I have a SqlDataSource defined in my aspx file that I use to call a StoredProcedure. It takes a hiddenField as its control parameter.
<asp:HiddenField ID="input" runat="server" />
<asp:SqlDataSource ID="source" runat="server"
ConnectionString="<%$ ConnectionStrings:ConnectionString %>"
SelectCommand="sp" SelectCommandType="StoredProcedure">
<SelectParameters>
<asp:ControlParameter ControlID="input" Name="input" Type="String" />
</SelectParameters>
</asp:SqlDataSource>
Is there a way I can grab that parameter from the ViewState instead? Preferably while keeping the datasource definition in the aspx file.
The solution in your case is very easy. Just create your own class inherit it from Parameter and override Evaluate method.
[DefaultProperty("ViewStateKey")]
public class ViewStateParameter : Parameter
{
public string ViewStateKey
{
get
{
return (string)ViewState["ViewStateKey"] ?? string.Empty;
}
set
{
if (ViewStateKey == value)
return;
ViewState["ViewStateKey"] = value;
OnParameterChanged();
}
}
protected override object Evaluate(HttpContext context, Control control)
{
if (control == null || string.IsNullOrEmpty(ViewStateKey))
return null;
return ViewState[ViewStateKey];
}
}
After that you will be able to use your parameter like following (just remember to register it at the top of your page or in web.config):
<asp:SqlDataSource ID="source" runat="server"
ConnectionString="<%$ ConnectionStrings:ConnectionString %>"
SelectCommand="sp" SelectCommandType="StoredProcedure">
<SelectParameters>
<my:ViewStateParameter Name="input" Type="String" ViewStateKey="input" />
</SelectParameters>
</asp:SqlDataSource>
And your parameter will get its value from viewstate by key input.
I dont feel that the code for ViewStateParameter is of the first class. Maybe you will want to decorate it with more attributes and/or extra parameter checks with assertions.
I have similar problem. I dont want to use hidden fields to bind data source parameters because of security reasons.
I have googled one work-around - use asp:label instead of hidden field (make sure Visible=false). And then your label goes to view state and you can bind label to data source parameters.
Related
I am trying to set the SelectedValue of a RadDropDownList in the EditTemplate of my RadGrid. The DataItemBound event appears to be throwing an error on compilation.
ASP.NET
<telerik:GridTemplateColumn DataField="givenAnswer" HeaderText="givenAnswer" UniqueName="givenAnswer">
<ItemTemplate>
<%# DataBinder.Eval(Container.DataItem, "givenAnswer") %>
</ItemTemplate>
<EditItemTemplate>
<telerik:RadDropDownList ID="ddlGivenAnswer" runat="server" OnItemDataBound="ddlGivenAnswer_DataBound">
<Items>
<telerik:DropDownListItem Text="Yes" Value="Yes" />
<telerik:DropDownListItem Text="No" Value="No" />
</Items>
</telerik:RadDropDownList>
</EditItemTemplate>
</telerik:GridTemplateColumn>
C#
protected void ddlGivenAnswer_DataBound(object sender, GridItemEventArgs e)
{
if ((e.Item.IsInEditMode))
{
GridEditFormItem item = (GridEditFormItem)e.Item;
RadDropDownList ddl = (RadDropDownList)item.FindControl("ddlgivenAnswer");
ddl.SelectedValue = (string)DataBinder.Eval(e.Item.DataItem, "givenAnswer").ToString();
}
}
Error
CS0123: No overload for 'ddlGivenAnswer_DataBound' matches delegate 'DropDownListItemEventHandler'
This error is being throw on the telerik:RadDropDownList open tag line in ASP.NET. What am I missing here?
Main Edit:
Error CS0123:
First typing CS0123 in Google show me that you were using wrong parameter for your event. Probably a copypast fail. Delete the even in the aspx and ask to intelisense to create a new one. Or copypast this one.
protected void ddlGivenAnswer_ItemDataBound(object sender, Telerik.Web.UI.DropDownListItemEventArgs e)
ItemDataBound:
ItemDataBound occure when a data is bound in a control.
I'am pretty sure that inline declaration are not going to fire this event.
Minor Misconception:
Why would someone change the Value of a selected element dynamically?
It's like changing the value of a vote without changing the vote him self or the name on the vote.
What you want is to check the rigth item.
To check Waldo in the drop down list :
ddlGivenAnswer.FindItemByValue("Waldo").Selected = true;
To check the right Item:
ddlGivenAnswer.FindItemByValue(
DataBinder.Eval(e.Item.DataItem, "givenAnswer").ToString()
).Selected = true;
I have a page in MVC3 with a model of "pageModel".
In this page I have:
#{ Html.RenderPartial("_subPage", Model.subModel); } (Pagemodel.submodel)
In my controller I am doing:
[Authorize]
[AcceptVerbs(HttpVerbs.Post)]
public ActionResult Results(pagemodel model, string frmAction)
{
}
The page loads fine the first time, but when I postback into the httpPost action, model.submodel is always null.
My question is, how do I return an updated model from the RenderPartial (if at all). I can get my model INTO the partial, but not back!
The problem with partials is that they do not preserve the navigational context. This means that any input fields that you might have put inside this partial will have incorrect names and the default model binder will not be able to retrieve the values back when you POST. Your HTML will look like this:
<input type="text" name="Prop1" value="property 1 value" />
<input type="text" name="Prop2" value="property 2 value" />
whereas the correct is:
<input type="text" name="subModel.Prop1" value="property 1 value" />
<input type="text" name="subModel.Prop2" value="property 2 value" />
In order to achieve this correct markup I would recommend you using editor templates.
So you replace:
#{ Html.RenderPartial("_subPage", Model.subModel); }
with:
#Html.EditorFor(x => x.subModel)
and then you move your _subPage.cshtml partial into ~/Views/Shared/EditorTemplates/SubModelType.cshtml where SubModelType is the type of the subModel property:
#model SubModelType
#Html.EditorFor(x => x.Prop1)
#Html.EditorFor(x => x.Prop2)
Now when you look at the generated HTML the corresponding input field names should be prefixed with subModel and inside the POST controller action the model.subModel property will this time be properly initialized and populated from the values that were entered by the user in the input fields.
you'll need to change your partialview to accept the top level model, i.e:
#{ Html.RenderPartial("_subPage", Model); }
which would then render your properties in the partialview with the correct property names i.e. :
<input type="text" name="subModel.MyProperty" value="somevalue" />
It would also mean that your returned model in the HttpPost action will have to correct navigational relationship intact.
this is just one of those caveats related to viewmodels and hierarchies. Oh, btw, in mvc3, you don't need the verbose [AcceptVerbs(HttpVerbs.Post)] for posts. You can simply use [HttpPost]
You can also perform the following.
#Html.RenderPartial(
"_subPage",
Model.subModel,
new ViewDataDictionary
{
TemplateInfo = new TemplateInfo
{
HtmlFieldPrefix = "subModel"
}
});
Your partial view will remain as is, using the #model SubModel
On my page I have a button that opens a list of items in a popup. When I select 1 item in the list, I want to pass the id of the item to the backingbean of my first page. Is it possible? It tried to do it with a4j:jsFunction and a4j:param but it does'nt work.
This is my code:
page 1:
<a4j:jsFunction name="renderGuarantor" render="guarantor" actionListener="#{prospectDetail.setNewGuarantor}">
<a4j:param name="param1" assignTo="#{prospectDetail.newGuarantorId}" />
</a4j:jsFunction>
popuppage:
<h:outputLink value="" onclick="window.opener.renderGuarantor(#{applicant.deposit_id});window.close();">
<h:graphicImage style="padding:0 1px; border:0" value="${path.staticRootUrl}images/confirm.gif" alt="${msg.applicantslist_select}" title="${msg.applicantslist_select}"/>
</h:outputLink>
And this is the backing bean code for the first page
private Integer newGuarantorId;
public void setNewGuarantor() {
guarantor = newGuarantorId;
}
public Integer getNewGuarantorId() {
return newGuarantorId;
}
public void setNewGuarantorId(Integer newGuarantorId) {
this.newGuarantorId = newGuarantorId;
}
When selecting in the popup the method in my backingbean is called, but newGuarantorId is null and setNewGuarantorId is never called.
Is there a solution to my problem?
Hmm.. thats strange, nothing looks wrong..Not an answer to your question but try this workaround - instead of assigning the value to guarantorId, keep the param as <a4j:param name="param1"/> and in the actionListener method retrieve this param1 from the request as String param1 = FacesContext.getCurrentInstance().getExternalContext().getRequestParameterMap().get("param1");.
And then convert this param to int and utilize it further. That should work
Try switching from actionListener to action:
<a4j:jsFunction name="renderGuarantor" render="guarantor" action="#{prospectDetail.setNewGuarantor}">
<a4j:param name="param1" assignTo="#{prospectDetail.newGuarantorId}"/>
</a4j:jsFunction>
Here is recommended reading on the topic: a4j:jsFunction
I think you can try this:
<a4j:jsFunction name="renderGuarantor" render="guarantor"
actionListener="#{prospectDetail.setNewGuarantor(prospectDetail.newGuarantorId)}" />
And in your Managed bean, define the setNewGuarantor method as following:
public void setNewGuarantor(int newGuarantorId) {
guarantor = newGuarantorId;
}
I have an employee entity in my EF model. I then added a class to the project to add a custom property
public partial class Employee
{
public string Name
{
get { return string.Format("{0} {1}", this.FirstName, this.LastName); }
}
}
On a aspx form (inside a FormView), I want to bind a DropDownList to the employee collection:
<asp:Label runat="server" AssociatedControlID="ddlManagerId"
Text="ManagerId" />
<asp:DropDownList ID="ddlManagerId" runat="server"
DataSourceID="edsManagerId"
DataValueField="Id"
DataTextField="Name"
AppendDataBoundItems="true"
SelectedValue='<%# Bind("ManagerId") %>'>
<asp:ListItem Text="-- Select --" Value="0" />
</asp:DropDownList>
<asp:EntityDataSource ID="edsManagerId" runat="server"
ConnectionString="name=Entities"
DefaultContainerName="Entities"
EntitySetName="Employees"
EntityTypeFilter="Employee"
EnableFlattening="true">
</asp:EntityDataSource>
Unfortunately, when I fire up the page, I get an error:
DataBinding: 'System.Web.UI.WebControls.EntityDataSourceWrapper' does not contain a property with the name 'Name'.
Any ideas what I'm doing wrong?
After much searching I discovered that that the EntityDataSource does not support custom properties in the partial classes. It only returns the entity that is in the model.
As per this article:
The issue is that we’re using the EntityDataSourceWrapper and not our actual entity. The solution? Stop using the wrapper!
Disable flattening, like this:
<asp:EntityDataSource
...
EnableFlattening="False"
...
</asp:EntityDataSource>
More information on Flattening is here.
Could you verify that both your partial Employee classes are in the same namespace?
I wonder if it is possible for me to freeze or disable the entire update form? I have an input h:form with a check box in it. when users check the box, I would like to freeze or disable the entire form so that disallow users from changing inputs.
Thanks, and I am using JSF, Spring Web Flow, Facelets, and Trinidad.
You would want to use javascript to set all the form inputs to disabled when the user checks the checkbox. Something like:
document.getElementById('id').disabled = true;
You would do this for each input element where 'id' is the ID of that element.
If you want to disable only certain inputs, It is a good idea to enumerate them:
function OptCheckBox(chkd) {
if (chkd == 'y') {
document.frm.input1.disabled = true;
document.frm.input2.disabled = true;
}
}
You cannot disable an entire form at once. You really need to disable each of the input elements. There are basically two ways to achieve this.
First way is to use Javascript to submit the form to the server when the checkbox is clicked, so that you can use JSF component's disabled attribute to disable the elements. Here's a basic example:
<h:form>
<h:selectBooleanCheckbox value="#{bean.freeze}" onclick="submit()" />
<h:inputText value="#{bean.value1}" disabled="#{bean.freeze}" />
<h:inputText value="#{bean.value2}" disabled="#{bean.freeze}" />
<h:inputText value="#{bean.value3}" disabled="#{bean.freeze}" />
</h:form>
Here #{bean.freeze} should point to a boolean property.
Second way is to write a Javascript function for this. This does not require a form submit and saves you from one HTTP request-response cycle, which is better for user experience.
<h:form>
<h:selectBooleanCheckbox onclick="disableForm(this)" />
<h:inputText value="#{bean.value1}" />
<h:inputText value="#{bean.value2}" />
<h:inputText value="#{bean.value3}" />
</h:form>
The JS function disableForm() is basically simple. Just pass the checkbox in as function argument by this so that you can get the parent form by checkboxElement.form and then get all form elements by form.elements. You only need to make sure that you don't disable the checkbox itself, so that you could re-enable the form again :)
function disableForm(checkboxElement) {
var elements = checkboxElement.form.elements;
for (var i = 0; i < elements.length; i++) {
var element = elements[i];
if (element != checkboxElement) {
element.disabled = checkbox.checked;
}
}
}
No need to know the ID's beforehand and this makes the JS code generic and reuseable.