I am trying to build a system to list items within my Back office system on eBay via the eBay ASP.NET SDK.
Since loading eBay categories isn't terribly fast, and infrequently changing, I figured I'd cache the responses from the requests I'll make.
I have a function which returns a list of eBay categories as an eBay CategoryTypeCollection and I am trying to Cache it, then check for it and retrieve new if necessary:
Dim CategoryList As New CategoryTypeCollection
If HttpRuntime.Cache.Get("eBayCategories") Is Nothing Then
CategoryList = Categories.DisplayCategories()
HttpRuntime.Cache.Insert("eBayCategories", CategoryList, Nothing, DateTime.UtcNow.AddMinutes(30), TimeSpan.FromMinutes(0))
Else
CategoryList = HttpRuntime.Cache.Get("eBayCategories")
End If
However, it is always getting new data.
This is part of a much bigger project, and caching is working for other things, I can't see what I am doing wrong here?
The cache is expiring immediately because you specify 0 minutes to expire.
Change it to Cache.NoSlidingExpiration instead.
HttpRuntime.Cache.Insert("eBayCategories", connectionString, Nothing, DateTime.UtcNow.AddMinutes(30), Cache.NoSlidingExpiration)
See MSDN Cache.Insert.
Related
Current Project:
ASP.NET 4.5.2
MVC 5
PayPal API
I am using this example to build myself a PayPal transaction (and yes, my code is virtually identical), as I do not know of any other method that will return the three values in the title.
My main problem is that, the example I am utilizing is much more concise and compact than the one I used for a much older Web Forms application, and as such, I am unsure as to where or even how to grab the three values I need.
My initial thought was to do so right after the ACK, and indeed I was able to obtain the CorrelationId as well as the TimeStamp, but because this was prior to the user being carted off to PayPal’s site (sandbox in this case -- see the return new PayPalRedirect contained within the if), the TransactionId was blank. And in this example, PayPal explicitly redirects the user to a Success page without returning to the Action that sent the user to PayPal in the first place, and I am not seeing any GET values in the URL at all aside from the Token and the PayerId, much less ones that could provide me with the TransactionId.
Suggestions?
I have also looked at the following examples:
For ASP.NET Core, was unsure how to adapt to my current project particularly due to appsettings.json, but it looked quite well done. I really liked how the values were rolled up in lists.
For MVC 4, but I couldn’t find where ACK was being used to determine success or successwithwarning so I couldn’t hook into that.
I have also found the PayPal content to be like trying to drink from a fire hose at full blast -- not only was the content was hopelessly outdated (Web Forms code, FTW!) but there was also so many different examples it would have taken me days to determine which one was most appropriate to use.
Any assistance would be greatly appreciated.
Edit: my initial attempt at modifying the linked code has this portion:
values = Submit(values);
var ack = values["ACK"].ToLower();
if(ack == "success" || ack == "successwithwarning") {
using(_db = new ApplicationDbContext()) {
var updateOrder = await _db.Orders.FirstOrDefaultAsync(x => x.OrderId == order.OrderId);
if(updateOrder != null) {
updateOrder.OrderProcessed = false;
updateOrder.PayPalCorrelationId = values["CORRELATIONID"];
updateOrder.PayPalTransactionId = values["TRANSACTIONID"];
updateOrder.PayPalTimeStamp = values["TIMESTAMP"];
updateOrder.IPAddress = HttpContext.Current.Request.UserHostAddress;
_db.Entry(updateOrder).State = EntityState.Modified;
await _db.SaveChangesAsync();
}
}
return new PayPalRedirect {
Token = values["TOKEN"],
Url = $"https://{PayPalSettings.CgiDomain}/cgi-bin/webscr?cmd=_express-checkout&token={values["TOKEN"]}"
};
}
Everything within and including the using() is my added content. As I mentioned, the CorrelationId and the TimeStamp come through just fine, but I have yet to successfully obtain the TransactionId.
Edit 2:
More problems -- the transactions that are “successful” through the sandbox site (the ReturnUrl is getting called) aren’t reflecting properly on my Facilitator and Buyer accounts, even when I do payments straight from the buyer’s PayPal account (not using the Credit Card). I know I am supposed to see transactions in the Buyer’s account, either through the overall Dev account (Accounts -> Profile -> balance or Accounts -> Notifications) or through the Buyer’s account in the sandbox front end. And yet -- multiple transactions returning me to the ReturnUrl path, and yet no transactions in either.
Edit 3:
Okay, this is really, really weird. I have gone over all settings with a fine-toothed comb, and intentionally introduced errors to see where things should crap out. It turns out that the entire process goes swimmingly - except nothing shows up in my notifications and no amounts get moved between my different accounts (Facilitator and Buyer). It’s like all my transactions are going into /dev/null, yet the process is successful.
Edit 4: A hint!
In the sandbox, where Buyer accepts the transaction, there is a small note, “You will be able to review the transaction before completing it” or something like that -- suggesting that an additional page is not coming up and that the user is being uncerimoniously dumped back to the success page. Why the success page? No clue. But it’s happening.
It sounds like you are only doing the first part of the process.
Express Checkout consists of 3 API calls:
SetExpressCheckout
GetExpressCheckoutDetails
DoExpressCheckoutPayment
SEC generates a token, and then you redirect to PayPal where the user signs in and reviews the transactions before agreeing to pay.
They are then sent to the ReturnURL included in your SEC request, and this is where you'll call GECD in order to obtain all the buyer details that are now available since they signed in.
Using that data you can complete the final DECP request, which is what finalizes the procedure. No money is actually processed until this final call is completed successfully.
I have an ASP.Net application that accesses user data from a SQL database.
Visual Studio Version 2012
Windows Server 2012 Standard 6.2
Sql Server 2012
Program in Service since 11/2007 (with problem having never happened previously)
Problem:
First reported by 2 of my customers but I was not experiencing the problem until after a recent MS update.
Unsure of the particulars of those updates or whether it was only a coincident.
Log into application and go around to a few pages, all seems ok, than I select a new Active Company (auto filters list screens by Active Company ID from a session variable, changing active company changes the ID stored in the session variable), everything works fine for a while (1 - 4 mins) switching between screens and even different active companies, than at one point I go to a page that I've been to several times (that worked fine) and it shows everything from the last time I accessed it (literally the identical page from a few mins ago). I change to another page and it appears to be updated, go back to the screen that did not update and it no matter what, will not update again. I query the database and it is indicating the correct active company ID and query the session variable and that too is correct.
** The strange thing is I can wait 4 -5 mins (I just stop doing anything) and than try to access the page again and now it updates.
I have been beating at this now for almost 2 weeks and have not been able to determine to source of the problem.
I literally have tried every settings for session caching I could read up on with no (or minimal) affect.
Since our software utilizes session variables to hold user variables to control their environment (like active company selection), I went to go as far as removing the session variables and making the profile.variables (requiring Sql Session management) with minimal affect).
It seems to work fine for a few minutes (or page accesses) than once it stops updating the page, it will no longer update under any circumstance.
It will occur on pretty much any combination of page changes (after changing the active company, since it will actually change data displayed).
This design has been out in the field for over 8 years now (and is routinely brought up-to-date with the latest dot.net compiler updates, .net framework and IronSpeed Designer engine updates. This error has never occurred before now. No update to the development tools took place prior to the appearance of this issue.
I tried various tests.
Test 1:
I added java code to reset each page.
<script type="text/javascript">
function RefreshPage()
{
window.location.reload()
}
</script>
Result: No change
Test 2:
I stopped as soon as the page did not refresh and started timing when the page would update (1 -2 mins or going back and forth between the change active company and the reports screen several times)
Result:
After 60 - 90 secs, the current page seemed to do an update (the activity icon would appear than go away) so I would than check the page the was not refreshing and it was now correct.
Since I was using the report page for my tests, I would run a report when the screen update failed, to see what active company it thought it was on (since it was also reliant on the session variable, it was bringing up the correct report data, even though the page was not indicating the correct active company. Note: Every one of our screens indicate the current user and active company name at the top, so it is easy to see when it is not updating.
Any direction as to where to look from here would be greatly appreciated, I'm at a lost as to what to check now.
P.S. I installed MS Message Analyzer and had it monitor up to the point where I get a failure. I have never user MS MA before so I don't have much of an idea as to what to look for, other than the operation status was indicating Found (302) for the Get and Post and Ok (200) for the page I received the problem for.
Thanks in advanced!
John R
I propose to check caching options. I mean caching of page, controls, javascript, and browser. As workaround I propose to add some empty paramether to your page, ajax calls. For example instead opening "default.aspx" open "default.aspx?id=someNewGoid". Also consider adding some random paramethers to your ajax calls.
Try following coe for refresh:
<script type="text/javascript">
function S4() {
return (((1+Math.random())*0x10000)|0).toString(16).substring(1);
}
function guid()
{
var guid = (S4() + S4() + "-" + S4() + "-4" + S4().substr(0,3) + "-" + S4() + "-" + S4() + S4() + S4()).toLowerCase();
return guid;
}
function RefreshPage()
{
var url = window.location;
if (url.indexOf("?")>-1){
url = url.substr(0,url.indexOf("?"));
}//this par will cut of additional paramthers
window.location = url + "?id=" + guid();
window.location.reload()
}
</script>
I am using ASP.NET MVC 3 to track hits on a set of stored links. I run into problems when displaying the hits' counts. I think this is because since I am using lazy loading, whenever I call
link.Hits.Count
it loads all of each hit's data, including such things as agent and referrer information. (Hits is a Collection.) This is an issue when a link has over 9000 hits. Is there a way of just getting the Hits' Count without it pulling in the Hits' data?
If the Hits has been written like this, the Count will work:
Hits = repository.GetAll(....).Where(....);
But if like this, the Count will not work, because the ToList() has already loaded all the data:
Hits = repository.GetAll(....).Where(....).ToList();
I have a search box on the page (webservice-fed results) and I'd like to save the search TERMS for the user in a UL\LI list on the page. So the next time they come back to the page, the results are still there....but if they clear their cache then it gets reset.
What's the best way to go about that?...I can persist between postbacks easily, but this is a new one for me.
Thanks,
Steve
Probably use a cookie, but remember you're limited to 4kb of data.
Otherwise, store the session in a database. Then save that records ID to a cookie. That way you can load the data from the database based on the ID in the cookie. Then just flush any entries in DB older than say, 30 days or something.
Due to lack of sleep, I have given you an answer in PHP. Sorry about that, I'll leave it because the information is still correct, just the syntax will be slightly different in asp.net
You have two options for data-persistence in php; cookies and sessions.
Sessions are server-side, and last as long as the browser window stays open.
Cookies are client-side, and last until the user clears their cache.
So it sounds like you want a cookie option. So in your search query processor, add the line
setcookie('search_' . time(), $_POST['search_query'], (time() + 10368000));
This will create a cookie on the client machine, with the name search_xxxx where xxxx is a timestamp (each cookie has to have a unique name otherwise they will overwrite eachother).
The weird looking calculation at the end is an expire time, which is set to 120 days in the future.
Then in your php document that displays your search page, you need to spit out all these cookie values.
foreach($_COOKIES as $k => $v) {
if(substr($k, 0, 7) == 'search_') echo($v . '<br />');
}
This will spit out each of the search terms found on the clients machine. The if statement is to make sure it only displays search term cookies, and no others.
Use a cookie. Assuming you start with a List<string> of search terms called terms, do:
var sb = new StringBuilder();
foreach (var t in terms) sb.Append(t).Append(";")
var c = new HttpCookie("terms");
c.Value = sb.ToString().TrimEnd(';');
c.Expires = DateTime.Now.AddDays(30);
Response.Cookies.Add(aCookie);
Then when you need to access those terms again (to databind to a Repeater, or process in some other way for display on your page):
if (Request.Cookies["terms"] != null) {
var terms = new List<string>();
foreach (var t in Request.Cookies["terms"].Value.Split(';')) list.Add(t);
}
A Cookie is probably your solution for today, but HTML5 localStorage will eventually be the best bet. Only supported by modern browser versions right now, depends on your users.
I'm working on a content dripper custom plugin in WordPress that my client asked me to build. He says he wants it to catch a page view event, and if it's the right time of day (24 hours since last post), to pull from a resource file and output another post. He needed it to also raise a flag and prevent other sessions from firing that same snippet of code. So, raise some kind of flag saying, "I'm posting that post, go away other process," and then it makes that post and releases the flag again.
However, the strangest thing is occurring when placed under load with multiple sessions hitting the site with page views. It's firing instead of one post -- it's randomly doing like 1, 2, or 3 extra posts, with each one thinking that it was the right time to post because it was 24 hours past the time of the last post. Because it's somewhat random, I'm guessing that the problem is some kind of write caching where the other sessions don't see the raised flag just yet until a couple microseconds pass.
The plugin was raising the "flag" by simply writing to the wp_options table with the update_option() API in WordPress. The other user sessions were supposed to read that value with get_option() and see the flag, and then not run that piece of code that creates the post because a given session was already doing it. Then, when done, I lower the flag and the other sessions continue as normal.
But what it's doing is letting those other sessions in.
To make this work, I was using add_action('loop_start','checkToAddContent'). The odd thing about that function though is that it's called more than once on a page, and in fact some plugins may call it. I don't know if there's a better event to hook. Even still, even if I find an event to hook that only runs once on a page view, I still have multiple sessions to contend with (different users who may view the page at the same time) and I want only one given session to trigger the content post when the post is due on the schedule.
I'm wondering if there are any WordPress plugin devs out there who could suggest another event hook to latch on to, and to figure out another way to raise a flag that all sessions would see. I mean, I could use the shared memory API in PHP, but many hosting plans have that disabled. Can't use a cookie or session var because that's only one single session. About the only thing that might work across hosting plans would be to drop a file as a flag, instead. If the file is present, then one session has the flag. If the file is not present, then other sessions can attempt to get the flag. Sure, I could use the file route, but it's kind of immature in my opinion and I was wondering if there's something in WordPress I could do.
The key may be to create a semaphore record in the database for the "drip" event.
Warning - consider the following pseudocode - I'm not looking up the functions.
When the post is queried, use a SQL statement like
$ts = get_time_now(); // or whatever the function is
$sid = session_id();
INSERT INTO table (postcategory, timestamp, sessionid)
VALUES ("$category", $ts, "$sid")
WHERE NOT EXISTS (SELECT 1 FROM table WHERE postcategory = "$category"
AND timestamp < $ts - 24 hours)
Database integrity will make this atomic so only one record can be inserted.
and the insertion will only take place if the timespan has been exceeded.
Then immediately check to see if the current session_id() and timestamp are yours. If they are, drip.
SELECT sessionid FROM table
WHERE postcategory = "$postcategory"
AND timestamp = $ts
AND sessionid = "$sid"
The problem goes like this with page requests even from the same session (same visitor), but also can occur with page requests from separate visitors. It works like this:
If you are doing content dripping, then a page request is probably what you intercept with add_action('wp','myPageRequest'). From there, if a scheduled post is due, then you create the new post.
The post takes a little bit of time to write to the database. In that time, a query on get_posts() may not see that new record yet. It may actually trigger your piece of code to create a new post when one has already been placed.
The fix is to force WordPress to flush the write cache appears to be this:
try {
$asPosts = array();
$asPosts = # wp_get_recent_posts(1);
foreach($asPosts as $asPost) {break;}
# delete_post_meta($asPost['ID'], '_thwart');
# add_post_meta($asPost['ID'], '_thwart', '' . date('Y-m-d H:i:s'));
} catch (Exception $e) {}
$asPosts = array();
$asPosts = # wp_get_recent_posts(1);
foreach($asPosts as $asPost) {break;}
$sLastPostDate = '';
# $sLastPostDate = $asPost['post_date'];
$sLastPostDate = substr($sLastPostDate, 0, strpos($sLastPostDate, ' '));
$sNow = date('Y-m-d H:i:s');
$sNow = substr($sNow, 0, strpos($sNow, ' '));
if ($sLastPostDate != $sNow) {
// No post today, so go ahead and post your new blog post.
// Place that code here.
}
The first thing we do is get the most recent post. But we don't really care if it's not the most recent post or not. All we're getting it for is to get a single Post ID, and then we add a hidden custom field (thus the underscore it begins with) called
_thwart
...as in, thwart the write cache by posting some data to the database that's not too CPU heavy.
Once that is in place, we then also use wp_get_recent_posts(1) yet again so that we can see if the most recent post is not today's date. If not, then we are clear to drip some content in. (Or, if you want to only drip in like every 72 hours, etc., you can change this a little here.)