pdf-lib
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Create and modify PDF files with JavaScript
138 lines • 5.9 kB
JavaScript
export var toCharCode = function (character) { return character.charCodeAt(0); };
export var toCodePoint = function (character) { return character.codePointAt(0); };
export var toHexStringOfMinLength = function (num, minLength) {
return padStart(num.toString(16), minLength, '0').toUpperCase();
};
export var toHexString = function (num) { return toHexStringOfMinLength(num, 2); };
export var charFromCode = function (code) { return String.fromCharCode(code); };
export var charFromHexCode = function (hex) { return charFromCode(parseInt(hex, 16)); };
export var padStart = function (value, length, padChar) {
var padding = '';
for (var idx = 0, len = length - value.length; idx < len; idx++) {
padding += padChar;
}
return padding + value;
};
export var copyStringIntoBuffer = function (str, buffer, offset) {
var length = str.length;
for (var idx = 0; idx < length; idx++) {
buffer[offset++] = str.charCodeAt(idx);
}
return length;
};
export var addRandomSuffix = function (prefix, suffixLength) {
if (suffixLength === void 0) { suffixLength = 4; }
return prefix + "-" + Math.floor(Math.random() * Math.pow(10, suffixLength));
};
export var escapeRegExp = function (str) {
return str.replace(/[.*+?^${}()|[\]\\]/g, '\\$&');
};
export var cleanText = function (text) {
return text.replace(/\t|\u0085|\u2028|\u2029/g, ' ').replace(/[\b\v]/g, '');
};
export var escapedNewlineChars = ['\\n', '\\f', '\\r', '\\u000B'];
export var newlineChars = ['\n', '\f', '\r', '\u000B'];
export var isNewlineChar = function (text) { return /^[\n\f\r\u000B]$/.test(text); };
export var lineSplit = function (text) { return text.split(/[\n\f\r\u000B]/); };
export var mergeLines = function (text) {
return text.replace(/[\n\f\r\u000B]/g, ' ');
};
// JavaScript's String.charAt() method doesn work on strings containing UTF-16
// characters (with high and low surrogate pairs), such as 💩 (poo emoji). This
// `charAtIndex()` function does.
//
// Credit: https://github.com/mathiasbynens/String.prototype.at/blob/master/at.js#L14-L48
export var charAtIndex = function (text, index) {
// Get the first code unit and code unit value
var cuFirst = text.charCodeAt(index);
var cuSecond;
var nextIndex = index + 1;
var length = 1;
if (
// Check if it's the start of a surrogate pair.
cuFirst >= 0xd800 &&
cuFirst <= 0xdbff && // high surrogate
text.length > nextIndex // there is a next code unit
) {
cuSecond = text.charCodeAt(nextIndex);
if (cuSecond >= 0xdc00 && cuSecond <= 0xdfff)
length = 2; // low surrogate
}
return [text.slice(index, index + length), length];
};
export var charSplit = function (text) {
var chars = [];
for (var idx = 0, len = text.length; idx < len;) {
var _a = charAtIndex(text, idx), c = _a[0], cLen = _a[1];
chars.push(c);
idx += cLen;
}
return chars;
};
var buildWordBreakRegex = function (wordBreaks) {
var newlineCharUnion = escapedNewlineChars.join('|');
var escapedRules = ['$'];
for (var idx = 0, len = wordBreaks.length; idx < len; idx++) {
var wordBreak = wordBreaks[idx];
if (isNewlineChar(wordBreak)) {
throw new TypeError("`wordBreak` must not include " + newlineCharUnion);
}
escapedRules.push(wordBreak === '' ? '.' : escapeRegExp(wordBreak));
}
var breakRules = escapedRules.join('|');
return new RegExp("(" + newlineCharUnion + ")|((.*?)(" + breakRules + "))", 'gm');
};
export var breakTextIntoLines = function (text, wordBreaks, maxWidth, computeWidthOfText) {
var regex = buildWordBreakRegex(wordBreaks);
var words = cleanText(text).match(regex);
var currLine = '';
var currWidth = 0;
var lines = [];
var pushCurrLine = function () {
if (currLine !== '')
lines.push(currLine);
currLine = '';
currWidth = 0;
};
for (var idx = 0, len = words.length; idx < len; idx++) {
var word = words[idx];
if (isNewlineChar(word)) {
pushCurrLine();
}
else {
var width = computeWidthOfText(word);
if (currWidth + width > maxWidth)
pushCurrLine();
currLine += word;
currWidth += width;
}
}
pushCurrLine();
return lines;
};
// See section "7.9.4 Dates" of the PDF specification
var dateRegex = /^D:(\d\d\d\d)(\d\d)?(\d\d)?(\d\d)?(\d\d)?(\d\d)?([+\-Z])?(\d\d)?'?(\d\d)?'?$/;
export var parseDate = function (dateStr) {
var match = dateStr.match(dateRegex);
if (!match)
return undefined;
var year = match[1], _a = match[2], month = _a === void 0 ? '01' : _a, _b = match[3], day = _b === void 0 ? '01' : _b, _c = match[4], hours = _c === void 0 ? '00' : _c, _d = match[5], mins = _d === void 0 ? '00' : _d, _e = match[6], secs = _e === void 0 ? '00' : _e, _f = match[7], offsetSign = _f === void 0 ? 'Z' : _f, _g = match[8], offsetHours = _g === void 0 ? '00' : _g, _h = match[9], offsetMins = _h === void 0 ? '00' : _h;
// http://www.ecma-international.org/ecma-262/5.1/#sec-15.9.1.15
var tzOffset = offsetSign === 'Z' ? 'Z' : "" + offsetSign + offsetHours + ":" + offsetMins;
var date = new Date(year + "-" + month + "-" + day + "T" + hours + ":" + mins + ":" + secs + tzOffset);
return date;
};
export var findLastMatch = function (value, regex) {
var _a;
var position = 0;
var lastMatch;
while (position < value.length) {
var match = value.substring(position).match(regex);
if (!match)
return { match: lastMatch, pos: position };
lastMatch = match;
position += ((_a = match.index) !== null && _a !== void 0 ? _a : 0) + match[0].length;
}
return { match: lastMatch, pos: position };
};
//# sourceMappingURL=strings.js.map