I need to recursively traverse a very large and complicated object model to search for a particular value of an ID.
The value I'm looking for is in a property called "ID", but objects with a particular ID might have many children, some of which are arrays, each having a different ID, and each of those children in turn can have a different ID and so on and so forth.
So if I give you an object, say $web, and you know that deep down in it's object model there is a value of an object that you are looking for. How do you look for it using recursion and reflection?
Note: This is a generic powershell/recursion/programming question even though the topic is SharePoint.
How about using Format-Custom? For example, getting a lot of nested member data from a directory info is done like so,
(gci)[0] | fc > test.txt
Will give some 8800 lines of data for expanded members.
Related
I am developing a program to sync users between to different LDAP Servers. I have two types of user groups: Master-Groups and Target-Groups (those are predefined in a config-file. There can be multiple Master and Targets per Group definition).
Users in Master-Groups missing in the Target-Groups shall be added to the Targets, Users in Target-Groups missing in Master-Groups shall be removed from the Targets.
The Users in those Groups are Objects themselves. My problem is as follows:
I loop through my availiable master groups and have to perform a quick lookup wheter a user is already part of a target-group. I am struggeling to pick the right datastructure to solve this problem. I tried using a hash, but quickly realized that hash-keys are stringyfied, so I cannot perform
if ( exists( $master_members->{$target_user_object} ) )
When using an array for storing the objects, everytime I have to check if a user object exists, I have to loop through the whole array which essentially kills performance.
How do I perfom a lookup if a specific object exists in a list of objects?
Kind Regards,
Yulivee
You're right that hash keys are stringified. You cannot use objects as keys. But a hash is the right data structure.
Instead of just letting Perl stringify your references, build your own serializer. That could be as simple as using the cn. Or a concatenation of all the fields of the object. Make a sub, put that in there, call that sub within your exist.
... if exists $master_members->{ my_serializer($target_user_object) };
I have a Record bean. In that I am using an array of different objects. While writing the data into a CSV file I am not able to map that array for the Name property of BeanWrapperFieldExtractor.
How can I map the array of Address in BeanWrapperFieldExtractor? Or is there any alternate way to solve this issue?
Take a look at this old question dealing with files where multiple lines apply to the same record. Basically you would leverage a SingleItemPeekableItemReader, and each parent record would be augmented by the following addresses lines.
I have a document with many objects, and several aggregate processors that run on them.
Lets say the name of the objects document is Objects.
For one processor, I created another document called ProcessedObjects in which each instance is an object that contains one field "processedObjectPtr" which is a link to an object.
I would like to run the following basic loop :
for all objects that haven't been processed yet:
1 - process object
2 - add object to processed object list
The part which I don't know how to do in MongoDB is to get the list of objects that haven't been processed yet. Theoretically I could mark the object itself as processed by adding another field to it, but when I will have many processors that will get ugly, which is why I prefer to keep the 'processed object list' in a separate document.
Is there an elegant way to do this, or will I have to add the processed metadata to the actual objects?
I am using mongoengine, but any answer will do.
Thanks!
I ended up adding a 'processedFlags' list to my objects, so each processor could mark (via a flag) that it already processed this object, and also query which objects do not have the flag.
I am setting a managedObject up from data I am getting off the web, before I add this new object to the managedObjectContext I want to check if its all ready in the database. Is there a way to compare two managed objects in one hit, or do I have to compare each attribute individually to work out if they are identical or one contains a difference?
Simple Example:
Entity:Pet (Created but not inserted into database)
Attribute, Name: Brian
Attribute, Type: Cat
Attribute, Age: 12
Entity:Pet (Currently in database)
Attribute, Name: Brian
Attribute, Type: Cat
Attribute, Age: 7
In this example can I compare [Brian, Cat, 12] with [Brian, Cat, 7] or do I need to go through each attribute one by one to ascertain a full match?
Unique identifiers are often used to search for objects by only having to match the one field. As you note, matching on multiple fields could be annoying and inefficient, but it's perhaps not as bad as you think: you can construct an NSPredicate to quite easily match all the required fields on objects in Core Data.
Use of NSPredicate aside: suppose you just want to match one field. If you don't have a suitable unique identifier in the data as provided, you could derive one. The obvious way is to construct a hash code for everything you store, based on each field you want to match on. Then when you wish to check if an 'incoming' object is already in core data, compute the hash code for the new object, then just look for an object in core data with that same hash code. (Note: if you find an object that already exists with the same hash code, you might want to then compare all the fields to check that it really does represent the same object -- there's a tiny chance it might be a 'different' object, A.K.A. a hash collision).
A very naive hash code implementation for an object X would be something like:
hashcode(X) = hashcode(X.name) + hashcode(X.type) + hashcode(X.age)
To see a more realistic example of writing a hashcode function, see the accepted answer here.
By the way, I'm assuming that you don't want to load all your objects from core data into memory at once. If however that is acceptable (suppose you have quite a limited amount of items), an alternative is to implement isEqual and hash on your class, and then use regular foundation class methods like NSArray indexOfObject: (or, even better, NSDictionary objectForKey:) to locate objects of interest.
I have a set of objects that the user can sort arbitrarily. I would like to make my client remember the sorting of the set of objects so that when the user visits the page again the ordering he/she chose will be preserved. However, the client-side framework should also be able to quickly lookup the objects from whatever array/hashmap they are stored in based upon the ordering. What is the most efficient way of doing this?
The best way I have found for doing this is using an array that stores the IDs of the array in the particular order I wanted. From there, I can access the array of objects I wanted by converting the array to a hashmap using Underscore.js.