Develop Reference

How to define a line break in extendscript for Adobe Indesign

I am using extendscript to build some invoices from downloaded plaintext emails (.txt)
At points in the file there are lines of text that look like "Order Number: 123456" and then the line ends. I have a script made from parts I found on this site that finds the end of "Order Number:" in order to get a starting position of a substring. I want to use where the return key was hit to go to the next line as the second index number to finish the substring. To do this, I have another piece of script from the helpful people of this site that makes an array out of the indexes of every instance of a character. I will then use whichever array object is a higher number than the first number for the substring.
It's a bit convoluted, but I'm not great with Javascript yet, and if there is an easier way, I don't know it.
What is the character I need to use to emulate a return key in a txt file in javascript for extendscript for indesign?
Thank you.
I have tried things like \n and \r\n and ^p both with and without quotes around them but none of those seem to show up in the array when I try them.
//Load Email as String
var b = new File("~/Desktop/Test/email.txt");
b.open('r');
var str = "";
while (!b.eof)
str += b.readln();
b.close();
var orderNumberLocation = str.search("Order Number: ") + 14;
var orderNumber = str.substring(orderNumberLocation, ARRAY NUMBER GOES HERE)
var loc = orderNumberLocation.lineNumber
function indexes(source, find) {
var result = [];
for (i = 0; i < source.length; ++i) {
// If you want to search case insensitive use
// if (source.substring(i, i + find.length).toLowerCase() == find) {
if (source.substring(i, i + find.length) == find) {
result.push(i);
}
}
alert(result)
}
indexes(str, NEW PARAGRAPH CHARACTER GOES HERE)
I want all my line breaks to show up as an array of indexes in the variable "result".
Edit: My method of importing stripped all line breaks from the document. Using the code below instead works better. Now \n works.
var file = File("~/Desktop/Test/email.txt", "utf-8");
file.open("r");
var str = file.read();
file.close();

You need to use Regular Expressions. Depending on the fields do you need to search, you'l need to tweek the regular expressions, but I can give you a point. If the fields on the email are separated by new lines, something like that will work:
var str; //your string
var fields = {}
var lookFor = /(Order Number:|Adress:).*?\n/g;
str.replace(lookFor, function(match){
var order = match.split(':');
var field = order[0].replace(/\s/g, '');//remove all spaces
var value = order[1];
fields[field]= value;
})
With (Order Number:|Adress:) you are looking for the fields, you can add more fields separated the by the or character | ,inside the parenthessis. The .*?\n operators matches any character till the first break line appears. The g flag indicates that you want to look for all matches. Then you call str.replace, beacause it allows you to perfom a single task on each match. So, if the separator of the field and the value is a colon ':', then you split the match into an array of two values: ['Order number', 12345], and then, store that matches into an object. That code wil produce:
fields = {
OrderNumber: 12345,
Adresss: "my fake adress 000"
}

Please try \n and \r
Example: indexes(str, "\r");

If i've understood well, wat you need is to str.split():
function indexes(source, find) {
var order;
var result = [];
var orders = source.split('\n'); //returns an array of strings: ["order: 12345", "order:54321", ...]
for (var i = 0, l = orders.length; i < l; i++)
{
order = orders[i];
if (order.match(/find/) != null){
result.push(i)
}
}
return result;
}

Javascript regex replace with different values

I'd like to know if it is possible to replace every matching pattern in the string with not one but different values each time.
Let's say I found 5 matches in a text and I want to replace first match with a string, second match with another string, third match with another and so on... is it achievable?
var synonyms = ["extremely", "exceedingly", "exceptionally", "especially", "tremendously"];
"I'm very upset, very distress, very agitated, very annoyed and very pissed".replace(/very/g, function() {
//replace 5 matches of the keyword every with 5 synonyms in the array
});

You may try to replace the matches inside a replace callback function:
var synonyms = ["extremely", "exceedingly", "exceptionally", "especially", "tremendously"];
var cnt = 0;
console.log("I'm very upset, very distress, very agitated, very annoyed and very pissed (and very anxious)".replace(/very/g, function($0) {
if (cnt === synonyms.length) cnt = 0;
return synonyms[cnt++]; //replace 5 matches of the keyword every with 5 synonyms in the array
}));
If you have more matches than there are items in the array, the cnt will make sure the array items will be used from the first one again.

A simple recursive approach. Be sure your synonyms array has enough elements to cover all matches in your string.
let synonyms = ["extremely", "exceedingly", "exceptionally"]
let yourString = "I'm very happy, very joyful, and very handsome."
let rex = /very/
function r (s, i) {
let newStr = s.replace(rex, synonyms[i])
if (newStr === s)
return s
return r(newStr, i+1)
}
r(yourString, 0)
I would caution that if your replacement would also match your regex, you need to add an additional check.

function replaceExpressionWithSynonymsInText(text, regX, synonymList) {
var
list = [];
function getSynonym() {
if (list.length <= 0) {
list = Array.from(synonymList);
}
return list.shift();
}
return text.replace(regX, getSynonym);
}
var
synonymList = ["extremely", "exceedingly", "exceptionally", "especially", "tremendously"],
textSource = "I'm very upset, very distress, very agitated, very annoyed and very pissed",
finalText = replaceExpressionWithSynonymsInText(textSource, (/very/g), synonymList);
console.log("synonymList : ", synonymList);
console.log("textSource : ", textSource);
console.log("finalText : ", finalText);
The advantages of the above approach are, firstly one does not alter the list of synonyms,
secondly working internally with an ever new copy of the provided list and shifting it,
makes additional counters obsolete and also provides the opportunity of being able to
shuffle the new copy (once it has been emptied), thus achieving a more random replacement.

Using the example you've provided, here's what I would do.
First I would set up some variables
var text = "I'm very upset, very distress, very agitated, very annoyed and very pissed";
var regex = /very/;
var synonyms = ["extremely", "exceedingly", "exceptionally", "especially", "tremendously"];
Then count the number of matches
var count = text.match(/very/g).length;
Then I would run a loop to replace the matches with the values from the array
for(var x = 0; x < count; x++) {
text = text.replace(regex, synonyms[x]);
}

You can do it with the use of Replace() function, where you use 'g' option for global matching (finds all occurrences of searched expression). For the second argument you can use a function which returns values from your predefined array.
Here is a little fiddle where you can try it out.
var str = "test test test";
var rep = ["one", "two", "three"];
var ix = 0;
var res = str.replace(/test/g, function() {
if (ix == rep.length)
ix = 0;
return rep[ix++];
});
$("#result").text(res);
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<p id="result">
Result...
</p>

Yes it is achievable. There may be a more efficient answer than this, but the brute force way is to double the length of your regex. i.e. Instead of searching just A, search (/A){optionalText}(/A) and then replace /1 /2 as needed. If you need help with the regex itself, provide some code for what you're searching for and someone with more rep than me can probably comment the actual regexp.

Regular expression in Javascript: table of positions instead of table of occurrences

Regular expressions are most powerful. However, the result they return is sometimes useless:
For example:
I want to manage a CSV string using semicolons.
I define a string like:
var data = "John;Paul;Pete;Stuart;George";
If I use the instruction:
var tab = data.match(/;/g)
after what, "tab" contains an array of 4 ";" :
tab[0]=";", tab[1]=";", tab[2]=";", tab[3]=";"
This array is not useful in the present case, because I knew it even before using the regular expression.
Indeed, what I want to do is 2 things:
1stly: Suppress the 4th element (not "Stuart" as "Stuart", but "Stuart" as 4th element)
2ndly: Replace the 3rd element by "Ringo" so as to get back (to where you once belonged!) the following result:
data == "John;Paul;Ringo;George";
In this case, I would greatly prefer to obtain an array giving the positions of semicolons:
tab[0]=4, tab[1]=9, tab[2]=14 tab[3]=21
instead of the useless (in this specific case)
tab[0]=";", tab[1]=";", tab[2]=";", tab[3]=";"
So, here's my question: Is there a way to obtain this numeric array using regular expressions?

To get tab[0]=4, tab[1]=9, tab[2]=14 tab[3]=21, you can do
var tab = [];
var startPos = 0;
var data = "John;Paul;Pete;Stuart;George";
while (true) {
var currentIndex = data.indexOf(";", startPos);
if (currentIndex == -1) {
break;
}
tab.push(currentIndex);
startPos = currentIndex;
}
But if the result wanted is "John;Paul;Ringo;George", you can do
var tab = data.split(';'); // Split the string into an array of strings
tab.splice(3, 1); // Suppress the 4th element
tab[2] = "Ringo"; // Replace the 3rd element by "Ringo"
var str = tab.join(';'); // Join the elements of the array into a string
The second approach is maybe better in your case.
String.split
Array.splice
Array.join

You should try a different approach, using split.
tab = data.split(';') will return an array of the form
tab[0]="John", tab[1]="Paul", tab[2]="Pete", tab[3]="Stuart", tab[4]="George"
You should be able to achieve your goal with this array.

Why use a regex to perform this operation? You have a built-in function split, which can split your string based on the delimiter you pass.
var data = "John;Paul;Pete;Stuart;George";
var temp=data.split(';');
temp[0],temp[1]...

split string only on first instance of specified character

In my code I split a string based on _ and grab the second item in the array.
var element = $(this).attr('class');
var field = element.split('_')[1];
Takes good_luck and provides me with luck. Works great!
But, now I have a class that looks like good_luck_buddy. How do I get my javascript to ignore the second _ and give me luck_buddy?
I found this var field = element.split(new char [] {'_'}, 2); in a c# stackoverflow answer but it doesn't work. I tried it over at jsFiddle...

Use capturing parentheses:
'good_luck_buddy'.split(/_(.*)/s)
['good', 'luck_buddy', ''] // ignore the third element
They are defined as
If separator contains capturing parentheses, matched results are returned in the array.
So in this case we want to split at _.* (i.e. split separator being a sub string starting with _) but also let the result contain some part of our separator (i.e. everything after _).
In this example our separator (matching _(.*)) is _luck_buddy and the captured group (within the separator) is lucky_buddy. Without the capturing parenthesis the luck_buddy (matching .*) would've not been included in the result array as it is the case with simple split that separators are not included in the result.
We use the s regex flag to make . match on newline (\n) characters as well, otherwise it would only split to the first newline.

What do you need regular expressions and arrays for?
myString = myString.substring(myString.indexOf('_')+1)
var myString= "hello_there_how_are_you"
myString = myString.substring(myString.indexOf('_')+1)
console.log(myString)

I avoid RegExp at all costs. Here is another thing you can do:
"good_luck_buddy".split('_').slice(1).join('_')

With help of destructuring assignment it can be more readable:
let [first, ...rest] = "good_luck_buddy".split('_')
rest = rest.join('_')

A simple ES6 way to get both the first key and remaining parts in a string would be:
const [key, ...rest] = "good_luck_buddy".split('_')
const value = rest.join('_')
console.log(key, value) // good, luck_buddy

Nowadays String.prototype.split does indeed allow you to limit the number of splits.
str.split([separator[, limit]])
...
limit Optional
A non-negative integer limiting the number of splits. If provided, splits the string at each occurrence of the specified separator, but stops when limit entries have been placed in the array. Any leftover text is not included in the array at all.
The array may contain fewer entries than limit if the end of the string is reached before the limit is reached.
If limit is 0, no splitting is performed.
caveat
It might not work the way you expect. I was hoping it would just ignore the rest of the delimiters, but instead, when it reaches the limit, it splits the remaining string again, omitting the part after the split from the return results.
let str = 'A_B_C_D_E'
const limit_2 = str.split('_', 2)
limit_2
(2) ["A", "B"]
const limit_3 = str.split('_', 3)
limit_3
(3) ["A", "B", "C"]
I was hoping for:
let str = 'A_B_C_D_E'
const limit_2 = str.split('_', 2)
limit_2
(2) ["A", "B_C_D_E"]
const limit_3 = str.split('_', 3)
limit_3
(3) ["A", "B", "C_D_E"]

This solution worked for me
var str = "good_luck_buddy";
var index = str.indexOf('_');
var arr = [str.slice(0, index), str.slice(index + 1)];
//arr[0] = "good"
//arr[1] = "luck_buddy"
OR
var str = "good_luck_buddy";
var index = str.indexOf('_');
var [first, second] = [str.slice(0, index), str.slice(index + 1)];
//first = "good"
//second = "luck_buddy"

You can use the regular expression like:
var arr = element.split(/_(.*)/)
You can use the second parameter which specifies the limit of the split.
i.e:
var field = element.split('_', 1)[1];

Replace the first instance with a unique placeholder then split from there.
"good_luck_buddy".replace(/\_/,'&').split('&')
["good","luck_buddy"]
This is more useful when both sides of the split are needed.

I need the two parts of string, so, regex lookbehind help me with this.
const full_name = 'Maria do Bairro';
const [first_name, last_name] = full_name.split(/(?<=^[^ ]+) /);
console.log(first_name);
console.log(last_name);

Non-regex solution
I ran some benchmarks, and this solution won hugely:1
str.slice(str.indexOf(delim) + delim.length)
// as function
function gobbleStart(str, delim) {
return str.slice(str.indexOf(delim) + delim.length);
}
// as polyfill
String.prototype.gobbleStart = function(delim) {
return this.slice(this.indexOf(delim) + delim.length);
};
Performance comparison with other solutions
The only close contender was the same line of code, except using substr instead of slice.
Other solutions I tried involving split or RegExps took a big performance hit and were about 2 orders of magnitude slower. Using join on the results of split, of course, adds an additional performance penalty.
Why are they slower? Any time a new object or array has to be created, JS has to request a chunk of memory from the OS. This process is very slow.
Here are some general guidelines, in case you are chasing benchmarks:
New dynamic memory allocations for objects {} or arrays [] (like the one that split creates) will cost a lot in performance.
RegExp searches are more complicated and therefore slower than string searches.
If you already have an array, destructuring arrays is about as fast as explicitly indexing them, and looks awesome.
Removing beyond the first instance
Here's a solution that will slice up to and including the nth instance. It's not quite as fast, but on the OP's question, gobble(element, '_', 1) is still >2x faster than a RegExp or split solution and can do more:
/*
`gobble`, given a positive, non-zero `limit`, deletes
characters from the beginning of `haystack` until `needle` has
been encountered and deleted `limit` times or no more instances
of `needle` exist; then it returns what remains. If `limit` is
zero or negative, delete from the beginning only until `-(limit)`
occurrences or less of `needle` remain.
*/
function gobble(haystack, needle, limit = 0) {
let remain = limit;
if (limit <= 0) { // set remain to count of delim - num to leave
let i = 0;
while (i < haystack.length) {
const found = haystack.indexOf(needle, i);
if (found === -1) {
break;
}
remain++;
i = found + needle.length;
}
}
let i = 0;
while (remain > 0) {
const found = haystack.indexOf(needle, i);
if (found === -1) {
break;
}
remain--;
i = found + needle.length;
}
return haystack.slice(i);
}
With the above definition, gobble('path/to/file.txt', '/') would give the name of the file, and gobble('prefix_category_item', '_', 1) would remove the prefix like the first solution in this answer.
Tests were run in Chrome 70.0.3538.110 on macOSX 10.14.

Use the string replace() method with a regex:
var result = "good_luck_buddy".replace(/.*?_/, "");
console.log(result);
This regex matches 0 or more characters before the first _, and the _ itself. The match is then replaced by an empty string.

Javascript's String.split unfortunately has no way of limiting the actual number of splits. It has a second argument that specifies how many of the actual split items are returned, which isn't useful in your case. The solution would be to split the string, shift the first item off, then rejoin the remaining items::
var element = $(this).attr('class');
var parts = element.split('_');
parts.shift(); // removes the first item from the array
var field = parts.join('_');

Here's one RegExp that does the trick.
'good_luck_buddy' . split(/^.*?_/)[1]
First it forces the match to start from the
start with the '^'. Then it matches any number
of characters which are not '_', in other words
all characters before the first '_'.
The '?' means a minimal number of chars
that make the whole pattern match are
matched by the '.*?' because it is followed
by '_', which is then included in the match
as its last character.
Therefore this split() uses such a matching
part as its 'splitter' and removes it from
the results. So it removes everything
up till and including the first '_' and
gives you the rest as the 2nd element of
the result. The first element is "" representing
the part before the matched part. It is
"" because the match starts from the beginning.
There are other RegExps that work as
well like /_(.*)/ given by Chandu
in a previous answer.
The /^.*?_/ has the benefit that you
can understand what it does without
having to know about the special role
capturing groups play with replace().

if you are looking for a more modern way of doing this:
let raw = "good_luck_buddy"
raw.split("_")
.filter((part, index) => index !== 0)
.join("_")

Mark F's solution is awesome but it's not supported by old browsers. Kennebec's solution is awesome and supported by old browsers but doesn't support regex.
So, if you're looking for a solution that splits your string only once, that is supported by old browsers and supports regex, here's my solution:
String.prototype.splitOnce = function(regex)
{
var match = this.match(regex);
if(match)
{
var match_i = this.indexOf(match[0]);
return [this.substring(0, match_i),
this.substring(match_i + match[0].length)];
}
else
{ return [this, ""]; }
}
var str = "something/////another thing///again";
alert(str.splitOnce(/\/+/)[1]);

For beginner like me who are not used to Regular Expression, this workaround solution worked:
var field = "Good_Luck_Buddy";
var newString = field.slice( field.indexOf("_")+1 );
slice() method extracts a part of a string and returns a new string and indexOf() method returns the position of the first found occurrence of a specified value in a string.

This should be quite fast
function splitOnFirst (str, sep) {
const index = str.indexOf(sep);
return index < 0 ? [str] : [str.slice(0, index), str.slice(index + sep.length)];
}
console.log(splitOnFirst('good_luck', '_')[1])
console.log(splitOnFirst('good_luck_buddy', '_')[1])

This worked for me on Chrome + FF:
"foo=bar=beer".split(/^[^=]+=/)[1] // "bar=beer"
"foo==".split(/^[^=]+=/)[1] // "="
"foo=".split(/^[^=]+=/)[1] // ""
"foo".split(/^[^=]+=/)[1] // undefined
If you also need the key try this:
"foo=bar=beer".split(/^([^=]+)=/) // Array [ "", "foo", "bar=beer" ]
"foo==".split(/^([^=]+)=/) // [ "", "foo", "=" ]
"foo=".split(/^([^=]+)=/) // [ "", "foo", "" ]
"foo".split(/^([^=]+)=/) // [ "foo" ]
//[0] = ignored (holds the string when there's no =, empty otherwise)
//[1] = hold the key (if any)
//[2] = hold the value (if any)

a simple es6 one statement solution to get the first key and remaining parts
let raw = 'good_luck_buddy'
raw.split('_')
.reduce((p, c, i) => i === 0 ? [c] : [p[0], [...p.slice(1), c].join('_')], [])

You could also use non-greedy match, it's just a single, simple line:
a = "good_luck_buddy"
const [,g,b] = a.match(/(.*?)_(.*)/)
console.log(g,"and also",b)

Fastest / most efficient way to compare two string arrays Javascript

Hi I was wondering whether anyone could offer some advice on the fastest / most efficient way to compre two arrays of strings in javascript.
I am developing a kind of tag cloud type thing based on a users input - the input being in the form a written piece of text such as a blog article or the likes.
I therefore have an array that I keep of words to not include - is, a, the etc etc.
At the moment i am doing the following:
Remove all punctuation from the input string, tokenize it, compare each word to the exclude array and then remove any duplicates.
The comparisons are preformed by looping over each item in the exclude array for every word in the input text - this seems kind of brute force and is crashing internet explorer on arrays of more than a few hundred words.
i should also mention my exclude list has around 300 items.
Any help would really be appreciated.
Thanks

I'm not sure about the whole approach, but rather than building a huge array then iterating over it, why not put the "keys" into a map-"like" object for easier comparison?
e.g.
var excludes = {};//object
//set keys into the "map"
excludes['bad'] = true;
excludes['words'] = true;
excludes['exclude'] = true;
excludes['all'] = true;
excludes['these'] = true;
Then when you want to compare... just do
var wordsToTest = ['these','are','all','my','words','to','check','for'];
var checkWord;
for(var i=0;i<wordsToTest.length;i++){
checkWord = wordsToTest[i];
if(excludes[checkword]){
//bad word, ignore...
} else {
//good word... do something with it
}
}
allows these words through ['are','my','to','check','for']

It would be worth a try to combine the words into a single regex, and then compare with that. The regex engine's optimizations might allow the search to skip forward through the search text a lot more efficiently than you could do by iterating yourself over separate strings.

You could use a hashing function for strings (I don't know if JS has one but i'm sure uncle Google can help ;] ). Then you would calculate hashes for all the words in your exclude list and create an array af booleans indexed by those hashes. Then just iterate through the text and check the word hashes against that array.

I have taken scunliffe's answer and modified it as follows:
var excludes = ['bad','words','exclude','all','these']; //array
now lets prototype a function that checks if a value is inside an Array:
Array.prototype.hasValue= function(value) {
for (var i=0; i<this.length; i++)
if (this[i] === value) return true;
return false;
}
lets test some words:
var wordsToTest = ['these','are','all','my','words','to','check','for'];
var checkWord;
for(var i=0; i< wordsToTest.length; i++){
checkWord = wordsToTest[i];
if( excludes.hasValue(checkWord) ){
//is bad word
} else {
//is good word
console.log( checkWord );
}
}
output:
['are','my','to','check','for']

I'd opt for the regex version
text = 'This is a text that contains the words to delete. It has some <b>HTML</b> code in it, and punctuation!';
deleteWords = ['is', 'a', 'that', 'the', 'to', 'this', 'it', 'in', 'and', 'has'];
// clear punctuation and HTML code
onlyWordsReg = /\<[^>]*\>|\W/g;
onlyWordsText = text.replace(onlyWordsReg, ' ');
reg = new RegExp('\\b' + deleteWords.join('\\b|\\b') + '\\b', 'ig');
cleanText = onlyWordsText .replace(reg, '');
// tokenize after this