Language:
Rust
Rust regex crate: https://docs.rs/regex/1.5.4/regex/
Use case:
Printing friendly diagnostic message to user that inputs text that does not match an expected regex pattern
e.g.
if patterns are Regex::new(r"^--(\w+)=(\w+)$").unwrap(); and Regex = Regex::new(r"^-(\w+)$").unwrap();
and user inputs "---abc"
user can see diagnostic like:
"---abc"
^ Problem with character "-" at index 2.
Expecting format "--key=value".
^ Does not match expected format at index 2.
Possible solution:
Can I do something with capture groups? (They might only be relevant if there is a match). If no solution with capture groups, what else?
// "-a[bc..]" or "--key=value"
lazy_static! {
static ref SHORT_OPTION_RE: Regex = Regex::new(r"^-(\w+)$").unwrap();
static ref LONG_OPTION_RE: Regex = Regex::new(r"^--(\w+)=(\w+)$").unwrap();
}
// long option example
let caps = LONG_OPTION_RE.captures(s).ok_or(e_msg)?;
let key = caps.get(1).unwrap().as_str().to_string();
let value = caps.get(2).unwrap().as_str().to_string();
if key.is_some { }
Issue:
Can't get exact char index that caused capture group not to match.
Alternatives:
Just manually add in if/else checks for various indexes to try to catch every error scenario ("---a", "-a=b", etc) (Essentially implement mini parser that generates diagnostic message and problematic char index without using regex)
Out of scope:
I do not need recommendations for cli program libs/frameworks (unless you're pointing to an implementation detail within one)
Edit:
Modified question to be more generic than just regex.
I would use a parser like nom.
Here is a quick and partial implementation of your use case:
use nom::{
bytes::complete::tag, character::complete::alphanumeric1, combinator::map, sequence::tuple,
IResult,
};
#[derive(Debug)]
struct OptPair {
key: String,
value: String,
}
fn parse_option(input: &str) -> IResult<&str, OptPair> {
map(
tuple((tag("--"), alphanumeric1, tag("="), alphanumeric1)),
|(_, k, _, v): (&str, &str, &str, &str)| OptPair {
key: k.to_owned(),
value: v.to_owned(),
},
)(input)
}
fn test_parse(input: &str) {
println!("TEST: input = \"{}\":", input);
match parse_option(input) {
Ok((_, opt_pair)) => println!(" Ok, {:?}", opt_pair),
Err(err) => match err {
nom::Err::Incomplete(_) => eprintln!(" Incomplete"),
nom::Err::Error(err) => {
let offset = err.input.as_ptr() as usize - input.as_ptr() as usize;
eprintln!(" Error at index {}", offset);
}
nom::Err::Failure(_err) => println!(" Failure"),
},
}
}
fn main() {
test_parse("--foo=bar");
test_parse("---foo=bar");
test_parse("--foo=");
test_parse("Hello");
}
Output:
TEST: input = "--foo=bar":
Ok, OptPair { key: "foo", value: "bar" }
TEST: input = "---foo=bar":
Error at index 2
TEST: input = "--foo=":
Error at index 6
TEST: input = "Hello":
Error at index 0
class Article{
final String id;
final List<ArticleArray> arrays;
}
class ArticleArray {
final String id;
final String array;
}
TextFormField(
onChanged: (_searchinput) {
List<String> searcharray = _searchinput.split(',');
),
_articlesForDisplay = _articles.where((article){
for(int i = 0; i < article.arrays.length; i++)
{
searchinit = article.arrays[i].arrays.toLowerCase();
}
return searchinit.contains(
RegExp(//necessary code here, caseSensitive: false),
);})
basically what i am trying to do is i am trying to search
array by array like:
-Textformfields follows the user input and every time "," is entered,i
put that word into "searcharray".
-Then i initiate a search in my function(total code is not needed to write here,
i included necessary functions),i try to use "regexp" function to search for the arrays
in my article archives.
Example:
articles[0].arrays[0].array = 'a1'
articles[0].arrays[1].array = 'a2'
articles[1].arrays[0].array = 'a1'
articles[1].arrays[1].array = 'b2'
searcharray = ['a1','b2']
Here,basically what i try to do is i try to search my article arrays by every list of arrays as possible so it matches the right one. Thats what i want.
Not sure I understand your specific requirements.
Here, I define a RegExp that I try to match to at least one item of my data.
void main() {
List<String> data = ['a1','b2', 'c3', 'a4', 'a5', 'd6'];
RegExp exp = new RegExp(r"(a\d+)");
print(data.any((item) => exp.hasMatch(item)));
}
I have a textbox which should only accept Characters:-for that first regex has been set in constraint and it should not accept some reserved keywords that are A,R,F,U .Since two different constraints are set ,i want user to see the specific message ,for first it should be Illegal Value i.e default zkoss error and when he/she enters a reserved character ,it should show that reserved code has been put.
But somehow the following code doesnt work :
field_code.setConstraint("/[a-zA-Z]/ : {Illegal Value} ,/[^AaRrUuFf]/ : Reserved Code");
The output is the first regex works fine but on offending the same " {Illegal Value} ,/[^AaRrUuFf]/ : Reserved Code" is displayed as error.
You can't do it in the zul, but with help of a SimpleConstraint you could create this.
Create your own class, and extend SimpleConstraint.
Then hold 2 Matcher vars for each constraint.
At last, override the Validate method to something like this :
#Override
public void validate(Component comp, Object value) {
if (value != null && value instanceof String) {
String stringValue = (String) value;
if (!expression1.reset(stringValue).matches()) {
throw new WrongValueException(comp, errorMsg1);
}
if (!expression2.reset(stringValue).matches()) {
throw new WrongValueException(comp,errorMsg2);
}
} else {
// do what needs to be done when value is null or not a String.
}
}
EDIT: Please feel free to add additional validations that would be useful for others, using this simple directive.
--
I'm trying to create an Angular Directive that limits the characters input into a text box. I've been successful with a couple common use cases (alphbetical, alphanumeric and numeric) but using popular methods for validating email addresses, dates and currency I can't get the directive to work since I need it negate the regex. At least that's what I think it needs to do.
Any assistance for currency (optional thousand separator and cents), date (mm/dd/yyyy) and email is greatly appreciated. I'm not strong with regular expressions at all.
Here's what I have currently:
http://jsfiddle.net/corydorning/bs05ys69/
HTML
<div ng-app="example">
<h1>Validate Directive</h1>
<p>The Validate directive allow us to restrict the characters an input can accept.</p>
<h3><code>alphabetical</code> <span style="color: green">(works)</span></h3>
<p>Restricts input to alphabetical (A-Z, a-z) characters only.</p>
<label><input type="text" validate="alphabetical" ng-model="validate.alphabetical"/></label>
<h3><code>alphanumeric</code> <span style="color: green">(works)</span></h3>
<p>Restricts input to alphanumeric (A-Z, a-z, 0-9) characters only.</p>
<label><input type="text" validate="alphanumeric" ng-model="validate.alphanumeric" /></label>
<h3><code>currency</code> <span style="color: red">(doesn't work)</span></h3>
<p>Restricts input to US currency characters with comma for thousand separator (optional) and cents (optional).</p>
<label><input type="text" validate="currency.us" ng-model="validate.currency" /></label>
<h3><code>date</code> <span style="color: red">(doesn't work)</span></h3>
<p>Restricts input to the mm/dd/yyyy date format only.</p>
<label><input type="text" validate="date" ng-model="validate.date" /></label>
<h3><code>email</code> <span style="color: red">(doesn't work)</span></h3>
<p>Restricts input to email format only.</p>
<label><input type="text" validate="email" ng-model="validate.email" /></label>
<h3><code>numeric</code> <span style="color: green">(works)</span></h3>
<p>Restricts input to numeric (0-9) characters only.</p>
<label><input type="text" validate="numeric" ng-model="validate.numeric" /></label>
JavaScript
angular.module('example', [])
.directive('validate', function () {
var validations = {
// works
alphabetical: /[^a-zA-Z]*$/,
// works
alphanumeric: /[^a-zA-Z0-9]*$/,
// doesn't work - need to negate?
// taken from: http://stackoverflow.com/questions/354044/what-is-the-best-u-s-currency-regex
currency: /^[+-]?[0-9]{1,3}(?:,?[0-9]{3})*(?:\.[0-9]{2})?$/,
// doesn't work - need to negate?
// taken from here: http://stackoverflow.com/questions/15196451/regular-expression-to-validate-datetime-format-mm-dd-yyyy
date: /(?:0[1-9]|1[0-2])\/(?:0[1-9]|[12][0-9]|3[01])\/(?:19|20)[0-9]{2}/,
// doesn't work - need to negate?
// taken from: http://stackoverflow.com/questions/46155/validate-email-address-in-javascript
email: /^([\w-]+(?:\.[\w-]+)*)#((?:[\w-]+\.)*\w[\w-]{0,66})\.([a-z]{2,6}(?:\.[a-z]{2})?)$/i,
// works
numeric: /[^0-9]*$/
};
return {
require: 'ngModel',
scope: {
validate: '#'
},
link: function (scope, element, attrs, modelCtrl) {
var pattern = validations[scope.validate] || scope.validate
;
modelCtrl.$parsers.push(function (inputValue) {
var transformedInput = inputValue.replace(pattern, '')
;
if (transformedInput != inputValue) {
modelCtrl.$setViewValue(transformedInput);
modelCtrl.$render();
}
return transformedInput;
});
}
};
});
I am pretty sure, there is better way, probably regex is also not best tool for that, but here is mine proposition.
This way you can only restrict which characters are allowed for input and to force user to use proper format, but you will need to also validate final input after user will finish typing, but this is another story.
The alphabetic, numeric and alphanumeric are quite simple, for input and validating input, as it is clear what you can type, and what is a proper final input. But with dates, mails, currency, you cannot validate input with regex for full valid input, as user need to type it in first, and in a meanwhile the input need to by invalid in terms of final valid input. So, this is one thing to for example restrict user to type just digits and / for a date format, like: 12/12/1988, but in the end you need to check if he typed proper date or just 12/12/126 for example. This need to be checked when answer is submited by user, or when text field lost focus, etc.
To just validate typed character, you can try with this:
JSFiddle DEMO
First change:
var transformedInput = inputValue.replace(pattern, '')
to
var transformedInput = inputValue.replace(pattern, '$1')
then use regular expressions:
/^([a-zA-Z]*(?=[^a-zA-Z]))./ - alphabetic
/^([a-zA-Z0-9]*(?=[^a-zA-Z0-9]))./ - alphanumeric
/(\.((?=[^\d])|\d{2}(?![^,\d.]))|,((?=[^\d])|\d{3}(?=[^,.$])|(?=\d{1,2}[^\d]))|\$(?=.)|\d{4,}(?=,)).|[^\d,.$]|^\$/- currency (allow string like: 343243.34, 1,123,345.34, .05 with or without $)
^(((0[1-9]|1[012])|(\d{2}\/\d{2}))(?=[^\/])|((\d)|(\d{2}\/\d{2}\/\d{1,3})|(.+\/))(?=[^\d])|\d{2}\/\d{2}\/\d{4}(?=.)).|^(1[3-9]|[2-9]\d)|((?!^)(3[2-9]|[4-9]\d)\/)|[3-9]\d{3}|2[1-9]\d{2}|(?!^)\/\d\/|^\/|[^\d/] - date (00-12/00-31/0000-2099)
/^(\d*(?=[^\d]))./ - numeric
/^([\w.$-]+\#[\w.]+(?=[^\w.])|[\w.$-]+\#(?=[^\w.-])|[\w.#-]+(?=[^\w.$#-])).$|\.(?=[^\w-#]).|[^\w.$#-]|^[^\w]|\.(?=#).|#(?=\.)./i - email
Generally, it use this pattern:
([valid characters or structure] captured in group $1)(?= positive lookahead for not allowed characters) any character
in effect it will capture all valid character in group $1, and if user type in an invalid character, whole string is replaced with already captured valid characters from group $1. It is complemented by part which shall exclude some obvious invalid character(s), like ## in a mail, or 34...2 in currency.
With understanding how these regular expression works, despite that it looks quite complex, I think it easy to extend it, by adding additional allowed/not allowed characters.
Regular expression for validating currency, dates and mails are easy to find, so I find it redundant to post them here.
OffTopic. Whats more the currency part in your demo is not working, it is bacause of: validate="currency.us" instead of validate="currency", or at least it works after this modification.
In my opinion it is impossible to create regular expressions that will work for matching things like dates or emails with the
parser you use. This is mainly because you would need non-capturing groups in your
regular expressions (which is possible), which are not replaced by the
inputValue.replace(pattern, '') call you have in your parser function. And this is the
part that is not possible in JavaScript. JavaScript replaces what you put in non-capturing
groups as well.
So... you'll need to go for a different approach. I would suggest to go for positive
regular expressions, which will yield a match when the input is valid.
Then you need of course to change the code of your parser. You could for instance
decide to chop off characters from the end of the input text until what remains passes
the regular expression test. This you could code as follows:
modelCtrl.$parsers.push(function (inputValue) {
var transformedInput = inputValue;
while (transformedInput && !pattern.exec(transformedInput)) {
// validation fails: chop off last character and try again
transformedInput = transformedInput.slice(0, -1);
}
if (transformedInput !== inputValue) {
modelCtrl.$setViewValue(transformedInput);
modelCtrl.$render();
}
return transformedInput;
});
Now life has become a bit easier. Just pay attention that you make your regular
expressions in such a way that they do not reject partial input. So "01/" should be
considered valid for a date, otherwise the user can never get to type in a date. On
the other hand, as soon as it becomes clear that adding characters will no longer
allow for valid input, the regular expression should reject it. So "101" should be
rejected as a date, as you can never add characters at the end to make it a valid date.
Also, all of these regular expressions should check the whole input, so as a consequence
they need to make use of the ^ and $ symbols.
Here is what the regular expression for a (partial) date could look like:
^([0-9]{0,2}|[0-9]{2}[\/]([0-9]{0,2}|[0-9]{2}[\/][0-9]{0,4}))$
This means: an input of 0 to 2 digits is valid, or exactly 2 digits followed by a slash, followed by either:
0 to 2 digits, or
exactly 2 digits followed by a slash, followed by 0 to 4 digits
Admittedly, not as smart as the one you had found, but that one would need a lot of editing to allow for partially entered dates. It is possible, but
it represents a very long expression with a lot of brackets and |.
Once you have all the regular expressions set up, you could think to further improve
the parser. One idea would be to not let it chop off characters from the end, but to
let it test all strings with one character removed somewhere compared to the original,
and see which one passes the test. If there is no way found to remove one character and have
success, then remove two consecutive characters in any place of the input value,
then three, ... etc, until you find a value that passes the test or arrive at an empty value.
This will work better for cases where the user inserts characters half way their input.
Just an idea...
import { Directive, ElementRef, EventEmitter, HostListener, Input, Output, Renderer2 } from '#angular/core';
import { ControlValueAccessor, NG_VALUE_ACCESSOR } from '#angular/forms';
import { CurrencyPipe, DecimalPipe } from '#angular/common';
import { ValueChangeEvent } from '#goomTool/goom-elements/events/value-change-event.model';
const noOperation = () => {
};
#Directive({
selector: '[formattedNumber]',
providers: [{
provide: NG_VALUE_ACCESSOR,
useExisting: FormattedNumberDirective,
multi: true
}]
})
export class FormattedNumberDirective implements ControlValueAccessor {
#Input() public configuration;
#Output() public valueChange: EventEmitter<ValueChangeEvent> = new EventEmitter();
public locale: string = process.env.LOCALE;
private el: HTMLInputElement;
// Keeps track of the value without formatting
private innerInputValue: any;
private specialKeys: string[] =
['Backspace', 'Tab', 'End', 'Home', 'Enter', 'Shift', 'ArrowRight', 'ArrowLeft', 'Delete'];
private onTouchedCallback: () => void = noOperation;
private onChangeCallback: (a: any) => void = noOperation;
constructor(private elementRef: ElementRef,
private decimalPipe: DecimalPipe,
private currencyPipe: CurrencyPipe,
private renderer: Renderer2) {
this.el = elementRef.nativeElement;
}
public writeValue(value: any) {
if (value !== this.innerInputValue) {
if (!!value) {
this.renderer.setAttribute(this.elementRef.nativeElement, 'value', this.getFormattedValue(value));
}
this.innerInputValue = value;
}
}
public registerOnChange(fn: any) {
this.onChangeCallback = fn;
}
public registerOnTouched(fn: any) {
this.onTouchedCallback = fn;
}
// On Focus remove all non-digit ,display actual value
#HostListener('focus', ['$event.target.value'])
public onfocus(value) {
if (!!this.innerInputValue) {
this.el.value = this.innerInputValue;
}
}
// On Blur set values to pipe format
#HostListener('blur', ['$event.target.value'])
public onBlur(value) {
this.innerInputValue = value;
if (!!value) {
this.el.value = this.getFormattedValue(value);
}
}
/**
* Allows special key, Unit Interval, value based on regular expression
*
* #param event
*/
#HostListener('keydown', ['$event'])
public onKeyDown(event) {
// Allow Backspace, tab, end, and home keys . .
if (this.specialKeys.indexOf(event.key) !== -1) {
if (event.key === 'Backspace') {
this.updateValue(this.getBackSpaceValue(this.el.value, event));
}
if (event.key === 'Delete') {
this.updateValue(this.getDeleteValue(this.el.value, event));
}
return;
}
const next: string = this.concatAtIndex(this.el.value, event);
if (this.configuration.angularPipe && this.configuration.angularPipe.length > 0) {
if (!this.el.value.includes('.')
&& (this.configuration.min == null || this.configuration.min < 1)) {
if (next.startsWith('0') || next.startsWith('0.') || next.startsWith('.')) {
if (next.length > 1) {
this.updateValue(next);
}
return;
}
}
}
/* pass your pattern in component regex e.g.
* regex = new RegExp(RegexPattern.WHOLE_NUMBER_PATTERN)
*/
if (next && !String(next).match(this.configuration.regex)) {
event.preventDefault();
return;
}
if (!!this.configuration.minFractionDigits && !!this.configuration.maxFractionDigits) {
if (!!next.split('\.')[1] && next.split('\.')[1].length > this.configuration.minFractionDigits) {
return this.validateFractionDigits(next, event);
}
}
this.innerInputValue = next;
this.updateValue(next);
}
private updateValue(newValue) {
this.onTouchedCallback();
this.onChangeCallback(newValue);
if (newValue) {
this.renderer.setAttribute(this.elementRef.nativeElement, 'value', newValue);
}
}
private validateFractionDigits(next, event) {
// create real-time pattern to validate min & max fraction digits
const regex = `^[-]?\\d+([\\.,]\\d{${this.configuration.minFractionDigits},${this.configuration.maxFractionDigits}})?$`;
if (!String(next).match(regex)) {
event.preventDefault();
return;
}
this.updateValue(next);
}
private concatAtIndex(current: string, event) {
return current.slice(0, event.currentTarget.selectionStart) + event.key +
current.slice(event.currentTarget.selectionEnd);
}
private getBackSpaceValue(current: string, event) {
return current.slice(0, event.currentTarget.selectionStart - 1) +
current.slice(event.currentTarget.selectionEnd);
}
private getDeleteValue(current: string, event) {
return current.slice(0, event.currentTarget.selectionStart) +
current.slice(event.currentTarget.selectionEnd + 1);
}
private transformCurrency(value) {
return this.currencyPipe.transform(value, this.configuration.currencyCode, this.configuration.display,
this.configuration.digitsInfo, this.locale);
}
private transformDecimal(value) {
return this.decimalPipe.transform(value, this.configuration.digitsInfo, this.locale);
}
private transformPercent(value) {
return this.decimalPipe.transform(value, this.configuration.digitsInfo, this.locale) + ' %';
}
private getFormattedValue(value) {
switch (this.configuration.angularPipe) {
case ('decimal'): {
return this.transformDecimal(value);
}
case ('currency'): {
return this.transformCurrency(value);
}
case ('percent'): {
return this.transformPercent(value);
}
default: {
return value;
}
}
}
}
----------------------------------
export const RegexPattern = Object.freeze({
PERCENTAGE_PATTERN: '^([1-9]\\d*(\\.)\\d*|0?(\\.)\\d*[1-9]\\d*|[1-9]\\d*)$', // e.g. '.12% ' or 12%
DECIMAL_PATTERN: '^(([-]+)?([1-9]\\d*(\\.|\\,)\\d*|0?(\\.|\\,)\\d*[1-9]\\d*|[1-9]\\d*))$', // e.g. '123.12'
CURRENCY_PATTERN: '\\$?[-]?[0-9]{1,3}(?:,?[0-9]{3})*(?:\\.[0-9]{2})?$', // e.g. '$123.12'
KEY_PATTERN: '^[a-zA-Z\\-]+-[0-9]+', // e.g. ABC-1234
WHOLE_NUMBER_PATTERN: '^([-]?([1-9][0-9]*)|([0]+)$)$' // e.g 1234
});