abspath(os.path.join(self.resource_dir, template_filename)) 486 XSLForms.Prepare.ensure_stylesheet_fragment(template_path, fragment_path, node_identifier) 487 return template_path, fragment_path 488 489 def prepare_initialiser(self, input_identifier, init_enumerations): 490 491 """ 492 Prepare the initialising stylesheet for the resource class or object 'self' 493 corresponding to the given 'input_identifier' and 'init_enumerations' flag. 494 Return the template path and the initialising stylesheet path in a 2-tuple. 495 """ 496 497 template_filename, input_filename = self.init_resources[input_identifier] 498 input_path = os.path.abspath(os.path.join(self.resource_dir, input_filename)) 499 template_path = os.path.abspath(os.path.join(self.resource_dir, template_filename)) 500 XSLForms.Prepare.ensure_input_stylesheet(template_path, input_path, init_enumerations) 501 return template_path, input_path 502 503 def prepare_resources(cls): 504 505 "Prepare the resources associated with the class 'cls'." 506 507 for output_identifier in cls.template_resources.keys(): 508 prepare_output(cls, output_identifier) 509 for fragment_identifier in cls.in_page_resources.keys(): 510 prepare_fragment(cls, fragment_identifier) 511 512 # NOTE: Using init_enumerations=1 here. 513 514 for input_identifier in cls.init_resources.keys(): 515 prepare_initialiser(cls, input_identifier, 1) 516 517 # Convenience methods for specifying resources. 518 519 def split(filename): 520 521 """ 522 Return a tuple containing the directory and filename without extension for 523 'filename'. 524 """ 525 526 d, leafname = os.path.split(filename) 527 name, ext = os.path.splitext(leafname) 528 return d, name 529 530 def output(template_filename): 531 532 """ 533 Return a tuple containing the 'template_filename' and a suitable output 534 stylesheet filename. 535 """ 536 537 d, name = split(template_filename) 538 output_name = name.replace("_template", "_output") + os.path.extsep + "xsl" 539 return (template_filename, os.path.join(d, output_name)) 540 541 def input(template_filename): 542 543 """ 544 Return a tuple containing the 'template_filename' and a suitable output 545 stylesheet filename. 546 """ 547 548 d, name = split(template_filename) 549 input_name = name.replace("_template", "_input") + os.path.extsep + "xsl" 550 return (template_filename, os.path.join(d, input_name)) 551 552 def resources(filename, d="Resources"): 553 554 """ 555 Return the resource directory for the given 'filename', using the optional 556 directory name 'd' to indicate the directory relative to the directory of 557 'filename' (or the default directory name, indicating that the directory 558 called "Resources" - a sibling of 'filename' - is the resource directory). 559 560 It is envisaged that callers provide the value of the __file__ special 561 variable to get the resource directory relative to a particular module. 562 """ 563 564 return os.path.join(os.path.split(filename)[0], d) 565 566 # vim: tabstop=4 expandtab shiftwidth=4