Is breeze provide support to work with c# Enums - enums

Question

I want to populate my dropdowns with enum using breeze. It show enum in breeze metadata but I did not find a way how to consume it. Is breeze provide support yet to work c# enums?

Answer 1

If you are using a standard Breeze WebApi server then enum values should all be coming down as strings and can be saved back to the server also as strings. Out of the box, the default Breeze WebApi server implementation will convert the strings to the correct enum values automatically in both directions.
(Note: this will not work with a server using the current MS WebApi/OData provider because MS does not yet not support enums with this provider - MS will support this in their upcoming 4.0 release.)
So, for example, assuming that you had a server side enum that looked like this:
public enum RoleType {
Guest = 0,
Restricted = 1,
Standard = 2,
Admin = 3
}
in conjunction with a 'Role' class that had a 'RoleType' property, then the the following query would work:
var query = new EntityQuery("Roles").where("RoleType", "==", 'Restricted');
myEntityManager.executeQuery(query).then(...);
Similarly, if you wanted to change a RoleType for a given role then you could
role.RoleType = "Standard"; // assuming breeze backingStore adapter.
myEntityManager.saveChanges();

Answer 2

If you are generating offline breeze metadata then you can get all Enums definition in metadata itself and you can create a JS Dictionary(associated array) to populate all enum types and their definitions.
Well My situation was that I was using NancyFx(No EF) + Breeze + AngularJS for my web project. I generated metadata offline and stored it in a metadata.js file.
After creating EntityManager, I extracted enum defintions in a JS dictionary which I used later for binding dropdown, display corresponding enum strings etc.
Extract Enum Definition & Store in JS Dictionary
JSON.parse(window.app.metadata).schema.enumType.forEach(function (enumType) {
var newEnumValues = [];
enumType.member.forEach(function (enumValue) {
var newEnumValue = { id: enumValue.value, name: enumValue.name };
newEnumValues.push(newEnumValue);
});
enumDictionary[enumType.name] = newEnumValues;
});
Method to retrieve enum value on base of enum name and valueid
function GetEnumDictionaryValue(enumName, enumValueId) {
var result = null;
enumDictionary[enumName].some(function (enumValue) {
if (enumValue.id == enumValueId) {
result = enumValue.name;
return;
}
});
return result;
}
Binding Values to Dropdown
Now for binding dropdowns, just call enumDictionary[] and store result in a controller variable.
I was using Angular JS, so I used below code on html page
<select ng-options="type.id as type.name for type in <VariableName>"
></select>