Basic HTML5 form with custom validation. If the submitted value is not a number, the browser should display the error message “Field must be an number.” If you enter “abc” and press submit (or hit enter) the field is marked as invalid, but the error message does not appear. Press submi…
Tag: validation
How to check the validity of a number type input sing javascript?
I have implemented in a form a number type input, with specified min and max : The input type number works : if something else then a number is entered or if the number value is not in the specified range, the input becomes Red. I have a javascript function that submit the form on input change. I would like
Restrict to 2 decimal places in keypress of a text box?
I want to enter a decimal point in a text box. I want to restrict the user by entering more than 2 digits after the decimal point. I have written the code for achieving that in the Keypress event. The code is working but the issue is: if I enter “.75” and then change it to “1.75”, it i…
REGEX to match only VALID EXCEL COLUMNS (A-XFD)
Ok, I have ANOTHER REGEX question for everyone. I have a field that has multiple validation steps. The first step is to ensure it isn’t blank, second is to ensure that only between 1 and 3 CAPITAL LETTERS are entered, and third, to ensure it doesn’t contain “[” (an opening bracket will…
How to intercept HTML5 input validation with JavaScript?
Now, if I enter a location and hit ENTER, the browser tells me that an URL is required which is not an expected or desired outcome. The ENTER should just be ignored. Question How can I prevent the browser from checking the required field after hitting ENTER in the “location” input field and only l…
Check selected file matches accept attribute on an tag
I wish to prevent the user from uploading a file the server will reject from a page with minimal JavaScript on it, ideally without adding any heavy dependencies like jQuery purely to solve this one problem. Since I’m not targeting legacy users, I trued using the browser’s form validation system to…
Mobile Number Validation (Internationally)
i am trying to do Validation check on mobile number , somewhat similar to what gmail had implemented. Gmail signup page link but variation among the phone number across country is to much, so finding it difficult to frame a regex for this. i looked upon some of the q’s here , but they work for some coun…
How to get image size of a form field (formData) in Javascript
Any idea how to get size in bytes of an image within a validating javascript function so that user will be prompted to pick a valid image size. I have seen other answers which handle this out of the form logic, but I want to know if I can get the size within the validation javascript function. Thanks Here is
Why do we need both client side and server side validation? [closed]
Closed. This question is off-topic. It is not currently accepting answers. Want to improve this question? Update the question so it’s on-topic for Stack Overflow. Closed 9 years ago. Improve this question One argument for using both client side validation (JavaScript) and server side validation using a …
How do I prevent invalid characters from being entered into a form?
For example, if I have a form and I don’t want the user to enter numbers in it and I validate it with a function containing a regular expression, how do I prevent the invalid character the user entered (in this example, a digit) from showing up in the text form if it fails the regular expression test? T…