Databases
StackOverflow2013
Postsdbo
POSkip null values with custom resolver
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POSkip null values with custom resolver
    primarykey
    data
    text
    <p>I want to use automapper to map between my public data contracts and my DB models. I have created a class which automatically goes through all the contracts are creates mappings. The only problem I have is that I only want to map values from the contract to the DB model if the value is not null. I have looked at other question on here but cant see examples that use custom resolvers.</p> <p>Here is some of my code</p> <pre><code>var mapToTarget = AutoMapper.Mapper.CreateMap(contract, mappedTo); foreach (var property in contract.GetProperties().Where(property =&gt; property.CustomAttributes.Any(a =&gt; a.AttributeType == typeof(MapsToProperty)))) { var attribute = property.GetCustomAttributes(typeof(MapsToProperty), true).FirstOrDefault() as MapsToProperty; if (attribute == null) continue; mapToTarget.ForMember(attribute.MappedToName, opt =&gt; opt.ResolveUsing&lt;ContractToSourceResolver&gt;() .ConstructedBy(() =&gt; new ContractToSourceResolver(new MapsToProperty(property.Name, attribute.SourceToContractMethod, attribute.ContractToSourceMethod)))); } private class ContractToSourceResolver : ValueResolver&lt;IDataContract, object&gt; { private MapsToProperty Property { get; set; } public ContractToSourceResolver(MapsToProperty property) { Property = property; } protected override object ResolveCore(IDataContract contract) { object result = null; if (Property.ContractToSourceMethod != null) { var method = contract.GetType() .GetMethod(Property.ContractToSourceMethod, BindingFlags.Public | BindingFlags.Static); result = method != null ? method.Invoke(null, new object[] {contract}) : null; } else { var property = contract.GetType().GetProperties().FirstOrDefault(p =&gt; p.Name == Property.MappedToName); if (property != null) { result = property.GetValue(contract); } } return result; } } </code></pre> <p>And this is how I want to use it</p> <pre><code>AutoMapper.Mapper.Map(dataContract, dbModel) </code></pre> <p>This currently works great but if there is a NULL value in the dataContract then it will replace the existing value in the dbModel, this is not what I want. How do I make AutoMapper ignore null source values?</p> <p><strong>EDIT</strong></p> <p>As pointed out in one of the answers there is this </p> <pre><code>Mapper.CreateMap&lt;SourceType, DestinationType&gt;().ForAllMembers(opt =&gt; opt.Condition(srs =&gt; !srs.IsSourceValueNull)); </code></pre> <p>This would be ideal except for the fact that .ForAllMembers is not accessible from </p> <pre><code>Mapper.CreateMap(SourceType, DestinationType) </code></pre>
    singulars
    1. PO
      singulars
      1. PTAnswer
    1. This table or related slice is empty.
    1. PTQuestion
    1. USUwe Keim
    1. USMike Norgate
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PO
      singulars
      1. PTAnswer
    1. VO
      singulars
      1. POSkip null values with custom resolver
      1. USMike Norgate
      1. VTBountyStart
    2. VO
      singulars
      1. POSkip null values with custom resolver
      1. This table or related slice is empty.
      1. VTBountyClose
    1. This table or related slice is empty.
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload