Dome/Model.py

   1 from __future__ import nested_scopes
   2
   3 # An model contains:
   4 # - A DOM document
   5 # - The undo history
   6 # - The root program
   7 # All changes to the DOM must go through here.
   8 # Notification to views of changes is done.
   9
  10 from Ft.Xml.cDomlette import implementation, nonvalParse
  11 from Ft.Xml.Domlette import GetAllNs
  12 from Ft.Xml import XMLNS_NAMESPACE
  13
  14 from xml.dom import Node
  15 import support
  16 from Beep import Beep
  17 import constants
  18
  19 class Model:
  20         def __init__(self, path, root_program = None, dome_data = None, do_load = 1):
  21                 "If root_program is given, then no data is loaded (used for lock_and_copy)."
  22                 self.uri = 'Prog.dome'
  23                 import Namespaces
  24                 self.namespaces = Namespaces.Namespaces()
  25
  26                 if dome_data:
  27                         from Ft.Xml.InputSource import InputSourceFactory
  28                         isrc = InputSourceFactory()
  29                         dome_data = nonvalParse(isrc.fromUri(dome_data))
  30
  31                 self.clear_undo()
  32
  33                 doc = None
  34                 if path:
  35                         if path != '-':
  36                                 self.uri = path
  37                         if do_load and (path.endswith('.html') or path.endswith('.htm')):
  38                                 doc = self.load_html(path)
  39                         if not doc and not root_program:
  40                                 from Ft.Xml.InputSource import InputSourceFactory
  41                                 isrc = InputSourceFactory()
  42                                 try:
  43                                         doc = nonvalParse(isrc.fromUri(path))
  44                                 except:
  45                                         import rox
  46                                         rox.report_exception()
  47                 if not doc:
  48                         doc = implementation.createDocument(None, 'root', None)
  49                 root = doc.documentElement
  50
  51                 self.root_program = None
  52                 data_to_load = None
  53
  54                 from Program import Program, load_dome_program
  55                 if root.namespaceURI == constants.DOME_NS and root.localName == 'dome':
  56                         for x in root.childNodes:
  57                                 if x.namespaceURI == constants.DOME_NS:
  58                                         if x.localName == 'namespaces':
  59                                                 self.load_ns(x)
  60                                         elif x.localName == 'dome-program':
  61                                                 self.root_program = load_dome_program(x,
  62                                                                                 self.namespaces)
  63                                         elif x.localName == 'dome-data':
  64                                                 for y in x.childNodes:
  65                                                         if y.nodeType == Node.ELEMENT_NODE:
  66                                                                 data_to_load = y
  67                         if dome_data:
  68                                 data_to_load = dome_data.documentElement
  69                 elif (root.namespaceURI == constants.XSLT_NS and
  70                       root.localName in ['stylesheet', 'transform']) or \
  71                       root.hasAttributeNS(constants.XSLT_NS, 'version'):
  72                         import xslt
  73                         self.root_program = xslt.import_sheet(doc)
  74                         x = implementation.createDocument(None, 'xslt', None)
  75                         data_to_load = x.documentElement
  76                         src = doc.createElementNS(None, 'Source')
  77                         if file:
  78                                 # TODO: import_with_ns?
  79                                 src.appendChild(self.import_with_ns(doc,
  80                                                                 dome_data.documentElement))
  81                         data_to_load.appendChild(x.createElementNS(None, 'Result'))
  82                         data_to_load.appendChild(src)
  83                         dome_data = None
  84                 else:
  85                         data_to_load = root
  86
  87                 if root_program:
  88                         self.root_program = root_program
  89                 else:
  90                         if not self.root_program:
  91                                 self.root_program = Program('Root')
  92
  93                 if data_to_load:
  94                         self.doc = implementation.createDocument(None, 'root', None)
  95                         if not root_program:
  96                                 node = self.import_with_ns(data_to_load)
  97                                 self.doc.replaceChild(node, self.doc.documentElement)
  98                                 self.strip_space()
  99
 100                 self.views = []         # Notified when something changes
 101                 self.locks = {}         # Node -> number of locks
 102
 103                 self.hidden = {}        # Node -> Message
 104                 self.hidden_code = {}   # XPath to generate Message, if any
 105
 106         def load_ns(self, node):
 107                 assert node.localName == 'namespaces'
 108                 assert node.namespaceURI == constants.DOME_NS
 109                 for x in node.childNodes:
 110                         if x.nodeType != Node.ELEMENT_NODE: continue
 111                         if x.localName != 'ns': continue
 112                         if x.namespaceURI != constants.DOME_NS: continue
 113
 114                         self.namespaces.ensure_ns(x.getAttributeNS(None, 'prefix'),
 115                                                   x.getAttributeNS(None, 'uri'))
 116
 117         def import_with_ns(self, node):
 118                 """Return a copy of node for this model. All namespaces used in the subtree
 119                 will have been added to the global namespaces list. Prefixes will have been changed
 120                 as required to avoid conflicts."""
 121                 doc = self.doc
 122                 def ns_clone(node, clone):
 123                         if node.nodeType != Node.ELEMENT_NODE:
 124                                 return doc.importNode(node, 1)
 125                         if node.namespaceURI:
 126                                 prefix = self.namespaces.ensure_ns(node.prefix, node.namespaceURI)
 127                                 new = doc.createElementNS(node.namespaceURI,
 128                                                           prefix + ':' + node.localName)
 129                         else:
 130                                 new = doc.createElementNS(None, node.localName)
 131                         for a in node.attributes.values():
 132                                 if a.namespaceURI == XMLNS_NAMESPACE: continue
 133                                 new.setAttributeNS(a.namespaceURI, a.name, a.value)
 134                         for k in node.childNodes:
 135                                 new.appendChild(clone(k, clone))
 136                         return new
 137                 new = ns_clone(node, ns_clone)
 138                 return new
 139
 140         def clear_undo(self):
 141                 # Pop an (op_number, function) off one of these and call the function to
 142                 # move forwards or backwards in the undo history.
 143                 self.undo_stack = []
 144                 self.redo_stack = []
 145                 self.doing_undo = 0
 146
 147                 # Each series of suboperations in an undo stack which are part of a single
 148                 # user op will have the same number...
 149                 self.user_op = 1
 150
 151                 #import gc
 152                 #print "GC freed:", gc.collect()
 153                 #print "Garbage", gc.garbage
 154
 155         def lock(self, node):
 156                 """Prevent removal of this node (or any ancestor)."""
 157                 #print "Locking", node.nodeName
 158                 assert node.nodeType
 159                 self.locks[node] = self.get_locks(node) + 1
 160                 if node.parentNode:
 161                         self.lock(node.parentNode)
 162
 163         def unlock(self, node):
 164                 """Reverse the effect of lock(). Must call unlock the same number
 165                 of times as lock to fully unlock the node."""
 166                 l = self.get_locks(node)
 167                 if l > 1:
 168                         self.locks[node] = l - 1
 169                 elif l == 1:
 170                         del self.locks[node]    # Or get a memory leak...
 171                         if node == self.doc.documentElement:
 172                                 if node.parentNode:
 173                                         self.unlock(node.parentNode)
 174                                 return
 175                 else:
 176                         raise Exception('unlock(%s): Node not locked!' % node)
 177                 if node.parentNode:
 178                         self.unlock(node.parentNode)
 179
 180         def get_locks(self, node):
 181                 try:
 182                         return self.locks[node]
 183                 except KeyError:
 184                         return 0
 185
 186         def lock_and_copy(self, node):
 187                 """Locks 'node' in the current model and returns a new model
 188                 with a copy of the subtree."""
 189                 if self.get_locks(node):
 190                         raise Exception("Can't enter locked node!")
 191                 m = Model(self.get_base_uri(node), root_program = self.root_program, do_load = 0)
 192                 copy = m.import_with_ns(node)
 193                 root = m.get_root()
 194                 m.replace_node(root, copy)
 195                 self.lock(node)
 196                 return m
 197
 198         def mark(self):
 199                 "Increment the user_op counter. Undo will undo every operation between"
 200                 "two marks."
 201                 self.user_op += 1
 202
 203         def get_root(self):
 204                 "Return the true root node (not a view root)"
 205                 return self.doc.documentElement
 206
 207         def add_view(self, view):
 208                 "'view' provides:"
 209                 "'update_all(subtree) - called when a major change occurs."
 210                 #print "New view:", view
 211                 self.views.append(view)
 212
 213         def remove_view(self, view):
 214                 #print "Removing view", view
 215                 self.views.remove(view)
 216                 #print "Now:", self.views
 217                 if not self.views:
 218                         self.clear_undo()
 219
 220         def update_all(self, node):
 221                 "Called when 'node' has been updated."
 222                 "'node' is still in the document, so deleting or replacing"
 223                 "a node calls this on the parent."
 224                 for v in self.views:
 225                         v.update_all(node)
 226
 227         def update_replace(self, old, new):
 228                 "Called when 'old' is replaced by 'new'."
 229                 for v in self.views:
 230                         v.update_replace(old, new)
 231
 232         def strip_space(self, node = None):
 233                 if not node:
 234                         node = self.doc.documentElement
 235                 def ss(node):
 236                         if node.nodeType == Node.TEXT_NODE:
 237                                 #node.data = node.data.strip()
 238                                 #if node.data == '':
 239                                 #       node.parentNode.removeChild(node)
 240                                 if not node.data.strip():
 241                                         node.parentNode.removeChild(node)
 242                         else:
 243                                 for k in node.childNodes[:]:
 244                                         ss(k)
 245                 ss(node)
 246
 247         # Changes
 248
 249         def normalise(self, node):
 250                 old = node.cloneNode(1)
 251                 node.normalize()
 252                 self.add_undo(lambda: self.replace_node(node, old))
 253                 self.update_all(node)
 254
 255         def convert_to_element(self, node):
 256                 assert node.nodeType in (Node.COMMENT_NODE, Node.PROCESSING_INSTRUCTION_NODE,
 257                                          Node.TEXT_NODE)
 258                 new = self.doc.createElementNS(None, node.data.strip())
 259                 self.replace_node(node, new)
 260                 return new
 261
 262         def convert_to_text(self, node):
 263                 assert node.nodeType in (Node.COMMENT_NODE, Node.PROCESSING_INSTRUCTION_NODE,
 264                                          Node.TEXT_NODE, Node.ELEMENT_NODE)
 265                 if node.nodeType == Node.ELEMENT_NODE:
 266                         new = self.doc.createTextNode(node.localName)
 267                 else:
 268                         new = self.doc.createTextNode(node.data)
 269                 self.replace_node(node, new)
 270                 return new
 271
 272         def convert_to_comment(self, node):
 273                 assert node.nodeType in (Node.COMMENT_NODE, Node.PROCESSING_INSTRUCTION_NODE,
 274                                          Node.TEXT_NODE)
 275                 new = self.doc.createComment(node.data)
 276                 self.replace_node(node, new)
 277                 return new
 278
 279         def remove_ns(self, node):
 280                 print "remove_ns: Shouldn't need this now!"
 281                 return
 282
 283                 nss = GetAllNs(node.parentNode)
 284                 dns = nss.get(None, None)
 285                 create = node.ownerDocument.createElementNS
 286                 # clone is an argument to fix a wierd gc bug in python2.2
 287                 def ns_clone(node, clone):
 288                         if node.nodeType != Node.ELEMENT_NODE:
 289                                 return node.cloneNode(1)
 290                         new = create(dns, node.nodeName)
 291                         for a in node.attributes.values():
 292                                 if a.localName == 'xmlns' and a.prefix is None:
 293                                         print "Removing xmlns attrib on", node
 294                                         continue
 295                                 new.setAttributeNS(a.namespaceURI, a.name, a.value)
 296                         for k in node.childNodes:
 297                                 new.appendChild(clone(k, clone))
 298                         return new
 299                 new = ns_clone(node, ns_clone)
 300                 self.replace_node(node, new)
 301                 return new
 302
 303         def set_name(self, node, namespace, name):
 304                 if self.get_locks(node):
 305                         raise Exception('Attempt to set name on locked node %s' % node)
 306
 307                 new = node.ownerDocument.createElementNS(namespace, name)
 308                 self.replace_shallow(node, new)
 309                 return new
 310
 311         def replace_shallow(self, old, new):
 312                 """Replace old with new, keeping the old children."""
 313                 assert not new.childNodes
 314                 assert not new.parentNode
 315
 316                 old_name = old.nodeName
 317                 old_ns = old.namespaceURI
 318
 319                 kids = old.childNodes[:]
 320                 attrs = old.attributes.values()
 321                 parent = old.parentNode
 322                 [ old.removeChild(k) for k in kids ]
 323                 parent.replaceChild(new, old)
 324                 [ new.appendChild(k) for k in kids ]
 325                 [ new.setAttributeNS(a.namespaceURI, a.name, a.value) for a in attrs ]
 326
 327                 self.add_undo(lambda: self.replace_shallow(new, old))
 328
 329                 self.update_replace(old, new)
 330
 331         import __main__
 332         if __main__.no_gui_mode:
 333                 def add_undo(self, fn):
 334                         pass
 335         else:
 336                 def add_undo(self, fn):
 337                         self.undo_stack.append((self.user_op, fn))
 338                         if not self.doing_undo:
 339                                 self.redo_stack = []
 340
 341         def set_data(self, node, data):
 342                 old_data = node.data
 343                 node.data = data
 344                 self.add_undo(lambda: self.set_data(node, old_data))
 345                 self.update_all(node)
 346
 347         def replace_node(self, old, new):
 348                 if self.get_locks(old):
 349                         raise Exception('Attempt to replace locked node %s' % old)
 350                 old.parentNode.replaceChild(new, old)
 351                 self.add_undo(lambda: self.replace_node(new, old))
 352
 353                 self.update_replace(old, new)
 354
 355         def delete_shallow(self, node):
 356                 """Replace node with its contents"""
 357                 kids = node.childNodes[:]
 358                 next = node.nextSibling
 359                 parent = node.parentNode
 360                 for n in kids + [node]:
 361                         if self.get_locks(n):
 362                                 raise Exception('Attempt to move/delete locked node %s' % n)
 363                 for k in kids:
 364                         self.delete_internal(k)
 365                 self.delete_internal(node)
 366                 for k in kids:
 367                         self.insert_before_interal(next, k, parent)
 368                 self.update_all(parent)
 369
 370         def delete_nodes(self, nodes):
 371                 #print "Deleting", nodes
 372                 for n in nodes:
 373                         if self.get_locks(n):
 374                                 raise Exception('Attempt to delete locked node %s' % n)
 375                 for n in nodes:
 376                         p = n.parentNode
 377                         self.delete_internal(n)
 378                         self.update_all(p)
 379
 380         def delete_internal(self, node):
 381                 "Doesn't update display."
 382                 next = node.nextSibling
 383                 parent = node.parentNode
 384                 parent.removeChild(node)
 385                 self.add_undo(lambda: self.insert_before(next, node, parent = parent))
 386
 387         def insert_before_interal(self, node, new, parent):
 388                 "Insert 'new' before 'node'. If 'node' is None then insert at the end"
 389                 "of parent's children."
 390                 assert new.nodeType != Node.DOCUMENT_FRAGMENT_NODE
 391                 #assert parent.nodeType == Node.ELEMENT_NODE
 392                 parent.insertBefore(new, node)
 393                 self.add_undo(lambda: self.delete_nodes([new]))
 394
 395         def undo(self):
 396                 if not self.undo_stack:
 397                         raise Exception('Nothing to undo')
 398
 399                 assert not self.doing_undo
 400
 401                 uop = self.undo_stack[-1][0]
 402
 403                 # Swap stacks so that the undo actions will populate the redo stack...
 404                 (self.undo_stack, self.redo_stack) = (self.redo_stack, self.undo_stack)
 405                 self.doing_undo = 1
 406                 try:
 407                         while self.redo_stack and self.redo_stack[-1][0] == uop:
 408                                 self.redo_stack[-1][1]()
 409                                 self.redo_stack.pop()
 410                 finally:
 411                         (self.undo_stack, self.redo_stack) = (self.redo_stack, self.undo_stack)
 412                         self.doing_undo = 0
 413
 414         def redo(self):
 415                 if not self.redo_stack:
 416                         raise Exception('Nothing to redo')
 417
 418                 uop = self.redo_stack[-1][0]
 419                 self.doing_undo = 1
 420                 try:
 421                         while self.redo_stack and self.redo_stack[-1][0] == uop:
 422                                 self.redo_stack[-1][1]()
 423                                 self.redo_stack.pop()
 424                 finally:
 425                         self.doing_undo = 0
 426
 427         def insert(self, node, new, index = 0):
 428                 if len(node.childNodes) > index:
 429                         self.insert_before(node.childNodes[index], new)
 430                 else:
 431                         self.insert_before(None, new, parent = node)
 432
 433         def insert_after(self, node, new):
 434                 self.insert_before(node.nextSibling, new, parent = node.parentNode)
 435
 436         def insert_before(self, node, new, parent = None):
 437                 "Insert 'new' before 'node'. If 'node' is None then insert at the end"
 438                 "of parent's children."
 439                 if not parent:
 440                         parent = node.parentNode
 441                 if new.nodeType == Node.DOCUMENT_FRAGMENT_NODE:
 442                         for n in new.childNodes[:]:
 443                                 self.insert_before_interal(node, n, parent)
 444                 else:
 445                         self.insert_before_interal(node, new, parent)
 446                 self.update_all(parent)
 447
 448         def split_qname(self, node, name):
 449                 if name == 'xmlns':
 450                         namespaceURI = XMLNS_NAMESPACE
 451                         localName = name
 452                 elif ':' in name:
 453                         prefix, localName = name.split(':')
 454                         namespaceURI = self.prefix_to_namespace(node, prefix)
 455                 else:
 456                         namespaceURI = None
 457                         localName = name
 458                 return namespaceURI, localName
 459
 460         def set_attrib(self, node, name, value, with_update = 1):
 461                 """Set an attribute's value. If value is None, remove the attribute.
 462                 Returns the new attribute node, or None if removing."""
 463                 namespaceURI, localName = self.split_qname(node, name)
 464
 465                 if node.hasAttributeNS(namespaceURI, localName):
 466                         old = node.getAttributeNS(namespaceURI, localName)
 467                 else:
 468                         old = None
 469                 #print "Set (%s,%s) = %s" % (namespaceURI, name, value)
 470                 if value != None:
 471                         node.setAttributeNS(namespaceURI, name, value)
 472                 else:
 473                         node.removeAttributeNS(namespaceURI, localName)
 474
 475                 self.add_undo(lambda: self.set_attrib(node, name, old))
 476
 477                 if with_update:
 478                         self.update_all(node)
 479                 if value != None:
 480                         if localName == 'xmlns':
 481                                 localName = None
 482                         return node.attributes[(namespaceURI, localName)]
 483
 484         def prefix_to_namespace(self, node, prefix):
 485                 "Using attributes for namespaces was too confusing. Keep a global list instead."
 486                 if prefix is None: return None
 487                 try:
 488                         return self.namespaces.uri[prefix]
 489                 except KeyError:
 490                         raise Exception("Namespace '%s' is not defined. Choose "
 491                                 "View->Show namespaces from the popup menu to set it." % prefix)
 492
 493                 "Use the xmlns attributes to workout the namespace."
 494                 nss = GetAllNs(node)
 495                 if nss.has_key(prefix):
 496                         return nss[prefix] or None
 497                 if prefix:
 498                         if prefix == 'xmlns':
 499                                 return XMLNS_NAMESPACE
 500                         raise Exception("No such namespace prefix '%s'" % prefix)
 501                 else:
 502                         return None
 503
 504         def get_base_uri(self, node):
 505                 """Go up through the parents looking for a uri attribute.
 506                 If there isn't one, use the document's URI."""
 507                 while node:
 508                         if node.nodeType == Node.DOCUMENT_NODE:
 509                                 return self.uri
 510                         if node.hasAttributeNS(None, 'uri'):
 511                                 return node.getAttributeNS(None, 'uri')
 512                         node = node.parentNode
 513                 return None
 514
 515         def load_html(self, path):
 516                 """Load this HTML file and return the new document."""
 517                 data = file(path).read()
 518                 data = support.to_html_doc(data)
 519                 doc = support.parse_data(data, path)
 520                 self.strip_space(doc)
 521                 return doc