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Useful collection of JavaScript string utilities.
// String utils
//
// resources:
// -- mout, https://github.com/mout/mout/tree/master/src/string
/**
* "Safer" String.toLowerCase()
*/
function lowerCase(str){
return str.toLowerCase();
}
/**
* "Safer" String.toUpperCase()
*/
function upperCase(str){
return str.toUpperCase();
}
/**
* Convert string to camelCase text.
*/
function camelCase(str){
str = replaceAccents(str);
str = removeNonWord(str)
.replace(/\-/g, ' ') //convert all hyphens to spaces
.replace(/\s[a-z]/g, upperCase) //convert first char of each word to UPPERCASE
.replace(/\s+/g, '') //remove spaces
.replace(/^[A-Z]/g, lowerCase); //convert first char to lowercase
return str;
}
/**
* Add space between camelCase text.
*/
function unCamelCase(str){
str = str.replace(/([a-z\xE0-\xFF])([A-Z\xC0\xDF])/g, '$1 $2');
str = str.toLowerCase(); //add space between camelCase text
return str;
}
/**
* UPPERCASE first char of each word.
*/
function properCase(str){
return lowerCase(str).replace(/^\w|\s\w/g, upperCase);
}
/**
* camelCase + UPPERCASE first char
*/
function pascalCase(str){
return camelCase(str).replace(/^[a-z]/, upperCase);
}
function normalizeLineBreaks(str, lineEnd) {
lineEnd = lineEnd || 'n';
return str
.replace(/rn/g, lineEnd) // DOS
.replace(/r/g, lineEnd) // Mac
.replace(/n/g, lineEnd); // Unix
}
/**
* UPPERCASE first char of each sentence and lowercase other chars.
*/
function sentenceCase(str){
// Replace first char of each sentence (new line or after '.\s+') to
// UPPERCASE
return lowerCase(str).replace(/(^\w)|\.\s+(\w)/gm, upperCase);
}
/**
* Convert to lower case, remove accents, remove non-word chars and
* replace spaces with the specified delimeter.
* Does not split camelCase text.
*/
function slugify(str, delimeter){
if (delimeter == null) {
delimeter = "-";
}
str = replaceAccents(str);
str = removeNonWord(str);
str = trim(str) //should come after removeNonWord
.replace(/ +/g, delimeter) //replace spaces with delimeter
.toLowerCase();
return str;
}
/**
* Replaces spaces with hyphens, split camelCase text, remove non-word chars, remove accents and convert to lower case.
*/
function hyphenate(str){
str = unCamelCase(str);
return slugify(str, "-");
}
/**
* Replaces hyphens with spaces. (only hyphens between word chars)
*/
function unhyphenate(str){
return str.replace(/(\w)(-)(\w)/g, '$1 $3');
}
/**
* Replaces spaces with underscores, split camelCase text, remove
* non-word chars, remove accents and convert to lower case.
*/
function underscore(str){
str = unCamelCase(str);
return slugify(str, "_");
}
/**
* Remove non-word chars.
*/
function removeNonWord(str){
return str.replace(/[^0-9a-zA-Z\xC0-\xFF \-]/g, '');
}
/**
* Convert line-breaks from DOS/MAC to a single standard (UNIX by default)
*/
function normalizeLineBreaks(str, lineEnd) {
lineEnd = lineEnd || '\n';
return str
.replace(/\r\n/g, lineEnd) // DOS
.replace(/\r/g, lineEnd) // Mac
.replace(/\n/g, lineEnd); // Unix
}
/**
* Replaces all accented chars with regular ones
*/
function replaceAccents(str){
// verifies if the String has accents and replace them
if (str.search(/[\xC0-\xFF]/g) > -1) {
str = str
.replace(/[\xC0-\xC5]/g, "A")
.replace(/[\xC6]/g, "AE")
.replace(/[\xC7]/g, "C")
.replace(/[\xC8-\xCB]/g, "E")
.replace(/[\xCC-\xCF]/g, "I")
.replace(/[\xD0]/g, "D")
.replace(/[\xD1]/g, "N")
.replace(/[\xD2-\xD6\xD8]/g, "O")
.replace(/[\xD9-\xDC]/g, "U")
.replace(/[\xDD]/g, "Y")
.replace(/[\xDE]/g, "P")
.replace(/[\xE0-\xE5]/g, "a")
.replace(/[\xE6]/g, "ae")
.replace(/[\xE7]/g, "c")
.replace(/[\xE8-\xEB]/g, "e")
.replace(/[\xEC-\xEF]/g, "i")
.replace(/[\xF1]/g, "n")
.replace(/[\xF2-\xF6\xF8]/g, "o")
.replace(/[\xF9-\xFC]/g, "u")
.replace(/[\xFE]/g, "p")
.replace(/[\xFD\xFF]/g, "y");
}
return str;
}
/**
* Searches for a given substring
*/
function contains(str, substring, fromIndex){
return str.indexOf(substring, fromIndex) !== -1;
}
/**
* Truncate string at full words.
*/
function crop(str, maxChars, append) {
return truncate(str, maxChars, append, true);
}
/**
* Escape RegExp string chars.
*/
function escapeRegExp(str) {
var ESCAPE_CHARS = /[\\.+*?\^$\[\](){}\/'#]/g;
return str.replace(ESCAPE_CHARS,'\\$&');
}
/**
* Escapes a string for insertion into HTML.
*/
function escapeHtml(str){
str = str
.replace(/&/g, '&')
.replace(/</g, '&lt;')
.replace(/>/g, '&gt;')
.replace(/'/g, '&#39;')
.replace(/"/g, '&quot;');
return str;
}
/**
* Unescapes HTML special chars
*/
function unescapeHtml(str){
str = str
.replace(/&amp;/g , '&')
.replace(/&lt;/g , '<')
.replace(/&gt;/g , '>')
.replace(/&#39;/g , "'")
.replace(/&quot;/g, '"');
return str;
}
/**
* Escape string into unicode sequences
*/
function escapeUnicode(str, shouldEscapePrintable){
return str.replace(/[\s\S]/g, function(ch){
// skip printable ASCII chars if we should not escape them
if (!shouldEscapePrintable && (/[\x20-\x7E]/).test(ch)) {
return ch;
}
// we use "000" and slice(-4) for brevity, need to pad zeros,
// unicode escape always have 4 chars after "\u"
return '\\u'+ ('000'+ ch.charCodeAt(0).toString(16)).slice(-4);
});
}
/**
* Remove HTML tags from string.
*/
function stripHtmlTags(str){
return str.replace(/<[^>]*>/g, '');
}
/**
* Remove non-printable ASCII chars
*/
function removeNonASCII(str){
// Matches non-printable ASCII chars -
// http://en.wikipedia.org/wiki/ASCII#ASCII_printable_characters
return str.replace(/[^\x20-\x7E]/g, '');
}
/**
* String interpolation
*/
function interpolate(template, replacements, syntax){
var stache = /\{\{(\w+)\}\}/g; //mustache-like
var replaceFn = function(match, prop){
return (prop in replacements) ? replacements[prop] : '';
};
return template.replace(syntax || stache, replaceFn);
}
/**
* Pad string with `char` if its' length is smaller than `minLen`
*/
function rpad(str, minLen, ch) {
ch = ch || ' ';
return (str.length < minLen)? str + repeat(ch, minLen - str.length) : str;
}
/**
* Pad string with `char` if its' length is smaller than `minLen`
*/
function lpad(str, minLen, ch) {
ch = ch || ' ';
return ((str.length < minLen)
? repeat(ch, minLen - str.length) + str : str);
}
/**
* Repeat string n times
*/
function repeat(str, n){
return (new Array(n + 1)).join(str);
}
/**
* Limit number of chars.
*/
function truncate(str, maxChars, append, onlyFullWords){
append = append || '...';
maxChars = onlyFullWords? maxChars + 1 : maxChars;
str = trim(str);
if(str.length <= maxChars){
return str;
}
str = str.substr(0, maxChars - append.length);
//crop at last space or remove trailing whitespace
str = onlyFullWords? str.substr(0, str.lastIndexOf(' ')) : trim(str);
return str + append;
}
var WHITE_SPACES = [
' ', '\n', '\r', '\t', '\f', '\v', '\u00A0', '\u1680', '\u180E',
'\u2000', '\u2001', '\u2002', '\u2003', '\u2004', '\u2005', '\u2006',
'\u2007', '\u2008', '\u2009', '\u200A', '\u2028', '\u2029', '\u202F',
'\u205F', '\u3000'
];
/**
* Remove chars from beginning of string.
*/
function ltrim(str, chars) {
chars = chars || WHITE_SPACES;
var start = 0,
len = str.length,
charLen = chars.length,
found = true,
i, c;
while (found && start < len) {
found = false;
i = -1;
c = str.charAt(start);
while (++i < charLen) {
if (c === chars[i]) {
found = true;
start++;
break;
}
}
}
return (start >= len) ? '' : str.substr(start, len);
}
/**
* Remove chars from end of string.
*/
function rtrim(str, chars) {
chars = chars || WHITE_SPACES;
var end = str.length - 1,
charLen = chars.length,
found = true,
i, c;
while (found && end >= 0) {
found = false;
i = -1;
c = str.charAt(end);
while (++i < charLen) {
if (c === chars[i]) {
found = true;
end--;
break;
}
}
}
return (end >= 0) ? str.substring(0, end + 1) : '';
}
/**
* Remove white-spaces from beginning and end of string.
*/
function trim(str, chars) {
chars = chars || WHITE_SPACES;
return ltrim(rtrim(str, chars), chars);
}
/**
* Capture all capital letters following a word boundary (in case the
* input is in all caps)
*/
function abbreviate(str) {
return str.match(/\b([A-Z])/g).join('');
}
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