git.sesse.net Git - xml-template/blob - c++11/xml-template.cpp

   1 #include "xml-template.h"
   2
   3 #include <assert.h>
   4 #include <string.h>
   5 #include <libxml/parser.h>
   6
   7 using namespace std;
   8
   9 namespace {
  10
  11 void clean_node(xmlNode *node)
  12 {
  13         if (node->type != XML_ELEMENT_NODE) {
  14                 return;
  15         }
  16         if (node->ns != NULL &&
  17             strcmp(reinterpret_cast<const char *>(node->ns->href), "http://template.sesse.net/") == 0) {
  18                 while (node->children != NULL) {
  19                         xmlAddPrevSibling(node, node->children);
  20                 }
  21
  22                 xmlUnlinkNode(node);
  23                 xmlFreeNode(node);
  24         }
  25 }
  26
  27 // Does A begin with B?
  28 bool begins_with(const string &a, const string &b)
  29 {
  30         return (a.compare(0, b.size(), b) == 0);
  31 }
  32
  33 }  // namespace
  34
  35 Directive::~Directive() {}
  36
  37 string Directive::get_contents() { return ""; }
  38
  39 Replace::Replace(const string &str)
  40         : str(str) {}
  41
  42 void Replace::process(xmlNode *node, bool clean) {
  43         xmlNodeSetContentLen(node, reinterpret_cast<const xmlChar *>(str.data()), str.size());
  44         if (clean) {
  45                 clean_node(node);
  46         }
  47 }
  48
  49 string Replace::get_contents() { return str; }
  50
  51 ReplaceInclude::ReplaceInclude(xmlNodePtr included_node)
  52         : included_node(included_node),
  53           included_doc(NULL) {}
  54
  55 ReplaceInclude::ReplaceInclude(xmlDocPtr included_doc)
  56         : included_node(xmlDocGetRootElement(included_doc)),
  57           included_doc(included_doc) {}
  58
  59 ReplaceInclude::~ReplaceInclude()
  60 {
  61         if (included_doc != NULL) {
  62                 xmlFreeDoc(included_doc);
  63         } else {
  64                 xmlFreeNode(included_node);
  65         }
  66 }
  67
  68 void ReplaceInclude::process(xmlNode *node, bool clean) {
  69         xmlFreeNodeList(node->children);
  70         node->content = NULL;
  71         node->children = node->last = NULL;
  72
  73         xmlNode *new_node;
  74         xmlDOMWrapCloneNode(NULL, NULL, included_node, &new_node, node->doc, node, 1, 0);
  75         xmlAddChild(node, new_node);
  76
  77         if (clean) {
  78                 Substitute dummy_subs {};
  79                 dummy_subs.process(new_node, clean);
  80                 clean_node(node);
  81         }
  82 }
  83
  84 Clone::Clone(const vector<Directive *> &subdirectives)
  85         : subdirectives(subdirectives) {}
  86
  87 Clone::Clone(const vector<Substitute *> &subdirectives_subs)
  88 {
  89         for (auto it : subdirectives_subs) {
  90                 subdirectives.push_back(static_cast<Directive *>(it));
  91         }
  92 }
  93
  94 Clone::Clone(initializer_list<Directive *> subdirectives)
  95         : subdirectives(subdirectives) {}
  96
  97 Clone::~Clone()
  98 {
  99         for (auto it : subdirectives) {
 100                 delete it;
 101         }
 102 }
 103
 104 void Clone::process(xmlNode *node, bool clean)
 105 {
 106         // We can't use xmlNewDocFragment, since xmlDOMWrapCloneNode only knows
 107         // how to clone elements.
 108         vector<xmlNode *> new_nodes;
 109
 110         for (auto it : subdirectives) {
 111                 if (it == NULL) {
 112                         continue;
 113                 }
 114                 xmlNode *new_node;
 115                 xmlDOMWrapCloneNode(NULL, node->doc, node, &new_node, node->doc, NULL, 1, 0);
 116                 it->process(new_node, clean);
 117                 while (new_node->children != NULL) {
 118                         xmlNode *child = new_node->children;
 119                         xmlUnlinkNode(child);
 120                         new_nodes.push_back(child);
 121                 }
 122                 xmlFreeNode(new_node);
 123         }
 124
 125         xmlFreeNodeList(node->children);
 126         node->content = NULL;
 127         node->children = node->last = NULL;
 128
 129         for (auto child : new_nodes) {
 130                 xmlAddChild(node, child);
 131         }
 132         if (clean) {
 133                 clean_node(node);
 134         }
 135 }
 136
 137 Alternate::Alternate(const string &attribute,
 138                      const vector<Substitute *> &subdirectives_subs,
 139                      const vector<string> &alternatives)
 140     : Clone(subdirectives_subs)
 141 {
 142         unsigned jx = 0;
 143         for (unsigned ix = 0; ix < subdirectives_subs.size(); ++ix) {
 144                 if (subdirectives_subs[ix] == NULL) {
 145                         continue;
 146                 }
 147                 string value = alternatives[jx++ % alternatives.size()];
 148                 Replace *r = new Replace { value };
 149                 subdirectives_subs[ix]->substitution_map.insert(make_pair(
 150                         attribute,
 151                         new Replace { value }));
 152         }
 153 }
 154
 155 Substitute::Substitute(const unordered_map<string, Directive*> &substitution_map)
 156         : substitution_map(substitution_map) {}
 157
 158 Substitute::Substitute(initializer_list<pair<const string, Directive*>> substitution_map)
 159         : substitution_map(substitution_map) {}
 160
 161 Substitute::~Substitute()
 162 {
 163         for (auto it : substitution_map) {
 164                 delete it.second;
 165         }
 166 }
 167
 168 void Substitute::process(xmlNode *node, bool clean)
 169 {
 170         xmlNode *next_child;
 171         for (xmlNode *child = node->children; child != NULL; child = next_child) {
 172                 next_child = child->next;
 173                 Directive *next_processor = this;
 174
 175                 if (child->type == XML_ELEMENT_NODE) {
 176                         // Find the ID, if any.
 177                         string id;
 178                         xmlAttr *id_attr = NULL;
 179                         for (xmlAttr *attr = child->properties; attr != NULL; attr = attr->next) {
 180                                 if (attr->ns != NULL &&
 181                                     strcmp(reinterpret_cast<const char *>(attr->ns->href), "http://template.sesse.net/") == 0 &&
 182                                     strcmp(reinterpret_cast<const char *>(attr->name), "id") == 0) {
 183                                         xmlChar *id_buf = xmlNodeGetContent(attr->children);
 184                                         id = reinterpret_cast<const char *>(id_buf);
 185                                         xmlFree(id_buf);
 186                                         id_attr = attr;
 187                                 }
 188                         }
 189                         if (clean && id_attr != NULL) {
 190                                 xmlRemoveProp(id_attr);
 191                         }
 192
 193                         // Check all substitutions to see if we found anything appropriate.
 194                         string tag = reinterpret_cast<const char *>(child->name);
 195                         for (auto it : substitution_map) {
 196                                 assert(it.second != nullptr);
 197                                 // Attribute substitution.
 198                                 if (begins_with(it.first, tag + "/")) {
 199                                         string contents = it.second->get_contents();
 200                                         const xmlChar *attr_key = reinterpret_cast<const xmlChar *>(
 201                                                 it.first.c_str() + tag.size() + 1);
 202                                         const xmlChar *attr_value = reinterpret_cast<const xmlChar *>(
 203                                                 contents.c_str());
 204                                         xmlSetProp(child, attr_key, attr_value);
 205                                 } else if ((!id.empty() && begins_with(it.first, "#" + id + "/"))) {
 206                                         string contents = it.second->get_contents();
 207                                         const xmlChar *attr_key = reinterpret_cast<const xmlChar *>(
 208                                                 it.first.c_str() + id.size() + 2);
 209                                         const xmlChar *attr_value = reinterpret_cast<const xmlChar *>(
 210                                                 contents.c_str());
 211                                         xmlSetProp(child, attr_key, attr_value);
 212                                 }
 213
 214                                 // Regular substitution. (Don't call process() immediately, because
 215                                 // that might delete the element, which would cause problems.)
 216                                 if (it.first == tag ||
 217                                     (!id.empty() && it.first == ("#" + id))) {
 218                                         next_processor = it.second;
 219                                 }
 220                         }
 221                 }
 222
 223                 next_processor->process(child, clean);
 224         }
 225         if (clean) {
 226                 clean_node(node);
 227         }
 228 }
 229
 230 xmlDocPtr process_file(const string &input_filename,
 231                        Directive *root_directive,
 232                        bool clean)
 233 {
 234         LIBXML_TEST_VERSION
 235
 236         xmlDocPtr doc = xmlParseFile(input_filename.c_str());
 237         root_directive->process(xmlDocGetRootElement(doc), clean);
 238         xmlCleanupParser();
 239         xmlMemoryDump();
 240         return doc;
 241 }
 242
 243 void output_to_fd_and_free(xmlDocPtr doc, int fd)
 244 {
 245         xmlOutputBufferPtr buf = xmlOutputBufferCreateFd(fd, NULL);
 246         xmlSaveFileTo(buf, doc, NULL);
 247         xmlFreeDoc(doc);
 248 }