Comment utiliser l'attribut comme mot-clé de recherche avec TinyXML2 (C++)

Question

J'essaie d'utiliser l'attribut comme mot-clé pour trouver l'élément que je veux. cela peut fonctionner mais seulement quand c'est le premier élément.

bool readXML(){ 
string gateWay_str="",user_Input=""; 
XMLDocument XML_file; 
XML_file.LoadFile("exception_ip.xml");      //XML file Name 
XMLHandle docHandle(&XML_file);       //XMLHandle 
XMLNode* node_ctrl;           //Node pointer 
XMLElement* gateWay_Ele = docHandle.FirstChildElement("exception_ip").FirstChildElement("ip").ToElement(); //Get Node by XMLHandle and turn to Element 
cout<<"Test ip3=";           //show to user 
cin>>user_Input;           //user input 

if(gateWay_Ele){           //is gateWay_Ele null? 
    gateWay_str=gateWay_Ele->Name();      //get Element name and show 
    cout<< "Got gateWay_Ele = "<<gateWay_str<<endl; 
} 
if(gateWay_Ele ->Attribute("ip3",(user_Input.c_str()))){ //find Attribute where ip3 = "user input" 
     node_ctrl=gateWay_Ele->FirstChild();    //make node_ctrl point FirstChild 
     if(node_ctrl==nullptr){        //is nullptr? 
      cout<<"node_ctrl = nullptr"; 
      return false; 
     } 
     else{            
      gateWay_Ele=node_ctrl->ToElement();    //turn node_ctel to Element 
      gateWay_str = gateWay_Ele->GetText();   //get Text 
      cout<<"GateWay = "<<gateWay_str<<endl;   //show 
      return true;         //return true 
     } 
    } 
return false; 

}

et mon XML est

<?xml version="1.0" ?> 
 
<exception_ip> 
 
\t <ip ip3="23"> \t 
 
     <gateway>123.123.23.1</gateway> 
 
     <dnsp>dnsp23</dnsp> 
 
     <dnss>dnss23</dnss> 
 
\t </ip> 
 
\t <ip ip3="24"> \t 
 
     <gateway>123.123.24.1</gateway> 
 
     <dnsp>dnsp24</dnsp> 
 
     <dnss>dnss24</dnss> 
 
\t </ip> 
 
</exception_ip>

Il fonctionne uniquement lorsque l'entrée est de 23

et je l'avais essayé l'utilisation NextSiblingElement ("ip" pour faire le point keep goin g à l'élément frère suivant. mais juste boucle infinie

do{ 
if(gateWay_Ele ->Attribute("ip3",(user_Input.c_str()))){ //find Attribute where ip3 = "user input" 
     node_ctrl=gateWay_Ele->FirstChild();    //make node_ctrl point FirstChild 
     if(node_ctrl==nullptr){        //is nullptr? 
      cout<<"node_ctrl = nullptr"; 
      return false; 
     } 
     else{            
      gateWay_Ele=node_ctrl->ToElement();    //turn node_ctel to Element 
      gateWay_str = gateWay_Ele->GetText();   //get Text 
      cout<<"GateWay = "<<gateWay_str<<endl;   //show 
      return true;         //return true 
     } 
    } 
else{ 
    gateWay_Ele->NextSiblingElement("ip"); 
} 
}while(true); 

Merci!

Answer 1

Vous devez parcourir tous les éléments "ip", en testant l'attribut "ip3" jusqu'à ce que vous trouviez celui que vous voulez. Mais voici un moyen facile de le faire en utilisant my tinyxml2 extension:

#include <string> 
#include <iostream> 
#include <conio.h> // for _getch() 
// include the header for tinyxml2ex which includes tinyxml2, remember to put them on your include path 
#include "tixml2ex.h" 

using namespace std; 

int main() 
{ 
    // put the XML into a string for simplicity 
    string testXml{ R"-(
<?xml version="1.0" ?> 
<exception_ip> 
    <ip ip3="23"> 
     <gateway>123.123.23.1</gateway> 
     <dnsp>dnsp23</dnsp> 
     <dnss>dnss23</dnss> 
    </ip> 
    <ip ip3="24"> 
     <gateway>123.123.24.1</gateway> 
     <dnsp>dnsp24</dnsp> 
     <dnss>dnss24</dnss> 
    </ip> 
</exception_ip> 
)-"s }; 

    auto doc = tinyxml2::load_document (testXml); 
    // find the required element by XPath and list its member elements 
    if (auto ip = find_element (*doc, "/exception_ip/ip[@ip3='24']"s)) 
    { 
     for (auto e : ip) 
      cout << e->Name() << " " << text (e) << endl; 
    } 
    else 
     cout << "could not find ip element" << endl; 

    return 0; 
} 

Answer 2

J'itérer sur tous les éléments d'une autre manière et cela fonctionne.

bool readXML(){ 
    string gateway_str="",user_Input="",dnsp_str="",dnss_str=""; 
    XMLDocument XML_file; 
    if(XML_file.LoadFile("exception_ip.xml")){ 
     cout<<"Can't find exception_ip.xml"<<endl; 
     return false;                 //XML file Name 
    } 
    XMLHandle docHandle(&XML_file);                  //XMLHandle 
    XMLNode* node_ctrl = docHandle.FirstChildElement("exception_ip").FirstChildElement("ip").ToNode(); 
    XMLElement* element_main = node_ctrl->ToElement(); 

    cout<<"Test ip3=";           //show to user 
    cin>>user_Input;           //user input 


    if(element_main){           //do if element_main not null 
     do{ 
      element_main = node_ctrl ->ToElement();    //let node turn to element 

      if(element_main ->Attribute("ip3",(user_Input.c_str()))) //if Attribute is what we wnat? 
      { 
       element_main = element_main ->FirstChildElement();  //make element to child 

       gateway_str = element_main ->GetText();       //get test put into str 

       element_main = element_main->NextSiblingElement(); 

       dnsp_str = element_main->GetText(); 

       element_main = element_main->NextSiblingElement(); 

       dnss_str = element_main->GetText(); 


       cout<<"ip3="<<user_Input<<endl<<"GW= "<<gateway_str<<endl<<"DNS1= "<<dnsp_str<<endl<<"DNS2= "<<dnss_str<<endl;    //output 
       return true;           //return 1 
      } 
      else{              //if Attribute not match 
       if(node_ctrl=element_main ->NextSibling()){}   //make pointer to next element (Sibling) 
       else{ 
        cout<<"Can't find "<<user_Input<<endl;    //Can't find what we want QQ 
        return false;          //bye 
       } 
      } 

     }while(true); 
    } 
    return false;              //total fail -file can't found? 
}