For a specific use case, I needed to write a C routine inside vcl script. There I needed to set the Location header dynamically. After going through varnish tutorial and few stack overflow (I would love to mention this https://stackoverflow.com/a/27717417), I got some good insight and then wrote the following routine:
char* set_location_with_param(void *sp, const char *key, const char *value){
const char *key_value_separator = "=";
const char *req_url = VRT_r_req_url(sp);
const char *req_host = VRT_GetHdr(sp, HDR_REQ, "\005Host:");
const char *param_separator = strchr(req_url, '?') ? "&" : "?";
char *query_string = malloc(strlen(param_separator) + strlen(key) + strlen(key_value_separator) + strlen(value) + 1);
if(query_string != NULL){
strcpy(query_string, param_separator);
strcat(query_string, key);
strcat(query_string, key_value_separator);
strcat(query_string, value);
VRT_SetHdr(sp, HDR_OBJ, "\011Location:", "https://", req_host, req_url, query_string, vrt_magic_string_end);
free(query_string);
}
}
And then I am calling this from sub vcl_error. Here is a portion of that:
if (obj.status == somevalue) {
C{set_location_with_param(sp, "something", "somethingelse");}C
set obj.status = 302;
return(deliver);
}
Need expert opinion on writing C function and setting header using VRT_SetHdr method. Is there any potential risk if I go with the above solution?
Related
With the CHtmlView class I was able to select all the text and copy to the clipboard like this:
void CChristianLifeMinistryHtmlView::CopyToClipboard()
{
ExecWB(OLECMDID_COPY, OLECMDEXECOPT_DONTPROMPTUSER, nullptr, nullptr);
}
void CChristianLifeMinistryHtmlView::SelectAll()
{
ExecWB(OLECMDID_SELECTALL, OLECMDEXECOPT_DONTPROMPTUSER, nullptr, nullptr);
}
I am trying to find out how to do the same with the new WebView2 API.
Update
The WebView2 control supports by design:
CTRL + A to select all the content.
CTRL + C to copy the selected text to the clipboard.
I found a VB.NET solution to programatically copy all the page to the clipboard:
Sub Async GetText()
v = Await wv.ExecuteScriptAsync("document.body.innerText")
End Sub
But I am using Visual C++ and I do not see this method exposed. Also, I am not sure it is what I want because I do not want to copy as plain text data but HTML data (suitable for pasting in Word) like with the hotkeys. I have made a GitHub issue for this too.
Update
So I have now tried this code but it does not appear to do anything:
void CWebBrowser::CopyToClipboard()
{
if (m_pImpl->m_webView != nullptr)
{
m_pImpl->m_webView->ExecuteScript(_T("document.body.innerText"), nullptr);
}
}
Update
According to this article it states:
Alternately, for ICoreWebView2::ExecuteScript, you provide an instance that has an Invoke method that provides you with the success or failure code of the ExecuteScript request. Also provide the second parameter that is the JSON of the result of running the script.
Trying to find example.
Update
I now understand that I need to do something like this:
void CWebBrowser::CopyToClipboard()
{
if (m_pImpl->m_webView != nullptr)
{
m_pImpl->m_webView->ExecuteScript(L"document.body.innerText",
Callback<ICoreWebView2ExecuteScriptCompletedHandler>(
[](HRESULT error, PCWSTR result) -> HRESULT
{
if (error != S_OK) {
ShowFailure(error, L"ExecuteScript failed");
}
SetClipboardText(result);
AfxMessageBox(L"HTML copied to clipboard!", MB_OK);
return S_OK;
}).Get());
}
}
The variable result has the contents of the HTML page. But it does not like my call to SetClipboardText now. This is the error:
This is the function:
void CWebBrowser::SetClipboardText(CString strText)
{
BYTE* pbyText;
TCHAR* pcBuffer;
HANDLE hText;
UINT uLength;
//USES_CONVERSION ;
if (::OpenClipboard(nullptr))
{
// Empty it of all data first.
::EmptyClipboard();
// Replace previous text contents.
uLength = strText.GetLength();
//pcBuffer = T2A( (LPTSTR)(LPCTSTR)strText);
pcBuffer = strText.GetBuffer(uLength);
if (pcBuffer != nullptr)
{
hText = ::GlobalAlloc(GMEM_MOVEABLE | GMEM_DDESHARE, (uLength + 1) * sizeof(TCHAR));
if (hText != nullptr)
{
pbyText = (BYTE*)::GlobalLock(hText);
if (pbyText != nullptr)
{
// Deliberately not _tcscpy().
//strcpy_s( (char *)pbyText, uLength+1, pcBuffer);
_tcscpy_s((TCHAR*)pbyText, uLength + 1, pcBuffer);
::GlobalUnlock(hText);
::SetClipboardData(CF_UNICODETEXT, hText);
// Don't free this memory, clipboard owns it now.
}
}
}
::CloseClipboard();
strText.ReleaseBuffer(uLength);
}
}
This is the only way I know (to date) to copy to clipboard. So I have two issues here:
It will not let me use this function.
I expect it will copy just text (CF_UNICODETEXT) and I don't know if that is sufficient for pasting the data as HTML into Word?
Concerning issue 1, I needed to make the method static. Then it compiled and copied the information to the clipboard.
Concerning issue 2, as expected, the pasted data was stripped HTML and I was left with just the text. And the new line characters were displayed as "\n" in the text. It was one huge paragraph. So I do indeed need the CF_HTML format.
It is a pity that the WebView2 does not expose the copy to clipboard feature that it already has functional.
Update
This is the clipboard method that I found on the internet for CF_HTML:
// CopyHtml() - Copies given HTML to the clipboard.
// The HTML/BODY blanket is provided, so you only need to
// call it like CopyHtml("<b>This is a test</b>");
void CopyHTML(char* html)
{
// Create temporary buffer for HTML header...
char* buf = new char[400 + strlen(html)];
if (!buf) return;
// Get clipboard id for HTML format...
static int cfid = 0;
if (!cfid) cfid = RegisterClipboardFormat("HTML Format");
// Create a template string for the HTML header...
strcpy(buf,
"Version:0.9\r\n"
"StartHTML:00000000\r\n"
"EndHTML:00000000\r\n"
"StartFragment:00000000\r\n"
"EndFragment:00000000\r\n"
"<html><body>\r\n"
"<!--StartFragment -->\r\n");
// Append the HTML...
strcat(buf, html);
strcat(buf, "\r\n");
// Finish up the HTML format...
strcat(buf,
"<!--EndFragment-->\r\n"
"</body>\r\n"
"</html>");
// Now go back, calculate all the lengths, and write out the
// necessary header information. Note, wsprintf() truncates the
// string when you overwrite it so you follow up with code to replace
// the 0 appended at the end with a '\r'...
char* ptr = strstr(buf, "StartHTML");
wsprintf(ptr + 10, "%08u", strstr(buf, "<html>") - buf);
*(ptr + 10 + 8) = '\r';
ptr = strstr(buf, "EndHTML");
wsprintf(ptr + 8, "%08u", strlen(buf));
*(ptr + 8 + 8) = '\r';
ptr = strstr(buf, "StartFragment");
wsprintf(ptr + 14, "%08u", strstr(buf, "<!--StartFrag") - buf);
*(ptr + 14 + 8) = '\r';
ptr = strstr(buf, "EndFragment");
wsprintf(ptr + 12, "%08u", strstr(buf, "<!--EndFrag") - buf);
*(ptr + 12 + 8) = '\r';
// Now you have everything in place ready to put on the clipboard.
// Open the clipboard...
if (OpenClipboard(0))
{
// Empty what's in there...
EmptyClipboard();
// Allocate global memory for transfer...
HGLOBAL hText = GlobalAlloc(GMEM_MOVEABLE | GMEM_DDESHARE, strlen(buf) + 4);
// Put your string in the global memory...
char* ptr = (char*)GlobalLock(hText);
strcpy(ptr, buf);
GlobalUnlock(hText);
::SetClipboardData(cfid, hText);
CloseClipboard();
// Free memory...
GlobalFree(hText);
}
// Clean up...
delete[] buf;
}
But it is not compatible with the PCWSTR variable.
Update
I have now realised after doing debugging that ExecuteScript does return the actual HTML data if I use document.body.innerText. The resulting string is just text with \n characters for the new lines. It is not in HTML format. So I am back to square one.
Just use ICoreWebView2::ExecuteScript.
I am showing this as an alternative because the current approach does not include the actual HTML content. The information I found on the internet was misleading about using document.body.innerText.
One solution to this is to use the document.execCommand() route. I added the following methods to my browser class:
void CWebBrowser::SelectAll()
{
if (m_pImpl->m_webView != nullptr)
{
m_pImpl->m_webView->ExecuteScript(L"document.execCommand(\"SelectAll\")", nullptr);
}
}
void CWebBrowser::CopyToClipboard2()
{
if (m_pImpl->m_webView != nullptr)
{
m_pImpl->m_webView->ExecuteScript(L"document.execCommand(\"Copy\")", nullptr);
}
}
Then I added the following button handlers to my dialog to test:
void CMFCTestWebView2Dlg::OnBnClickedButtonSelectAll()
{
if (m_pWebBrowser != nullptr)
{
m_pWebBrowser->SelectAll();
}
}
void CMFCTestWebView2Dlg::OnBnClickedButtonCopyToClipboard()
{
if (m_pWebBrowser != nullptr)
{
m_pWebBrowser->CopyToClipboard2();
}
}
This does work and appears to be the simplest solution for now. I see references to the Calendar API as an alternative but I am not sure yet how to implement that approach.
My only concern with execCommand is that I have seen it documented as deprecated.
Am using Rcpp packages and can get my C function to compile and run in R, but now I want to return a large, user-defined data structure to R. The fields in the structure are either numbers or strings - no new or odd types within the structure. The example below is simplified and doesn't compile, but it conveys the idea of my problem.
typedef struct {
char* firstname[128];
char* lastname[128];
int nbrOfSamples;
} HEADER_INFO;
// [[Rcpp::export]]
HEADER_INFO* read_header(Rcpp::StringVector strings) {
FILE *fp;
MEF_HEADER_INFO *header;
char * filename = (char*)(strings(0));
char * password = (char*)(strings(1));
header = (HEADER_INFO*)malloc(sizeof(HEADER_INFO));
memset(header, 0, sizeof(HEADER_INFO));
fp = fopen(filename, "r");
(void)read_header(header, password);
return header;
}
I'm pretty sure that I could package the entries in the header back into a StringVector, but that seems like a brute-force approach. My question is whether a more elegant solution exists. It is not clear to me what form such a structure would even have in R: a named List?
Thanks!
The right structure in R depends on what your struct looks like exactly. A named list is the most general one. Here a simple sample implementation for a wrap function as referred to in the comments:
#include <RcppCommon.h>
typedef struct {
char* firstname[128];
char* lastname[128];
int nbrOfSamples;
} HEADER_INFO;
namespace Rcpp {
template <>
SEXP wrap(const HEADER_INFO& x);
}
#include <Rcpp.h>
namespace Rcpp {
template <>
SEXP wrap(const HEADER_INFO& x) {
Rcpp::CharacterVector firstname(x.firstname, x.firstname + x.nbrOfSamples);
Rcpp::CharacterVector lastname(x.lastname, x.lastname + x.nbrOfSamples);
return Rcpp::wrap(Rcpp::List::create(Rcpp::Named("firstname") = firstname,
Rcpp::Named("lastname") = lastname,
Rcpp::Named("nbrOfSamples") = Rcpp::wrap(x.nbrOfSamples)));
};
}
// [[Rcpp::export]]
HEADER_INFO getHeaderInfo() {
HEADER_INFO header;
header.firstname[0] = (char*)"Albert";
header.lastname[0] = (char*)"Einstein";
header.firstname[1] = (char*)"Niels";
header.lastname[1] = (char*)"Bohr";
header.firstname[2] = (char*)"Werner";
header.lastname[2] = (char*)"Heisenberg";
header.nbrOfSamples = 3;
return header;
}
/*** R
getHeaderInfo()
*/
Output:
> getHeaderInfo()
$firstname
[1] "Albert" "Niels" "Werner"
$lastname
[1] "Einstein" "Bohr" "Heisenberg"
$nbrOfSamples
[1] 3
However, for this particular case a data.frame would be more natural to use, which can be achieved by replacing above wrap with:
template <>
SEXP wrap(const HEADER_INFO& x) {
Rcpp::CharacterVector firstname(x.firstname, x.firstname + x.nbrOfSamples);
Rcpp::CharacterVector lastname(x.lastname, x.lastname + x.nbrOfSamples);
return Rcpp::wrap(Rcpp::DataFrame::create(Rcpp::Named("firstname") = firstname,
Rcpp::Named("lastname") = lastname));
};
Output:
> getHeaderInfo()
firstname lastname
1 Albert Einstein
2 Niels Bohr
3 Werner Heisenberg
I have method of a class, that accepts a key variable and looks up the key in an underdone map. The Value is a string example: "12132, jack_arog, 1990:12:8:3:25:3"; method will use peek() in stringstream to recognize ',' and ' ' to ignore them and put the rest in a vector. Afterwards method will assign members of vector to attributes of an object.
Error is recieve during compilation:
if (ss.peek() == ',' || ss.peek == ' ')
ss.ignore();
Error C3867 'std::basic_istream<char,std::char_traits<char>>::peek': non-standard syntax; use '&' to create a pointer to member
I looked up this error and most say you forgot () when calling a function, however i do not believe this is my problem.
Method:
void Account::find_account(std::string name, std::string ID)
{
std::string key = name + "," + ID;
Account new_account;
std::unordered_map<std::string, std::string>::const_iterator got = map.find(key);
if (got == map.end())
std::cout << "not found";
else
{
std::string my_string = got->second;
std::vector<std::string> holder;
std::stringstream ss(my_string);
std::string i;
while (!my_string.empty() && ss >> i)
{
holder.push_back(i);
if (ss.peek() == ',' || ss.peek == ' ')
ss.ignore();
}
for (int i = 0; i < holder.size(); i++)
{
if (i = 0)
new_account.ID = holder.at(i);
if (i = 1)
new_account.account_holder = holder.at(i);
if (i = 2)
{
std::string::size_type sz;
new_account.amount_available = std::stof(holder.at(i), &sz);
}
if (i = 3)
{
new_account.date_created = holder.at(i);
}
}
}
}
"I looked up this error and most say you forgot () when calling a function, however i do not believe this is my problem."
How can you say that when your compiler tells you that the error is exactly on this line? Moreover it is telling you that the error is specifically tied to your (ab)use of peek, I quote:
"...peek': non-standard syntax; use '&' to create a pointer to member
I translate: The compiler thinks you are not trying to call peek, since you did not type the required () to do so. So, if you are by any chance trying to get the function address, you should prepend & to the function name for the syntax to be correct.
Computers are dumb, I'll give you that, but they are rarely wrong.
hi i write method which must to know that is size of specified directory i get response from server which contains flags of file name size and other info and on the different ftp servers format of answer is different how to know format of answer?
unsigned long long GetFtpDirSize(String^ ftpDir) {
unsigned long long size = 0;
int j = 0;
StringBuilder^ result = gcnew StringBuilder();
StreamReader^ reader;
FtpWebRequest^ reqFTP;
reqFTP = (FtpWebRequest^)FtpWebRequest::Create(gcnew Uri(ftpDir));
reqFTP->UseBinary = true;
reqFTP->Credentials = gcnew NetworkCredential("anonymous", "123");
reqFTP->Method = WebRequestMethods::Ftp::ListDirectoryDetails;
reqFTP->KeepAlive = false;
reqFTP->UsePassive = false;
try {
WebResponse^ resp = reqFTP->GetResponse();
Encoding^ code;
code = Encoding::GetEncoding(1251);
reader = gcnew StreamReader(resp->GetResponseStream(), code);
String^ line = reader->ReadToEnd();
array<Char>^delimiters = gcnew array<Char>{
'\r', '\n'
};
array<Char>^delimiters2 = gcnew array<Char>{
' '
};
array<String^>^words = line->Split(delimiters, StringSplitOptions::RemoveEmptyEntries);
array<String^>^DetPr;
System::Collections::IEnumerator^ myEnum = words->GetEnumerator();
while ( myEnum->MoveNext() ) {
String^ word = safe_cast<String^>(myEnum->Current);
DetPr = word->Split(delimiters2);
}
}
Basically, you can't. You are interpreting the raw result and there is no defined format for this data (or is there any requirement that this data be returned at all in the response). And the FTP protocol does not define any other way of getting this.
What that leaves you with is a collection of parsing patterns for the server types you know about and working through them looking for valid data. Not entirely easy.
what would be the best way to implement kind of cheat codes in general?
I have WinForms application in mind, where a cheat code would unlock an easter egg, but the implementation details are not relevant.
The best approach that comes to my mind is to keep index for each code - let's consider famous DOOM codes - IDDQD and IDKFA, in a fictional C# app.
string[] CheatCodes = { "IDDQD", "IDKFA"};
int[] CheatIndexes = { 0, 0 };
const int CHEAT_COUNT = 2;
void KeyPress(char c)
{
for (int i = 0; i < CHEAT_COUNT; i++) //for each cheat code
{
if (CheatCodes[i][CheatIndexes[i]] == c)
{ //we have hit the next key in sequence
if (++CheatIndexes[i] == CheatCodes[i].Length) //are we in the end?
{
//Do cheat work
MessageBox.Show(CheatCodes[i]);
//reset cheat index so we can enter it next time
CheatIndexes[i] = 0;
}
}
else //mistyped, reset cheat index
CheatIndexes[i] = 0;
}
}
Is this the right way to do it?
Edit: Probably the worst thing I should have done was to include the first cheat codes that came from the top of my head as an example. I really did not want to see Doom's source code or their implementation, but general solution to this problem.
Why not download the DOOM source and see for yourself? =)
http://www.doomworld.com/idgames/?id=14576
I think this one's a bit easier to understand, though your original will probably perform better than this one:
using System.Collections.Generic;
void KeyPress(char c)
{
string[] cheatCodes = { "IDDQD", "IDKFA"};
static Queue<char> buffer; //Contains the longest number of characters needed
buffer.Enqueue(c);
if (buffer.Count() > 5) //Replace 5 with whatever your longest cheat code is
buffer.Dequeue();
bufferString = new System.String(buffer.ToArray());
foreach(string code in cheatCodes) {
if (bufferString.EndsWith(code)) {
//Do cheat work
}
}
}
here is the DOOM cheat implementation from the doom source:
#define SCRAMBLE(a) \
((((a)&1)<<7) + (((a)&2)<<5) + ((a)&4) + (((a)&8)<<1) \
+ (((a)&16)>>1) + ((a)&32) + (((a)&64)>>5) + (((a)&128)>>7))
int cht_CheckCheat ( cheatseq_t* cht, char key )
{
int i;
int rc = 0;
if (firsttime)
{
firsttime = 0;
for (i=0;i<256;i++) cheat_xlate_table[i] = SCRAMBLE(i);
}
if (!cht->p)
cht->p = cht->sequence; // initialize if first time
if (*cht->p == 0)
*(cht->p++) = key;
else if
(cheat_xlate_table[(unsigned char)key] == *cht->p) cht->p++;
else
cht->p = cht->sequence;
if (*cht->p == 1)
cht->p++;
else if (*cht->p == 0xff) // end of sequence character
{
cht->p = cht->sequence;
rc = 1;
}
return rc;
}