Android TextView : "Do not concatenate text displayed with setText"

Pratik Butani picture Pratik Butani · Oct 16, 2015 · Viewed 90.6k times · Source

I am setting text using setText() by following way.

prodNameView.setText("" + name);

prodOriginalPriceView.setText("" + String.format(getString(R.string.string_product_rate_with_ruppe_sign), "" + new BigDecimal(price).setScale(2, RoundingMode.UP)));

In that First one is simple use and Second one is setting text with formatting text.

Android Studio is so much interesting, I used Menu Analyze -> Code Cleanup and i got suggestion on above two lines like.

enter image description here

Do not concatenate text displayed with setText. Use resource string with placeholders. less... (Ctrl+F1)

When calling TextView#setText:

  • Never call Number#toString() to format numbers; it will not handle fraction separators and locale-specific digits properly. Consider using String#format with proper format specifications (%d or %f) instead.
  • Do not pass a string literal (e.g. "Hello") to display text. Hardcoded text can not be properly translated to other languages. Consider using Android resource strings instead.
  • Do not build messages by concatenating text chunks. Such messages can not be properly translated.

What I can do for this? Anyone can help explain what the thing is and what should I do?

Answer

Blackbelt picture Blackbelt · Oct 16, 2015

Resource has the get overloaded version of getString which takes a varargs of type Object: getString(int, java.lang.Object...). If you setup correctly your string in strings.xml, with the correct place holders, you can use this version to retrieve the formatted version of your final String. E.g.

<string name="welcome_messages">Hello, %1$s! You have %2$d new messages.</string>

using getString(R.string.welcome_message, "Test", 0);

android will return a String with

 "Hello Test! you have 0 new messages"

About setText("" + name);

Your first Example, prodNameView.setText("" + name); doesn't make any sense to me. The TextView is able to handle null values. If name is null, no text will be drawn.