v8 prevalues from a specific data type

Ólafur Hólm Eyþórsson 3 posts 94 karma points

Mar 18, 2019 @ 18:04

Umbraco 8

Hi, how do i get the prevalues from a specific data type in v8 ?

at my work place we've always been doing the example below in v7

public static string GetPreValue(string id)
{
   var value = string.Empty;
   if (!string.IsNullOrEmpty(id))
   {
       int preId = 0;
       var parse = Int32.TryParse(id, out preId);

       if (parse)
       {
           var helper = new UmbracoHelper(UmbracoContext.Current);

           value = helper.GetPreValueAsString(preId);
       }
   }
   return value;
}

and

public List<SelectListItem> GetPreValuesFromDataTypeId(int dataTypeId)
        {
            List<SelectListItem> preValueSelectorList = new List<SelectListItem>();

            XPathNodeIterator iterator = umbraco.library.GetPreValues(dataTypeId);
            iterator.MoveNext();
            XPathNodeIterator preValues = iterator.Current.SelectChildren("preValue", "");

            while (preValues.MoveNext())
            {
                string preValueIdAsString = preValues.Current.GetAttribute("id", "");
                int preValueId = 0;
                int.TryParse(preValueIdAsString, out preValueId);
                string preValue = preValues.Current.Value;
                preValueSelectorList.Add(new SelectListItem { Value = preValue, Text = preValue });
            }

            return preValueSelectorList;
        }

but that is no longer possible to do :/

So any information on this would be of appreciated :)

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David Knittl 13 posts 114 karma points

Mar 20, 2019 @ 12:10

Hi,

I have a similar problem. I also work with the prevalues of a dropdown field in my code. In v7 I accessed the prevalues through

Services.DataTypeService.GetPreValuesCollectionByDataTypeId(dataTypeId).PreValuesAsDictionary

That's not working any more in v8. Now through debugging I found a property called "Configuration" on the IDataType interface. All prevalues are in there (I see them in debugging) and that object is of type

Umbraco.Core.PropertyEditors.DropDownFlexibleConfiguration

Now if I try to access this property and cast it to DropDownFlexibleConfiguration (or if I use the "ConfigurationAs

Does anyone have an idea how to access the prevalues in v8?

Cheers, David

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Philip Hayton 98 posts 435 karma points

Apr 27, 2019 @ 09:52

Did anybody get to the bottom of this?

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Rhys Hamilton 140 posts 942 karma points

May 22, 2019 @ 09:18

I'm not sure if this is the best way to do this, but a sample class that I've put together, returns the ID for a prevalue that matches a string value (e.g - the id for "Item1" in my dropdown list). It's a bit specific to my use case, but it retrieves the prevalues perfectly for me.

private readonly IDataTypeService _dataTypeService;

public DefaultComposer(IDataTypeService dataTypeService)
{
    _dataTypeService = dataTypeService;
}

// Additional methods/logic can go here
// etc. etc.

// Returns the ID of the prevalue that matches the string value
private int GetDataTypePreValues(int id, string value)
{
    var dataType = _dataTypeService.GetDataType(id); // The ID of the DataType you want to access
    ValueListConfiguration prevalues = (ValueListConfiguration)dataType.Configuration;
    int selected = 0;

    if (prevalues != null && prevalues.Items != null && prevalues.Items.Any())
    {
        selected = prevalues.Items.Where(x => x.Value == value).Select(i => i.Id).FirstOrDefault();
    }

    return selected;
}

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Peter Aderhold 30 posts 204 karma points

Jan 05, 2020 @ 13:12

This is exactly the way we do it and it works.

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andrew shearer 506 posts 653 karma points

Sep 18, 2019 @ 20:16

hello - is there an equivalent helper method of GetPreValueAsString in v8 yet? maybe on second thoughts we shouldn't be using it anyway as it results in a sql hit to get the prevalue.. from the cache would be better.

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Rasmus Styrk 1 post 72 karma points

Sep 24, 2019 @ 04:41

Hi guys,

I got the prevalues for my dropdown field with this code.

@using Umbraco.Core.Services;
@using Umbraco.Core.PropertyEditors;

@{
    IDataTypeService dataTypeService = Services.DataTypeService;
    IDataType dataType = dataTypeService.GetDataType(1154); // Change number to your id from the data types section in backoffice
    ValueListConfiguration prevalues = (ValueListConfiguration)dataType.Configuration;

    foreach (ValueListConfiguration.ValueListItem item in prevalues.Items) {
        <p>@item.Value</p>
    }
}

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Mike Chambers 635 posts 1252 karma points c-trib

Oct 09, 2019 @ 12:17

Just stumbled across this myself, but think prevalue id's now aren't unique? as seeing cloud udas..

"EditorAlias": "Umbraco.CheckBoxList",
  "DatabaseType": 1,
  "Configuration": {"items":[{"id":1,"value":"Head of State"},{"id":2,"value":"Government Minister"},{"id":3,"value":"Civil Servant"},{"id":4,"value":"NGO Worker"},{"id":5,"value":"Teacher"},{"id":6,"value":"Student"},{"id":7,"value":"General Public"}]},

and another checkboxlist on the same site..

  "EditorAlias": "Umbraco.DropDown.Flexible",
  "DatabaseType": 1,
  "Configuration": {"multiple":false,"items":[{"id":2,"value":"Course"},{"id":3,"value":"E-Book"},{"id":4,"value":"Event"},{"id":6,"value":"Network"},{"id":7,"value":"News"},{"id":10,"value":"Video"},{"id":9,"value":"External Link"},{"id":11,"value":"Briefing"},{"id":12,"value":"Report"},{"id":13,"value":"Learning Resource"},{"id":14,"value":"Teaching Resource"},{"id":15,"value":"Infographic"},{"id":16,"value":"Policy Document"},{"id":17,"value":"Webinar"},{"id":18,"value":"Paper"}]},

and values stored in the db are json.. jsut the value. UmbracoPropertyData table

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Phil Whittaker 63 posts 267 karma points MVP 3x c-trib

Dec 15, 2019 @ 09:55

After lots of hunting around the code, the way that Umbraco 8 does this is

       var propEditor = Current.PropertyEditors.Where(x => x.Alias == dataType.EditorAlias).FirstOrDefault();
       var config = propEditor.GetConfigurationEditor().ToValueEditor(dataType.Configuration);

The first line just gets you the property editor for the DataType, the second line is the important one, it returns an IDictionary

This can be serialised into a json object

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V8 Prevalues from a specific data type