Is there a data structure within LiveCode that can be used as a "holder" for associated data, letting me handle it collectively? I come from a Java / Javascript / C background so I am looking for a Class or Struct sort of data structure.
I've found examples of Groups, which seem to have some of this functionality, but it feels a bit like I'm bending the language to meet my needs.
As a specific example, suppose I had an image field on my screen that would randomly display an image and, when pressed, play an associated sound clip. I'd expect to create a list of "structures" that contained the path to the image and the path to the associated sound clip, and use that data to populate the image field and to decide what sound clip to play.
Would a Group be the correct structure to use in this case? Or am I approaching this in a way that isn't really fitting with the way LiveCode works?
It takes a little getting used to, but the xTalk world is much simpler and more open than any ordinary procedural language. So much of what you once had to manage is no longer required.
So when splash21 said that you could store all your image and sound references in a custom property, he was really saying that the LiveCode environment contains intrinsic, high level functionality that makes these sorts of things instantly accessible, and the only thing required of you is to call for them, and they simply work.
The only way to appreciate this is to make a few simple programs, to really see what is possible. Make your application. Everything you mentioned can be accomplished with perhaps a dozen lines of code in a single handler. I recommend that you join the LiveCode use list and forums. The community is vibrant and eager to help, frequently with full blown solutions to specific problems, but more importantly, as guides and mentors to new users
Craig Newman
Arrays in LiveCode are actually associative arrays (like hash maps). A key is associated with a value. The value might be as well an array.
Chapter 5.5.7 of the User's Guide says
Array elements may contain nested or sub-elements, making them multi-dimensional.
This type of array is ideal for processing hierarchical data structures such as trees or
XML. To access a sub-element, simply declare it using an additional set of square
brackets.
put "ABC" into myVariable["myKeyName"][“aChildElement”]
see also
How to store pictures in a stack?
Dave- I'm hoping to get a struct-like container implemented in the near future. Meanwhile you can, as splash21 mentioned, use custom properties (or better yet, custom property sets) to do what you want. This will give you a pseudo-struct for each object and you can implement the file and sound specifications into the properties. And if you use that in conjunction with a behavior object you'll end up very close to a real inheritable class formation.
Related
So, I have this list of attributes that I would like to represent in my Go code. That is, I'm looking for some data structure that can convey all these.
Mind like a diamond
Knows what's best
Shoes that cut
Eyes that burn like cigarettes
The right allocations
Fast
Thorough
Sharp as a tack
Playing with her jewellry
Putting up her hair
Touring the facilities
Picking up slack
Short skirt
Long jacket
Gets up early
Stays up late
Uninterrupted prosperity
Uses a machete to cut through red tape
Fingernails that shine like justice
Voice that is dark like tinted glass
Smooth liquidation
Right dividends
Wants a car with a cupholder arm rest
Wants a car that will get her there
Changing her name from Kitty to Karen
Trading her MG for a white Chrysler LeBaron
They're not going to change any time soon, but I will want to do the following things with them:
Read them from and write them to a JSON file.
Associate a boolean with each attribute (bonus points for a way to associate any one arbitrary type).
Easily display these strings to a human.
Easily count how many are "set" (That is, a function that, when called on someone who gets up early, has the right dividends, and is sharp as a tack, but nothing else, returns 3).
Should be as strongly typed as possible (It should be impossible, or at least difficult, to ask for an attribute that doesn't exist. You should be able to see all the attributes by looking at the code).
Preserving this order would be a plus, but not strictly necessary.
The approaches I've thought of so far are:
A struct with all of these as fields, but the count function is inelegant to write, and the 'nice' string name of the fields has to be stored elsewhere. Even if that can be solved with tags, the count problem remains.
A map with constant keys (or an array with enumerated values). Counting is a simple loop, and the keys can be the nice string names. However, this creates the problem of asking for keys that don't exist, and you have to hide the dictionary behind a function to stop users from trying to add new keys.
Is there something I'm missing here, or will I have to compromise?
I'd use a uint64 as a bitset (or an actual bitset type, of which none are built in but some are open source). It meets your requirements in the following ways:
JSON storage as "010101" string or base64 (11 chars).
Easy display: just define an array of the strings in the same order they are stored in the bitset.
Easily count how many are "set" - use "popcount" (open source implementations are easy to come by).
Order is naturally preserved--the first attribute will always be bit 0, etc.
If you have more than 64 attributes, you can use math/big.
You can use map[int]interface{} to store the value of any length inside the interface with integer as key or you can also use slice of interface for looping inside the data like this []interface{}. Later on you can easily type assert the interface to get underlying value which is string in your case.
Since it will be slice of interface or map of interface you can easily marshal it to convert it into json and save into file which can be read or write easily.
I am currently working on my first small desktop menubar app (macOS, Swift 3). It needs to access
a) A list of words (Think word dictionary, 1k-5k words, per supported language)
b) A list of structured data (Think simple structs, ~500)
I am currently pondering, whether to build these in code - maybe a factory class per language. Or include them in my app as json and parse at runtime. Or maybe build an SQLite file and read that during runtime, although that approach would be harder to diff in source control ...
As I am new to the platform I was wondering whether there might be a better way that I am not aware of, or maybe performance considerations that render one of the mentioned approaches useless.
As usual, thanks in advance folks !
Your listed solutions can be used for this task. However I think for such kind of tasks the best solution is to use CoreData, where you can store a list of words as well as structured data, also make relations between them if you need it
I am trying to create a new GUI element within DrRacket's text window, like picts or syntax objects. As far as I can tell, the most standard way of doing this is with a snip%.1
Unfortunately, the documentation for creating new snips, while comprehensive, is a bit impenetrable and leaves some questions to be answered.
For starters, what is the difference between a snip% and a snip-class%? Why do these need to be separated out into two classes, rather than simply being combined into one class? Is it because multiple snips will use one snip class?
Second off, what is snip-reader<%>? Not only why does it need to be a separate class, but why is the module providing it supposed to be installed?2 If it does need to be a new class, why can't it just be referred to directly. Why go through this whole process of constructing and then parsing a string of the form: "(lib ...)\n(lib ...)"?
I mean, there might now be any reason for this design, and it might just be a remnant of an old API. If so, has anyone thought of making a new more consistent API? Or if there is a reason for this design, can you please tell me what it is, as the docs don't seem to make that clear.
I mean, as of right now, I can copy/paste the sample given in the docs on creating a new snip. But I'm having a hard time understanding the design going on here, so I can use them properly.
1I know there are other ways to do it, but I also want to have interactive buttons and whatnot.
2I know it doesn't need to be installed as a library per se, but the documentation seems to strongly push you in that direction.
Okay, I think I finally found the answer. Broadly speaking:
The snip% class includes the methods for drawing the snip, telling the editor how much space to reserve for the picture, and handling events such as mouse clicks.
Next, the snip-class% class is used for encoding and decoding snips. This must be a separate class because when saved to a file, the editor needs to encode what type of snip it is, and for obvious reasons it can't just put the literal snip% class in there. The value it stores in the file is the snip-class%'s 'class name'. This can be anything, and as long as the editor has the classname associated to a snip-class%, it can be loaded. Additionally, if it is of the form "(lib ...)" or "(lib ...) (lib ...)" Racket will just automatically load it into the list for you.
Nothing 'needs' to be installed per se, its just the easiest way to go about it. Otherwise you manually need to tell the editor how to handle the snip before actually loading the file.
I'm trying to figure out how to re-position sheets in Numbers. There is no way to insert things at specific location so I am hoping that I can find another way. The move verb drew my attention (it is in the Numbers dictionary) however there is little or no information, examples, usage scenarios or even what object types it works with.
Any insight in the context of the title?
The move in the Numbers dictionary is part of the Standard Suite, which typically works with files. I have tried using it to move text items and tables from one sheet to another, but it always fails. It is probably something they hope to provide functionality for some day.
OK, I'm feeling really REALLY stupid for asking this question, but I've managed to stump myself so hard that I doubt I have the proper detachment to figure out the answer for myself any more. My apologies in advance...
I have been playing around with bindings for a while now and LOVE them. That and the KVO/KVC conventions built into Objective-C 2.0 have allowed me to dramatically slim down my applications while increasing their reliability, flexibility, etc. I say this for no other reason than to illustrate that I am at least moderately comfortable with bindings in general. That being said, my problem is this:
I have an application where I'd like to store an editable set of keywords by way of the preferences controller. Easy, right? Unfortunately, for the life of me I can't figure out how to do it. I set up an array controller and point it to the shared preferences object and give it a keypath for the array. The problem is that the objects being stored in the array are NSStrings and I don't see how NSStrings can be KVC-compliant for this kind of operation due to the lack of any "stringValue/setStringValue" methods. Without those, what keypath do I use in the NSTableView I have set up to facilitate manipulation of that list?
Also, since the shared preferences object is not one that I own, I'm not sure how to go about setting up a new array to represent an unedited/newly installed state. (Registering them as defaults doesn't seem to be working for me.)
So to reiterate my questions more succinctly: How can you bind a table view to an array of NSStrings and how can you store said array in an application's preferences?
Any pointers or advice that you can offer would be VERY much appreciated. The headaches I'm getting from this are starting to get the better of me. :)
You don't. You hold an array of model objects, each with at least one property (that of the string), and you bind the table column through an array controller to this array, with the model key path set to that of the string property.
Assuming your app is not simply a list-of-strings editor, you probably have other things that you can move into this model class. You should do so.
I know this question is pretty old but I had a similar problem and landed to this page. I wanted to contribute with my solution.
What I need is not a big list of strings. In fact a table view looked very ugly for my needs. I then remembered another control, NSTokenField. It binds to an array of string out of the box and looks even better for small list of short strings :)