So I'm using CoreData and wish to append an array of activities. The issue is, it will only append one/the latest entry within the view model array. This works as a one too many relationship.
let activity = Activity(context: self.moc)
activity.trip = Trip(context: self.moc)
activity.trip?.destinationName = destinationName
for activityIndex in flightOverViewModel.selectedActivites {
let ind = Activity()
ind.title = activityIndex.title
ind.name = activityIndex.name
ind.longitude = activityIndex.longitude
ind.latitude = activityIndex.latitude
}
try? self.moc.save()
I've tried activity.trip?.activitiesArray.append(ind) but get an error saying 'Cannot use mutating member on immutable value: 'activitiesArray' is a get-only property'.
Any ideas on how I can index and append each value in flightOverViewModel.selectedActivites array to CoreData?
Thank you.
Related
This question already has answers here:
Access struct field by variable
(3 answers)
Closed last month.
I am new to rust with a javaScript background and i am stuck with getting a value of a json key dynamically.
In JS if i have an object = { "xyz" : "one" , "jkl" : "two" }; and if i have a variable name = "xyz"; , then i can find the corresponding value of 'xyz' key in the object using object[name] which will give me "one" as a result.
Now i have the exact same flow in rust, where i have
let obj = config.clone(); // because config is struct (only cloning could remove the error)
let name = "xyz"; // A variable which is a key in the object
let result = obj[name];` // result which is giving me "cannot index into a value of type `Configuration`" error
I am aware that creating a dict or hashmap will exponentially reduce the time, but the object i have can contain upto 1000 keys and values or more.
If i can create a hashmap with the object I already have, that would be a relief ( only if i knew ).
I have tried multiple ways by just googling a bunch of stuff
let result = obj[name];
let result = obj.&name];
let result = obj[$name];
let result = obj[&name];
let result = obj.$name;
none of them seems to solve the issue.
Thanks in advance.
Accessing fields of structs dynamically is not possible out of the box. See this earlier question.
I have CoreData with simple relationships as you can see below. One entity Word with 4 attributes and a Chapter entity with a one to many relationship (each word figures in only one chapter and chapters contains several words). When I try to import a file with a list of words and associated chapter, the chapters which are not yet in the database are created (which is what I want) but the chapters that already exists are created a 2nd time (new same entry in coredata). Is there an option I can activate in xcdatamodel to check and avoid duplicate entries on the relation entity?
Code details ->
fileprivate func saveAllWords(_ items: [(name: String, definition: String, example: String, chapter: String)]?) {
for item in items! {
let newWord = Word(context: self.context)
newWord.name = item.name.trimmingCharacters(in: .whitespaces)
newWord.definition = item.definition.trimmingCharacters(in: .whitespaces)
newWord.example = item.example.trimmingCharacters(in: .whitespaces)
newWord.option = 10 // option tag indicating that it's a new entry from external fileI generate a classic word
//
let myNewChapter = Chapter(context: self.context)
myNewChapter.name = item.chapter
newWord.chapter = myNewChapter
}
……
// Save the data in Core Data
do {
try self.context.save()
}
catch {
}
Any recommendation how to implement this uniqueness constraint to solve my duplicate issue?
You have to create a constraint for the unique attribute. It looks like you want the name of the Chapter to be unique
In your xcdatamodeld select your attribute, then right constraint and add they attribute.
Last but not least you will have to add merge policy for your Context, mostly likely in your AppDelegate. There are different merge policy. You should check them out which fits your needs most
context.mergePolicy = NSMergeByPropertyObjectTrumpMergePolicy
I am iterating over a collection of data, in my case, an array of objects. Here is a sample of 2 data points from it:
{
violation_id: '211315',
inspection_id: '268804',
violation_category: 'Garbage and Refuse',
violation_date: '2012-03-22 0:00',
violation_date_closed: '',
violation_type: 'Refuse Accumulation' },
{
violation_id: '214351',
inspection_id: '273183',
violation_category: 'Building Conditions',
violation_date: '2012-05-01 0:00',
violation_date_closed: '2012-04-17 0:00',
violation_type: 'Mold or Mildew' }
I need to create a new array of objects from this, one for each "violation_category" property. If Violation category already exists in the new array I am creating, i simply add the information to that existing category object (instead of having two "building conditions" objects for example, I would just add to an existing one).
However, I am having trouble assigning to the existing object if the current one exists (it's easy to check if it does not, but not the other way around). This is what am attempting to do currently:
if (violationCategory.uniqueCategoryName) {
violationCategory.uniqueCategoryName.violations = results[i].violation_id;
violationCategory.uniqueCategoryName.date = results[i].violation_date;
violationCategory.uniqueCategoryName.closed =
results[i].violation_date_closed;
} else {
category.violations = results[i].violation_id;
category.date = results[i].violation_date;
category.closed = results[i].violation_date_closed;
violationCategory.push(category);
}
In first condition, if this category (key) exists, I simply add to it, and in the second condition, this is where I am struggling. Any help appreciated. Thanks guys.
Just add an empty object to the key if there no object there :
violationCategory.uniqueCategoryName = violationCategory.uniqueCategoryName || {};
And only then, add the data you want to the object.
violationCategory.uniqueCategoryName.violations = results[i].violation_id;
violationCategory.uniqueCategoryName.date = results[i].violation_date;
violationCategory.uniqueCategoryName.closed =
results[i].violation_date_closed;
No condition needed.
Good luck!
Assuming that you have an input variable which is an array of objects, where the objects are looking like the objects of the question, you can generate your output like this:
var output = {};
for (var item of input) {
if (!output[item.violation_category]) output[item.violation_category] = [];
output[item.violation_category].push(item);
}
Of course you might customize it like you want.
I am trying to copy data from one list to other list (both lists are on different sites) along with lookup columns. But, I am getting an error for lookup field as:
Value does not fall within the expected range
Code works and data gets copied for other non-lookup fields. I tried every possible way including increasing List View Lookup Threshold and all possible ways of code but still error persists at ExecuteQuery().
Below is my code for lookup field:
if (field is FieldLookup && field.InternalName == "Country")
{
var CountryLookup = (item.FieldValues["Country"] as FieldLookupValue).LookupValue.ToString();
var CountryLookupId = (item.FieldValues["Country"] as FieldLookupValue).LookupId.ToString();
FieldLookupValue flvRDS = new FieldLookupValue();
flvRDS.LookupId = int.Parse(CountryLookupId);
itemToCreate["Country"] = flvRDS;
itemToCreate.Update();
destContext.ExecuteQuery();
}
Help is really appreciated.
I assume item is the new ListItem you're trying to create on your target list.
But you're never in fact reading any value from field here! So basically, you're trying to set your new FieldLookup.LookupId with the item["Country"].LookupId, which should logically be empty at this moment.
Here's a method I use to retrieve a lookup field ListItem from a value, feel free to modify it to fit your need, since I don't know how you want to retrieve it (SPList is an alias for Microsoft.SharePoint.Client.List).
private ListItem GetLookupItem(FieldLookup lookupField, string lookupValue)
{
string mappingField = lookupField.LookupField;
Microsoft.SharePoint.Client.List lookupList = Context.Web.Lists.GetById(new Guid(lookupField.LookupList));
Context.Load(lookupList);
Context.ExecuteQuery();
ListItemCollection libListItems = lookupList.GetItems(CamlQuery.CreateAllItemsQuery());
Context.Load(libListItems, items => items.Include(
itemlookup => itemlookup.Id,
itemlookup => itemlookup[mappingField]));
Context.ExecuteQuery();
foreach (ListItem mappedItem in libListItems)
{
object mappedField = mappedItem[mappingField];
if (mappedField != null && mappedField.ToString().Equals(lookupValue))
return mappedItem;
}
return null;
}
Now that you have the corresponding ListItem, you can set your item.LookupId with its Id:
if (field is FieldLookup && field.InternalName == "Country")
{
FieldLookupValue flvRDS = new FieldLookupValue();
flvRDS.LookupId = GetLookupItem(field as FieldLookup, "France").Id; // here, dunno how you get your country's name
itemToCreate["Country"] = flvRDS;
itemToCreate.Update();
destContext.ExecuteQuery();
}
Feel free to add some more previous code if you want an answer more suited for your specific issue.
Using the with closure is possible in creating new Instance of an object easier and simpler as stated here. But how can I use this closure when updating the entity values of my object?
Say I want to update the fields of my Person object that has an id = 1.
def p = Person.findById(1)
p.fname = 'First'
p.lname = 'Last'
p.save()
You mean like:
Person.findById(1).with {
fname = 'First'
lname = 'Last'
save()
}
It's not 100% clear from the question that this is what you mean...