I am new to using chrome extensions and i have a run into a little problem with setting up a chrome extension. I want the extension to read specific values from a web page and then open up a specific page (form with a number of input fields) from a flask application that I have built in a new tab and then use the values that have been scraped to populate specific fields in the page from my flask app.
I have managed to get the extension to generate a new tab and to load the page from my flask app but I am unable to get the fields to populate. It would seem that the page gets loaded before the fields are populated. I have pasted some code to show you how far I have got. The other issue is that I am using the code parameter from executeScripts to perform the populating action but I don't seem to be able to pass arguments into the code string (I suspect this is not the way to do this but I am working off an answer that I have found very helpful up to this point from here https://stackoverflow.com/a/41094570/1977981 Any help would be much appreciated.
manifest.json
{
"manifest_version": 2,
"name": "My Cool Extension",
"version": "0.1",
"permissions": [
"http://localhost:****/lesson/1/note/new/"
],
"content_scripts": [
{
"matches": [
"<all_urls>"
],
"js": ["jquery-3.2.1.min.js", "content.js"]
}
],
"browser_action": {
"default_icon": "icon.png"
},
"background": {
"scripts": ["jquery-3.2.1.min.js", "background.js"]
}
}
content.js
// Triggered by sendMessage function in background.js
chrome.runtime.onMessage.addListener(
function(request, sender, sendResponse) {
// listening for request message
if( request.message === "clicked_browser_action" ) {
// Retrieve Lesson title from current tab
var lesson = $('._tabbed-sidebar--title--1Dx5w').find('span').text()
// output this value to the console
console.log(lesson);
// Send a single message to the event listener in your extension i.e. background.js
chrome.runtime.sendMessage({"message": "open_new_tab", "lesson": lesson})
}
}
);
background.js
// Called when the user clicks on the browser action icon.
chrome.browserAction.onClicked.addListener(function(tab) {
// Send a message to the active tab
chrome.tabs.query({active: true, currentWindow: true}, function(tabs) {
// take the current tab shown in the window
var activeTab = tabs[0];
// Send a message to contents.js - this message is being listened for by contents.js and the runtime.onMessage event is fired in content.js script
chrome.tabs.sendMessage(activeTab.id, {"message": "clicked_browser_action"});
});
});
// listening for "open_new_tab" message from content.js
chrome.runtime.onMessage.addListener(
function(request, sender, sendResponse) {
if( request.message === "open_new_tab" ) {
// create new tab but do not activate the tab yet
chrome.tabs.create({"url": "http://localhost:5000/lesson/1/note/new/", active: false }, function(tab){
// load jquery functionality execute script
chrome.tabs.executeScript(tab.id, {file: "jquery-3.2.1.min.js"}, function(results){
chrome.tabs.executeScript(tab.id,{code:`
(function(arguments){
var count = 100; //Only try 100 times
function autofill(){
var lesson = $('.lesson_subsection');
console.log(lesson);
if(lesson){
lesson.value = arguments[0].lesson;
} else {
if(count-- > 0 ){
//The elements we need don't exist yet, wait a bit to try again.
setTimeout(autofill,250);
}
}
}
autofill();
}, request)();
`}, function(results){
chrome.tabs.update(tab.id,{active:true});
}); //END OF second executeScript function
}); // END OF first executeScript function
} // END OF chrome.tabs.create anonymous function
); // END OF chrome.tabs.create
} // END OF if( request.message === "open_new_tab" ) {
}); // END OF addListener anonymous function
Thank you @wOxxOm your comments were very helpful. I was able to use JSON.stringify to load the arguments in to the injected code string. I also had to load the input element from my form using document.getElementsByClassName() instead of using the jquery version of the object. This also meant i didn't have to load the jquery library see line shown below
var less = document.getElementsByClassName('lesson_subsection')[0];
Now my chrome.runtime.onMessage.addListener function in my background.js script is as follows:
// See content.js function
chrome.runtime.onMessage.addListener(
function(request, sender, sendResponse) {
if( request.message === "open_new_tab" ) {
chrome.tabs.create({"url": "http://localhost:5000/lesson/1/note/new/", active: false }, function(tab){
console.log('Attempting to inject script into tab:',tab);
chrome.tabs.executeScript(tab.id,{code:`
(function(argument){
var count = 100; //Only try 100 times
function autofill(){
var less = document.getElementsByClassName('lesson_subsection')[0];
if(less){
less.value = argument;
} else {
if(count-- > 0 ){
//The elements we need don't exist yet, wait a bit to try again.
setTimeout(autofill,250);
}
}
}
autofill();
})(` + JSON.stringify(request.lesson) + `);
`}, function(results){
// chrome.tabs.sendMessage(tab.id, {"message": "need to update tab", "tab": tab.id});
chrome.tabs.update(tab.id, { active: true });
}); //END OF executeScript function
} // END OF chrome.tabs.create anonymous function
); // END OF chrome.tabs.create
} // END OF if( request.message === "open_new_tab" ) {
}); // END OF addListener anonymous function
The technical post webpages of this site follow the CC BY-SA 4.0 protocol. If you need to reprint, please indicate the site URL or the original address.Any question please contact:yoyou2525@163.com.