I have followed this tutorial for the most part to explain what I am doing. http://www.asp.net/data-access/tutorials/creating-a-business-logic-layer-vb
What i need to do is figure out the best way to approach to be able to update my formview. I do not understand what the tutorial is trying to explain to me so i tried it the way i have updated a gridview before. But I am receiving "No parameterless constructor defined for this object." I tried to debug and view the callstack but it does not really tell me much.
I have my sql stored procedure to update which when executed works fine.
I also have another class in which i reference the application details class
applicant.vb
This is the code in order for when you click the view details link on the gridview it passes you off to another page that shows that applicants details it is within the same applicant.vb class
I am trying to update using the following method on the .aspx page but i receive the following error "No parameterless constructor defined for this object."
Memberdetails.aspx
Without knowing which line of code is causing that error, I can't say for sure, however, my guess is that your error is on this line of code.
_applicantadapter = New applicantTableAdapter
Put an open parentheses after applicantTableAdapter to see the different constructor signatures available to you for that type. I bet you'll see none of the options allow no parameters.
That error means that the object type you are trying to instantiate requires that you include parameter(s) (and you are not).
Related
I am using asp.net MVC3 and I am very new to this technology.
My models are designed in such a way that the properties will throw validation errors if the data is invalid. In this case, the properties are not set with invalid data.
When I redisplay my editing-view, validation error messages are shown; however the values that the user previously entered are gone because the model that it is bound to only contains the old-valid data.
For example, say I had a Person class and the Name property cannot be a null or empty string otherwise it throws a validation exception and prevents the property from being set. Now say the user removes the value from the Name property and tries to save the Person from the web. A validation exception will be thrown and handled properly to add the error to the ModelState so that it is displayed on the screen; however the old value for the Name is redisplayed since the invalid, empty string never made it into the property.
I do not know how to solve this problem and any advice on the issue would be greatly appreciated.
My advise is allow invalid data but use validation attributes. You wont save invalid entities so there is no problem and this is the standard approach these days. If you don't want do that, there is no easy solution. Most simple solution would be using the info from Request.Form
You should implement IValidatableObject to performe this kind of validation at server side.
From MSDN IValidatableObject Interface:
Provides a way for an object to be invalidated.
Theres an exemple here Using IValidatableObject Custom Validation, also from MSDN.
The solution to this problem was to create a ViewModel that allowed invalid data to be entered into this. This solution also simplified my ModelBinder classes because it took on most of the work.
Listed below is the definition of my function (vb).
I am trying to check the value of a checkbox inside the function. I am currently unable to do this without getting an error stating that
"Error 305: Cannot refer to an instance member of a class from within a shared method or shared member initializer without an explicit instance of the class."
Is there anything I can change so that I can get the value to see that if a checkbox is checked or not? The method must be shared, so it works with the existing javascript and the use of pagemethods
Thanks
<System.Web.Services.WebMethod()> _
Public Shared Function Load(inputs here - taken out for stack overflow) As String
edit- the only other solution i can think of is to find a way for the page's javascript onload to run before the server side, this would solve my issue as well if anyone knows how this can be done.
Yes. Do what the message suggests and make the method non-shared, then you'll be able to access the members of the page.
After creating a model and adding it to a repository I want to have the new ID for different purposes (creating a mail, updating other fields outside the Extbase world)
$page = t3lib_div::makeInstance('Tx_MyExt_Domain_Model_Page');
$page->setTitle('Hello World');
$this->pageRepository->add($page);
At this point $page hasn't got an ID yet, uid is null.
$page->getUid(); // returns null
When does it get it? And how can I retrieve in on runtime?
In ExtBase, objects are "managed". This means every persistence transaction (add/remove/update) is simply noted in the underlying logic, but not yet executed until the appropriate time (like the end of processing a request). So, just because you add an object to a repository doesn't mean that it's actually added yet. That actually happens once $persistenceManager->persistAll() is called, which isn't something you need to do manually, ever. The point is, your $page object won't have a UID until it's saved and that's why $page->getUid() returns null. Look here for a great explanation.
I suspect that you are trying to do something outside of the ExtBase object/MVC lifecycle. At least, last time I got null when I tried to get the UID of an object, it was because I wasn't operating within the framework appropriately.
However, if you post some more code and give us a bigger picture of what you're trying to achieve, maybe we can help you get to a point where that object actually has a UID. For instance, if you're in a Controller object, tell us which Action method you're in, or if you're in a Repository object, tell us what you're trying to get from the repository and where/how you plan on using the query results.
EDIT
Just guessing here, but I'm assuming you're executing this code in some action of a controller. Since after the controller is executed a view is rendered, you can just pass the page object to the view:
$this->view->assign('page', $page);
And then in your view you can use the page object in a link:
<f:link.action action="show" arguments="{page:page}">
See this page object
</f:link.action>
And then in the show action of your controller you can show the page:
public function showAction(Tx_MyExt_Domain_Model_Page $page) {
// Do whatever you need to show the page in the `Show.html` template
}
I really am just guessing here. If you can give us a larger picture of what you're trying to do, what your action methods are supposed to do and things like that, we can answer your question a little more confidently.
(I'm also assuming that your page object isn't a replacement for the regular TYPO3 pages and that they are something totally different. It's much easier to deal with those TYPO3 pages through the backend interface than at the php level.)
You can call persistence manager explicitly in Your controller like this
#TYPO3 4.x
$persistenceManager = $this->objectManager->create('Tx_Extbase_Persistence_Manager');
$persistenceManager->persistAll();
#TYPO3 6.x
$persistenceManager = \TYPO3\CMS\Core\Utility\GeneralUtility::makeInstance('TYPO3\CMS\Extbase\Persistence\Generic\PersistenceManager');
$persistenceManager->persistAll();
I have created a Telerik report and I am setting the datasource on runtime to an object with some properties and a List. I am using the properties in the page and report header sections and i want to use the list as the details. Now the problem is binding to the List's item properties in the details section. I have played around with the expression builder and it seems that i should access the properties like this :
[=Fields.myList.Item.myProperty]
when i run the program i get a nice big red rectangle with the following error :
An error has occured while processing TextBox 'textBox28':Common Language Runtime detected an invalid program.
I have tried to change different variants of expression which also gives me other errors
[=Fields.myList.myPropery]
An error has occured while processing TextBox 'textBox28': The expression contains object 'myProperty' that is not defined in the current context.
The closest i have gotton was with the object it self, which outputs the object.toString()
[=Fields.myList]
I found a working solution although not what i was looking for, I created my own class with properties and made a List. I then retrieved the data from the db did the changes i wanted to do in the class and set the datasource of the report to the list. This is working quite well.
I struggled with this error:
An error has occured while processing TextBox 'textBox28': The expression contains object 'myProperty' that is not defined in the current context.
The solution I came up with was to make my model object inherit from List. For example:
public class MyReportModel : List<MyEntityDto> {
}
The look of the report wizard makes it seem like this isn't necessary, but I found no other way around this error.
This is for Telerik Reporting Q3 2013.
I am using methods with the Attribute [WebMethod] in my aspx pages. I don't use any asp.net ajax but jQuery to call these methods and return objects in JSON. This all works fine.
Next I added an authorization check inside the webMethod, if the current user doesn't have access to the feature I need to let the calling JavaScript know.
So I am throwing an AccessViolationException exception which can then be parsed by the OnError callback function in JavaScript. This works too but the exception includes the full StackTrace and I don't want to make this available to the calling client.
What other ways I could use to return an "Access Denied" to the client when the WebMethod returns a business object?
I'm using ASP.Net 3.5SP1 and jQuery 1.32
You can also add a:
customErrors mode="On"/
in your web.config, this will cut away the stack trace and leave you only the exception message
Why propagate errors through the wire? why not use an error response ?
Just wrap your object in a response object wich can contain an error code for status and an error message to present to users.
As suggested by NunFur I changed my approach and rather than throwing an error, I return a 'richer' object.
There are at least two options, the first one would be to encapsulate my business object into a response object with some status properties. I tried this but it makes the JSON more complicated.
So rather than adding a new object I added two properties to my business object, something like ServiceStatus and ServiceMessage. By default these are 200 and '', but can be set by the WebMethod code if anything goes wrong (no access, proper error). In this case they business object will be 'empty' (no data). The JavaScript code then first checks for the ServiceStatus and reacts appropriately.
I add the two fields to all my objects that are returned by WebMethods, even a simple string. They have to implement an Interface with those two properties.
Now I have complete control over that goes over the wire in case something unexpected is happening.
Thanks for the input
I save exceptions for when things go really wrong. (e.g. can't connect to the database)
Either return nothing (null/nill/whatever), or return a false bool value.
Sorry that I don't have a better answer than that...I'll have to keep looking myself.
You could look at SoapException: http://msdn.microsoft.com/en-us/library/system.web.services.protocols.soapexception(VS.71).aspx
I'm just not sure, if it will work when it is called from JavaScript. Espeially if it's called with a get-request.
BTW AccessViolationException is to my best knowlegde ment to be thrown when the application is accessing memory it has no access to.
/Asger