Updating Data in tiny Xml element

问题

My question is: is it possible to change the data in an xml element?

What i want to do is change the data in the element depending on what button is pressed. I currently have it reading and writing to the xml file working but i want to change it to, write a new element first time round and then after that edit the element as it currently just keeps writing a new element each time.

This is my current code for writing the new element

if (doc.LoadFile(XMLDOC) == tinyxml2::XML_SUCCESS){
    //Get Root Node
    tinyxml2::XMLElement* rootNode = doc.FirstChildElement();//Assets
    //Get Next Node
    tinyxml2::XMLElement* childNode = rootNode->FirstChildElement();//imagePaths
    //Temp Element 
    tinyxml2::XMLElement* temp = nullptr;
    tinyxml2::XMLElement* temp2 = childNode->FirstChildElement();//path

    while (temp2 != nullptr){
        temp = temp2;
        temp2 = temp2->NextSiblingElement("path");
    }
    if (temp != nullptr){
        //write the text
        tinyxml2::XMLComment* newComment = doc.NewComment("Selected Player");
        tinyxml2::XMLElement* newElement = doc.NewElement("path");

            //get text passed in 
            newElement->SetText(choice.c_str());

            newElement->SetAttribute("name", "selected_player");
            childNode->InsertAfterChild(temp, newComment);
            childNode->InsertAfterChild(newComment, newElement);

    }
    //doc.Print();
    doc.SaveFile(XMLDOC);
    }
    else{
        std::cout << "Could Not Load XML Document : %s" << XMLDOC << std::endl;
    }
}

Thanks for helping in advanced

回答1:

I'm not 100% sure what the desired behavior you want. Here is a code sample based off of your question code sample:

#include "tinyxml2.h"
#include <iostream>
#include <string>

#define XMLDOC "test.xml"

std::string choice = "New Text";

int main()
{
   tinyxml2::XMLDocument doc;
   if (doc.LoadFile(XMLDOC) == tinyxml2::XML_SUCCESS){
      //Get Root Node
      tinyxml2::XMLElement* rootNode = doc.FirstChildElement();//Assets
      //Get Next Node
      tinyxml2::XMLElement* childNode = rootNode->FirstChildElement();//imagePaths
      //Path Node
      tinyxml2::XMLElement* pathNode = childNode->FirstChildElement();//path

      if (pathNode == nullptr){
         //write the text
         tinyxml2::XMLComment* newComment = doc.NewComment("Selected Player");
         tinyxml2::XMLElement* newElement = doc.NewElement("path");

         newElement->SetAttribute("name", "selected_player");
         newElement->SetText(choice.c_str());

         childNode->InsertFirstChild(newComment);
         childNode->InsertAfterChild(newComment, newElement);
      }
      else{
         pathNode->SetText(choice.c_str());
      }
      doc.SaveFile(XMLDOC);
   }
   else{
      std::cout << "Could Not Load XML Document : " << XMLDOC << std::endl;
   }
}

Given a XML file that looks like this:

<Assets>
<ImagePaths>
</ImagePaths>
</Assets>

After running it would look like this:

<Assets>
<ImagePaths>
    <!--Selected Player-->
    <path name="selected_player">New Text</path>
</ImagePaths>
</Assets>

And if you run the program again you get just the single path node with the text that your choice string contains.

Hope that helps!

来源：https://stackoverflow.com/questions/29513830/updating-data-in-tiny-xml-element

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xml

tinyxml2