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wxWidgets/include/wx/private/jsscriptwrapper.h
Tobias Taschner 8613f3aa6b Apply suggestions from code review
Co-authored-by: VZ <vz-github@zeitlins.org>
2021-11-05 09:41:39 +01:00

209 lines
8.6 KiB
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///////////////////////////////////////////////////////////////////////////////
// Name: wx/private/jsscriptwrapper.h
// Purpose: JS Script Wrapper for wxWebView
// Author: Jose Lorenzo
// Created: 2017-08-12
// Copyright: (c) 2017 Jose Lorenzo <josee.loren@gmail.com>
// Licence: wxWindows licence
///////////////////////////////////////////////////////////////////////////////
#ifndef _WX_PRIVATE_JSSCRIPTWRAPPER_H_
#define _WX_PRIVATE_JSSCRIPTWRAPPER_H_
#include "wx/regex.h"
// ----------------------------------------------------------------------------
// Helper for wxWebView::RunScript()
// ----------------------------------------------------------------------------
// This class provides GetWrappedCode(), GetOutputCode() and GetCleanUpCode()
// functions that should be executed in the backend-appropriate way by each
// wxWebView implementation in order to actually execute the user-provided
// JavaScript code, retrieve its result (if it executed successfully) and
// perform the cleanup at the end.
class wxJSScriptWrapper
{
public:
enum OutputType
{
JS_OUTPUT_STRING, // All return types are converted to a string
JS_OUTPUT_WEBKIT, // Some return types will be processed
JS_OUTPUT_IE, // Most return types will be processed
JS_OUTPUT_RAW // The return types is returned as is
};
wxJSScriptWrapper(const wxString& js, OutputType outputType)
: m_escapedCode(js), m_outputType(outputType)
{
// Adds one escape level.
const char *charsNeededToBeEscaped = "\\\"\n\r\v\t\b\f";
for (
size_t pos = m_escapedCode.find_first_of(charsNeededToBeEscaped, 0);
pos != wxString::npos;
pos = m_escapedCode.find_first_of(charsNeededToBeEscaped, pos)
) {
switch (m_escapedCode[pos].GetValue())
{
case 0x0A: // '\n'
m_escapedCode[pos] = 'n';
break;
case 0x0D: // '\r'
m_escapedCode[pos] = 'r';
break;
case 0x0B: // '\v'
m_escapedCode[pos] = 'v';
break;
case 0x09: // '\t'
m_escapedCode[pos] = 't';
break;
case 0x08: // '\b'
m_escapedCode[pos] = 'b';
break;
case 0x0C: // '\f'
m_escapedCode[pos] = 'f';
break;
}
m_escapedCode.insert(pos, '\\');
pos += 2;
}
}
// Get the code to execute, its returned value will be either the value,
// if it executed successfully, or the exception message prefixed with
// "__wxexc:" if an error occurred.
//
// Either use SetOutput() to specify the script result or access it directly
// Using GetOutputRef()
//
// Execute ExtractOutput() later to get the real output after successful
// execution of this code or the proper error message.
wxString GetWrappedCode() const
{
wxString code = wxString::Format(
wxASCII_STR("(function () { try { var res = eval(\"%s\"); "),
m_escapedCode);
switch (m_outputType)
{
case JS_OUTPUT_STRING:
code += wxASCII_STR(
"if (typeof res == 'object') return JSON.stringify(res);"
"else if (typeof res == 'undefined') return 'undefined';"
"else return String(res);"
);
break;
case JS_OUTPUT_WEBKIT:
code += wxASCII_STR(
"if (typeof res == 'object') return JSON.stringify(res);"
"else if (typeof res == 'undefined') return 'undefined';"
"else return res;"
);
break;
case JS_OUTPUT_IE:
code += wxASCII_STR(
"try {"
"return (res == null || typeof res != 'object') ? String(res)"
": JSON.stringify(res);"
"}"
"catch (e) {"
"try {"
"function __wx$stringifyJSON(obj) {"
"if (!(obj instanceof Object))"
"return typeof obj === \"string\""
"? \'\"\' + obj + \'\"\'"
": \'\' + obj;"
"else if (obj instanceof Array) {"
"if (obj[0] === undefined)"
"return \'[]\';"
"else {"
"var arr = [];"
"for (var i = 0; i < obj.length; i++)"
"arr.push(__wx$stringifyJSON(obj[i]));"
"return \'[\' + arr + \']\';"
"}"
"}"
"else if (typeof obj === \"object\") {"
"if (obj instanceof Date) {"
"if (!Date.prototype.toISOString) {"
"(function() {"
"function pad(number) {"
"return number < 10"
"? '0' + number"
": number;"
"}"
"Date.prototype.toISOString = function() {"
"return this.getUTCFullYear() +"
"'-' + pad(this.getUTCMonth() + 1) +"
"'-' + pad(this.getUTCDate()) +"
"'T' + pad(this.getUTCHours()) +"
"':' + pad(this.getUTCMinutes()) +"
"':' + pad(this.getUTCSeconds()) +"
"'.' + (this.getUTCMilliseconds() / 1000)"
".toFixed(3).slice(2, 5) + 'Z\"';"
"};"
"}());"
"}"
"return '\"' + obj.toISOString(); + '\"'"
"}"
"var objElements = [];"
"for (var key in obj)"
"{"
"if (typeof obj[key] === \"function\")"
"return \'{}\';"
"else {"
"objElements.push(\'\"\'"
"+ key + \'\":\' +"
"__wx$stringifyJSON(obj[key]));"
"}"
"}"
"return \'{\' + objElements + \'}\';"
"}"
"}"
"return __wx$stringifyJSON(res);"
"}"
"catch (e) { return \"__wxexc:\" + e.name + \": \" + e.message; }"
"}");
break;
case JS_OUTPUT_RAW:
code += wxASCII_STR("return res;");
break;
}
code +=
wxASCII_STR("} catch (e) { return \"__wxexc:\" + e.name + \": \" + e.message; }"
"})()");
return code;
}
// Extract the output value
//
// Returns true if executed successfully
// string of the result will be put into output
// Returns false when an exception occurred
// string will be the exception message
static bool ExtractOutput(const wxString& result, wxString* output)
{
if (output)
*output = result;
if (result.starts_with(wxASCII_STR("__wxexc:")))
{
if (output)
output->Remove(0, 8);
return false;
}
else
{
return true;
}
}
private:
wxString m_escapedCode;
OutputType m_outputType;
wxDECLARE_NO_COPY_CLASS(wxJSScriptWrapper);
};
#endif // _WX_PRIVATE_JSSCRIPTWRAPPER_H_