I want to test my Progressive web application for offline status. I want that if my webapp if offline, it should respond with a 200 status code. What can be the possible code for that?
Your question is not detailed enough to give a detailed answer but in general:
it sounds like the 200 status code is from an HTTP request, in which case if your PWA uses javascript (e.g. via ajax) to make the remote API calls (e.g. GET) then you just handle the state in the returned event object, e.g. you have to handle other states (e.g. other types of failures too). For example see: https://developer.mozilla.org/en-US/docs/Web/Guide/AJAX/Getting_Started
You also could also test the online/offline state before making the HTTP request.
See discussion of using navigator.onLine or adding
window.addEventListener('offline', function(e) {//do something}, false);
window.addEventListener('online', function(e) {//do something}, false);
Another example is I use Polymer webcomponents and firebase authentication for my PWAs and in Polymerfire it's simply a case of handling the online property.
Related
I am using Perl WWW::Mechanize::Chrome to automate a JS heavy website.
In response to a user click the page among many other requests, requests and loads a JSON file using XHR.
Is there some way to save this particular JSON data to a file?
To intercept requests like that, you generally need to use the webRequest API to filter and retrieve specific responses. I do not think you can do that via WWW::Mechanize::Chrome.
WWW::Mechanize::Chrome tries to give you the content of all requests, but Chrome itself does not make the content of XHR requests available ( https://bugs.chromium.org/p/chromium/issues/detail?id=457484 ). So the approach I take in (for example ) Net::Google::Keep is to replay the XHR requests using plain Perl LWP requests by copying the cookies and parameters from the Chrome requests-
Please note that the official support forum for WWW::Mechanize::Chrome is https://perlmonks.org , not StackOverflow.
I want to 301 redirect the URLs from previous site that are nested, as pencilblue doesn’t support them,
e.g. a/b to page/b
For this I have been experimenting in include/http/request_handler.js but facing some issues.
Call never comes inside RequestHandler.prototype.handleRequest or even RequestHandler.prototype.onSessionRetrieved (seems these methods are not being called from anywhere)
Therefore I placed the code in RequestHandler and after confirming that req is not for public resource or api, I create a new url and execute
return this.doRedirect(newUrl, 301)
This actually works but at the same time I receive
Can’t render headers after they are sent error
#1075 has not helped me much as I’m not sure which specific controller I should modify. I need to catch the req as early as possible and see if it’s a page then redirect to page prefixed url.
Thanks in advance.
There are couple of ways to do redirects. You can do them from a controller or from middleware. You are correct in that, some of the functions in the request handler are not called. These are deprecated despite the fact pencilblue team didn't mark them as such. They replaced a good deal of the request handler functionality with /include/http/router.js and include/http/middleware/index.js. Plugins can register their own middleware to hijack the request pipeline.
See Advanced Routing on wiki for more info about creating your own middleware.
Using the routing framework your plugin would be able to register middleware that would be able to inspect the request and then redirect based on your specific criteria. The Router will be accessible from req.router and from there you could call req.router.redirect (Source).
Reference: #1224
Is there any possibility of "listening" to the state of GET SiteCatalyst image requests ?
I'd like to run a callback function only when the requests are over, to be more clear when they receive the 200 status code and I'm sure they're done.I'm confident no "built-in" method is available and maybe I should hack the core s.track.s.t() function...?Thanks a lot.
You are right, there is no global "built-in" callback method for when the Adobe Analytics request is complete.
A couple notes I should mention to you about attempting to hack the core code:
1) If you are using the AppMeasurement library version 1.4.1+, in some circumstances, a POST request may be made instead of an image request.
2) Responses that are not 200/OK or otherwise completed/successful does not necessarily mean the data failed to be sent to Adobe. Most common scenario is a NS_BINDING_ABORTED error returned.
The main bad effect I'm getting here is what I previously thought as a double XHR request.
It wasn't. In reality the first request gets redirected as it would be the first visit of a new visitor (302 status) and a new visitorID is brought down by Adobe server.
Then the redirected "200 status" request is made with this new visitorID within.This is bad because every XHR requests would result in a new visit of a new visitor even though a previously set "s_vi" cookie is there in browser, with the lack of previous collected data for that user.I know what XHR redirects couldn't be blocked so I'm wondering if there is a way to "tell" Adobe server it's not the first request ever made, in order to stop the redirect and do not use a new visitorID.
I have a web service in the form `http://....../methodName
It returns a jsonp result such as:
methodName(["a":"a", "b":"b"])
GWT provides JsonpRequestBuilder class to parse jsonp.
JsonpRequestBuilder rb = new JsonpRequestBuilder();
rb.setCallbackParam("callback");
rb.requestObject("http://...../methodName", new AsyncCallback<TestJS>(){
...
});
This structure makes a request to url :
"http://...../methodName/?callback=__gwt_jsonp_P0.onSuccess".
My web service returns a callback with methodName not with __gwt_json.....
So gwt could not create a JavaScriptObject from that response.
Also JsonpRequestBuilder works with GET not POST.
How can I achieve those: Sending requests with POST and modifying GWT's default callback name.
JSONP will NOT work with POST. Its not a GWT limitation btw.
JSONP is essentially including a javascript file from your server. So, when you make a JSONP call, a temporary tag is added to the DOM.
Now, a <script> tag can always makes a GET request. That's a browser thing, and GWT cannot do much about it.
If you want to make a cross-domain POST call, you have to chose from one of the following options (and they have nothing to do with GWT)
Use Flash plus a crossdomain.xml that allows cross domain posts
Use Cross Origin Resource Sharing, or CORS. NOTE that this is only supported in modern browsers
Use a proxy server on your domain
Unfortunatly, this isn't how JsonP works. The requests are made by adding a tag to the page, and the results are passed into a function wrapped around the data – in your case, __gwt_jsonp_P0.onSuccess.
The callback name can't be affected, at least while using JsonpRequestBuilder – the system needs to account for the fact that you could send multiple requests out at once, possibly even to different endpoints. A JsonP endpoint that doesn't allow the caller to customize the callback function name is very unusual, and even more odd is an endpoint expecting JsonP calls that expects an impossible POST.
You can implement your own JsonP client side code by using the ScriptElement type, and registering your own global callback to call into your GWT java code.
Look into the API docs for the web service, and see if there is perhaps a better way to communicate with it, perhaps by using a proxy on your own server, avoiding the cross domain issue altogether.
Why does using Fiddler break my site sometimes on page transitions.
After a server side redirect -- in the http response (as found in Fiddler) I get this:
Object moved
Object moved to here.
The site is an ASP.NET 1.1 / VB.NET 1.1 [sic] site.
Why doesnt Fiddler just go there for me? i dont get it.
I'm fine with this issue when developing but I'm worried that other proxy servers might cause this issue for 'real customers'. Im not even clear exactly what is going on.
That's actually what Response.Redirect does. It sends a 302 - Object moved response to the user-agent. The user-agent then automatically goes to the URL specified in the 302 response. If you need a real server-side redirect without round-tripping to the client, try Server.Transfer.
If you merely constructed the request using the request builder, you're not going to see Fiddler automatically follow the returned redirect.
In contrast, if you are using IE or another browser, it will generally check the redirect header and follow it.
For IE specifically, I believe there's a timing corner case where the browser will fail to follow the redirect in obscure situations. You can often fix this by clicking Tools / Fiddler Options, and enabling both the "Server" and "Client" socket reuse settings.
Thanks user15310, it works with Server.Transfer
Server.Transfer("newpage.aspx", true);
Firstly, transferring to another page using Server.Transfer conserves server resources. Instead of telling the browser to redirect, it simply changes the "focus" on the Web server and transfers the request. This means you don't get quite as many HTTP requests coming through, which therefore eases the pressure on your Web server and makes your applications run faster.
But watch out: because the "transfer" process can work on only those sites running on the server, you can't use Server.Transfer to send the user to an external site. Only Response.Redirect can do that.
Secondly, Server.Transfer maintains the original URL in the browser. This can really help streamline data entry techniques, although it may make for confusion when debugging.
That's not all: The Server.Transfer method also has a second parameter—"preserveForm". If you set this to True, using a statement such as Server.Transfer("WebForm2.aspx", True), the existing query string and any form variables will still be available to the page you are transferring to.
Read more here:
http://www.developer.com/net/asp/article.php/3299641/ServerTransfer-Vs-ResponseRedirect.htm