I am trying to write an app that searches a website, and takes all of the results and puts them into a customized table. I am an Objective-C and iPhone SDK noob, and am hoping that this logic is what I am trying to accomplish:
1) Searching multiple search engines and pulling all of the data off of each website, storing each into a different array (for example: Searching Google, Yahoo, and Bing for "Shoes", and taking all of the different search results, hyperlinks and all, and storing them into three different arrays)
2) Pulling the data out of each array, and putting into a table (Table view in Interface Builder)
I am assuming that I need to declare global variables, so that they can be called from different classes......right?
What's the syntax for doing this?
How do I set this up in IB?
Did I bite off more than I can chew for this first app?
Thanks for your help!
Aaron, I also think you're biting off more than you can chew WRT a single question on SO, but let me point you to a resource I wrote on a similar topic about how to structure your program.
As an Obj-C noob, you're going to need to take extra care to remember the Model-View-Controller pattern. Extracting data from a web site is a bit of work - and you want to keep that very separate from your display and control code.
Have a clean API model that extracts and sorts data, and have a clear view controller class that reads data from the API.
My advice is to write the whole app in psuedo-code first and try out your thinking on us.
Related
I am using asp.net core and Razor - and as it is a help system I would like to implement some kind of search facility to bring back a list of results hyperlinked based on the search terms.
I would like the search to iterate essentially over the content contained within the and tags and then link this to the appropriate page/view.
What is the best way to do this?
I'm not even sure how you get a handle on the actual content of your own cshtml pages and then go from there.
This question is far too broad. However, I can provide you some pointers.
First, you need to determine what you're actually wanting to surface and where that data lives. Your question says "static web pages", but then you mention .cshtml. Traditionally, when it comes to creating your own search, you're going to have access to some particular dataset (tables in a database, for example). It's much simpler to search across the more structured data than the end result of it being dumped in various and sundry places over a web page.
Search engines like Google only index in this way because they typically don't have access to the raw data (although some amount of "access" can be granted via things like JSON-LD and other forms of Schema.org markup). In other words, they actually read from the web page out of necessity, because that's what they have to work with. It's certainly not the approach you would take if you have access to the data directly.
If for some reason you need to actually spider an index your own site's HTML content, then you'll essentially have to do what the big boys do: create a bot, run it on a schedule, crawl your site, link by link, downloading each document, and then parse and process it. The end result would be to create a set of structured data that you can actually query against, which is why all this is pretty much just wasted effort if you already have that data.
Once you have the data, however you got there, you simply query it. In the most basic of forms, you could store it in a table in a database and literally issue SQL queries against it. Your search keywords/parameters are essentially the WHERE of the SELECT statement, so you'd have to figure out a way to map the keywords/parameters you're receiving to an acceptable WHERE clause that achieves that.
More traditionally, you'd use an actual search engine: essentially a document database that is designed and optimized for search, and generally provides a more search-appropriate API to query against. There's lots of options in this space from roll your own to hosted SaaS solutions, and anywhere in between. Of course the cost meter goes down the more work you have to do and goes up the more out of the box it is.
One popular open-source and largely free option is Elasticsearch. It uses Lucene indexes, which it stitches to together in a clustered environment to provide failover and scale. Deployment is a beast, to say the least, though it's gotten considerably better with things like containerization and orchestration. You can stand up an Elasticsearch cluster in something like Kubernetes with relative ease, though you still will probably need to do a bit of config. Elasticsearch does also have hosted options, but you know, cost.
So i have developed an application in vb.net but recently i came across the requisite of allowing multiple languages for it. I dont know if there is any 'common' way of doing this kind of things, but my approach to accomplish that is the following:
I'll need to search in the code for components, error messages and everything that is displayed in the GUI of the application to be translated.
Secondly i will create a class in which i'll store in memory a dictionary of everything that will be translated
after, i'll replace the stuff to be translated withing an entry of the dictionary
then when the application start i'll load the dictionary
later on, i'll replace the static dictionary and will load it in memory from the database
So for example, my dictionary class:
Dim dictionary As New Dictionary(Of String, String)
dictionary.Add("00011", "hello there!")
Somewhere in my code i'll replace:
mylabel.text = "hello there!"
With:
mylabel.text = dictionary.item("00011")
Later on i will, instead of having a static dictionary, create that dictionary getting the information from a database like this (and load it at the start of the application:
_______________________________________
word_code ### word_EN ### word_FR
_______________________________________
00011 ### hello there ### bonjour il
I will load the dictionary considering which language is selected.
I'm not very confortable with this approach and i have no idea if this is the right thing to do, but if so i have a couple of questions:
is a dictionary the best data-structure to do so?
will this be memory-heavy considering i'll have 1000 entries, 1m entries or 10m entries?
is there any logic and faster way of accomplish the same?
Thank you so much in advanced,
J
It's a common way of doing it - having a system name along side a language code being used to look up a translated value. However, generally speaking I'd only advice you to do this for something like system texts and smaller text segments.
The reason is that in for example CMS/ecommerce systems, pages with lots of text likely will need to be translated in a data model to support it to begin with; and then you already have the language division.
So in that situation, you're better off making a page structure with a translated data model where the detail will be language specific per language for your current website.
For example, you'll have a product -> product_detail where detail keeps the translated values for said product. Similar for article -> article_detail and so on.
But for general translations and system texts which needs to be displayed, it's a common way to do it.
And as you suggest yourself, structures like like dictionary would be a good structures to to make fast look ups and can be cached in the system so you do not need to retrieve them all the time.
Some ways you can expand on it, is by sub dividing your translations into sub groups; say you have an order page and a product page. Then you can have translations assigned to "product" and to "order" with a "common" group as well.
It will also make it easier to build smaller cache objects, extract less data from your data storage etc, so a page which only revolves around orders don't need to worry about product translations.
It will require memory, but unless you put entire CMS systems into the translations, it should be "minor".
I would however question a need of 10 million entities of translations and wonder whether or not your system actually requires that many and if it does, then maybe consider an alternate approach and whether it might be better to make multiple versions of the "page" to eliminate the need for translations.
I would also advice you to not use "00011" as a system code to begin, and go for a more "readable" version (like "hello") to ease the readability and maintainability of your code. Then if you want a 'system value' which is like "00011", it's easy to do a search/replace.
For a hobby project I am building an application to keep track of my money. Register everything that comes in and goes out. I am using sqlite as a database backend.
I have two data access models in mind.
Creating one master object as a sort of database connector, which contains methods which execute the queries and provide the required sets of data as a list of objects
Have objects who need data execute the queries themselves
Which one of these is 'the best' and why? Or are there different, better models out there?
The latter option is better. In the first option, you would end up having to touch your universal data access object for just about any update to the code that wasn't purely a change in display logic. If you have different data access objects, then you will have much more testable, maintainable code.
I suggest you read up a bit on the model-view-controller paradigm. The wikipedia article on it is a good start: http://en.wikipedia.org/wiki/Model%E2%80%93view%E2%80%93controller.
Also, you didn't say which language/platform you were coding in, but most platforms have numerous options for auto-generating a starting point your data access classes from your database. You may find something like that useful.
Much of a muchness really, the thing to avoid is having the "same" sql sprinkled all over your code base.
The key point is. You've just added a new column to Table1. When you do Find In Files "Table1", how many hits are you going to get and where.
If you use one class and there's a lot of db operations, it's going to get very messy very quickly, but if you have one interface (say IModel) with one implementation, you can swap backends very easily.
So how many db operations, and how likely is it you will move away from SqlLite.
I have a list of about 10,000 phrases (1-5 words each). When the user starts to type in the searchbar, I want to display a tableview that filters through these phrases to find matches. ie: it will function like auto-fill in your browser.
My question is: What is the best way to store this data? Should I just put it in an array that gets initialized when the user searches? Or should it be stored in an external file?
(I am working with iOS).
Thanks!
You could easily do it with an array, but the performance would be very poor.
It would be best to have it in a SQLite (or Core Data) database and search that.
I think having it in a file could be even worse performance than the array.
Save it in a SQLite or Core Data database. You could also use a .plist file, although that might take longer to read through.
I'm currently looking for the best way to save data in my iPhone application; data that will persist between opening and closing of the application. I've looked into archiving using a NSKeyedArchiver and I have been successful in making it work. However, I've noticed that if I try to save multiple objects, they keep getting overwritten every time I save. (Essentially, the user will be able to create a list of things he/she wants, save the list, create a few more lists, save them all, then be able to go back and select any of those lists to load at a future date.)
I've heard about SQLite, Core Data, or using .plists to store multiple arrays of data that will persist over time. Could someone point me in the best direction to save my data? Thanks!
Core Data is very powerful and easy to use once you get over the initial learning curve. here's a good tutorial to get you started - clicky
As an easy and powerful alternative to CoreData, look into ActiveRecord for Objective-C. https://github.com/aptiva/activerecord
I'd go with NSKeyedArchiver. Sounds like the problem is you're not organizing your graph properly.
You technically have a list of lists, but you're only saving the inner-nested list.
You should be added the list to a "super" list, and then archiving the super-list.
CoreData / SQL seems a bit much from what you described.
Also you can try this framework. It's very simple and easy to use.
It's based on ActiveRecord pattern and allow to use migrations, relationships, validations, and more.
It use sqlite3 only, without CoreData, but you don't need to use raw sql or create tables manually.
Just describe your iActiveRecord and enjoy.
You want to check out this tutorial by Ray Wenderlich on Getting started with CoreData. Its short and goes over the basics of CoreData.
Essentially you only want to look at plists if you have a small amount of data to store. A simple list of settings or preferences. Anything larger than that and it breaks down specifically around performance. There is a great video on iTunesU where the developers at LinkedIn describe their performance metrics between plists and CoreData.
Archiving works, but is going to be a lot of work to store and retrieve your data, as well as put the performance challenge on your back. So I wouldn't go there. I would use CoreData. Its extremely simple to get started with and if you understand the objects in this stack overflow question then you know everything you need to get going.