Currently, I am using react-hook-form for form transmission.
and, I want to render the number of characters included in input and textarea.
The code I implemented is as follows.
<input
id="title"
type="text"
placeholder="title"
{...register('title', {
required: true,
})}
/>
<span>
{watch('title').length}/20
</span>
As shown above, I tried to render the number of characters input through watch, but failed. How do you represent the number of characters?
Update your watch with the condition for undefined.
{ watch('title') ? (watch('title').length)/20 : '' }
Can check working code from here : https://stackblitz.com/edit/stackoverflow-095?file=src%2FApp.jsx
Related
pattern="[a-zA-Z ]*"
im trying to limit the input to be only letters no numbers or symbols should be allowed
but the given code is not working
<input
name="cardName"
type="text"
required
pattern="[a-zA-Z ]*"
defaultValue={kardName}
/>
i have also tried to use onChange method but it wasn't working too
anyhelp would be highly apperciated
The pattern attribute specifies a regular expression that the element's value is checked against on form submission.
You can see from the snippet below, that if you hit submit, the pattern is checked and it's actually working.
<form>
<input
name="cardName"
type="text"
required
pattern="[a-zA-Z ]*"
/>
<input type="submit" />
</form>
If you want to prevent the user from inserting some character, the pattern attribute won't help you.
What You can do is check the character inside the onKeyDown function, and prevent the insertion there. Something like this:
const onKeyDown = (event) => {
if (!event.key.match(/[A-Za-z ]/)) {
event.preventDefault()
}
...
<input
name="cardName"
type="text"
required
onKeyDown={onKeyDown}
/>
I'm trying to clear input item after click on Add. It's on line 49 but doesn't work:
Code: https://stackblitz.com/edit/react-wbn3ms?file=src%2FStepsForm.js
setForm({date: '', distance: ''});
Could you please help why?
Assign form.date,form.distance from form state to value attribute in date and distance input fields
<input id="date" name="date" onChange={handleChange} value={form.date} />
<input id="distance" name="distance" onChange={handleChange} value={form.distance}/>
without the value attribute, the input fields are uncontrolled.
You haven't set value={form.date} and value={form.distance} on those inputs, so changes done into the state don't get reflected back into the input elements.
When I click on Submit, it gives an error "required". But when i type text it doesn't take first character. On entering first character it only removes "required" message.
Can you please tell me why it is not showing first character.
<div className="input-field">
<label htmlFor="state">State</label>
<input
placeholder="State"
name="state"
autoComplete="off"
type="text"
value={state}
onChange = { e => setState(e.target.value)}
ref={register({required:'required'})}
/>
<span className="error">{errors.state && errors.state.message}</span>
</div>
It's probably related to the usage of react-hook-form with your custom controlled logic (value and onChange).
If you don't need the input to be controlled, I would recommend dropping the value and onChange props from the input, as they seem to be conflicting with the package.
Most likely, because setState is an asynchronous method. Try to add the async on your onChange function and await this.setState(). It should capture all the input characters.
Somewhat new to react and having trouble passing multiple state values to an input.
Specifically, state from drop-down menus. I can accomplish this in a p tag by chaining the various state values together.
This works
<p>
{this.state.one}_
{this.state.two}_
{this.state.three}_
{this.state.four}_
{this.state.five}
</p>
This will return
one_two_three_four_five
Whenever I try to pass these same values into a single input I get an error.
This does not work
<label>
Title:
<input
value=
{this.state.one}_
{this.state.two}_
{this.state.three}_
{this.state.four}_
{this.state.five}
type="text" />
</label>
How can one pass multiple state values into a single input?
Template literals with variables :
<input
value={ `${this.state.one}_${this.state.two}` }
/>
You have to pass a single expression to the value attribute. Change to this:
<label>
Title:
<input value={`${this.state.one}_
${this.state.two}_
${this.state.three}_
${this.state.four}_
${this.state.five}`
}
type="text" />
</label>
Note: this is ES6 string interpolation. The ES5 alternative is the regular string concatenation with "+"
I am able to validate my AngularStrap datetimepicker, but I cannot differentiate between a required validation failure and an invalid date failure. The only error that ever shows on screen is the required error, whether it is required or an invalid string. Is it possible in cases where a string has been entered that is invalid to show a different validation message? Here is my code :
<div class="control-group" ng-class="{error: form.BirthDate.$invalid}">
<label class="control-label" for="BirthDate">{{'_BirthDate_' | i18n}}</label>
<div class="controls">
<input id="BirthDate" name="BirthDate" title="BirthDate" type="text" ng-model="user.BirthDate" data-date-format="dd/mm/yyyy" bs-datepicker required>
<span ng-show="form.BirthDate.$dirty && form.BirthDate.$error.required">{{'_BirthDateRequired_' | i18n}}</span>
<!--<span ng-show="form.BirthDate.$dirty && form.BirthDate.$error.pattern">{{'_BirthDateInvalid_' | i18n}}</span>-->
</div>
</div>
What I want is something similar to the ng-pattern check but specific to the datetimepicker.
first of all, I think this has no real link with the date picker or not, if I understand your problem, you are trying to display different messages according to the error that lead to the $invalid for the form
If it's the case, the code you provided will only show a message when the date is invalid (but only because you commented the part for the pattern ;) )
I was super lazy while testing, so I didn't use the datepicker, you'll have to enter a date manually, but I did this fiddle : http://jsfiddle.net/DotDotDot/ELf5A/2/
As I didn't know exactly in what context you were using it, I used different methods to display validation error messages
The HTML part is simple. There is a form, two fields required, one with a pattern check for the date, the other only for the required validation. I added 2 error messages for the date, one displayed when the form hasn't been touched, telling you what format is expected, the other only shows up when the pattern is wrong.
You can click on the button to check the whole validation and then show another message, which will tell you if the form is valid or not, and if not, if it's because of the pattern of the date.
<div ng-controller='theCtrl'>
<form name='theForm'>
Enter something here : <input type='text' ng-model='someField' name='someField' required /> <br/>
Enter a date here : <input type='text' ng-model='theDate' name='theDate' ng-pattern='datePattern' required />
<span ng-show='theForm.theDate.$error.pattern'>Your date format is invalid, please check it again</span>
<span ng-show='theForm.theDate.$pristine'>Enter a valid date here : DD/MM/YYYY</span>
<br/> <input type='button' ng-click='validation(theForm)' value='Try to validate me!' />
<br /> {{errorMsg}}
</form>
</div>
The JS part is not very complicated either. When you click on the button, the form is being sent to the validation function, which will actually do all the checks you want, I only did the one corresponding to the pattern, but you could totally check whatever you want about the validation
$scope.validation=function(aForm){
//console.log(aForm)
if(aForm.theDate.$error.pattern)
$scope.errorMsg='The pattern you entered isn\'t good enough, try again !'
else{
if(aForm.$invalid)
$scope.errorMsg='Something is invalid, please check all the fields !'
else//valid
{
$scope.errorMsg='Not bad !'
alert("good job !")
//maybe you can also submit this form here ;)
}
}
}
This validation function could totally be used as the trigger in a ng-show/ng-hide too, this is why I also added another function :
$scope.whatToDisplay=function(aForm){
if(aForm.$valid)
return 'valid';
if(aForm.theDate.$error.pattern)
return 'date';
if (aForm.$invalid)
return 'notdate';
}
This will return a string corresponding to what is happening during the validation, which will be handled with ng-show :
<span ng-show='whatToDisplay(theForm)=="date"'>Displayed if the date is wrong</span>
<span ng-show='whatToDisplay(theForm)=="notdate"'>This is displayed if the form is invalid, but not because of the date format</span>
<span ng-show='whatToDisplay(theForm)=="valid"'>Displayed if the form is valid</span>
To summarize a bit, you can use 4 different methods
A validation function triggered with a click (useful for submit buttons), corresponding to the validation() function in my fiddle
A function associated with some ng-show, which will automatically watch every change, like the whatToDisplay() function
The ng-show associated with only the form attributes, like what you were doing with your code
The class automatically applied to the form ( I didn't explain it, but you can see it in the fiddle, the border change if the pattern is wrong or if it's only invalid )
Sorry, I had some difficulties to make this short, I let you play with the code, it's easier to understand that way, I hope this will help you
You should use ngMessages in AngularJS 1.3 to do the error messaging with less code and complexity. The bs-angular directive creates a message for the "date" string value of ng-message in your list of messages.
<div class="control-group" ng-class="{error: form.BirthDate.$invalid}">
<label class="control-label" for="BirthDate">
{{'_BirthDate_' | i18n}}
</label>
<div class="controls">
<input id="BirthDate" name="BirthDate" title="BirthDate" type="text"
ng-model="user.BirthDate" data-date-format="dd/mm/yyyy"
bs-datepicker required>
<span ng-show="form.BirthDate.$dirty && form.BirthDate.$error.required">{{'_BirthDateRequired_' | i18n}}</span>
</div>
<div class='alert alert-danger' ng-messages='myForm.BirthDate.$error'
ng-if='!myForm.BirthDate.$valid'>
<div ng-message="date">Please enter a valid date</div>
<div ng-message="required">Birthdate is required</div>
</div>
</div>
This code helps to show the invalid datetime error message
$scope.date=='Invalid Date'
{
err('Your error message');
}