I recently noticed something with Chrome and Websockets (particularly with node/socket.io) where the browser will connect my socket when I paste the URL to my page into the URL bar (without actually going through with the page request). I can verify this by simply consoling out "Connected!" and "Disconnected" in their respective socket events.
Now, I've read that Chrome has the ability to preload some parts of webpages when they are typed into the URL bar, and I would imagine that this is what is happening, however, the second part to this issue is that when I remove the url from the bar, it does not disconnect. Furthermore, if I even go to another page in that same tab, still no disconnect.
Also, it seems if I re-paste the url into the bar, the server disconnects and then reconnects.
I feel this could be a major hassle with some implementations of sockets (at least mine). Does anyone have more information about this or a way around it? Am I using the wrong events?
Chrome version: 34.0.1847.131
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I have an application in Node/Express that is exhibiting some strange (to me, at least) behavior. I am not sure why this happens, but as soon as I begin typing in the URL, the web page instantly comes up. All the logs start populating data and I have my home screen. This is on a local instance for now as I'm still trying to work out bugs related here. I believe these two may be inter-related, but I can't find any data online; perhaps I'm using the wrong search terms, but the long and the short of it is this:
I'm connected to a VM (CentOS7) and everything is run through AWS. I type in my IP:PORT (e.g. 12.34.56.78:9999). As SOON as I type the '1' in the URL, all the logs fire, running through all the scripts. Since I'm at my home page, I hit 'Enter' and is SUPPOSED to go through a redirect to an authorization page (e.g. 12.34.56.78:9999/auth). At that point we're running into my original post, identified above, but this question is simply an attempt to understand why my web page is being shown before I ever 'finish' the call by hitting the 'Enter' key. Is this normal behavior when an application is being accessed locally?
Because your browser is "smart" and guesses that you want to open that website and will therefore load it before you complete the url. That of course only happens if you have previously visited that site, otherwise the browser does not know the url yet. What logic the browser internally uses for this decision depends mostly on the browser and its settings, wether it factors in how recently you visited it or how often, or ...
If you actually want to browse that website when you finish typing the browser has already loaded the page and can instantly display it instead of now loading it and letting you wait a couple of seconds. If you decide you want to go to 123.com instead the browser simply discards the preloaded page and continues as normal.
I'm working on a Node.js website, I've taken the work on for a charity and I confess I'm learning on the job.
The page in question starts with content rendered, but invisible. When you click a button that redirects to a URL starting with a # ( which means it gets appended to the page ), no get occurs, but the content is revealed . The issue is, it needs to be filtered. However, I cannot figure out what is triggering this. The word 'hashchange' does not occur in the code base. The window.onhashchange event is null. Where would I look to try to track down the code that is doing this ?
The content after the hash mark is called an URL fragment. URL fragments are not sent to the server and appending an URL fragment does not typically invoke a page fetch, so it makes sense that no get occurs.
URL fragments are commonly used to keep track of navigation state on the browser side. This is common with single page apps (SPA) that will only fetch the entire page from the server once, and handle the rest of navigation using javascript, pushState, and AJAX queries.
This is presumably what is happening when you navigate to different tabs. The client side javascript is appending URL fragment in order to push state onto the browser history without forcing an unnecessary page reload. Note that this code does not need to listen to the onhashchange event in order for this to work, which is why you don't see any mention of it in your code search.
I'm creating a simple webpage with NodeJS that'll upload a picture, resize it, pull some information from the web about the picture, and then save to the database. Easy stuff, all of it done server side. Though I'm trying to write an new feature that I'm a bit lost on how to go about. What I'd like to do is 'print' to the client when it's started each step of the process I mentioned about.
Imagine it like a white box, and every time something happens on the server, a new line is written says what for the client to read. How would I go about this? Any help is appreciated!
Use socket.io or some other websocket library. When the page loads, open a connection (in the browser's javascript). On the server, as events happen, send them as socket.io messages. In the browser, as events arrive, set them into a "status" element or append them to a list or whatever. You should be able to find lots of examples of chat servers out there and just convert chat messages to progress updates and there you have your architecture.
http://howtonode.org/websockets-socketio
Try something, then post a code snippet.
I have a node.js app which routes events to a web page's "shotbox" which is similar to a chatbox on the home page. This shoutbox requires a sessionVar and sessionId that changes based on your browser, session_id, and some other things. I have been successful in getting these variables from my browser, but if I close that browser page, my node.js app no longer works. I assume this has to do with a keep-alive header or something (i'm not sure, I don't know all that much about http to be honest). I want to have my node.js app be free from needing the browser up at all. I'm thinking I could, upon starting up the node.js app, login into the site, and retrieve these custom variables. But how do I achieve the same effect that the browser accomplishes when staying open?
Basically, how do I implement a keep-alive browser session in node.js?
The browser session is supposed to end when you close it, that's expected behavior. Your app shouldn't care if anywhere between 0 - [huge number] of sessions are active at any given time; it sounds like something really basic is wrong with your server. Post some code...
How can I perform a post through the chrome extention, lets say I want to send the current tab page title to a webpage
You can do POST XHRs from chrome extensions to any URL, as long as you have host permissions defined in your manifest. See these docs.
In a chrome extension the best way to try and do what i think you want is via a content script see documentation a word of warning however pinging your server with a POST request every time someone with your extension installed opens a web page is going to be extremely heavy going on your servers especially if you have a lot of installs. A possible solution is to use the content script to keep tally of the sites a user visits and save this data in a HTML5 database (wich chrome supports) then using background.html sending the data at given intervals in bulk with an AJAX request, this will significantly cut down the number of times your server is pinged.