So I have a question about MVC5.
I want to change the order of items listed on the view.
When a new record is created with the create view it automatically puts the new one under the old one when showed on the index view. I want it the other way around. So that the new record which is showing in the view is on top. I have no clue on how to achieve this. Hope someone can help me.
You should have a order column in your table. and order Items by that, this can be an integer, but however I Prefer a datetime type.
If you want to change the order of items just change their order field value.
Imagine that you are ordering descending, then setting current datetime to an item will move it to the end.
It is difficult to give a good answer to this question because of the lack of details in the question. Assuming however that you are creating the data in a database and returning a list from there you can add this to the Linq expression providing you with the list
OrderByDescending(x => x.ID)
where ID is the ID of the entity being created.
Related
It's a struggle with any application that provides select fields, that are populated by a certain datasource: Everything works fine in the first place, but once the application ages, some older entries might be deleted, leading to the problem that prior select fields can no longer access the entity in question.
Opening a view, where a select points to an already deleted datarow will (best case) show empty string.
We designed our system in a way, that deletions are not real delete-operations, but only the setting of a deleted flag. (So, all the information is still there)
However, when using Databindings along with C# (or even if not) the most blatant use case is still not covered by general mechanics (I assume):
Select-Field should show all NOT-Deleted-Entities while creating a new object containing references to the entity in question.
Select-Field (populated the very same way) should show the "deleted" entity, if it was selected "days/months/years" ago.
Is there a "handy" solution to this?
Currently we are using a "Proxy-Method" for every datasource, which will reload the data of the deleted entity, if it's not in the "available data" collection - but it's hard to believe there is no better way to deal with this, as this problem applies for almost every language out there?
In a normalized database you would have a constraint with ON DELETE NO ACTION/RESTRICT event that would prevent removal of a referenced element from the list. It would force you to decide what is to be done with the referencing rows.
With your manually-controlled deletions this could have been covered by a trigger. As none of these were implemented, you are left with only one thing to do: updating the dropdown with the selected option before rendering the UI. My approach (in Java, I'm not good at C#):
List<String> options = getNonDeletedWhatever();
if (!options.contains(currentEntity.getWhatever())) {
options.add(currentEntity.getWhatever()); // This optionally inserts an outdated value
}
or simply:
Set<String> options = getNonDeletedWhatever();
options.add(currentEntity.getWhatever()); // This optionally inserts an outdated value
I solve it by creating a list of available (non-deleted) items and if the selected item is a deleted one, then I add that item to the list.
This list becomes the data source for my dropdown.
my following problem is, that I have a List of Items and want to index those with elasticsearch. I have a running elasticsearch instance, and this instance has an index called "default".
So I'm running following code:
var items = GetAListOfItem();
var response = Client.IndexMany(items);
I also tried it with Client.IndexManyAsync(items). But that didn't do anything.
Only 1 Item of this List gets indexed. Nothing more. I think its the last item, which got indexed.
I thought it could be a thing with IEnumerable and multiple enumerations, but i parsed it as a List<Item>.
Another Question would be about the best practice with Elasticsearch. Is it common to use a Index per Model. So if I'm gathering data from for example Exchange and another system, I would do 2 indeces?
ExchangeIndex
OtherSystemIndex
Thank you for your help.
Update: I saw that my Client.Index does all those calls succesful, but all those objects got the same ID from NEST. Normally she had to increment by herself, isnt it?
Update 2: I fixed the Indexing Problem. I had setup an empty ID-Field.
But still have the question mit best practive about Elasticsearch.
If you are uploading all the data with the same id, it will not increment the id, that will update the record with that id and you will have only one record, so you can upload the data without an id or give wherever unique id to identified the records.
The other common problem is that your records have not the same mapping that you give for the index.
About the other question, in the indexes, you store the information that is relevant for you, even if that have content from many models, the only thing that you have to avoid is mix information, if you have an index about server logs dont mix it with user activities for example.
I have a list of Grid items called gridCache.
I have a TabItem called ti.
This line of code:
gridCache.Last().Name = ti.Name;
...is updating the Name property of every single Grid item in the list. It should just be updating the last item's Name property.
Why is it doing this?
Maybe I'm rubberducking here, but I've followed it through a break point while debugging and they all just update simultaneously when this line is called.
EDIT: I'd like to basically make 'copies' of flyGrid as it's modified to store them for later use. The idea is to use this to cache data from some SQL calls. Here's what I'm trying:
//some stuff that defines flyGrid
Grid cacheGrid = new Grid();
cacheGrid = flyGrid;
cacheGrid.Name = ti.Name;
gridCache.Add(cacheGrid);
After this recurs 3 or 4 times, the Name property of every item in the list is always the last name supplied.
How can I make a copy of flyGrid that is its own instance each time this code recurs?
SOLUTION EDIT:
I ended up solving the root problem in a completely different way. The idea was to get cached ReportParameterInfoCollection items to keep from talking to the database constantly.
I ended up creating a simple class for an object with two properties: one random string of letters, and a list of ReportParameterInfoCollection items.
This allowed me to populate this list as tabs are opened, and assign these tabs unique IDs that match the parameter information stored in this list of objects.
I didn't really solve the question, so I decided not to post this as an answer.
That would happen if every Grid is the same instance.
Make sure you're actually creating multiple instances when populating the list.
To elaborate on what I'm asking here, I'm working in C# trying to order a list of data that is coming out of a database. A certain object (table) has two separate properties (columns) which can hold dates. I want to sort this list based on date, meaning for each data row, I want to take the maximum of the two dates and use that for the sort.
Is there an elegant way to do this? At the moment I'm thinking that I should just get the max time from each record, and store it as a key in a Dictionary, with the data row being the value, and then iterate through the Dictionary with the sorted keys. Although this wouldn't be terrible to code, I'm trying to see if there is a nicer way to do this using Linq. Any help would be appreciated. Thanks.
If you want an alternative for sorting your collection everytime, .NET contains a class called SortedList. Here is the link to the MSDN article: http://msdn.microsoft.com/en-us/library/system.collections.sortedlist(v=vs.110).aspx
MSDN states that a SortedList:
Represents a collection of key/value pairs that are sorted by the keys and are accessible by key and by index.
So if you want to sort by date you can declare your sorted list as:
SortedList<DateTime, YourData> mySortedList = new SortedList<DateTime, YourData>();
and when you add values to it, it will already be sorted. Or you can just go with LINQ and #Alexander answer.
Edit
I just understood what you want to do. You can do:
table.OrderBy(item => Math.Max(item.Date1.Ticks, item.Date2.Ticks));
Note: The linq query above will not be performant on a large collection.
I'm using a DataTable as the datasource for my ComboBox and I need to sort the Data into a strict order. The problem is that the I don't need in Ascending Order or Descending, it's how the customer see's the items as a priority, so there's not really any logic too it.
Will I need to create a column that has an ordering value and then sort the data by that column? I'm just looking for the best way to do this. In time, more items may be added and the ordering may need to change. This is something i want to achieve without hard coding each time.
The Data at present only has two columns, which look like below:-
ApplicationName | ApplicationType
I just need the best way of doing this.
Thanks