1 #!/usr/bin/python 2 3 # 4 # Copyright (C) 2012 The Android Open Source Project 5 # 6 # Licensed under the Apache License, Version 2.0 (the "License"); 7 # you may not use this file except in compliance with the License. 8 # You may obtain a copy of the License at 9 # 10 # http://www.apache.org/licenses/LICENSE-2.0 11 # 12 # Unless required by applicable law or agreed to in writing, software 13 # distributed under the License is distributed on an "AS IS" BASIS, 14 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 15 # See the License for the specific language governing permissions and 16 # limitations under the License. 17 # 18 19 """ 20 Usage: 21 metadata_validate.py <filename.xml> 22 - validates that the metadata properties defined in filename.xml are 23 semantically correct. 24 - does not do any XSD validation, use xmllint for that (in metadata-validate) 25 26 Module: 27 A set of helpful functions for dealing with BeautifulSoup element trees. 28 Especially the find_* and fully_qualified_name functions. 29 30 Dependencies: 31 BeautifulSoup - an HTML/XML parser available to download from 32 http://www.crummy.com/software/BeautifulSoup/ 33 """ 34 35 from bs4 import BeautifulSoup 36 from bs4 import Tag 37 import sys 38 39 40 ##################### 41 ##################### 42 43 def fully_qualified_name(entry): 44 """ 45 Calculates the fully qualified name for an entry by walking the path 46 to the root node. 47 48 Args: 49 entry: a BeautifulSoup Tag corresponding to an <entry ...> XML node 50 51 Returns: 52 A string with the full name, e.g. "android.lens.info.availableApertureSizes" 53 """ 54 filter_tags = ['namespace', 'section'] 55 parents = [i['name'] for i in entry.parents if i.name in filter_tags] 56 57 name = entry['name'] 58 59 parents.reverse() 60 parents.append(name) 61 62 fqn = ".".join(parents) 63 64 return fqn 65 66 def find_parent_by_name(element, names): 67 """ 68 Find the ancestor for an element whose name matches one of those 69 in names. 70 71 Args: 72 element: A BeautifulSoup Tag corresponding to an XML node 73 74 Returns: 75 A BeautifulSoup element corresponding to the matched parent, or None. 76 77 For example, assuming the following XML structure: 78 <static> 79 <anything> 80 <entry name="Hello" /> # this is in variable 'Hello' 81 </anything> 82 </static> 83 84 el = find_parent_by_name(Hello, ['static']) 85 # el is now a value pointing to the '<static>' element 86 """ 87 matching_parents = [i.name for i in element.parents if i.name in names] 88 89 if matching_parents: 90 return matching_parents[0] 91 else: 92 return None 93 94 def find_all_child_tags(element, tag): 95 """ 96 Finds all the children that are a Tag (as opposed to a NavigableString), 97 with a name of tag. This is useful to filter out the NavigableString out 98 of the children. 99 100 Args: 101 element: A BeautifulSoup Tag corresponding to an XML node 102 tag: A string representing the name of the tag 103 104 Returns: 105 A list of Tag instances 106 107 For example, given the following XML structure: 108 <enum> # This is the variable el 109 Hello world # NavigableString 110 <value>Apple</value> # this is the variale apple (Tag) 111 <value>Orange</value> # this is the variable orange (Tag) 112 Hello world again # NavigableString 113 </enum> 114 115 lst = find_all_child_tags(el, 'value') 116 # lst is [apple, orange] 117 118 """ 119 matching_tags = [i for i in element.children if isinstance(i, Tag) and i.name == tag] 120 return matching_tags 121 122 def find_child_tag(element, tag): 123 """ 124 Finds the first child that is a Tag with the matching name. 125 126 Args: 127 element: a BeautifulSoup Tag 128 tag: A String representing the name of the tag 129 130 Returns: 131 An instance of a Tag, or None if there was no matches. 132 133 For example, given the following XML structure: 134 <enum> # This is the variable el 135 Hello world # NavigableString 136 <value>Apple</value> # this is the variale apple (Tag) 137 <value>Orange</value> # this is the variable orange (Tag) 138 Hello world again # NavigableString 139 </enum> 140 141 res = find_child_tag(el, 'value') 142 # res is apple 143 """ 144 matching_tags = find_all_child_tags(element, tag) 145 if matching_tags: 146 return matching_tags[0] 147 else: 148 return None 149 150 def find_kind(element): 151 """ 152 Finds the kind Tag ancestor for an element. 153 154 Args: 155 element: a BeautifulSoup Tag 156 157 Returns: 158 a BeautifulSoup tag, or None if there was no matches 159 160 Remarks: 161 This function only makes sense to be called for an Entry, Clone, or 162 InnerNamespace XML types. It will always return 'None' for other nodes. 163 """ 164 kinds = ['dynamic', 'static', 'controls'] 165 parent_kind = find_parent_by_name(element, kinds) 166 return parent_kind 167 168 def validate_error(msg): 169 """ 170 Print a validation error to stderr. 171 172 Args: 173 msg: a string you want to be printed 174 """ 175 print >> sys.stderr, "Validation error: " + msg 176 177 178 def validate_clones(soup): 179 """ 180 Validate that all <clone> elements point to an existing <entry> element. 181 182 Args: 183 soup - an instance of BeautifulSoup 184 185 Returns: 186 True if the validation succeeds, False otherwise 187 """ 188 success = True 189 190 for clone in soup.find_all("clone"): 191 clone_entry = clone['entry'] 192 clone_kind = clone['kind'] 193 194 parent_kind = find_kind(clone) 195 196 find_entry = lambda x: x.name == 'entry' \ 197 and find_kind(x) == clone_kind \ 198 and fully_qualified_name(x) == clone_entry 199 matching_entry = soup.find(find_entry) 200 201 if matching_entry is None: 202 error_msg = ("Did not find corresponding clone entry '%s' " + \ 203 "with kind '%s'") %(clone_entry, clone_kind) 204 validate_error(error_msg) 205 success = False 206 207 return success 208 209 # All <entry> elements with container=$foo have a <$foo> child 210 # If type="enum", <enum> tag is present 211 # In <enum> for all <value id="$x">, $x is numeric 212 def validate_entries(soup): 213 """ 214 Validate all <entry> elements with the following rules: 215 * If there is a container="$foo" attribute, there is a <$foo> child 216 * If there is a type="enum" attribute, there is an <enum> child 217 * In the <enum> child, all <value id="$x"> have a numeric $x 218 219 Args: 220 soup - an instance of BeautifulSoup 221 222 Returns: 223 True if the validation succeeds, False otherwise 224 """ 225 success = True 226 for entry in soup.find_all("entry"): 227 entry_container = entry.attrs.get('container') 228 229 if entry_container is not None: 230 container_tag = entry.find(entry_container) 231 232 if container_tag is None: 233 success = False 234 validate_error(("Entry '%s' in kind '%s' has type '%s' but " + \ 235 "missing child element <%s>") \ 236 %(fully_qualified_name(entry), find_kind(entry), \ 237 entry_container, entry_container)) 238 239 enum = entry.attrs.get('enum') 240 if enum and enum == 'true': 241 if entry.enum is None: 242 validate_error(("Entry '%s' in kind '%s' is missing enum") \ 243 % (fully_qualified_name(entry), find_kind(entry), 244 )) 245 success = False 246 247 else: 248 for value in entry.enum.find_all('value'): 249 value_id = value.attrs.get('id') 250 251 if value_id is not None: 252 try: 253 id_int = int(value_id, 0) #autoguess base 254 except ValueError: 255 validate_error(("Entry '%s' has id '%s', which is not" + \ 256 " numeric.") \ 257 %(fully_qualified_name(entry), value_id)) 258 success = False 259 else: 260 if entry.enum: 261 validate_error(("Entry '%s' kind '%s' has enum el, but no enum attr") \ 262 % (fully_qualified_name(entry), find_kind(entry), 263 )) 264 success = False 265 266 return success 267 268 def validate_xml(file_name): 269 """ 270 Validate all XML nodes according to the rules in validate_clones and 271 validate_entries. 272 273 Args: 274 file_name - a string path to an XML file we wish to validate 275 276 Returns: 277 a BeautifulSoup instance if validation succeeds, None otherwise 278 """ 279 280 xml = file(file_name).read() 281 soup = BeautifulSoup(xml, features='xml') 282 283 succ = validate_clones(soup) 284 succ = validate_entries(soup) and succ 285 286 if succ: 287 return soup 288 else: 289 return None 290 291 ##################### 292 ##################### 293 294 if __name__ == "__main__": 295 if len(sys.argv) <= 1: 296 print >> sys.stderr, "Usage: %s <filename.xml>" % (sys.argv[0]) 297 sys.exit(0) 298 299 file_name = sys.argv[1] 300 succ = validate_xml(file_name) is not None 301 302 if succ: 303 print "%s: SUCCESS! Document validated" %(file_name) 304 sys.exit(0) 305 else: 306 print >> sys.stderr, "%s: ERRORS: Document failed to validate" %(file_name) 307 sys.exit(1) 308
