Develop Reference

Angular - How disable a field keeping the value

Good night guys, I have a very simple angular question. I have a form, it has a specific field that I set the value for a patch value but at the same time I need to disable this field. However after the disable, the value is not sent to the back end to be inserted anymore. I've done the test and I saw that only with the patch value, the value is sent normally and inserted in backend normally, but when I disable it, it loses the value and is not sent to the back, I already tried onlyself but I didn't succeed , I would like your help if possible, thanks for your attention. Ah I know that html disable works, but I would like to know if there is any way for me to do this in typescript by disabling the field in the form.
iniciarSituacaoCadastro(){
if(this.visualizar){
this.formPesquisar.controls['address'].patchValue(Address.ATIVO);
this.formPesquisar.controls['address'].disable({onlySelf: true});
}
}

Use getRawValue() instead of value.
https://angular.io/api/forms/FormGroup#getRawValue
getRawValue() retrieves all values regardless of disabled status. The
value property is the best way to get the value of the group, because
it excludes disabled controls in the FormGroup.

Radio buttons and checkboxes. Prevent changing of the value attribute

So you have a checkbox or a radio button with a predifined value to be sent to the database:
<input name="statement" type="radio" value="AWENSOME">
But someone or a script, with bad intention can easily change the value of your checkbox/radio button with for example a basic "browser page inspect" and then send other value to the databse. For example:
<input name="statement" type="radio" value="NOT SO AWENSOME! STUPID">
How can one prevent that guys? Thank you.

No, you can't, the best way is to gather all allowable input values in the database and check those values everytime on the server. It is easy in case of inputs like checkbox, select, radio, because you know exactly what the values can be. In case of text inputs, you have to use regex and sanitanization.

Maybe something like this in your model would help if your are using php:
if ($data['statement'] == 'AWENSOME' || $data['statement'] == 'FOOBAR' )
{
$statement = $data['statement'];
} else
{
// abort the app or return an error to the user
}

You cannot totally prevent the user from modifying the html scripts in the browser, but you can prevent unnecessary data to enter in your database..
In order to prevent that, you should have a validator in your php scripts in the server side.
There are many ways in preventing invalid data to enter in the db:
make a list of valid values in the database and once the user selects it, the server will check if the value in the checkbox or radio is existing
make the value fo radio/checkbox an encrypted or lets say there is some unique format like zkdie23doo44s that can be identified by your server..
periodically, check the html checkboxes and reload the values based from the original html script in the server
hope this helped you get an idea or two..

You can't do that you have to check once again on the server side and for the boxes like check box you know the value and for text box you can use regular expression

JQuery fill the form but failed to be recognized

I am using Flask as the backend. And I wrote a simple form with WTForm, say,
field = StringField('input:', validators=[Required()])
And I write a JQuery to fill it automatically
$('#theidofthefield').val('fillingin');
And I click the submit button in the form but it shows that the field is empty. And I check the request.form.field.data is also empty.
Hope to get a solution.

I have no idea about WTForm but you can check if your field element has got the name attribute, which is required to send back to the backend code.
Your field has to be something like this:
<input type="text" name="thenameofthefield" id="theidofthefield" />
//-----------------^^^^^^^^^^^^^^^^^^^^^^^---name attribute is required.

Another way to fill value is:
$('#theidofthefield').attr('value','filling');
Lets see if it works..
In case variable field is pointer to the object then..
$(field).val('dfsdf') or $(field).attr('value','filling') may work.

How do I access form data submitted by a user in Javascript?

I'm relatively new to programming, but understand the basics of HTML, CSS, and Javascript (including jQuery). Due to my greenness, I'd appreciate it if answers contained both a simple solution and a reason as to why the solution works. Thanks!
So I've got a form, with a text input and a submit button:
<form>
<input type="text">
<button type="submit">Submit</button>
</form>
When the user types data into the text field and clicks submit, how do I gain access to this data? If a user inputs their name, how do I grab that information? I don't intend to store it or write it anywhere, just to hold onto it as a variable in javascript, which I'll assign to a jQuery cookie.
So how do I access the data that the user has submitted, preferably using only Javascript (with jQuery)? Thanks for the help!

You access the data on the server side (in PHP via $_POST['username'] for example). The form sends data to your sever for any named input, so you would probably have to change the input to:
<input type=text name=username>
If you want to access it on the client side (with JavaScript), you can do that too, but you have to prevent the form from submitting:
$("form").on('submit', function (e) {
$.cookie('username', $(this).find('[name=username]').val());
//stop form from submitting
e.preventDefault();
});

say you had an html input tag such as:
<input id="textfield" type="text">
using javascript, you can store the value of that field in a variable like this:
var inputvalue = $('#textfield').val();
of course, you'll need something to run the script.
the reason this works is that the the textfield is an object. you might think of it as a tree trunk with different branches coming out. one of these "branches" is the value contained inside of it. since you know jquery, you know that $('#textfield') gets the element by a selector. the period says we're getting one of the branches, and "value" says we want the branch that tells what's in the textfield.
hope this helps.

How to clear HTML input textbox via Javascript

I am using the same input textbox to collect multiple values.
After collecting the first input, I will clear the field by calling
document.getElementById("textbox").value= "";
On the surface, above snippet appears to clear the textbox.
But when I blur the textbox by clicking elsewhere, the old value reappears.
MORE CODES >>>
My HTML >>
<input id="textbox" placeholder="Start">
Javascript >>
After getting the first input, I like to reset the input value >>>
document.getElementById("textbox").value= "";
document.getElementById("textbox").setAttribute("placeholder","End");
This is how I do my data collection >>>
The same textbox is first used to collect a Google "place", and then subsequently to collect some user entered comment. In addition to collecting the data, someFunction() also try to clear the textbox by calling .value= ""
google.maps.event.addListener(textbox, "place_changed", function() {
someFunction();
});

Here is something i found googling fast for an answer; i think you can play around indeed with onFocus() a bit:
<input type="text" value="Click here to clear text" onfocus="if(!this._haschanged){this.value=''};this._haschanged=true;"/>
It may require a bit of usage of onBlur as well.
Also some other pointer, to get you going with jQuery if you want.

Looks like your input's value is stored in separate variable to be used for some other actions. So you should maybe check your code and clear thar variable.

I have practically implemented and used this solution whch is already suggested by my friend above:
document.getElementById("textbox").setAttribute("placeholder","End");
So, this works for me pretty well.(context:"placeholder" attribute used)
ICDT
..tc:)