Angular 6 disable button if form invalid

Disable submit button when form invalid with AngularJS

GitHub is home to over 40 million developers working together to host and review code, manage projects, and build software together. Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community. Already on GitHub? Sign in to your account. If you create a disabled field in a formGroup, even with no validators, the control for this field will be invalid. The control should be valid since the field's property can't be changed the field is disabled, it's only shown for read-only informations. I believe that it was already fixed in master via c. Sure, but as OP pointed out disabled inputs should be always considered valid. Also even the validator is not added, form will not be valid. This is by design. A control that is disabled is It is not considered valid or invalid. Problem is that the boolean member valid has to be true or false. So if you want to be able to consider disabled input you have to check if the input is disabled before checking its control, it seems a bit strange to me that you have to check if the input is enabled before checking its control, the control should be valid if it is disabled, else, what's the purpose of the disabled parameter passed to FormControl 's constructor? PS: Thank you VirrageSI assumed that the commit was fixing my issue without actually checking that it was fixing it So if you want to be able to consider disabled input you have to check if the input is disabled before checking its control, it seems a bit strange to me that you have to check if the input is enabled before checking its control. That's not the current design. I will let kara comment more but here is my thinking: if a control is disabled a user can't interact with it. Since a user can't interact with the control it can't change control's value. So what is the point of validating sth that can't happen? Once again, there is no point of kicking off validation if a user can't interact with the control. The whole purpose of validation is to determine if user's input is valid or not. If we've got no input we can't talk about validation result really. As I described in my StackOverflow question on this problema warning is shown if you want to disable input using HTML disabled attribute. This warning says :. So either this warning should be changed, or the control should be valid if the input is disabled. I think that the point is to be able to create every control with the same logic, and let the control decide if the provided value is valid or not.

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By using our site, you acknowledge that you have read and understand our Cookie PolicyPrivacy Policyand our Terms of Service. Stack Overflow for Teams is a private, secure spot for you and your coworkers to find and share information. I have two input fields, one button. Handled validations for that two fields, will enable the button once two fields are entered. I have disable the button when the form is invalid. But it is not working. I suggest you to read Angular Forms Article as well as you have many questions about angular forms. How are we doing? Please help us improve Stack Overflow. Take our short survey. Learn more. Disable the button when fields are empty in Angular5 [ invalid form ] Ask Question. Asked 1 year, 10 months ago. Active 1 year, 10 months ago. Viewed 3k times. I am learning Angular5, new to this. Thanks in Advance. Elavarasan M. Elavarasan M Elavarasan M 1 1 silver badge 10 10 bronze badges. Active Oldest Votes. Sajeetharan Sajeetharan 1. How do you prevent blanks and empty space? Arash Arash 1, 2 2 gold badges 15 15 silver badges 31 31 bronze badges. Sign up or log in Sign up using Google. Sign up using Facebook. Sign up using Email and Password. Post as a guest Name. Email Required, but never shown. The Overflow Blog. Podcast Cryptocurrency-Based Life Forms. Q2 Community Roadmap. Featured on Meta. Community and Moderator guidelines for escalating issues via new response…. Feedback on Q2 Community Roadmap. Triage needs to be fixed urgently, and users need to be notified upon…. Dark Mode Beta - help us root out low-contrast and un-converted bits.

Valid and Invalid in Angular Forms


In Angular one of most common ways to validate forms is to disable the submit button. So to disable the button we use something like this. So above there are two most common ways to disable button when the form is not valid. Have you ever thought about the difference between form. Although logically they must be the same, but actually there is a slight difference between them. To demonstrate this we will create a simple form with one input that checks if given email exists in database. For that we will use Reactive Forms and a custom async validator. So the markup is very simple, we have a form and one input inside of it. We also have a button to submit the form which is disabled with form. We also have a div to display a simple loading spinner while we will check the existence of given email in database. We applied required and email validators from Angular and one custom async validator to check the email. So here this. In real applications you might need to have a service, to send a request to database, check if the email exists and return the result. To keep things simple we will emulate that call to backend with setTimeout. So our checkValidEmail function will compare given email from input field with a static email. If they match it means email is busy and we need to inform the user to choose another email and also we need to disable the button. So now we are ready. The reason why for a short time button was enabled is that there is one more state except valid and invalid. And that is pending state. Initially pending is set to falsebut when we use async validator pending becomes true and valid and invalid become false.

Angular techniques: Improve submit button’s UX by NOT disabling it.


In this article we will learn different approaches of validating all form fields when user clicks on submit button for Angular Reactive Forms. We will also learn how to disable the submit button if the form is invalid. When working with forms we have 2 options: the first one is to disable the submit button if the form is invalid meaning there is at least one invalid field and the second option is to validate the form before the HTTP POST action is executed by the code and display a message to the user to fix any pending validation errors. For this example we will use Bootstrap v3 framework for the CSS styles. The first option we have when working with forms is to disable the submit button if the form is invalid. It is easy for the user to guess it is needed to inform both fields before the submit button becomes available:. It is the file simple-form. In the code above we have an Angular Reactive Forms with only 2 fields: email and password and both are required. Please note that in this form we do not have any visual indicator that the email and password fields are required. We also do not display any validation error message. So the user have to guess that something is missing before the submit button is enabled. However, specially when working with enterprise projects, we have forms with lots of fields. And disabling the submit form when the form is invalid is not appropriate. For this example, we will work on the validate-fields-submit-form. In this form we have nameemail and a set of address fields. Note that the fields related to the address are grouped under the form control named address. Since we are using Boostrap classes in our project, each form-group is a row of our form. For the fields we want to occupy an entire row we can use the class col-sm part of the Bootstrap grid system. Boostrap 3 has built in validation styles for form fields. For error styles, it consists in adding has-error class along with form-group class. We can also add icons by adding the class has-feedback. For this example, we will consider a field has validation error when the field is not valid and it has been touched meaning it has received focus. Please check the references at the end of this post for more information about the states of form controls. We can use Angular ngClass directive to display the validation styles in our form fields:. Now imagine doing this for all 7 fields of our small form? We are going to repeat a lot of code. Just remember that if you have nested controls you need to pass the complete path of the control:. To display the validation error message of each field and also the X icon when the field is invalid we can create a presentational component or dumb component. In the field-error-display. And in the field-error-display. In each of our form controls fields we can simply use the following code to display the error messages:. Then, in the labels of the required fields we can add the class required along with the Boostrap label class control-label. Angular does not have a way of retrieving if a form control is required programatically. There is an open issue about this topic.

Angular Reactive Forms: trigger validation on submit

Angular makes working with forms a blast, but it also promotes one unfortunate form behaviour that is not the most user friendly. Thankfully it is also really easy to fix. The thirst thing I have learnt when building Angular forms is that I can track their validation states very easily:. What is wrong with this picture? It shows the initial state of the form — right after a user navigates into the view… full of validation errors. So I thought: Ooh, now I know what these other form controls properties that Angular gives us are for! This behaviour seems to be better — initially, when the form loads, the user sees no errors and only after he started interacting with a field the message will appear. Nothing on the frontend was preventing user form submitting the form to the backend, and the backend would return a page will all validation messages that described which fields were missing. This is a behaviour that we will likely want to use throughout our application so we will implement it as a directive :. So whenever we want to use this directive we now need to pass a reference to the form and set a success callback. Not that bad. If we could only make it even better…. Now our html code gets down to this:. This is literally as simple as it can be. And this is the form in action:. You can see the working example with the code in the StackBlitz sandbox. Did you learn something new? If so, you can:. Sign in. Implementation: This is a behaviour that we will likely want to use throughout our application so we will implement it as a directive : we will want to add it on submit buttons and use instead of click events for saving forms the directive needs to know about the form we are working with — the obvious way but not the only one, read on is to pass it as an Input the directive will listen for a click on the button element via HostListener 'click' when a click happens the directive will loop through all controls of the form and run markAsDirty or markAsTouched so that the validation messages displaying logic will be triggered if the form is valid the click will also make the directive emit the event so that we know we can send the form The code:. Noteworthy - The Journal Blog Follow.

Building Forms in Angular Apps - Mosh



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