Chrome extension: insertCSS once per tab - google-chrome-extension

My extension has a button that injects a stylesheet with insertCSS. When they press the button again, it'll inject the again, causing a repaint. How can I best prevent this?
My current solution: keep an array in the background script with every tabId that has CSS inserted. I remove the tabId from the array when a tab is unloaded. Works fine, but it seems this could be simpler. E.g. window.insertedCSS = true, but doing this from the background script affects all tabs.

You can use a content script to check if the CSS was already injected before actually injecting it, like:
function myButtonClicked(){
chrome.tabs.executeScript({code:`
(function(){
if (window.insertCSS === true) return false; //if already inserted return false;
window.insertCSS = true; //if not, set the page's variable and return it
return true;
})();
`}, function (result) {
if (result[0]) { //if CSS was not inserted, insert it.
chrome.tabs.insertCSS({file:'myCSS.css'});
}
});
}

Related

cancel tab closing in p:accordionPanel

I have a p:accordionPanel and inside of each tab of the panel there is some info that the user can manipulate, what i need to do is if the user close the tab show a confirm dialog (before the tab get closed) whit something like "are you sure you wanna close the tab? if you do your changes will be lost". here is what i tried
<p:ajax event="tabClose" onstart="return myFunction()"
listener" {myBean.myMethod}" process="#this" />
function myFunction() {
var answer = confirm("are you sure you wanna close the tab? if you do your changes will be lost");
if(answer){
//some logic
return true;
}else{
//some logic
return false;
}
}
The problem is that if i choose cancel on the confirm dialog the tab get close anyway. Shouldn't the tab closing be canceled by the onStart="return false"? is there a way to achieve what i'm trying to do?
Finally I solved my problem, apparently the onStart="return false" does not prevent the tab from change its statatus but the onTabChange attribute of the p:accordionPanel does, the only problem is that for some reason the onTabchange event of the accordion don't get execute when the tab is been closed just when the tab is been opened so i have to override the acordionPanel unselect function of primefaces to call the onTabChange event
PrimeFaces.widget.AccordionPanel.prototype.unselect = (function(index) {
var cached_function = PrimeFaces.widget.AccordionPanel.prototype.unselect;
return function() {
var panel = this.panels.eq(index);
if(this.cfg.onTabChange) {
var result = this.cfg.onTabChange.call(this, panel);
if(result === false)
return false;
}
var result = cached_function.apply(this, arguments);
return result;
};
})();
then i only had to placed myFunction(); on the onTabChange event of the accordiong panel (onTabChange="return myFunction()")and it works.

Chrome extension:How to get the element in the tab?

I want to assign value to the element and auto submit after page completely load.I encounter some question.
1.How to get the element in the tab?
2.How to fire submit event when assigned value?
I want to fire as the follow code:
chrome.tabs.onUpdated.addListener(function (tabId, changeInfo, tab) {
var url = tab.url;
var config = null;
if (tab.status !== "complete") {
return;
}
else {
// assign value and fire submit event
}
});
Help!!
I wouldn't do it this way. Why not use jQuery in a content script and trigger your action on ($document).ready()? That way you'll have the document and can use jQuery selectors to get the elements that interest you. To submit, just get button using a selector and call click().

Chrome page action popup disappears

I need a page action popup icon to appear when a tab has a specific URL in the address bar.
I have this in my background page
chrome.tabs.query({url:"MYURL.COM"} , function(tab)
{
for(i=0;i<tab.length;i++)
{
console.log(tab[i].id);
chrome.pageAction.show(tab[i].id);
}
});
The popup shows whenever I reload the extension but as soon as user refreshes, it goes away and doesn't come back.
The reason is that the background.js page is only loaded once, so you need to add a listener to every time the page tab is updated to check whether the page action should be shown, something like this:
chrome.tabs.onUpdated.addListener(function (tabId, changeInfo, tab) {
if (tab.url.indexOf("MYURL.COM") > -1) {
chrome.pageAction.show(tabId);
}
});
There is no reason to iterate over each tab as you have done.
As Adam has already said, the tabs.onUpdated event is the way to do it.
Anyway, it [seems like I'm not the only one who experienced that the tabs.onUpdated event doesn't always fire when it should - even when waiting for complete status.
So if you're having the same issue, you might want to try my modified version that has proven reliable for me 100%.
chrome.tabs.onUpdated.addListener(function(tabId, change) {
if (change.status == "complete") {
chrome.tabs.query({active: true}, function(tabs) {
var tab = tabs[0];
// Now do stuff with tab .. Eg:
if (tab.url.indexOf("MYURL.COM") > -1) {
chrome.pageAction.show(tab.id); }
else {
chrome.pageAction.hide(tab.id); }
});
}
});
Use chrome.tabs.onUpdated to listen to new tabs and tab reloads of the domain you are interested in.

SharePoint: commonModalDialogClose does not close cross-domain dialog

I have a page hosted in 'virtualcasa1' domain opening a modal dialog:
var options = {
title: "Repro",
width: 400,
height: 600,
url: http://domain2:999/sites/blank/_layouts/XDomainTest/XDomainTestTarget.aspx //[1]
//url: http://virtualcasa1/sites/blank/_layouts/XDomainTest/XDomainTestTarget.aspx [2]
};
SP.UI.ModalDialog.showModalDialog(options);
And I have this code to close it:
alert(document.domain);
SP.UI.ModalDialog.commonModalDialogClose(SP.UI.DialogResult.cancel, 'Cancelled clicked');
If both are in the same domain (case [2] above), the dialog closes well, no issues.
But - if target page hosted in the dialog (case [1] above), dialog does NOT close :-(
document.domain above shows the correct domain where page exists.
I suspect I'm facing a cross-domain issue here (duh), but how to fix it? Or am I wrong and issue is not XDomain-related?
Thanks much!
HTML5's postMessage is your answer.
https://developer.mozilla.org/en-US/docs/Web/API/Window.postMessage
Your parent window that initiates the dialog must have the following javascript:
function listener(event) {
//alert(event.data);
if (event.data == 'Cancel') {
SP.UI.ModalDialog.commonModalDialogClose(SP.UI.DialogResult.cancel, 'Cancel clicked');
}
else {
SP.UI.ModalDialog.commonModalDialogClose(SP.UI.DialogResult.OK, event.data);
}
}
if (window.addEventListener) {
addEventListener("message", listener, false)
} else {
attachEvent("onmessage", listener)
}
Javascript for OK and Cancel buttons in your popup:
<input type="button" value="OK" onclick="parent.postMessage('Message to be displayed by the parent', '*');" class="ms-ButtonHeightWidth" />
<input type="button" value="Cancel" onclick="parent.postMessage('Cancel', '*');" class="ms-ButtonHeightWidth" />
Ajay's answer from the 1st of August 2014 is good, but it needs a bit more explanation. The reason for the failure to close the dialog is simple. Cross site scripting security features of modern browsers disallow a few things, one of which is the use of window.frameElement from within the framed window. This is a read-only property on the window object and it becomes set to null (or with IE, it actually throws an exception when you try to access it). The ordinary Cancel event handlers in the modal dialog conclude with a call to window.frameElement.cancelPopup(). This will fail of course. The ordinary Save handler where the Save worked on the server side results in SharePoint sending back a single line as the replacement document, which is a scriptlet to call window.frameElement.commitPopup(). This also will not work, and it's a real pain to overcome because the page has been reloaded and there is no script available to handle anything. XSS won't give us access to the framed DOM from the calling page.
In order to make a cross domain hosted form work seamlessly, you need to add script to both the page that opens the dialog and the framed page. In the page that opens the dialog, you set the message listener as suggested by Ajay. In the framed form page, you need something like below:
(function() {
$(document).ready(function() {
var frameElement = null;
// Try/catch to overcome IE Access Denied exception on window.frameElement
try {
frameElement = window.frameElement;
} catch (Exception) {}
// Determine that the page is hosted in a dialog from a different domain
if (window.parent && !frameElement) {
// Set the correct height for #s4-workspace
var frameHeight = $(window).height();
var ribbonHeight = $('#s4-ribbonrow').height();
$('#s4-workspace').height(frameHeight - ribbonHeight);
// Finds the Save and Cancel buttons and hijacks the onclick
function applyClickHandlers(theDocument) {
$(theDocument).find('input[value="Cancel"]').removeAttr('onclick').on('click', doTheClose);
$(theDocument).find('a[id="Ribbon.ListForm.Edit.Commit.Cancel-Large"]').removeAttr('onclick').removeAttr('href').on('click', doTheClose);
$(theDocument).find('input[value="Save"]').removeAttr('onclick').on('click', doTheCommit);
$(theDocument).find('a[id="Ribbon.ListForm.Edit.Commit.Publish-Large"]').removeAttr('onclick').removeAttr('href').on('click', doTheCommit);
}
// Function to perform onclick for Cancel
function doTheClose(evt) {
evt.preventDefault();
parent.postMessage('Cancel', '*');
}
// Function to perform onclick for Save
function doTheCommit(evt) {
evt.preventDefault();
if (!PreSaveItem()) return false;
var targetName = $('input[value="Save"]').attr('name');
var oldOnSubmit = WebForm_OnSubmit;
WebForm_OnSubmit = function() {
var retVal = oldOnSubmit.call(this);
if (retVal) {
var theForm = $('#aspnetForm');
// not sure whether following line is needed,
// but doesn't hurt
$('#__EVENTTARGET').val(targetName);
var formData = new FormData(theForm[0]);
$.ajax(
{
url: theForm.attr('action'),
data: formData,
cache: false,
contentType: false,
processData: false,
method: 'POST',
type: 'POST', // For jQuery < 1.9
success: function(data, status, transport) {
console.log(arguments);
// hijack the response if it's just script to
// commit the popup (which will break)
if (data.startsWith('<script') &&
data.indexOf('.commitPopup()') > -1)
{
parent.postMessage('OK', '*');
return;
}
// popup not being committed, so actually
// submit the form and replace the page.
theForm.submit();
}
}).fail(function() {
console.log('Ajax post failed.');
console.log(arguments);
});
}
return false;
}
WebForm_DoPostBackWithOptions(
new WebForm_PostBackOptions(targetName,
"",
true,
"",
"",
false,
true)
);
WebForm_OnSubmit = oldOnSubmit;
}
applyClickHandlers(document);
}
});
})();
This solution makes use of the jQuery library, which our organization uses extensively. It is our preferred framework (chosen by me). I'm sure someone very clever could rewrite this without that dependency, but this is a good starting point. I hope someone finds it useful, as it represents a good two days work. Some things to note:
SharePoint does a postback on all sorts of events on the page, including putting the page into edit mode. Because of this, it makes more sense to trap the specific button clicks, both on the form and in the ribbon, rather than wholesale redefinition of, for example, the global WebForm_OnSubmit function. We briefly override that on a Save click and then set it back.
On any Save click event, we defeat the normal posting of the form and replace that with an identical POST request using AJAX. This allows us to discard the returned scriptlet when the form was successfully posted. When the form submission was not successful, perhaps because of blank required values, we just post the form properly to allow the page to be updated. This is fine, since the form will not have been processed. An earlier version of this solution took the resulting HTML document and replaced all of the page contents, but Internet Explorer doesn't like this.
The FormData api allows us to post the form as multipart-mime. This api has at least basic support in all modern browsers, and there are workarounds for older ones.
Another thing that seems to fail in the cross domain hosted dialog is the scrolling of the content window. For whatever reason, the height is not set correctly on the div with id s4-workspace, so we also set that in the solution.
EDIT:
Almost forgot. You may also need to add this control to your framed ASPX page, which can be done with SharePoint Designer:
<WebPartPages:AllowFraming runat="server"/>
I have exactly the same issue - a dialog opening a view page for an item works fine when opened from a site collection on the same web app/domain, but the Close button fails to work when opening the same item from a site collection hosted in a separate web application. I'm assuming it is a cross-domain thing so I've altered the solution to accomodate this restriction, however, I'm not 100% happy about it as it does make the overall solution a little awkward to use from a user-perspective. I've put the issue to one side for now due to project timescales, but I'm still curious as to why. The only things I can think of is the whole cross-domain thing causing it and that maybe it is there by design to prevent XSS security holes.

Browser does not remember position of page last viewed

I have done a few searches for this issue and I have come up empty handed. I hope somebody can clarify things for me and point me in the right direction.
Problem: I have a page that displays a list of results after submitting a search form. When a user clicks on one of the results, the browser goes to a new page showing more information about the result. When the user then clicks the 'back' button to go pack to the results, my browser reloads the page and shows the top of the page instead of the result that was last clicked.
Goal: What I would like is this: when the user click's the back button, the browser should go back to the previous page and, instead of showing the top of the page, show the page at the previous position.
Solution: I am completely lost as how this result can be achieved. Could it have something to do with javascript, or headers sent to the browsers, maybe something to do with caching.
If this is incredibly important, I'd suggest investigating the following:
add ids to each outgoing link
use JavaScript to capture the onClick for the links
when a link is clicked, redirect the user to that link's id fragment identifier, then link out as desired
When the user hits the back button, they'll return to that specific link, e.g. http://www.example.com/#link27 instead of http://www.example.com/
You may be able to get some ideas from here:
Stack Overflow:
Is it possible to persist (without reloading) AJAX page state across BACK button clicks?
YUI Browser History Manager
Ajax Patterns: Unique URLs
You can use javascript and jquery to set the scroll position of the window and cookies to store the position to scroll to. In the javascript of the page with the search results you could have something like this:
var COOKIE_NAME = "scrollPosition";
$(document).ready( function() {
// Check to see if the user already has the cookie set to scroll
var scrollPosition = getCookie(COOKIE_NAME);
if (scrollPosition.length > 0) {
// Scroll to the position of the last link clicked
window.scrollTo(0, parseInt(scrollPosition, 10));
}
// Attach an overriding click event for each link that has a class named "resultLink" so the
// saveScrollPosition function can be called before the user is redirected.
$("a.resultLink").each( function() {
$(this).click( function() {
saveScrollPosition($(this));
});
});
});
// Get the offset (height from top of page) of the link element
// and save it in a cookie.
function saveScrollPosition(link) {
var linkTop = link.offset().top;
setCookie(COOKIE_NAME, linkTop, 1);
}
// Boring cookie helper function
function getCookie(name) {
if (document.cookie.length > 0) {
c_start = document.cookie.indexOf(name + "=");
if (c_start != -1) {
c_start = c_start + name.length + 1;
c_end = document.cookie.indexOf(";", c_start);
if (c_end ==- 1) c_end = document.cookie.length;
return unescape(document.cookie.substring(c_start, c_end));
}
}
return "";
}
// Another boring cookie helper function
function setCookie(name, value, expiredays) {
var exdate = new Date();
exdate.setDate(exdate.getDate() + expiredays);
document.cookie = name + "=" + escape(value) +
((expiredays==null) ? "" : ";expires=" + exdate.toGMTString());
}
This assumes your search result links have class="resultLink".
The first part of the answer is that you use anchors to land on a page somewhere other than the top. So if I have this in my html at the bottom of my page:
<a name="f"></a>
then I can have the user land there by appending the anchor to the end of he url:
http://www.bullionvalues.com/glossary.aspx#f
So, if you are talking about ASP.Net you can place the anchor in a hidden field on the page info page and then read it from the search page by using: Page.PreviousPage property.
protected void Page_Load(object sender, EventArgs e)
{
if (Page.PreviousPage != null)
{
Object o = PreviousPage.FindControl("hfAnchor");
if (o != null)
{
HiddenField hf = o as HiddenField;
Response.Redirect(Request.Url+"#"+hf.Value);
}
}
}
I fixed this issue by sending headers with php. This was my solution:
header("Expires: 0");
header("Last-Modified: " . gmdate("D, d M Y H:i:s") . " GMT");
header("Cache-Control: store, cache, must-revalidate");
header("Cache-Control: post-check=0, pre-check=0", FALSE);
Thanks to everybody for the help.

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