I have a set of data in a matrix which I would like to display in my iPhone app with all of the rows and columns intact. Everything I can find on the web dealing with "tables iPhone" gives me information on UITableView, which only lets you show a list of items to the user - not an actual table in the HTML sense. What's the best way on the iPhone to display an actual table of data to the user, with column & row headings and table cells?
The solution that I found was simply to use a UIWebView. Then I can build the HTML table dynamically and load it into the web view.
The UITableView class was specifically designed to only show one column at a time due to the small size of the screen. If the data of your application absolutely needs to be laid out in one big grid on one screen the right way to do it, would be to add each cell as a subview to a custom view. Then implement the layoutSubviews method on your custom view to lay out the frames of the subviews in the grid you want.
Related
New to Swift. I am trying to write a recipe-sharing app for fun. One of the features is to let users create a new recipe. On this page, users should be able to give an intro to the recipe to be created, upload an image THEN add a LIST of ingredients dynamically (as we have no idea how many ingredients in total beforehand).
I have created a UIViewController, which includes a UIViewTable, an image view and a "add another ingredient" button. I have created a class for the ingredient. And when the "add" button is pressed, a new "Ingredient" cell will be added to the table. However, I found that adjusting the UIViewTable height dynamically is quite hard.
I want my table to adjust its height according to the number of cells (rows). I haven't found much useful info online.
Or maybe I should've not even used this structure. Instead, just use UITableController (The entire page is a table)? But I got confused that some of the elements (image view, submit a recipe button, recipe-intro textfield etc) will be only created once. Why do I bother making them as prototype cells and add them to my view programmatically?
Thanks in advance!
First of all, welcome to Swift!
You put a few questions together, I will try to answer them one by one. Let's start with the simple stuff.
Don't try to change the height of UITableView based on the number of items. If you want to achieve similar functionality, take a look at UIStackView. Set fixed size for the tableView, ideally with constraints using auto layout.
UITableView is supposed to fill specified space and scroll items inside or show cell on top if there are not enough cells to cover all space.
UITableView is highly optimized to scroll over huge amount of cells as the cells are reused on the background. If you are new to the iOS world, take a look at this function https://developer.apple.com/documentation/uikit/uitableviewcell/1623223-prepareforreuse it can save you hours of debugging (I have been there)
UITableView vs UITableController
UITableController can save you a few lines of code, but using UITableView inside of UIViewController can give you more freedom and save you refactoring if your app is likely to change in the future. There is no specific advantage of UITableController
If you want to provide the extra elements (image view, submit button, text field etc), you can use several methods and this is where the UIViewController with your own UITableView comes in handy.
You can put some buttons, like a plus icon or "Done" button into the navigation bar, as the native Calendar app does.
You can put the static content (intro text field, image view) above the table view (visible always). Use constraints to place the static content on the viewController.view and constraint the table view under your static content. The table view will take less space on the view keeping the space for your content.
Insert your static content as a table view header (will scroll out with the content). Search "HeaderView" here on stack overflow to see how to achieve that.
Place your content over the tableView. If your button is small (rounded), you can place it over the tableView, eg. Twitter uses this for a new tween button.
Hope this answer your questions. Cheers!
I am writing a Swift app, and on my main screen I have a long scrollview with several regions of content in it (upcoming events, announcements, and then featured products, and finally some basic info). So it's this really long scroll, and you can swipe down to the bottom.
So visualize 4 boxes, if you will, stacked vertically.
The 3rd box shows featured products. This can be anywhere from 1 to 30 items, depending upon any filters the user has in their settings.
My first try was using a UITableView for region#3 inside of this parent scrollview, but the problem is it only shows the first few items/rows and then the rest you scroll inside the table (which is the default/natural behavior of a table, right?). Unfortunately, the requirement I have is that the inner table can't scroll - it needs to display everything at once and you have to scroll (in the main UIScrollView) to get to the bottom (not scroll inside the inner uitableview scroll). Also, everyone seems to say don't use UITableView inside of a scroll.
So how do I create some sort of list where I create one template (like how you would in a xib/tablecell, and then assign a data source to it, and then repeat down without scrolling? Should I use a tableview after all, and just make the height of it very high and turn scrolling off?
Do I somehow instantiate xibs in a for loop and assign them dynamically to some view?
Thanks so much!
Sounds like you want a Table View with Grouped style. That would make it fairly easy to keep your "4 boxes" segregated, and your "3rd box" would simply be 1 to 30 rows in that section.
On note: you don't want to have a "very tall" table view - or any other type of view, for that matter. You want to allow iOS to manage memory for you, and to load and display only those parts of your content that is visible at any one time.
In other words, use a table view like its designed to be used :)
I'm building an RSS Reader for iPhone where I get articles and their HTML from the server and I want to display this list of articles for the user in a UITableView.
I've explored options like DTCoreText to be able to use HTML with a UILabel or UITextView, but it unfortunately just doesn't offer rich enough support of all the HTML I could be dealing with. So UIWebView or WKWebView seem like my only options for accurately representing the content.
The problem lies with how content having varying height. Detecting the content's height isn't too bad, but when you use it with a UITableView, the table view asks for the heights of all the rows first, and with web views you have to load the content first, and then in the callback for having finished loaded, only then can you find out the height. Which is annoying, because in my case the HTML is simple enough that it takes very little time for the web view to render it.
So you have this issue where the table view asks for the height of a row, and you basically say "Just a second, take this random value for now and I'll tell you in a second when I find out." This works terribly, because when you're scrolling through the table it takes the intermediate value, then loads content after and updates, causing a jump, which is especially bad if you're scrolling up as you're being bounced around as the heights for the rows above you are being calculated. Caching the height the first time you see it doesn't seem to work either, because the user can rotate the device and have that cached value be invalid.
So I'm wondering, is there any way to be able to use web views in a table view?
You can if you've preloaded the web content. Simply modify your approach and don't tell the table view the rows exist until you have the web content for that row. Then once the content is loaded you can get its height and insert the row at the bottom of the table view. Continue this process until all the content is loaded.
I am currently working on an iPad application that uses a table view to present data, I was inspired by the iTunes application in iPad that present it's data in multiple columns in a very nice and neat manner, and the most interesting thing is that during the portrait mode the itunes application displays data in 2 columns but when the user switches to landscape mode, it switches the display to 3 columns (since there are plenty of space to display data horizontally).
This is what i'm talking about:
but i found out that iOS SDK only supports single column for tableview (it would be nice to utilize the entire space provided on iPad screen to present data), i did some research and i found out that the best way to present data in multiple columns yet like spreadsheet style is to use datagridview instead, but iOS SDK did not provide any data grid view controls for iOS developers.
I found out over the internet some customized tables like:
AQGridView.
DTGridView.
and also the one from this:
http://usxue.is-programmer.com/posts/14176.html
and the one from this:
http://xebee.xebia.in/2011/04/14/building-editable-gridview-for-iphone-apps/
But sadly none of these ever met the requirements of the application i was working on.
Could you guys provide me some ideas or share some sample codes or links on how to display data in somehow-data grid view, to achieve similar effect used in iTunes application (as shown above).. Any form of help would be pretty much appreciated. Thank you guys!
The summary answer is, place multiple data "views" across in a single cell.
The more detailed answer:
Create custom views that represent the single cells you want. You can for this purpose make them resizable enough to work two across or three across (they will get loaded into 1/2 or 1/3 of the cells bounds).
Then make a custom UITableView cell, that can take two or three data items - load up an instance of the custom view previously created in the cell for each data item you have, placing them next to each other. You can have the cell do the view layout when groups of data items are added.
In the cellForRow code in the table delegate/datasource, you use your data source in groups of two or three (and report the row count accordingly) to pass along to the custom cell.
Sorry I can't share code, but I have used this technique before in other applications.
What's wrong with creating a UIView class to represent a single cell, and another that lays out an array of those cells in a grid? Put your grid view in a UIScrollView and you're about done.
UITableView is obviously a pretty complex class. Much of that is to make it very general, very reusable, and able to support a huge number of rows. Your class doesn't necessarily need to be that complicated -- if you have a fairly small number of cells, your "grid" could really just be a UIView in which you lay out cells in rows and columns. UITableView removes cells that aren't seen in order to save memory; you might need to do something similar if you have hundreds of cells, especially if they're large, but a few dozen probably won't require that.
In short, since you need a grid view for a particular use, you don't need to do all the extra work that would be required for a general, reusable solution.
i want to display name phone number and salary of a employee in an ipad in the form of table with multiple columns for that i take three table views and successfully displayed data in them . the table views are scrolling independently.but i want to implement if one table view is scrolled the second and third must be moved parallel. can any one please tell me how to implement that one....
If you want all your UITableViews dependants and scrolling at the same time, there is no reason to create multiple table view.
You can just create un custom UITableViewCell with the layout and style you want! This will be easier and will consume less resources.
find out position of cell in first table depending on that change position of cell in next table.
You can use following property of UITableView - – scrollToRowAtIndexPath:atScrollPosition:animated: