I decided to implement caching to improve the performance of the product pages.
Each page contains a large amount of the product's images.
I created the following code in a Razor view.
#{
var productID = UrlData[0].AsInt();
var cacheItemKey = "products";
var cacheHit = true;
var data = WebCache.Get(cacheItemKey);
var db = Database.Open("adldb");
if (data == null) {
cacheHit = false;
}
if (cacheHit == false) {
data = db.Query("SELECT * FROM Products WHERE ProductID = #0", productID).ToList();
WebCache.Set(cacheItemKey, data, 1, false);
}
}
I'm using the data with the following code:
#foreach (dynamic p in data)
{
<a href="~/Products/View/#p.ProductID"
<img src="~/Thumbnail/#p.ProductID"></a>
}
The caching code works well, but when passing the new query string parameter (changing the version of the page) the result in browser is the same for the declared cashing time.
How to make caching every version of the page?
Thanks
Oleg
A very simple approach might be to convert your key (productID) to a string and append it to the name of your cacheItemKey.
So you might consider changing the line:
var cacheItemKey = "products";
to read:
var cacheItemKey = "products" + productID.ToString();
This should produce the behavior you are looking for -- basically mimicking a VaryByParam setup.
ps. Please keep in mind I have not added any sort of defensive code, which you should do.
Hope that helps.
Related
I've followed this tutorial to create a custom dynamic backend configuration with serialized data, and everything is working as expected. yay
But now I want to take another step and only show some inputs when a specific value is selected in a select box. I know that I can use when doing this with system.xml, but how can I accomplish the same thing via code with dynamics serialized tables?
I ended up doing some kind of Javascript workaround to enable/disable a certain input.
function togleSelect(element)
{
var val = element.value;
var name = element.name;
if (val == 0) // select value to be triggered
{
name = name.substr(0, name.lastIndexOf("[")) + "[name_of_my_input]";
var target = document.getElementsByName(name);
target[0].disabled = false;
}
else
{
name = name.substr(0, name.lastIndexOf("[")) + "[name_of_my_input]";
var target = document.getElementsByName(name);
target[0].disabled = true;
}
}
It's not the best solution but it's working.
I am getting the following error when I try to update tree of object using asp.net webapi OData:
"UpdateRelatedObject method only works when the sourceProperty is not collection."
My code is provided below. I got this error when the mehod "UpdateRelatedObject" is called. Can you please advise what is wrong with my code and how to update tree of objects (meaning object contains collection of child objects) using asp.net webapi odata v4.
var container = new Container(new Uri("http://JohnAlbert.com/MyOdataTest/odata"));
Product product = container.Products.Expand(p=> p.ProductItems).Expand(p=>p.ProductInvoices).Where(p => p.PId == Guid.Parse("28C508B8-F2DC-45C2-B401-7F94E79AB347")).FirstOrDefault();
if (product != null)
{
product.Name = product.Name + "_Modified";
var pitem1 = product.ProductItems[0];
product.ProductItems.Remove(pitem1);
container.UpdateRelatedObject(product, "ProductItems", pitem1);
var pitem2 = product.ProductItems[0];
pitem2.Price = 999;
container.UpdateRelatedObject(product, "ProductItems", pitem1);
var pInv1 = product.ProductInvoices[0];
product.ProductInvoices.Remove(pInv1);
container.UpdateRelatedObject(product, "ProductInvoices", pInv1);
}
container.UpdateObject(product);
container.SaveChanges(SaveChangesOptions.BatchWithSingleChangeset);
What you actually want to delete the relationship between some items in a collection-valued navigation property of an entity and itself. In such case DeleteLink() is the right method to use. In this case the following code should do the work:
if (product != null)
{
var pitem1 = product.ProductItems[0];
var pitem2 = product.ProductItems[0];
var pInv1 = product.ProductInvoices[0];
container.DeleteLink(product, "ProductItems", pitem1);
container.DeleteLink(product, "ProductItems", pitem2);
container.DeleteLink(product, "ProductInvoices", pInv1);
container.SaveChanges();
}
You may think the above way isn't as intuitive as directly removing the navigation items from the entity using .Remove() as you did. For this problem, the entity tracking enabled by using DataServiceCollection<T> can help. You can use this blog post as a tutorial for how to use DataServiceCollection<T>: http://blogs.msdn.com/b/odatateam/archive/2014/04/10/client-property-tracking-for-patch.aspx
To delete a contained navigation property, you can use DataServiceContext.DeleteObject.
To delete a relationship between an entity and its navigation property, you can use DataServiceContext.DeleteLink
To update an object, you can use DataServiceContext.UpdateObject.
So according to your scenario, you could use following code
if (product != null)
{
product.Name = product.Name + "_Modified";
dsc.UpdateObject(product);
var pitem1 = product.ProductItems[0];
//This is to remove relationship
container.DeleteLink(product, "ProductItems", pitem1);
// This is to remove the object
//container.DeleteObject(pitem1);
var pitem2 = product.ProductItems[0];
pitem2.Price = 999;
container.UpdateObject(pitem2);
var pInv1 = product.ProductInvoices[0];
//This is to remove relationship
container.DeleteLink(product, "ProductInvoices", pInv1);
// This is to remove the object
//container.DeleteObject(pInv1);
container.SaveChanges(SaveChangesOptions.BatchWithSingleChangeset);
}
I am querying data from our IBM i and displaying it in a grid. The purpose of displaying all records is for a couple reasons:
The existing software isn't used properly and people aren't closing out the items. (user/training issue yes, but see other items). So narrowing down the list to just open items isn't accurate.
It allows a user to query all history (this is property based and history can be important)
However, there currently is 28,000 items and will ever increase. Right now, I am using MvcContrib grid. Here is my code:
public ActionResult Index(GridSortOptions gridSortOptions, int? page, int? filterPropertyUniqueKey, int? filterPermitNumber)
{
#region Filter and Sort
var permits = buildingPermitRepository.GetOpenPermits();
// Set default sort and apply filters
if (filterPermitNumber.HasValue)
{
permits = permits.Where(w => w.PermitId == filterPermitNumber.Value);
}
// TODO add more filters
if (String.IsNullOrEmpty(gridSortOptions.Column))
{
gridSortOptions.Column = "DateApplied";
gridSortOptions.Direction = SortDirection.Descending;
}
var permitsPagedList = permits.OrderBy(gridSortOptions.Column, gridSortOptions.Direction).AsPagination(page ?? 1, 20);
#endregion
var viewModel = new PermitIndexViewModel
{
BuildingPermits = permitsPagedList,
GridSortOptions = gridSortOptions
};
return View(viewModel);
}
What would you suggest I do differently to improve the display speed? At least for subsequent views.
I don't know how AsPagination method works, but we use Skip and Take methods.
So after all filtering is done your code could look like this:
var permitsPagedList = permits.OrderBy(gridSortOptions.Column, gridSortOptions.Direction).Skip(pageSize * (page -1)).Take(pageSize).ToList();
This simple method returns only those rows which we actualy needs.
<dx:ASPxGridView ID="ASPxGridView1" runat="server" AutoGenerateColumns="False"
KeyFieldName="CategoryID">
<SettingsEditing Mode="Inline" />
<Columns>
<dx:GridViewCommandColumn VisibleIndex="0">
<EditButton Visible="True"></EditButton>
<NewButton Visible="True"></NewButton>
<DeleteButton Visible="True"></DeleteButton>
</dx:GridViewCommandColumn>
<dx:GridViewDataTextColumn Caption="CategoryID" FieldName="CategoryID"
VisibleIndex="1">
</dx:GridViewDataTextColumn>
<dx:GridViewDataTextColumn Caption="CategoryName" FieldName="CategoryName"
VisibleIndex="2">
</dx:GridViewDataTextColumn>
<dx:GridViewDataTextColumn Caption="Description" FieldName="Description"
VisibleIndex="3">
</dx:GridViewDataTextColumn>
</Columns>
</dx:ASPxGridView>
C# syntax:
NorthwindDataContext db = new NorthwindDataContext();
var lresult = (db.Categories
.Select(p => new { p.CategoryID, p.CategoryName, p.Description}));
ASPxGridView1.DataSource = lresult;
ASPxGridView1.DataBind();
If you run the code, you get a gridview which is filled by NorthWind Categories table. If you click on command button of grid whose are on left side, you get insert/update field, but you have not access to give input. They are gone to read only mode.
If I replace the above C# syntax with below
NorthwindDataContext db = new NorthwindDataContext();
var lresult = (db.Categories);
ASPxGridView1.DataSource = lresult;
ASPxGridView1.DataBind();
then it works fine. Now you can work with command button with out facing any problem.
I want to know what the problem is, why the first syntax does not work. Maybe you say
Anonymous types are class types that consist of one or more public read-only properties. But when you need to join more than one table and need to select several fields not all than what you do. Hope you not say linq is fail to do that or Don't think it is possible. Hope there must be any technique or else something to bind control with Anonymous type. Plz show some syntax .
The problem is that the result set is collection of Anonymous type as you supposed and the grid doesn't know how to treat it. What you have to do is to use RowInserting and RowUpdating events of the grid.
Here is an example of how I use DevExpress grid with NHibernate:
protected void gridAgentGroups_RowInserting(object sender, DevExpress.Web.Data.ASPxDataInsertingEventArgs e)
{
ASPxGridView currentGrid = sender as ASPxGridView;
var currentAgentGroup = new AgentGroup();
if (e.NewValues.Contains("Name"))
{
var newValue = (string)e.NewValues["Name"];
currentAgentGroup.Name = newValue;
}
if (e.NewValues.Contains("PhysicalAddress"))
{
var newValue = (string)e.NewValues["PhysicalAddress"];
currentAgentGroup.PhysicalAddress = newValue;
}
AgentGroupsDataAccess.SaveAgentGroup(currentAgentGroup);
e.Cancel = true;
currentGrid.CancelEdit();
currentGrid.DataBind();
}
protected void gridAgentGroups_RowUpdating(object sender, DevExpress.Web.Data.ASPxDataUpdatingEventArgs e)
{
ASPxGridView currentGrid = sender as ASPxGridView;
int currentAgentGroupId = (int)((AgentGroup)currentGrid.GetRow(currentGrid.EditingRowVisibleIndex)).Id;
var currentAgentGroup = AgentGroups.Where(ag => ag.Id == currentAgentGroupId).FirstOrDefault();
if (e.NewValues.Contains("Name"))
{
var newValue = (string)e.NewValues["Name"];
currentAgentGroup.Name = newValue;
}
if (e.NewValues.Contains("PhysicalAddress"))
{
var newValue = (string)e.NewValues["PhysicalAddress"];
currentAgentGroup.PhysicalAddress = newValue;
}
AgentGroupsDataAccess.SaveAgentGroup(currentAgentGroup);
e.Cancel = true;
currentGrid.CancelEdit();
currentGrid.DataBind();
}
I hope this will help.
Just a wild guess - you're binding your data to the grid using field names - yet, your anonymous type doesn't really have any field names.
Does it make any difference if you try this code:
NorthwindDataContext db = new NorthwindDataContext();
var lresult = (db.Categories
.Select(p => new { CategoryID = p.CategoryID,
CategoryName = p.CategoryName,
Description = p.Description}));
ASPxGridView1.DataSource = lresult;
ASPxGridView1.DataBind();
Again - I don't have the means to test this right now, it's just a gut feeling..... try it - does that help at all??
You actually can bind with anonymous type as you see the already filled rows. But: the grid itself cannot know how you build the query and what to add additionally to the visible columns (if there are valid default values).
As you use Developer Express' grid you have the option to provide your own update / edit form and handle everything needed on your own.
I have a property in umbraco that uses a drop down data type with a set of prevalues that you can select from.
How do I retrieve a list of all the possible prevalues that are in this drop down list?
There's a helper method in umbraco.library that does that.
From xslt:
<xsl:variable name="prevalues" select="umbraco.library:GetPreValues(1234)" />
From code:
using umbraco;
XPathNodeIterator prevalues = library.GetPrevalues(1234);
Replace 1234 with the id of your datatype (You can see it in the bottom of your browser when hovering your mouse over the datatype in the developers section)
Regards
Jesper Hauge
Here is the code that I use in one of my Umbraco datatypes to get a DropDownList containing all possible prevalues:
var prevalues = PreValues.GetPreValues(dataTypeDefinitionId);
DropDownList ddl = new DropDownList();
if (prevalues.Count > 0)
{
for (int i = 0; i < prevalues.Count; i++)
{
var prevalue = (PreValue)prevalues[i];
if (!String.IsNullOrEmpty(prevalue.Value))
{
ddl.Items.Add(new ListItem(prevalue.Value, prevalue.DataTypeId.ToString()));
}
}
}
Replace dataTypeDefinitionId with the id of your datatype.
I know this is an old question, but I created this method based on the information provided in this answer and I think it is worth documenting:
public static class UmbracoExtensions
{
public static IEnumerable<string> GetDropDownDataTypeValues(int dataTypeId)
{
var dataTypeValues = umbraco.library.GetPreValues(dataTypeId);
var dataTypeValuesEnumerator = dataTypeValues.GetEnumerator();
while (dataTypeValues.MoveNext())
{
dynamic dataTypeItem = dataTypeValues.Current;
yield return dataTypeItem.Value;
}
}
}