Preparing & Translating Supported File Types

iOS Strings


Extension .strings
Smartling Identifier ios
Resources String Resources

When downloading translated iOS Strings files via the File API, setting the parameter includeOriginalStrings=false will strip untranslated elements from the file.


Every string is created with key/variant metadata based on the keys in the file. If the keys are different for two strings with the same value, Smartling will create two strings using the key as context metadata.

String Instructions

Smartling will automatically ingest and display file comments as instructions for translators. The comments must immediately precede the string. For example, for the following comment, the text “Back button label” will be captured as a file instruction

/* Back button label */
"Back" = "Back";

If the comment contains the following text: ~ / No comment provided by engineer. / ~

or if a line separates the comment and string, such as:

/* Back button label */

"Back" = "Back";

Smartling will not create an instruction.

Standard Placeholder Format

By default, Smartling recognizes ios-style placeholders in iOS String files.

See Placeholders in Resource Files for more on placeholders.

Placeholders in iOS files are numbered when downloaded from Smartling. Placeholder numbering follows the guidelines set by Apple

iOS Placeholder Numbering

One problem that often occurs during translation is that the translator may need to reorder parameters inside translated strings to account for differences in the source and target languages. If a string contains multiple arguments, the translator can insert special tags of the form n$ (where n specifies the position of the original argument) in between the formatting characters. These tags let the translator reorder the arguments that appear in the original string. The following example shows a string whose two arguments are reversed in the translated string:

/ Message in alert dialog when something fails /
"%@ Error! %@ failed!" = "%2$@ blah blah, %1$@ blah!";


File directives are supported, both inline and via our APIDirectives are specified in comments within the files, in the following format:

Inline File Format

// smartling.[directive_name] = [value]

API Parameter

smartling.[directive_name] = [value] 

Here are some examples of [directive_name], along with example values or paths.


Exact delivery depends on file type.

Values auto (default) | true | yes | false | no

Controls whether base characters ( > < & " ) are "escaped" into entities when delivering translations. This can be set universally for the whole file via API, or by setting the directive at the top/start of the file. The directive can also be placed inline to control the behavior of specific strings.

To use inline:
<!-- smartling.entity_escaping = false -->

<!-- smartling.entity_escaping = auto -->


For example, your translation might look like this:
This is an <hr> & " example string4

By default, using the "auto" setting, we will assume this is HTML from the <hr> tag.

When the translated file is downloaded, the translated string will be escaped as:
This is an <hr> &amp; &quot; example string4

Using <!-- smartling.entity_escaping = false --> will allow This is an <hr> & " example string4 to appear unescaped.

XML Characters (always escaped)

Character (name) Escape sequence

< (less-than)


> (greater-than)


& (ampersand)


' (apostrophe or single quote)


" (double-quote)




Exact delivery depends on file type.


html4 (default)|html5



By default, all html4 entities are unescaped, except the basic set: &lt; &gt; &amp; &quot;.

When this directive is set to html5, all html5 entities will be unescaped as well.


<!-- smartling.entity_escaping_type = html5 --> 



Values propagate | none

Used to retain entity escaping for all non-base entities. For example normally we turn &copy; into © but if we use this new directive the translation will automatically update to use escaping from the source. For each entity character we'll check to see if it was escaped in the source and try to match (propagate) it in the target.

The default is none which is the current behavior, which recognizes HTML4 entities only - if HTML5 entities are required as well, you must use the entity_escaping_type=propagate directive.

propagate will only affect non-base entities - all named entities except &amp; , &quot;, &lt;, &gt; . Base entities continue to be controlled by HTML detection and the entity_escaping directive.

If the same character is both escaped and unescaped in the same string propagate will return the characters in the translation escaped in the same order as they were in the source. However, if there are a different number of characters in the translation where the translation process removed or added some and the escaping is inconsistent among them, propagate will escape all entities for that character.

This directive can be placed inline, in the API or in a template (consult your SA about configuring directive templates).

This does not affect source content at all - so using it will not result in new strings.

Numerical entities are not considered at all with this directive, and are treated normally.


To use inline:
<!-- smartling.entity_escaping_strategy = propagate-->


Description Used to specify a standard placeholder format. 

// smartling.placeholder_format = IOS

Specifies iOS-style placeholders for the file.





1) Custom Java compatible regular expression. 

2) NONE - disables any current custom placeholders

Description Specifies a custom placeholder format. Any text in your file matching the regular expression you provide will be captured as a placeholder. 

// smartling.placeholder_format_custom=\{([^}]+)\}

Any characters surrounded by curly brackets, e.g., {first name}, will be treated as a placeholder.

See Placeholders in Resource Files for more on placeholders.


Values integer - Accepted values are 0 - 100 
Description Sets the percentage by which original strings are inflated when downloading pseudo translations. If this directive is not set, pseudo translations are 30 percent longer than the original strings. 

// smartling.pseudo_inflation = 80

Downloaded pseudo translations will increase the length of original strings by 80 percent.



Values integer or NONE 
Description Sets or removes the maximum characters allowed for a translation. If NONE is specified, character limits will be removed. 

// smartling.character_limit = 25

The directive should go directly before the string where the character limit should be applied. This will apply a character limit of 25 to the string on the line after the directive.

// smartling.character_limit = NONE

This will remove any character limits set for a string even if the character limit was set manually in the Dashboard





on|yes|true or off|no|false or leading|trailing

The default value is on


A whitespace is any character or series of characters that represent horizontal or vertical space in typography. When rendered, a whitespace character is not a visible mark, but does occupy an area or space on a page.

Although whitespaces are necessary within a string (typically to separate words), unnecessary whitespaces can be found at the start of a string (leading) and at the end of a string (trailing).

With this directive, you can trim whitespaces, as it enables or disables whitespace trim management for the ingested strings.

Whitespace is optionally trimmed from content then re-inserted on download for convenience so that translators do not have to manage the extra spaces. However, content owners may want to retain surrounding whitespace so that translators can manipulate it during translation.

By default, the leading and trailing whitespaces are trimmed.

You can choose to disable trimming or specify trimming for leading or trailing whitespaces.

The directive can be used inline or as the API request parameter.


<// smartling.whitespace_trim=on -->

Smartling will trim leading and trailing whitespaces (default)

<// smartling.whitespace_trim=off -->

Smartling will not trim leading or trailing whitespaces

<// smartling.whitespace_trim=leading -->

Smartling will trim only leading whitespaces

<// smartling.whitespace_trim=trailing -->

Smartling will trim only trailing whitespaces


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