I've a requirement to persist a flowchart built by users into database. Until now, I've been using BLOBs to store the flowchart image. But I want to serialize the flow chart and persist them as a structured data.
For example, a flow chart will have start and end, process box, input/output box, decision flow etc. All these elements will be connected by arrows. I'm blanking out on how to model data structure that will store this information. Any tips would be appreciated?
Sorry, but this question is too vague.
Perhaps the best question to start off asking yourself:
Q: Do I really want to invent my own format, or find an existing "flowchart"
format that does what I need?
If you want to invent your own, I'd strongly suggest:
Using JSON or XML (instead of something completely ad-hoc), and
Finding JSON or XML examples for storing "graphs" (nodes, edges, etc).
Here is one such example: http://jsongraphformat.info/
But then your next challenge would be how to DISPLAY your flowchat, after you've read it from the database.
ANOTHER SUGGESTION:
Assume, for example, you're using Visio. I'd just store the .vsd in your database!
Related
I'm new to OSM querying, but would like to query vector data for a large area. Thus I need to limit the results I would like to get by tagging the request.
http://www.informationfreeway.org/api/0.6/way[tag=value][bbox=x,y,z,j]
I'd like to filter for specific tag/values when querying for a way. Though I don't know which tags/values exist. Is there a list listing the most common of them?
You are approaching your problem from the wrong direction. The number of different tags is almost unlimited. According to taginfo there are currently 75 380 856 different tags. I'm pretty sure you are not interested in most of them. Likewise you are probably not even interested in many of the most common tags.
What data do you want to query?
The OSM wiki should be your starting point for generating a list of tags you are interested in. For a generic overview take a look at the map features. Are you interested in streets? Then visit at the highway key. Routing? Then take a look at the routing wiki page.
Always remember that these lists aren't complete. People can use any tag they like (but should use well-established tags whenever possible of course).
Also consider using Overpass API instead of XAPI. Overpass API is much more powerful.
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.
In my web application I am going to use OpenLayers.Strategy.AnimatedCluster strategy due to the fact that I need to visualize a great amount of point features. Here is a very good example of what it looks like. In both examples in above mentioned example the data (point features) are generated of taken from the GeoJSON file.
So, can anybody provide me with a file containing 100 000+ (better is even 500 000+) features (world cities, for instance), or explain how I can generate them so that they will be located all over the world (not like in Spain in the first example in above mentioned link).
use a geolocation database to supply you the data you need. GeoLite, for example
If 400K+ locations is ok, use download their CSV CITY LIST
If you want more, then you might want to give the Nominatim downloads, but they are quite bulky (more than 25GB) and parsing data is not as simple as a csv file.
I am new to programming. Now i have been learning for a few weeks and am now making my first app. Probably not for public, just for me. At least for now. So here it goes. I want the user to be able to enter his information (for example weight or something like that) into textField and then save it, so I can later form a graph (for example of weight loss through time). Now the graph should not be that much of a problem, since there are many tutorials on that. I am more interested in how to enter information, then save it so it can be later accessed. Any help? What should I read?
Thanks!
Working with UITextFields in Objective C is pretty straightforward - you can grab the NSString from such an object using the 'text' property. Use plists for storage locally, or JSON.
Look at core data tutorials especially related to Apples' doc on “Core Data and Cocoa Bindings”
CoreData shows how to setup objects and save them to a file or simple database. Cocoa Bindings are how to make input screens pass data to object models.
You should be able to write a program to enter weights, save them and show in a table without writing any code.
Is it possible to update an rdf file dynamically from user generated input through a webform? The exact scenario would beskos concept definitions being created and updated through user input to html forms.
I was considering xpath but is there a better / generally accepted / best practice way of doing this kind of thing?
For this type of thing there are IMO two approaches:
1 - Using Named Graphs in a Triple Store
Rather than editing an actual fixed file you use a Graph which is stored as a named graph in a Triple Store that supports triple level updates (i.e. you can change individual Triples in a Graph). For example you could use a store like Virtuoso or a Jena based store (Jena SDB/TDB) to do this, basically any store that supports the SPARUL language or has it's own equivalent.
2 - Using a fixed RDF file and altering it
From your mention of XPath I assume that you are intending to store your file as RDF/XML. While XPath would potentially work for this it's going to be dependent on the exact serialization of your file and may get very complex. If your app is going to allow users to submit and edit their own files then they'll be no guarantees over how the RDF has been serialized into RDF/XML so your XPath expressions might not work. If you control all the serialization and processing of the RDF/XML then you can keep it in a format that your XPath will work on.
From my point of view the simplest way to do this approach is to load the file into memory using an appropriate RDF library, manipulate it in memory and then persist the whole thing back to disk when the user is done (or at regular intervals or whatever is appropriate to your application)