git.sesse.net Git - xml-template/blob - c++0x/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 (strcmp(reinterpret_cast<const char *>(node->ns->href), "http://template.sesse.net/") == 0) {
  16                 xmlNode *frag = xmlNewDocFragment(node->doc);
  17                 xmlReplaceNode(node, frag);
  18                 frag->children = node->children;
  19                 frag->last = node->last;
  20
  21                 node->children = node->last = NULL;
  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 Clone::Clone(const vector<Directive *> &subdirectives)
  51         : subdirectives(subdirectives) {}
  52
  53 Clone::Clone(const vector<Substitute *> &subdirectives_subs)
  54 {
  55         for (auto it : subdirectives_subs) {
  56                 subdirectives.push_back(static_cast<Directive *>(it));
  57         }
  58 }
  59
  60 Clone::Clone(initializer_list<Directive *> subdirectives)
  61         : subdirectives(subdirectives) {}
  62
  63 Clone::~Clone()
  64 {
  65         for (auto it : subdirectives) {
  66                 delete it;
  67         }
  68 }
  69
  70 void Clone::process(xmlNode *node, bool clean)
  71 {
  72         // We can't use xmlNewDocFragment, since xmlDOMWrapCloneNode only knows
  73         // how to clone elements.
  74         vector<xmlNode *> new_nodes;
  75
  76         for (auto it : subdirectives) {
  77                 if (it == NULL) {
  78                         continue;
  79                 }
  80                 xmlNode *new_node;
  81                 xmlDOMWrapCloneNode(NULL, node->doc, node, &new_node, node->doc, NULL, 1, 0);
  82                 it->process(new_node, clean);
  83                 while (new_node->children != NULL) {
  84                         xmlNode *child = new_node->children;
  85                         xmlUnlinkNode(child);
  86                         new_nodes.push_back(child);
  87                 }
  88                 xmlFreeNode(new_node);
  89         }
  90
  91         xmlFreeNodeList(node->children);
  92         node->content = NULL;
  93         node->children = node->last = NULL;
  94
  95         for (auto child : new_nodes) {
  96                 xmlAddChild(node, child);
  97         }
  98         if (clean) {
  99                 clean_node(node);
 100         }
 101 }
 102
 103 Alternate::Alternate(const string &attribute,
 104                      const vector<Substitute *> &subdirectives_subs,
 105                      const vector<string> &alternatives)
 106     : Clone(subdirectives_subs)
 107 {
 108         unsigned jx = 0;
 109         for (unsigned ix = 0; ix < subdirectives_subs.size(); ++ix) {
 110                 if (subdirectives_subs[ix] == NULL) {
 111                         continue;
 112                 }
 113                 string value = alternatives[jx++ % alternatives.size()];
 114                 subdirectives_subs[ix]->substitution_map.insert(make_pair(
 115                         attribute,
 116                         new Replace { value }));
 117         }
 118 }
 119
 120 Substitute::Substitute(const unordered_map<string, Directive*> &substitution_map)
 121         : substitution_map(substitution_map) {}
 122
 123 Substitute::Substitute(initializer_list<pair<const string, Directive*>> substitution_map)
 124         : substitution_map(substitution_map) {}
 125
 126 Substitute::~Substitute()
 127 {
 128         for (auto it : substitution_map) {
 129                 delete it.second;
 130         }
 131 }
 132
 133 void Substitute::process(xmlNode *node, bool clean)
 134 {
 135         xmlNode *next_child;
 136         for (xmlNode *child = node->children; child != NULL; child = next_child) {
 137                 next_child = child->next;
 138                 bool processed = false;
 139
 140                 if (child->type == XML_ELEMENT_NODE) {
 141                         // Find the ID, if any.
 142                         string id;
 143                         xmlAttr *id_attr = NULL;
 144                         for (xmlAttr *attr = child->properties; attr != NULL; attr = attr->next) {
 145                                 if (attr->ns != NULL &&
 146                                     strcmp(reinterpret_cast<const char *>(attr->ns->href), "http://template.sesse.net/") == 0 &&
 147                                     strcmp(reinterpret_cast<const char *>(attr->name), "id") == 0) {
 148                                         xmlChar *id_buf = xmlNodeGetContent(attr->children);
 149                                         id = reinterpret_cast<const char *>(id_buf);
 150                                         xmlFree(id_buf);
 151                                         id_attr = attr;
 152                                 }
 153                         }
 154                         if (clean && id_attr != NULL) {
 155                                 xmlRemoveProp(id_attr);
 156                         }
 157
 158                         // Check all substitutions to see if we found anything appropriate.
 159                         for (auto it : substitution_map) {
 160                                 string tag = reinterpret_cast<const char *>(child->name);
 161
 162                                 // Attribute substitution.
 163                                 if (begins_with(it.first, tag + "/")) {
 164                                         const xmlChar *attr_key = reinterpret_cast<const xmlChar *>(
 165                                                 it.first.substr(tag.size() + 1).c_str());
 166                                         const xmlChar *attr_value = reinterpret_cast<const xmlChar *>(
 167                                                 it.second->get_contents().c_str());
 168                                         xmlSetProp(child, attr_key, attr_value);
 169                                 } else if ((!id.empty() && begins_with(it.first, "#" + id + "/"))) {
 170                                         const xmlChar *attr_key = reinterpret_cast<const xmlChar *>(
 171                                                 it.first.substr(tag.size() + 2).c_str());
 172                                         const xmlChar *attr_value = reinterpret_cast<const xmlChar *>(
 173                                                 it.second->get_contents().c_str());
 174                                         xmlSetProp(child, attr_key, attr_value);
 175                                 }
 176
 177                                 if (processed) {
 178                                         continue;
 179                                 }
 180
 181                                 // Regular substitution.
 182                                 if (it.first == tag ||
 183                                     (!id.empty() && it.first == ("#" + id))) {
 184                                         it.second->process(child, clean);
 185                                         processed = true;
 186                                 }
 187                         }
 188                 }
 189
 190                 if (!processed) {
 191                         process(child, clean);
 192                 }
 193         }
 194         if (clean) {
 195                 clean_node(node);
 196         }
 197 }
 198
 199 xmlDocPtr process_file(const string &input_filename,
 200                        Directive *root_directive)
 201 {
 202         LIBXML_TEST_VERSION
 203
 204         xmlDocPtr doc = xmlParseFile(input_filename.c_str());
 205         root_directive->process(xmlDocGetRootElement(doc), true);
 206         xmlCleanupParser();
 207         xmlMemoryDump();
 208         return doc;
 209 }
 210
 211 void output_to_fd_and_free(xmlDocPtr doc, int fd)
 212 {
 213         xmlOutputBufferPtr buf = xmlOutputBufferCreateFd(fd, NULL);
 214         xmlSaveFileTo(buf, doc, NULL);
 215         xmlFreeDoc(doc);
 216 }