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Mar 24, 2015
Jun 16, 2016
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100644
28 lines (28 sloc)
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/**
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* There are cases where important information is at the end of the string and truncating the end isn't helpful.
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* This function solves that.
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*
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* @param {string} str String to be truncated
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* @param {number} frontLen Number of characters to be remained in front.
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* @param {number} backLen Number of characters to be remained at the back.
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* @param {string} truncateStr String that is replaced the truncated portion
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* @return {string} Truncated string. Defaults to '…' if unspecified.
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*/
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module.exports = function (str, frontLen, backLen, truncateStr) {
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if (str === null) {
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return ''
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}
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var strLen = str.length
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// Setting default values
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frontLen = ~~frontLen // will cast to integer
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backLen = ~~backLen
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truncateStr = truncateStr || '…'
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if (frontLen === 0 && backLen === 0 || frontLen >= strLen || backLen >= strLen || (frontLen + backLen) >= strLen) {
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return str
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} else if (backLen === 0) {
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return str.slice(0, frontLen) + truncateStr
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} else {
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return str.slice(0, frontLen) + truncateStr + str.slice(strLen - backLen)
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}
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}