My Asp.Net Core 2.1 app can generate two HTML reports. Each report has a button for outputting the report as a PDF file using DinkToPDF. The button calls a controller for that report that provides all the parameters that DinkToPDF needs and then generates the PDF. An essential parameter is the URL of the page to be converted, which is not the original HTML report but a lookalike from which javascript etc. has been removed.
The first report would output the login page instead of the report data until I put [AllowAnonymous] above the class name. Then it worked fine.
The second report used the files from the first report as a template. In all necessary places everything was renamed appropriately. But even though this page of course has [AllowAnonymous], it will only generate a PDF of the login page.
I can step through the controller code and watch the DinkToPDF params get their values. But when "convert" method of DinkToPDF is called, something goes wrong.
Is there a way to watch inside that method to see why it thinks it must authenticate?
After I thought to look in the Output window, I saw that this was one of those "Qt: Could not initialize OLE" errors. I also found that the database context object being injected into my class was null. Evidently the context was being lost somehow. In the original report, that didn't matter because I had sidestepped EF Core and was accessing the database by old-style ADO-type calls.
Therefore, in the new report, I replaced all EF Core with ADO-type calls, and the problem went away. Just had to work out some routing.
Related
I have a ASP.NET MVC web application that is very dynamic in it's nature:
A controller loads data from some service. Based on this response, it calls others sub-controller's actions which in turn may or may not render certain views. The response of the service is dependent upon a lot of factors and may change a lot of the page's output.
Now we're in a situation that only if a certain sub-view is rendered, we need to include a javascript bundle:
If a certain sub-controller renders a certain sub-view, we must include the script reference.
We must not include this bundle in the page when this certain sub-view ist not rendered.
The availability of the sub-view is determined dynamically from some other sub-controllers remote call.
The script absolutely needs to be included in the page header, since it executes certain code that will cause problems if done later (setting document.domain and stuff).
How can we achieve that in a clean and MVCy-way?
I'm upgrading from .NET 2.0 to MVC 4. Back in .NET 2.0 webform, we had to inject license information on the fly to the footer of the software by override the "Render" function in .aspx.cs page (using HtmlTextWriter), find a particular spot of the footer and then insert the license text info there.
The reason I don't want to directly put that in the viewstart page or any razor page themselves using HTMLhelper is because I don't want my customers to mess with it. So hard code is not an option.
I use Glimpse and I see Glimpse is enabled by adding a HTTPModule,etc in web.config and magically, an icon appears on my app. Something similar ?
Bottom line is, I need to hijack the finished HTML output, modify it and return the final result to client.
How do you do this in MVC? HttpModule?
Thanks!
Glimpse uses a feature of ASP.NET called a ResponseFilter to change the output HTML on the fly.
The ResponseFilter, in the case of Glimpse, is set inside the HttpModule - but it could be set anywhere.
Four Guys From Rolla has an old but still relevant article on how to create ResonseFilters.
I am trying to do something very simple and I seem to be missing something. I tried to scour the internet for results but haven't gotten anywhere so I was wondering if someone can please advise on this seemingly easy and straightforward task.
I have a working MVC Application and have created Models, Controllers, Views using the defaults (scaffolding).
Now I want to create a new view for one of my controller actions:
public ActionResult Index()
{
return View(db.Blog.ToList());
}
So I right click on Action Result and click Add View.
This gives me a dialog box where I specify a view name of "Test", I click "Create a Strongly Typed View" check box and select model class of Blog.
For scaffold template, I leave empty (note I have tried index without any good result)
Now I click the Add button.
As expected this creates a new view test.cshtml under Views/Blogs
Now when I begin without debugging and go to url: localhost:12341/Blog/Test
I get the following error:
Server Error in '/' Application.
The resource cannot be found.
Description: HTTP 404. The resource you are looking for (or one of its dependencies) could have been removed, had its name changed, or is temporarily unavailable. Please review the following URL and make sure that it is spelled correctly.
Requested URL: /Blog/test
Version Information: Microsoft .NET Framework Version:4.0.30319; ASP.NET Version:4.0.30319.17929
There could be a lot of issues with why it doesn't work. It is probably worth your while to look into ASP.NET MVC routing. For now, Mystere Man's solution might be a "quick fix" assuming you have everything else set up to their defaults.
In particular, when you tell your browser to go to localhost:12341/Blog/Test then it will (probably) look for a Controller called BlogController and then perform the Test action. In your case, your action is called Index so you would want to go to localhost:12341/Blog/Index (though you may be able to omit Index since it's the default action). Lastly, since your action is called Index then the View() function will automatically look for Index.cshtml. This is detailed somewhat in the msdn documentation:
http://msdn.microsoft.com/en-us/library/dd492930(v=vs.100).aspx
In particular:
If the ViewName property is empty, the current action name is used in place of the ViewName property.
Your action method is called Index, not Test. If you want the url to be /Test, then you need to name the action method Test (there are other ways to do it, but this is the best way)
If you want to use the view Test, then you need to specify it in your View() method.
return View("Test", db.Blogs.ToList());
However, you will still need to use the Index url /Blogs/Index because your action method is Index.
Situation: I needed to add form with POST method to CMS page. I created custom hook and a module displaying the form successfully. Then I need to react to user input errors eg. when user doesn't enter email address I need to detect it, display the whole page again together with the form and with "errors" in user input clearly stated.
Problem: The problem is to display the WHOLE page again with connected information (eg. about errors etc.). In the module PHP file when I add this kind of code,
return $this->display(__FILE__, 'modulename.tpl');
it (naturally) displays ONLY the form, not the whole CMS page with the form.
In case of this code,
Tools::redirectLink('cms.php?id_cms=7');
I can't get to transfer any information by GET neither POST method.
$_POST['test'] = 1;
Tools::redirectLink('cms.php?id_cms=7&test');
I tried to assign to smarty variables too
$smarty->assign('test', '1');
(I need to use it in .tpl file where the form itself is created) but no way to get it work.
{if isset($test)}...,
{if isset($smarty.post.test)}...,
{if isset($_POST['test'])}... {* neither of these conditionals end up as true *}
Even assigning a GET parameter to url has no impact, because there is link rewriting to some kind of friendly url I guess, no matter I included other argument or not. ([SHOPNAME]/cms.php?id_cms=7&test -> [SHOPNAME]/content/7-cmspage-name)
My question is: is there a way to "redirect" or "reload" current page (or possibly any page generally) in prestashop together with my own data included?
I kind of explained the whole case so I'm open to hear a better overall solution than my (maybe I'm thinking about the case in a wrong way at all). This would be other possible answer.
The simplest method would be to use javascript to validate the form - you can use jQuery to highlight the fields that are in error; providing visual feedback on how the submission failed. In effect you don't allow the user to submit the form (and thus leave the page) until you're happy that the action will succeed. I assume that you will then redirect to another page once a successful submission has been received.
There's lots of articles and how-tos available for using javascript, and indeed jQuery for form validation. If you want to keep the site lean and mean, then you can provide an override for the CMS controller and only enqueue the script for the specific page(s) you want to use form validation on.
If the validation is complex, then you might be best using AJAX and just reloading the form section of your page via a call to your module. Hooks aren't great for this kind of thing, so you might want to consider using an alternative mnethod to inject your code onto the cms page. I've written a few articles on this alternative approach which can be found on my prestashop blog
I have a huge website (containing around 5000+) pages. There is a theme functionality in the website where user can choose different colors for their profile. Now i want to use the ASP.net theme feature and put different CSS (for different colors) in the theme folder and in Global.asax i want check the user theme and render appropriate link element with the css. But my problem is, i am not able to access the Page element for adding the link in the page.
Here is my code
Dim page As System.Web.UI.Page = TryCast(System.Web.HttpContext.Current.Handler,System.Web.UI.Page)
page.StyleSheetTheme = "Black"
But when i run this code I get a Null reference error.
P.s : My application is very huge so its not possible to have a master page or a base class and inherit it in every page.
Please suggest.
The page is not available in PreRequestExecute. This function is called before asp.net steps in to handle things, and asp.net is responsible for the page. Think of PreRequestExecute as being earlier in the scheme of things, like when IIS is first trying to figure out what to do with this thing it has, the thing is not even a page yet.
You might want to look into some of the other events that you can hook, there are events that would take place after the page has loaded that may allow you to do what you are suggesting.
Rather than going into global.asax for this, consider using master pages. One possibility is to have nested master pages, where the first master page sets up overall layout, and the nested master handles the theme. (Or one of several nested master pages, all referencing the same top-level master page). If necessary, you can use the PreInit event in the page to change master pages, and select the master that matches your theme selection.
You can centralize this function by having your own class that inherits System.Web.UI.Page, and have all your own pages inherit this new class. Handle the PreInit event there. (As well as other useful functions, like page-level handling of unhandled exceptions, general security issues, etc.
EDITED TO ADD: As #aepheus correctly notes, the page hasn't been instantiated at the PreRequestHandlerExecute event. So there's no page class you can access.