rtlcss
Advanced tools
Changelog
v1.7.4 - 23 Feb. 2016
Readme
RTLCSS is a framework for converting Left-To-Right (LTR) Cascading Style Sheets(CSS) to Right-To-Left (RTL).
| Why RTLCSS | Install | Basic Usage | CLI | Advanced Usage | Options |
|---|
In a right-to-left, top-to-bottom script (commonly shortened to right to left or abbreviated RTL), writing starts from the right of the page and continues to the left. For example Arabic script (the most widespread RTL writing system in modern times ).
Web development depends heavily on CSS to create visually engaging webpages, user interfaces for web applications, and user interfaces for many mobile applications. CSS defines how HTML elements are to be displayed via Positioning, Box model, Typographic and Visual properties, such as left:10px, padding-left:1em, text-align:right, ... etc.
Browsers will apply these properties AS IS regardless of the document language direction. This means in order for an international website to support RTL languages, it should adjust the entire CSS to render from right to left.
For example, this is how different github would be if it was to be viewed in an RTL language:
Just like a mirror, where everything gets flipped.
Instead of authoring two sets of CSS files, one for each language direction. Now you can author the LTR version and RTLCSS will automatically create the RTL counterpart for you!
.example {
display:inline-block;
padding:5px 10px 15px 20px;
margin:5px 10px 15px 20px;
border-style:dotted dashed double solid;
border-width:1px 2px 3px 4px;
border-color:red green blue black;
box-shadow: -1em 0 0.4em gray, 3px 3px 30px black;
}
Will be transformed into:
.example {
display:inline-block;
padding:5px 20px 15px 10px;
margin:5px 20px 15px 10px;
border-style:dotted solid double dashed;
border-width:1px 4px 3px 2px;
border-color:red black blue green;
box-shadow: 1em 0 0.4em gray, -3px 3px 30px black;
}
npm install rtlcss
var rtlcss = require('rtlcss');
var result = rtlcss.process("body { direction:ltr; }");
//result == body { direction:rtl; }
RTLCSS preserves original input formatting and indentations.
CSS Syntax
A CSS rule has two main parts: a selector, and one or more declarations:
background
background-image
background-position
background-position-x
border-bottom-left-radius
border-bottom-right-radius
border-color
border-left
border-left-color
border-left-style
border-left-width
border-radius
border-right
border-right-color
border-right-style
border-right-width
border-style
border-top-left-radius
border-top-right-radius
border-width
box-shadow
clear
cursor
direction
float
left
margin
margin-left
margin-right
padding
padding-left
padding-right
right
text-align
text-shadow
transform
transform-origin
transition
transition-property
When RTLing a CSS document, there are cases where it's impossible to know whether to mirror a property value, whether to change a rule selector, or whether to update a non-directional property. In such cases, RTLCSS provides processing directives in the form of CSS comments. Both standard /*rtl:...*/ and special/important /*!rtl:...*/ notations are supported.
Two sets of processing directives are available, on Rule and Declaration level.
Rule level directives are placed before the CSS rule.
| Directive | Description |
|---|---|
/*rtl:ignore*/ | Ignores processing of this rule. |
/*rtl:rename*/ | Forces selector renaming by applying String Map. |
Example
/*rtl:ignore*/
.code{
direction:ltr;
text-align:left;
}
Output
.code{
direction:ltr;
text-align:left;
}
Declaration level directives are placed any where inside the declaration value.
| Directive | Description |
|---|---|
/*rtl:ignore*/ | Ignores processing of this declaration. |
/*rtl:{value}*/ | Replaces the declaration value with {value}. |
/*rtl:append:{value}*/ | Appends {value} to the end of the declaration value. |
/*rtl:prepend:{value}*/ | Prepends {value} to the begining of the declaration value. |
/*rtl:insert:{value}*/ | Inserts {value} to where the directive is located inside the declaration value. |
Example
body{
font-family:"Droid Sans", "Helvetica Neue", Arial/*rtl:prepend:"Droid Arabic Kufi", */;
font-size:16px/*rtl:14px*/;
}
Output
body{
font-family:"Droid Arabic Kufi", "Droid Sans", "Helvetica Neue", Arial;
font-size:14px;
}
Convert LTR CSS files to RTL using the command line.
$ rtlcss input.css output.rtl.css
For usage and available options see CLI documentaion.
// directly processes css and return a string containing the processed css
output = rtlcss.process(css [, options , rules, declarations, properties]);
output // processed CSS
// create a new RTLCSS instance, then process css with postcss options (such as source map)
result = rtlcss([options , rules, declarations, properties]).process(css, postcssOptions);
result.css // Processed CSS
result.map // Source map
// you can also group all configuration settings into a single object
result = rtlcss.configure(config).process(css, postcssOptions);
result.css // Processed CSS
result.map // Source map
Built on top of PostCSS, an awesome framework, providing you with the power of manipulating CSS via a JS API.
It can be combined with other processors, such as autoprefixer:
var processed = postcss()
.use(rtlcss([options , rules, declarations, properties]).postcss)
.use(autoprefixer().postcss)
.process(css);
| Option | Default | Description |
|---|---|---|
preserveComments | true | Preserves modified declarations comments as much as possible. |
preserveDirectives | false | Preserves processing directives. |
swapLeftRightInUrl | true | Swaps left and right in URLs. |
swapLtrRtlInUrl | true | Swaps ltr and rtl in URLs. |
swapWestEastInUrl | true | Swaps west and east in URLs. |
autoRename | true | Applies to CSS rules containing no directional properties, it will update the selector by applying String Map.(See Why Auto-Rename?) |
greedy | false | A false value forces selector renaming and url updates to respect word boundaries, for example: .ultra { ...} will not be changed to .urtla {...} |
stringMap | see String Map | Applies to string replacement in renamed selectors and updated URLs |
enableLogging | false | Outputs information about mirrored declarations to the console. |
minify | false | Minifies output CSS, when set to true both preserveDirectives and preserveComments will be set to false . |
String map is a collection of map objects, where each defines a mapping between directional strings. It is used in renaming selectors and URL updates. The following is the default string map:
[
{
'name' : 'left-right',
'search' : ['left', 'Left', 'LEFT'],
'replace' : ['right', 'Right', 'RIGHT'],
'options' : {
'scope': options.swapLeftRightInUrl ? '*' : 'selector',
'ignoreCase': false
}
},
{
'name' : 'ltr-rtl',
'search' : ['ltr', 'Ltr', 'LTR'],
'replace' : ['rtl', 'Rtl', 'RTL'],
'options' : {
'scope': options.swapLtrRtlInUrl ? '*' : 'selector',
'ignoreCase': false
}
},
{
'name':'west-east',
'search': ['west', 'West', 'WEST'],
'replace': ['east', 'East', 'EAST'],
'options' : {
'scope': options.swapWestEastInUrl ? '*' : 'selector',
'ignoreCase': false
}
}
]
To override any of the default maps, just add your own with the same name. A map object consists of the following:
| Property | Type | Description |
|---|---|---|
name | string | Name of the map object |
search | string or Array | The string or list of strings to search for or replace with. |
replace | string or Array | The string or list of strings to search for or replace with. |
options | object | Defines map options. |
The map options is optional, and consists of the following:
| Property | Type | Default | Description |
|---|---|---|---|
scope | string | * | Defines the scope in which this map is allowed, 'selector' for selector renaming, 'url' for url updates and '*' for both. |
ignoreCase | Boolean | true | Indicates if the search is case-insensitive or not. |
greedy | Boolean | reverts to options.greedy | A false value forces selector renaming and url updates to respect word boundaries. |
Example
// a simple map, for swapping "prev" with "next" and vice versa.
{
"name" : "prev-next",
"search" : "prev",
"replace" : "next"
}
// a more detailed version, considering the convention used in the authored CSS document.
{
"name" : "prev-next",
"search" : ["prev", "Prev", "PREV"],
"replace" : ["next", "Next", "NEXT"],
options : {"ignoreCase":false}
}
Array of RTLCSS rule Processing Instructions (PI), these are applied on the CSS rule level:
| Property | Type | Description |
|---|---|---|
name | string | Name of the PI (used in logging). |
expr | RegExp | Regular expression object that will be matched against the comment preceeding the rule. |
important | boolean | Controls whether to insert the PI at the start or end of the rules PIs list. |
action | function | The action to be called when a match is found, and it will be passed a rule node. the functions is expected to return a boolean, true to stop further processing of the rule, otherwise false. |
Visit PostCSS to find out more about rule node.
// RTLCSS rule processing instruction
{
"name" : "ignore",
"expr" : /\/\*rtl:ignore\*\//img,
"important" : true,
"action" : function (rule) {
return true;
}
}
Array of RTLCSS declaration Processing Instructions (PI), these are applied on the CSS declaration level:
| Property | Type | Description |
|---|---|---|
name | string | Name of the PI (used in logging). |
expr | RegExp | Regular expression object that will be matched against the declaration raw value. |
important | boolean | Controls whether to insert the PI at the start or end of the declarations PIs list. |
action | function | The action to be called when a match is found, and it will be passed a decl node. the functions is expected to return a boolean, true to stop further processing of the declaration, otherwise false. |
Visit PostCSS to find out more about decl node.
// RTLCSS declaration processing instruction
{
"name" : "ignore",
"expr" : /(?:[^]*)(?:\/\*rtl:ignore)([^]*?)(?:\*\/)/img,
"important" : true,
"action" : function (decl) {
if (!config.preserveDirectives)
decl._value.raw = decl._value.raw.replace(/\/\*rtl:[^]*?\*\//img, "");
return true;
}
},
Array of RTLCSS properties Processing Instructions (PI), these are applied on the CSS property level:
| Property | Type | Description |
|---|---|---|
name | string | Name of the PI (used in logging). |
expr | RegExp | Regular expression object that will be matched against the declaration property name. |
important | boolean | Controls whether to insert the PI at the start or end of the declarations PIs list. |
action | function | The action to be called when a match is found, it will be passed a prop (string holding the CSS property name) and value (string holding the CSS property raw value). If options.preserveComments == true, comments in the raw value will be replaced by the Unicode Character 'REPLACEMENT CHARACTER' (U+FFFD) � (this is to simplify pattern matching). The function is expected to return an object containing the modified version of the property and its value. |
// RTLCSS property processing instruction
{
"name" : "direction",
"expr" : /direction/im,
"important" : true,
"action" : function (prop, value) {
return { 'prop': prop, 'value': util.swapLtrRtl(value) };
}
}
Have a bug or a feature request? please feel free to open a new issue .
v1.7.4 [23 Feb. 2016]
v1.7.3 [30 Jan. 2016]
v1.7.2 [04 Dec. 2015]
v1.7.1 [10 Nov. 2015]
v1.7.0 [19 Sep. 2015]
calc support.rename directive.v1.6.3 [28 Aug. 2015]
v1.6.2 [21 Jul. 2015]
v1.6.1 [17 Mar. 2015]
v1.6.0 [15 Mar. 2015]
matrix3d transform.v1.5.2 [28 Feb. 2015]
v1.5.1 [14 Feb. 2015]
v1.5.0 [30 Jan. 2015]
-e,--ext to set output files extension when processing a directory.v1.4.3 [24 Jan. 2015]
v1.4.2 [24 Oct. 2014]
v1.4.1 [24 Oct. 2014]
v1.4.0 [10 Oct. 2014]
v1.3.1 [29 Sep. 2014]
v1.3.0 [28 Sep. 2014]
v1.2.0 [26 Sep. 2014]
v1.1.0 [26 Sep. 2014]
border-color, border-style and background-position-xv1.0.0 [24 Aug. 2014]
v0.9.0 [10 Aug. 2014]
rtlcssConfig property.rtlcssrc or .rtlcssrc.jsonv0.8.0 [8 Aug. 2014]
v0.7.0 [4 Jul. 2014]
v0.6.0 [4 Jul. 2014]
ignore/rename rule level directives.v0.5.0 [11 Jun. 2014]
v0.4.0 [5 Apr. 2014]
v0.3.0 [5 Apr. 2014]
v0.2.1 [20 Mar. 2014]
v0.2.0 [20 Mar. 2014]
v0.1.3 [7 Mar. 2014]
v0.1.2 [5 Mar. 2014]
v0.1.1 [4 Mar. 2014]
FAQs
Framework for transforming cascading style sheets (CSS) from left-to-right (LTR) to right-to-left (RTL)
The npm package rtlcss receives a total of 545,273 weekly downloads. As such, rtlcss popularity was classified as popular.
We found that rtlcss demonstrated a healthy version release cadence and project activity because the last version was released less than a year ago. It has 1 open source maintainer collaborating on the project.
Did you know?
Socket for GitHub automatically highlights issues in each pull request and monitors the health of all your open source dependencies. Discover the contents of your packages and block harmful activity before you install or update your dependencies.
Product
Socket now supports four distinct alert actions instead of the previous two, and alert triaging allows users to override the actions taken for all individual alerts.
Security News
Polyfill.io has been serving malware for months via its CDN, after the project's open source maintainer sold the service to a company based in China.
Security News
OpenSSF is warning open source maintainers to stay vigilant against reputation farming on GitHub, where users artificially inflate their status by manipulating interactions on closed issues and PRs.