Source Code for Module attribute

  1  # Name:         attribute.py 
  2  # Purpose:      Attribute classes 
  3  # Author:       Roman Rolinsky <rolinsky@femagsoft.com> 
  4  # Created:      25.06.2007 
  5  # RCS-ID:       $Id$ 
  6   
  7  ''' 
  8  Attribute processing classes. 
  9   
 10  This module contains some predefined classes which can be used to store and 
 11  retrieve XML data into Python objects. 
 12  ''' 
 13   
 14  import cPickle 
 15  from model import Model 
 16   
 17 -class Attribute: 
 18      '''Base class, used for simple attributes, i.e. single attributes 
 19      storing data as text strings.''' 
 20      @staticmethod 
 21 -    def add(parentNode, attribute, value): 
 22          '''Store attribute value in DOM as a text node. 
 23   
 24          @param attribute: Attribute name. 
 25          @param value: Attribute value (Python string). 
 26          ''' 
 27          if attribute == '': 
 28              elem = parentNode 
 29          else: 
 30              elem = Model.dom.createElement(attribute) 
 31              parentNode.appendChild(elem) 
 32          text = Model.dom.createTextNode(value) 
 33          elem.appendChild(text) 
 34      @staticmethod 
 35 -    def get(node): 
 36          '''Get value (or return a default value) from a DOM C{Element} object.''' 
 37          if node is None: return '' 
 38          try: 
 39              n = node.childNodes[0] 
 40              return n.wholeText 
 41          except IndexError: 
 42              return '' 
 43   
 44 -class ContentAttribute: 
 45      '''Content attribute class. Value is a list of strings.''' 
 46      @staticmethod 
 47 -    def add(parentNode, attribute, value): 
 48          contentElem = Model.dom.createElement(attribute) 
 49          parentNode.appendChild(contentElem) 
 50          for item in value: 
 51              elem = Model.dom.createElement('item') 
 52              text = Model.dom.createTextNode(item) 
 53              elem.appendChild(text) 
 54              contentElem.appendChild(elem) 
 55      @staticmethod 
 56 -    def get(node): 
 57          if node is None: return [] 
 58          value = [] 
 59          for n in node.childNodes: 
 60              if n.nodeType == node.ELEMENT_NODE and n.tagName == 'item': 
 61                  value.append(Attribute.get(n)) 
 62          return value 
 63   
 64 -class CheckContentAttribute: 
 65      '''CheckList content. Value is a list of tuples (checked, string).''' 
 66      @staticmethod 
 67 -    def add(parentNode, attribute, value): 
 68          contentElem = Model.dom.createElement(attribute) 
 69          parentNode.appendChild(contentElem) 
 70          for checked,item in value: 
 71              elem = Model.dom.createElement('item') 
 72              if checked: 
 73                  elem.setAttribute('checked', '1') 
 74              text = Model.dom.createTextNode(item) 
 75              elem.appendChild(text) 
 76              contentElem.appendChild(elem) 
 77      @staticmethod 
 78 -    def get(node): 
 79          if node is None: return [] 
 80          value = [] 
 81          for n in node.childNodes: 
 82              if n.nodeType == node.ELEMENT_NODE and n.tagName == 'item': 
 83                  checked = bool(n.getAttribute('checked')) 
 84                  value.append((checked, Attribute.get(n))) 
 85          return value 
 86   
 87 -class DictAttribute: 
 88      '''DictAttribute uses dictionary object for passing data.''' 
 89      attributes = [] 
 90      @classmethod 
 91 -    def add(cls, parentNode, attribute, value): 
 92          fontElem = Model.dom.createElement(attribute) 
 93          parentNode.appendChild(fontElem) 
 94          for a in filter(value.has_key, cls.attributes): 
 95              elem = Model.dom.createElement(a) 
 96              text = Model.dom.createTextNode(value[a]) 
 97              elem.appendChild(text) 
 98              fontElem.appendChild(elem) 
 99      @staticmethod 
100 -    def get(node): 
101          if node is None: return {} 
102          value = {} 
103          for n in node.childNodes: 
104              if n.nodeType == node.ELEMENT_NODE: 
105                  value[n.tagName] = Attribute.get(n) 
106          return value 
107   
108 -class FontAttribute(DictAttribute): 
109      attributes = ['size', 'style', 'weight', 'underlined', 'family', 'face', 'encoding',  
110                    'sysfont', 'relativesize'] 
111   
112 -class CodeAttribute(DictAttribute): 
113      attributes = ['events', 'assign_var'] 
114   
115 -class MultiAttribute: 
116      '''Repeated attribute like growablecols.''' 
117      @staticmethod 
118 -    def add(parentNode, attribute, value): 
119          for v in value: 
120              elem = Model.dom.createElement(attribute) 
121              parentNode.appendChild(elem) 
122              text = Model.dom.createTextNode(v) 
123              elem.appendChild(text) 
124      @staticmethod 
125 -    def get(node): 
126          if node is None: return [] 
127          tag = node.tagName  # remember tag name 
128          value = [] 
129          # Look for multiple tags 
130          while node: 
131              if node.nodeType == node.ELEMENT_NODE and node.tagName == tag: 
132                  value.append(Attribute.get(node)) 
133              node = node.nextSibling 
134          return value 
135   
136 -class BitmapAttribute: 
137      '''Bitmap attribute.''' 
138      @staticmethod 
139 -    def add(parentNode, attribute, value): 
140          if not value[0] and not value[1]: return 
141          if attribute == 'object': 
142              elem = parentNode 
143          else: 
144              elem = Model.dom.createElement(attribute) 
145              parentNode.appendChild(elem) 
146          if value[0]: 
147              elem.setAttribute('stock_id', value[0]) 
148          else: 
149              if elem.hasAttribute('stock_id'): elem.removeAttribute('stock_id') 
150              text = Model.dom.createTextNode(value[1]) 
151              elem.appendChild(text) 
152      @staticmethod 
153 -    def get(node): 
154          if node is None: return [] 
155          return [node.getAttribute('stock_id'), Attribute.get(node)] 
156               
157 -class AttributeAttribute: 
158      '''Attribute as an XML attribute of the element node.''' 
159      @staticmethod 
160 -    def add(elem, attribute, value): 
161          if value: 
162              elem.setAttribute(attribute, value) 
163          else: 
164              if elem.hasAttribute(attribute): elem.removeAttribute(attribute) 
165      @staticmethod 
166 -    def getAA(elem, attribute): 
167          return elem.getAttribute(attribute) 
168   
169 -class EncodingAttribute(AttributeAttribute): 
170      '''Encoding is a special attribute stored in dom object.''' 
171      @staticmethod 
172 -    def add(elem, attribute, value): 
173          Model.dom.encoding = value 
174      @staticmethod 
175 -    def getAA(elem, attribute): 
176          return Model.dom.encoding 
177               
178 -class CDATAAttribute(Attribute): 
179 -    def add(parentNode, attribute, value): 
180          '''value is a dictionary.''' 
181          if value: 
182              elem = Model.dom.createElement(attribute) 
183              parentNode.appendChild(elem) 
184              data = Model.dom.createCDATASection(cPickle.dumps(value)) 
185              elem.appendChild(data) 
186      @staticmethod 
187 -    def get(node): 
188          '''Get XRCED data from a CDATA text node.''' 
189          try: 
190              n = node.childNodes[0] 
191              if n.nodeType == n.CDATA_SECTION_NODE: 
192                  return cPickle.loads(n.wholeText.encode()) 
193          except IndexError: 
194              pass 
195