Hi i am making google chrome extension and stucked with error

Uncaught TypeError: Cannot read property 'getSelected' of undefined 

My code is below

called function getQueryString(); inside if statement is creating error

key_event.js

if (window == top) {
window.addEventListener('keyup', doKeyPress, false); //add the keyboard handler

}
  trigger_key = 37; 
     function doKeyPress(e){
     if (e.ctrlKey && e.keyCode == 37)
     { 
            alert("leftpressed");
            getQueryString();
    }
    else if(e.ctrlKey && e.keyCode == 39){ // if e.shiftKey is not provided then script will run at all instances of typing "G"
         alert("rightpressed");

        getQueryString();
    }
    }

    function getParameterByName(name,urlPara) {
    name = name.replace(/[\[]/, "\\[").replace(/[\]]/, "\\]");
    var regex = new RegExp("[\\?&]" + name + "=([^&#]*)"),
    results = regex.exec(urlPara);
    return results == null ? "" : decodeURIComponent(results[1].replace(/\+/g, " "));
}

 function getQueryString() {
          chrome.tabs.getSelected(null, function(tab) {
          var tab = tab.url;
          var queryString = {};
          var substr = tab.replace(
          new RegExp("([^?=&]+)(=([^&]*))?", "g"),
          function($0, $1, $2, $3) { queryString[$1] = $3; }
      );  
      var current = getParameterByName('page',tab);
         var reExp = 'page=' + current;
         current = parseInt(current, 10)-1;
        var newUrl = tab.replace(reExp, 'page=' + current);
        console.log(newUrl);
        chrome.runtime.sendMessage({redirect: newUrl});
    });
}

help can bring cheers

Hi i am making google chrome extension and stucked with error

Uncaught TypeError: Cannot read property 'getSelected' of undefined 

My code is below

called function getQueryString(); inside if statement is creating error

key_event.js

if (window == top) {
window.addEventListener('keyup', doKeyPress, false); //add the keyboard handler

}
  trigger_key = 37; 
     function doKeyPress(e){
     if (e.ctrlKey && e.keyCode == 37)
     { 
            alert("leftpressed");
            getQueryString();
    }
    else if(e.ctrlKey && e.keyCode == 39){ // if e.shiftKey is not provided then script will run at all instances of typing "G"
         alert("rightpressed");

        getQueryString();
    }
    }

    function getParameterByName(name,urlPara) {
    name = name.replace(/[\[]/, "\\[").replace(/[\]]/, "\\]");
    var regex = new RegExp("[\\?&]" + name + "=([^&#]*)"),
    results = regex.exec(urlPara);
    return results == null ? "" : decodeURIComponent(results[1].replace(/\+/g, " "));
}

 function getQueryString() {
          chrome.tabs.getSelected(null, function(tab) {
          var tab = tab.url;
          var queryString = {};
          var substr = tab.replace(
          new RegExp("([^?=&]+)(=([^&]*))?", "g"),
          function($0, $1, $2, $3) { queryString[$1] = $3; }
      );  
      var current = getParameterByName('page',tab);
         var reExp = 'page=' + current;
         current = parseInt(current, 10)-1;
        var newUrl = tab.replace(reExp, 'page=' + current);
        console.log(newUrl);
        chrome.runtime.sendMessage({redirect: newUrl});
    });
}

help can bring cheers

• javascript
• google-chrome
• google-chrome-extension

1 Answer 1

Your script key_event.js is a content script. It is running in the context of the website rather than the extension context. As a result it cannot use all of the chrome API (like chrome.tabs).

In order to get the current website URL from inside the website context, you can use window.location.href. You can also get the query string using window.location.search. So no need to query chrome.tabs here.

Something in the lines of

var tabURL = window.location.href;
var queryString = window.location.search;