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

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