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#ifndef RSS_H
#define RSS_H
#include <cstddef>
#include <ctime>
#include <memory>
#include <regex>
#include <stack>
#include <stdexcept>
#include <string>
#include <iostream>
#include <utility>
#include <variant>
#include <vector>
class XML_leaf {
public:
std::string Raw;
std::string Name;
std::string Value = "";
std::vector<XML_leaf> leafs{};
XML_leaf(std::string raw, std::string value) {
Raw = raw;
Name = getTag(raw);
Value = value;
};
XML_leaf(std::string raw) {
// The smallest valid (?) XML element is <></>
if (raw.length() < 5 || raw[0] != '<')
throw std::runtime_error("The XML " + raw + " is invalid");
auto tokens = TokenizeXML(trimSpaces(raw));
if (tokens.size() < 3 || !isTag(tokens[0]))
throw new std::runtime_error("Invalid XML");
auto result = std::make_unique<XML_leaf>("<>", "");
std::stack<std::unique_ptr<XML_leaf>> stack{};
// Building a tree
for (size_t i = 1; i < tokens.size(); i++) {
const auto currentToken = tokens[i];
if (!isTag(currentToken)) {
if (stack.size() == 0)
continue;
stack.top()->setValue(currentToken);
continue;
}
if (stack.size() == 0 || !isClosingTagOf(currentToken, stack.top()->Raw)) {
if (IsSelfClosingTag(currentToken)) {
stack.top()->leafs.push_back(std::move(XML_leaf(currentToken, "")));
continue;
}
stack.push(std::make_unique<XML_leaf>(currentToken, ""));
continue;
}
auto complete = std::move(stack.top());
stack.pop();
if (stack.size() == 0) { // The node is closing a doc
result.swap(complete);
break;
}
stack.top()->leafs.push_back(std::move(*complete));
}
this->Raw = result->Raw;
this->Name = result->Name;
this->Value = result->Value;
this->leafs = result->leafs;
}
XML_leaf GetChild(std::string query) {
for (auto child : leafs) {
// std::cout << "Comparing " << child.Raw << " and " << query << std::endl;
if (child.Name == query)
return child;
}
return XML_leaf("<>", "empty");
}
std::vector<XML_leaf> GetChildren(std::string query) {
std::vector<XML_leaf> outp = {};
for (auto child : leafs) {
// std::cout << "Comparing " << child.Raw << " and " << query << std::endl;
if (child.Name == query)
outp.push_back(child);
}
return outp;
}
std::string GetValue() {
if (isCDATA(Value))
return getCDATA(Value, true);
return Value;
}
private:
void setValue(std::string newValue) {
Value = newValue;
}
static std::string trimSpaces(std::string raw) {
auto outp = std::regex_replace(raw, std::regex("\n"), "");
outp = std::regex_replace(outp, std::regex("> <"), "><");
outp = std::regex_replace(outp, std::regex(" +"), " ");
return outp;
}
static std::vector<std::string> TokenizeXML(std::string raw) {
std::vector<std::string> outp{};
// std::cout << "Called TokenizeXML()" << '\n';
ulong idx = 0;
while (idx < raw.length()) {
char ptr = raw[idx];
ulong next_idx = 0;
if (ptr == '<') {
if (isCDATA(raw.substr(idx, raw.length() - idx)))
next_idx = raw.find("]]>", idx) + 2;
else
next_idx = raw.find('>', idx);
} else {
next_idx = raw.find('<', idx) - 1;
}
outp.push_back(raw.substr(idx, (next_idx - idx) + 1));
idx = next_idx + 1;
}
return outp;
};
static bool isTag(std::string token){
return token.length() > 2
&& token[0] == '<'
&& token[token.length() - 1] == '>'
&& token[1] != '!';
}
static bool isCDATA(std::string token) {
return token.find("<![CDATA[") == 0;
}
// Assumes the string is CDATA
static std::string getCDATA(std::string token, bool toRawString = false) {
// 9 = "<!CDATA[".length
// 3 = "]]>".length
if (token.length() < 9 + 3) return token;
auto data = token.substr(9, token.length() - (9+3));
if (toRawString) {
data = std::regex_replace(data, std::regex("<[a-zA-Z/]+>"), "");
}
return data;
}
static bool isClosingTagOf(std::string token, std::string opening_tag){
if (!(token.length() > 3
&& token[0] == '<'
&& token[1] == '/'
&& token[token.length() - 1] == '>'))
return false;
if (!isTag(opening_tag)) return false;
return getTag(token).substr(1, token.length() - 1) == getTag(opening_tag);
}
static bool IsSelfClosingTag(std::string token) {
return token.length() > 3
&& token[0] == '<'
&& token[token.length() - 1] == '>'
&& token[token.length() - 2] == '/';
}
static std::string getTag(std::string full) {
if (!isTag(full)) return full;
auto space_idx = full.find_first_of(' ');
if (space_idx == std::variant_npos) {
return full.substr(1, full.length() - 2);
} else {
return full.substr(1, space_idx - 1);
}
}
};
struct ChannelInfo {
std::string Title = "";
std::string URL = "";
ChannelInfo(std::string url) {
URL = url;
};
ChannelInfo() {
};
void print() {
std::cout << Title <<'(' << URL << ")\n";
}
};
struct RSS_Entry {
std::string URL = "";
std::string Title = "";
std::string Contents = "";
std::tm pubDate = {};
RSS_Entry(XML_leaf node);
void print();
};
class RSS {
public:
std::string URL;
ChannelInfo channelInfo;
std::vector<RSS_Entry> Entries = {};
RSS(std::string url);
void print();
void print_latest(int minutesSpan);
private:
std::string request();
void parse(std::string contents);
};
#endif // RSS_H
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