How do I use regex to find FS.File on FS.Collection in meteor - meteor

How do I use regex to find FS.File on FS.Collection in meteor. My code is as follows and it is not working
partOfFileName = "*User_" + clickedResellerId + "_*";
var imgs = Images.find({fileName:{$regex:partOfFileName}});
//var imgs = Images.find();
return imgs // Where Images is an FS.Collection instance
In place of fileName I've also tried name and it is not working either. Please help

I don't think your regex is valid. Did you perhaps mean the following?
partOfFileName = ".*User_" + clickedResellerId + "_.*";
Please note that POSIX wildcard notation is different from regular expressions. in Regular expressions the * operators indicates repetition of the preceding operator (in my case a ., i.e., anything). A * by itself has no meaning, and it doesn't mean "anything" like in POSIX.

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Using the replace function in firestore security rules

I'm struggling with Firestore security rules. I want to check on a value that needs the replace function, i.e. an e-mail address. I can find some documentation in the general security docs, but that does not seem to work with Firestore.
For example this works:
allow write: if resource.data.members.data[(request.auth.token.email)] in ["admin"];
but this doesn't (and I changed the key in the members object accordingly):
allow write: if resource.data.members.data[(request.auth.token.email.replace('.' , ',')] in ["admin"];
Another option would be to have a way to use dots in the address of a query, so they don't have to be replaced like this:
var emailSanitized = email.replace('.' , '.');
db.collection('someCollection').where('members.' + emailSanitized, '==', 'admin')
Any ideas here?
A little late, but you can simulate the replace function on a string with this one :
function replace(string, replace, by) {
return string.split(replace).join(by);
}
So you need to define this function in your firestore.rules file and then you can call replace(request.auth.token.email, '.' , ',') to get the same result as request.auth.token.email.replace('.' , ',') in javascript.
There are two reasons why you might have been having issues.
The replace function was added to Security Rules after you asked your question.
The replace function uses regular expressions for the first argument and so matching on '.' will match literally everything.
Consider instead using: request.auth.token.email.replace('\\.' , ',')
var emailSanitized = email.replace('.' , '.');
db.collection('someCollection').where('members.' + emailSanitized, '==', 'admin')

Is it possible to turn off case insensitivity using pattern only?

Regex has set option IgnoreCase. Is it possible to turn off case insensitivity using pattern only (like negation of (?i))?
In example below, find pattern for which result would be "aBaaaBBaaB".
string pattern = "???";
string input = "aAaaaAAaaA";
var regex = new Regex(pattern, RegexOptions.IgnoreCase);
var result = regex.Replace(input, "B");
You can turn off options inline by using - before the option. E.g. the negation of (?i) is (?-i):
a minus sign (-) before an option or set of options turns those options off. For example, (?i-mn) turns case-insensitive matching (i) on, turns multiline mode (m) off, and turns unnamed group captures (n) off.

Find word (not containing substrings) in comma separated string

I'm using a linq query where i do something liike this:
viewModel.REGISTRATIONGRPS = (From a In db.TABLEA
Select New SubViewModel With {
.SOMEVALUE1 = a.SOMEVALUE1,
...
...
.SOMEVALUE2 = If(commaseparatedstring.Contains(a.SOMEVALUE1), True, False)
}).ToList()
Now my Problem is that this does'n search for words but for substrings so for example:
commaseparatedstring = "EWM,KI,KP"
SOMEVALUE1 = "EW"
It returns true because it's contained in EWM?
What i would need is to find words (not containing substrings) in the comma separated string!
Option 1: Regular Expressions
Regex.IsMatch(commaseparatedstring, #"\b" + Regex.Escape(a.SOMEVALUE1) + #"\b")
The \b parts are called "word boundaries" and tell the regex engine that you are looking for a "full word". The Regex.Escape(...) ensures that the regex engine will not try to interpret "special characters" in the text you are trying to match. For example, if you are trying to match "one+two", the Regex.Escape method will return "one\+two".
Also, be sure to include the System.Text.RegularExpressions at the top of your code file.
See Regex.IsMatch Method (String, String) on MSDN for more information.
Option 2: Split the String
You could also try splitting the string which would be a bit simpler, though probably less efficient.
commaseparatedstring.Split(new Char[] { ',' }).Contains( a.SOMEVALUE1 )
what about:
- separating the commaseparatedstring by comma
- calling equals() on each substring instead of contains() on whole thing?
.SOMEVALUE2 = If(commaseparatedstring.Split(',').Contains(a.SOMEVALUE1), True, False)

QRegExp: individual quantifiers can't be non-greedy, but what good alternatives then?

I'm trying to write code that appends ending _my_ending to the filename, and does not change file extension.
Examples of what I need to get:
"test.bmp" -> "test_my_ending.bmp"
"test.foo.bar.bmp" -> "test.foo.bar_my_ending.bmp"
"test" -> "test_my_ending"
I have some experience in PCRE, and that's trivial task using it. Because of the lack of experience in Qt, initially I wrote the following code:
QString new_string = old_string.replace(
QRegExp("^(.+?)(\\.[^.]+)?$"),
"\\1_my_ending\\2"
);
This code does not work (no match at all), and then I found in the docs that
Non-greedy matching cannot be applied to individual quantifiers, but can be applied to all the quantifiers in the pattern
As you see, in my regexp I tried to reduce greediness of the first quantifier + by adding ? after it. This isn't supported in QRegExp.
This is really disappointing for me, and so, I have to write the following ugly but working code:
//-- write regexp that matches only filenames with extension
QRegExp r = QRegExp("^(.+)(\\.[^.]+)$");
r.setMinimal(true);
QString new_string;
if (old_string.contains(r)){
//-- filename contains extension, so, insert ending just before it
new_string = old_string.replace(r, "\\1_my_ending\\2");
} else {
//-- filename does not contain extension, so, just append ending
new_string = old_string + time_add;
}
But is there some better solution? I like Qt, but some things that I see in it seem to be discouraging.
How about using QFileInfo? This is shorter than your 'ugly' code:
QFileInfo fi(old_string);
QString new_string = fi.completeBaseName() + "_my_ending"
+ (fi.suffix().isEmpty() ? "" : ".") + fi.suffix();

How to encode the plus (+) symbol in a URL

The URL link below will open a new Google mail window. The problem I have is that Google replaces all the plus (+) signs in the email body with blank space. It looks like it only happens with the + sign. How can I remedy this? (I am working on a ASP.NET web page.)
https://mail.google.com/mail?view=cm&tf=0&to=someemail#somedomain.com&su=some subject&body=Hi there+Hello there
(In the body email, "Hi there+Hello there" will show up as "Hi there Hello there")
The + character has a special meaning in [the query segment of] a URL => it means whitespace: . If you want to use the literal + sign there, you need to URL encode it to %2b:
body=Hi+there%2bHello+there
Here's an example of how you could properly generate URLs in .NET:
var uriBuilder = new UriBuilder("https://mail.google.com/mail");
var values = HttpUtility.ParseQueryString(string.Empty);
values["view"] = "cm";
values["tf"] = "0";
values["to"] = "someemail#somedomain.com";
values["su"] = "some subject";
values["body"] = "Hi there+Hello there";
uriBuilder.Query = values.ToString();
Console.WriteLine(uriBuilder.ToString());
The result:
https://mail.google.com:443/mail?view=cm&tf=0&to=someemail%40somedomain.com&su=some+subject&body=Hi+there%2bHello+there
If you want a plus + symbol in the body you have to encode it as 2B.
For example:
Try this
In order to encode a + value using JavaScript, you can use the encodeURIComponent function.
Example:
var url = "+11";
var encoded_url = encodeURIComponent(url);
console.log(encoded_url)
It's safer to always percent-encode all characters except those defined as "unreserved" in RFC-3986.
unreserved = ALPHA / DIGIT / "-" / "." / "_" / "~"
So, percent-encode the plus character and other special characters.
The problem that you are having with pluses is because, according to RFC-1866 (HTML 2.0 specification), paragraph 8.2.1. subparagraph 1., "The form field names and values are escaped: space characters are replaced by `+', and then reserved characters are escaped"). This way of encoding form data is also given in later HTML specifications, look for relevant paragraphs about application/x-www-form-urlencoded.
Just to add this to the list:
Uri.EscapeUriString("Hi there+Hello there") // Hi%20there+Hello%20there
Uri.EscapeDataString("Hi there+Hello there") // Hi%20there%2BHello%20there
See https://stackoverflow.com/a/34189188/98491
Usually you want to use EscapeDataString which does it right.
Generally if you use .NET API's - new Uri("someproto:with+plus").LocalPath or AbsolutePath will keep plus character in URL. (Same "someproto:with+plus" string)
but Uri.EscapeDataString("with+plus") will escape plus character and will produce "with%2Bplus".
Just to be consistent I would recommend to always escape plus character to "%2B" and use it everywhere - then no need to guess who thinks and what about your plus character.
I'm not sure why from escaped character '+' decoding would produce space character ' ' - but apparently it's the issue with some of components.

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