Below is a utility method to detect which web rendering engine is being used for a Web Area. the code only checks for the most frequently used browsers:

• Internet Explorer
• Safari
• Chrome
• Firefox
• Apple Web Kit (MacOS)

// Method: Util_WA_GetWebEngine // Description // Returns a 4D Web Area's Web Engine based on // the userAgent object // // Parameters // $1 - Text : Name of Web Area object // - Pointer : Pointer to Variable of Web Area object // // $0 - Object : Contains two properties // {"Browser" : Name of Browser, // "userAgent" : Full user agent string} // ---------------------------------------------------- C_OBJECT($0) C_VARIANT($1) C_POINTER($waPtr) C_TEXT($currURL) C_TEXT($js_t) C_OBJECT($res_ob) If ((Value type($1)=Is pointer) | (Value type($1)=Is text))    If (Value type($1)=Is text)      $waPtr:=OBJECT Get pointer(Object named;$1)    Else      $waPtr:=$1    End if    $currURL:=WA Get current URL($waPtr->)    If (($currURL=":///") | ($currURL=""))      WA OPEN URL($waPtr->;"about:blank")    End if    $js_t:="var res={\"userAgent\":navigator.userAgent};"    //Chrome    $js_t:=$js_t+"if(navigator.userAgent.indexOf(\"Chrome\") > -1) "    $js_t:=$js_t+"{ res.Browser=\"Chrome\"}"    //Safari    $js_t:=$js_t+"else if(navigator.userAgent.indexOf(\"Safari\") > -1)"    $js_t:=$js_t+" {res.Browser=\"Safari\";}"    //Internet Explorer    $js_t:=$js_t+"else if(navigator.userAgent.indexOf(\"MSIE\") > -1 || "    $js_t:=$js_t+"navigator.userAgent.indexOf(\"rv:\") > -1)"    $js_t:=$js_t+" {res.Browser= \"IE\";}"    //Firefox    $js_t:=$js_t+"else if(navigator.userAgent.indexOf(\"Firefox\") > -1)"    $js_t:=$js_t+" {res.Browser=\"Firefox\";}"    //AppleWebKit    $js_t:=$js_t+"else if(navigator.userAgent.indexOf(\"Macintosh\") > -1)"    $js_t:=$js_t+" {res.Browser=\"AppleWebKit\";}"    $js_t:=$js_t+"; res"    $res_ob:=WA Evaluate JavaScript($waPtr->;$js_t;Is object)    $0 := $res_ob End if

Below is an example of using the command:

// "Web Area" is the name of the Web Area object $currentEngine_t := Util_WA_GetWebEngine("Web Area")

or

// varWA is the variable of the Web Area object $currentEngine_t := Util_WA_GetWebEngine(->varWA)

An example result:
{"Browser" : "Chrome",
"userAgent" : "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/72.0.3626.121 Safari/537.36"}

If the embedded web rendering engine is not being used, a method like this can help identify the engine and help with debugging issues or enforcing consistency due to differences in the engines.