XML parsing fails in bada

Question

I did a program that reads rss news feeds. Its not working for some of the websites like (ABC News, TechCrunch, Engadget). These websites having their body length more than one lakh. I use XPATH method for parsing. Perhaps this problem due to I am new to Bada. The code which I am using for XML Parsing is

void
addfeed::OnTransactionReadyToRead(HttpSession& httpSession, HttpTransaction& httpTransaction, int availableBodyLen)
{
    pFrame = Osp::App::Application::GetInstance()->GetAppFrame()->GetFrame();
    FormMgr* pFormMgr = dynamic_cast<FormMgr*> (pFrame->GetControl("FormMgr"));
    bool flag1=0;
    AppLog("####### OnTransactionReadyToRead! #######");

    HttpResponse* pHttpResponse = httpTransaction.GetResponse();
    if (pHttpResponse->GetStatusCode() == NET_HTTP_STATUS_OK)
    {
        AppLog("%d",availableBodyLen);
        HttpHeader* pHttpHeader = pHttpResponse->GetHeader();

        String* tempHeaderString = pHttpHeader->GetRawHeaderN();

        ByteBuffer* pBuffer = pHttpResponse->ReadBodyN();

                    String str((const char*)pBuffer->GetPointer());
        AppLog("Response: %s",str.GetPointer());

        int limit(pBuffer->GetLimit());
        AppLog("Limit: %d",limit);

        xmlDoc * doc = NULL; 
                    xmlXPathContextPtr xpathCtx;
        xmlXPathObjectPtr xpathtitle;
        xmlXPathObjectPtr descriptionObj;
        xmlXPathObjectPtr linkObj;
        xmlXPathObjectPtr pubdateObj;

        doc = xmlParseMemory((const char*)pBuffer->GetPointer(),pBuffer->GetLimit());// Here itself my code fails

        if(doc==NULL)
        {
            flag1=1;
            AppLog("Failed to load xml doc!");
            xmlFreeDoc(doc);
            xmlCleanupParser();
        }
        else
        {
        AppLog("InTo XML Parsing");
        /* Create xpath evaluation context */
        xpathCtx = xmlXPathNewContext(doc);
        if(xpathCtx == NULL)
        {
                AppLog("Error: unable to create new XPath context");
                xmlFreeDoc(doc);
        }

        /* Evaluate xpath expression */
        xpathtitle = xmlXPathEvalExpression((xmlChar*)"//item/title", xpathCtx);
        if(xpathtitle == NULL)
        {
                AppLog("Error: unable to evaluate xpath expression");
                xmlXPathFreeContext(xpathCtx);
                xmlFreeDoc(doc);
        }
        descriptionObj = xmlXPathEvalExpression((xmlChar*)"//item/description",xpathCtx);
        if(descriptionObj == NULL)
        {
                AppLog("Error: unable to evaluate xpath expression");
                xmlXPathFreeContext(xpathCtx);
                xmlFreeDoc(doc);
        }
        linkObj = xmlXPathEvalExpression((xmlChar*)"//item/link",xpathCtx);
        if(linkObj==NULL)
        {
            AppLog("Error: unable to evaluate xpath expression");
            xmlXPathFreeContext(xpathCtx);
            xmlFreeDoc(doc);
        }
        pubdateObj=xmlXPathEvalExpression((xmlChar*)"//item/pubDate",xpathCtx);
        if(pubdateObj==NULL)
        {
            AppLog("Error: unable to evaluate xpath expression");
            xmlXPathFreeContext(xpathCtx);
            xmlFreeDoc(doc);
        }
        get_xpath_titles1(xpathtitle->nodesetval);
        get_xpath_description1(descriptionObj->nodesetval);
        get_xpath_link1(linkObj->nodesetval);
        get_xpath_pubdate1(pubdateObj->nodesetval);

        xmlFreeDoc(doc);
        xmlCleanupParser();

        delete tempHeaderString;
        delete pBuffer;
        }
    }
    else
    {
        flag1=1;
    }
    if(flag1==1)
    {
        pFormMgr->SendUserEvent(FormMgr::REQUEST_ID_ADD_FEED_FORM,null);
    }
}

Answer 1

I had the same problem as you. It is not a parsing problem, rather a download problem.

When downloading large files, in your case larger than one lakh

OnTransactionReadyToRead

is called more than once.

What you need to do is move the whole parsing code to

OnTransactionCompleted

which is called only once, when the file download finishes.

I would also suggest that you first save the xml to a file.