Access class name using @objc attribute

Roger Molas — Thu, 19 Mar 2020 12:41:55 +0000

Scenario

Create a Simple Table View app
Load customs cells each row
Cell identifier is the class name if the object is TableCell cell identifier is "TableCell"
Use common cell loading techniques
Use helper method to load cell using @objc attribute

Create UITableViewCell subclass

class HeaderCell: UITableViewCell {
    ...
}

class ContentsCell: UITableViewCell {
    ...
}

class AboutCell: UITableViewCell {
    ...
}

Load cell in Tableview in traditional way

func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    if indexPath.row == 0 {
        let cell = tableView.dequeueReusableCell(withIdentifier: "HeaderCell", for: indexPath) as? HeaderCell
        return cell
    }
    if indexPath.row == 2 {
        let cell = tableView.dequeueReusableCell(withIdentifier: "ContentsCell", for: indexPath) as? ContentsCell
        return cell
    }
    if indexPath.row == 1 {
        let cell = tableView.dequeueReusableCell(withIdentifier: "AboutCell", for: indexPath) as? AboutCell
        return cell
    }
    return UITableViewCell()
}

So whats @objc attribute?
When you apply it to a class or method it instructs Swift to make those things available to Objective-C as well as Swift code.

Most of the time you see @objc when you call a method from a UIBarButtonItem or UIButton, you’ll need to mark that method using @objc so it’s exposed – both of those, and many others, are Objective-C code.

In this case, we will use @objc to name our subclasses HeaderCell, ContentsCell, and AboutCell in Swift

Update our UITableViewCell subclass

@objc(HeaderCell)
class HeaderCell: UITableViewCell {
    ...
}

@objc(ContentsCell)
class ContentsCell: UITableViewCell {
    ...
}

@objc(AboutCell)
class AboutCell: UITableViewCell {
    ...
}

Create a Helper method to take the cell identifier using the AnyClass type from the UITableViewCell subclass.

Note: Cell identifier should be the class name

func getCell(_ cls: AnyClass, _ index: IndexPath) -> AnyObject {
    let identifier = NSStringFromClass(cls)
    let cell = tableView.dequeueReusableCell(withIdentifier: identifier, for: index)
    return cell
}

Load cell in Tableview using new way

func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    if indexPath.row == 0 {
        let cell = getCell(HeaderCell.self, indexPath) as! HeaderCell
        return cell
    }
    if indexPath.row == 2 {
        let cell = getCell(ContentsCell.self, indexPath) as! ContentsCell
        return cell
    }
    if indexPath.row == 1 {
        let cell = getCell(AboutCell.self, indexPath) as! AboutCell
        return cell
    }
    return UITableViewCell()
}

Looks clean right?, so @objc attribute is not just for methods, we use it to name our class as well.

Addition Tricks

Let's make it shorter, create an enum of rows called Row

enum Row: Int {
    case HeaderCell = 0
    case ContentsCell = 1
    case AboutCell  = 2

    var className: AnyClass {
        switch self {
            case .Header:
                return HeaderCell.self
            case .Contents:
                return ContentsCell.self
            case .About:
                return AboutCell.self
        }
    }
}

func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    let row = Row(rawValue: indexPath.row)
    let cell = getCell(row.className, indexPath) // dynamic binding
    return cell
}

That's it!
Thanks for your time

iOS and Android Localization Tool

Roger Molas — Mon, 13 Aug 2018 12:45:44 +0000

Localization is simply the process of translating your app into multiple languages.

In situation like you need support multiple language, including API response messages and dynamic strings you need a list of localizable .strings file, and you need to localized it based on the Language you want ( e.g English, Chinese, Japanese ).

Xcode has a built-in localizable file generator that generate your localizable .strings for each language you supported.

In this format

en.lproj  // directory
   |- localizable.strings

zh.lproj  // directory
   |- localizable.strings

ja.lproj  // directory
   |- localizable.strings

Thats Cool!!

But how about the contents?

You need to copy and paste it base on it corresponding laguage. For Chinese stings you put it on zh.lproj/ localizable.strings and for Japanese stings put it on ja.lproj/ localizable.strings and your good to go.

Holy Shiiit, i have 400 stings that needs to be localized in 3 or more languages 400 x 3 = 1,200

Just copy and paste your 1,200 lines of string, Good Luck!

To solve the pain of copy and pasting and save time.

you can use the tool called csv-localizer available on Github.

Just instruct you translator or someone working on translations to put all translated strings into CSV file based on the format provided.

csv-localizer can be installed from homebrew via

$ brew tap rogermolas/csv-localizer
$ brew install csv-localizer

Convert using the following command

$ csv-localizer -p ios -i path/csv_files/ -o path/output

Input directory, CSV files directory path, should not include the .csv file
"path/csv_files/" and not "~~path/csv_files/strings.csv~~"

The reason for that is, csv-localizer can process multiple csv files, thats why its only accept a directory path.

Generated files

en.lproj  // directory
   |- localizable.strings

zh.lproj  // directory
   |- localizable.strings

ja.lproj  // directory
   |- localizable.strings

Thats it, your ready to go. Easy Right?

It will generate the same format just like what Xcode did, but this time it has its localized contents in each corresponding laguage. :)

Also worked on Android it will generate string.xml with contents

$ csv-localizer -p android -i path/csv_files/ -o path/output

Don't forget give a

DEV Community: Roger Molas

Access class name using @objc attribute

iOS and Android Localization Tool

To solve the pain of copy and pasting and save time.