how to validate userinput with javascript

how to validate userinput with javascript - javascript

I have this scenario where i have 4 drop down boxes, where you can choose CM for a carport and a shed, within that carport.
I want to prompt the user with messages/errors in these scenarios:
the shed is chosen to be wider than it is long.
the shed is atleast 60cm smaller than the carports in both width and length
only one of the sheds dimensions being chosen
the form looks like this
<form name="createorder" action="FrontController" method="POST">
<input type="hidden" name="command" value="createorder">
<br>
Length of shed:<br>
<select name="lengthShed">
<option value="0">I do not want a shed</option>
<option value="180">180cm</option>
<option value="210">210cm</option>
<option value="240">240cm</option>
<option value="270">270cm</option>
<option value="300">300cm</option>
<option value="330">330cm</option>
<option value="360">360cm</option>
<option value="390">390cm</option>
<option value="420">420cm</option>
<option value="450">450cm</option>
<option value="480">480cm</option>
<option value="510">510cm</option>
<option value="540">540cm</option>
<option value="570">570cm</option>
<option value="600">600cm</option>
<option value="630">630cm</option>
<option value="660">660cm</option>
<option value="690">690cm</option>
<option value="720">720cm</option>
</select>
<br>
Width of shed:<br>
<select name="widthShed">
<option value="0">I do not want a shed</option>
<option value="18=">180cm</option>
<option value="210">210cm</option>
<option value="240">240cm</option>
<option value="270">270cm</option>
<option value="300">300cm</option>
<option value="330">330cm</option>
<option value="360">360cm</option>
<option value="390">390cm</option>
<option value="420">420cm</option>
<option value="450">450cm</option>
<option value="480">480cm</option>
<option value="510">510cm</option>
<option value="540">540cm</option>
<option value="570">570cm</option>
<option value="600">600cm</option>
<option value="630">630cm</option>
<option value="660">660cm</option>
<option value="690">690cm</option>
</select>
<br>
Width:<br>
<select name="width">
<option value="240">240cm</option>
<option value="270">270cm</option>
<option value="300">300cm</option>
<option value="330">330cm</option>
<option value="360">360cm</option>
<option value="390">390cm</option>
<option value="420">420cm</option>
<option value="450">450cm</option>
<option value="480">480cm</option>
<option value="510">510cm</option>
<option value="540">540cm</option>
<option value="570">570cm</option>
<option value="600">600cm</option>
<option value="630">630cm</option>
<option value="660">660cm</option>
<option value="690">690cm</option>
<option value="720">720cm</option>
<option value="750">750cm</option>
</select>
<br>
Length:<br>
<select name="length">
<option value="240">240cm</option>
<option value="270">270cm</option>
<option value="300">300cm</option>
<option value="330">330cm</option>
<option value="360">360cm</option>
<option value="390">390cm</option>
<option value="420">420cm</option>
<option value="450">450cm</option>
<option value="480">480cm</option>
<option value="510">510cm</option>
<option value="540">540cm</option>
<option value="570">570cm</option>
<option value="600">600cm</option>
<option value="630">630cm</option>
<option value="660">660cm</option>
<option value="690">690cm</option>
<option value="720">720cm</option>
<option value="750">750cm</option>
<option value="780">780cm</option>
</select>

Bind a function to your <select> elements onchange property.
let selects = document.querySelectorAll('select');
for(var i = 0; i < selects.length; i++){
selects[i].onchange = function(){
// Check for your conditions
// If your warning conditions are met, prompt user
}
}
That is, assuming you want the validation to happen when the user changes one of the select's values.
If you want to validate with a button click, you can instead bind the function to the click event of the button.
let button = document.getElementById(buttonID);
button.onclick = function(){
// Check for your conditions
// If conditions are met, prompt user
}
To prompt the user, you can use a simple alert() to which you pass your message. Or make a more elaborate function to do something custom.
As for your conditions, that sounds like commercial math. Might have to split your question in multiple questions here as there are a lot of possible awnsers.
It might be easier for you to add IDs to your selects so you can get them via document.getElementById(idString). You can then get their value through document.getElementById(idString).value. And to use it in math solving, you will need to parse the string that the <select> will return as value, like so parseInt(document.getelementById(idString).value).

Related

Change a select option thanks to another option

What I'm trying is something pretty basic, but I can't do it because the examples I see aren't anything similar to what I'm looking for.
There are 2 select, one of them you choose manually and the other dynamically changes depending on the value of the first one.
If the value of the first select is 1, that in the second one they only appear whose value is 1 as well.
I want to make it 100% JavaScript, I don't want any JQuery.
HTML.php
<select onchange="catch_value_types()" name="types" id="types">
<option value="1">Meat</option>
<option value="2">Fish</option>
<option value="3">Vegetables</option>
</select>
<select name="food" id="food">
<option value="1">Pork</option>
<option value="1">Cow</option>
<option value="1">Chicken</option>
<option value="2">Sardine</option>
<option value="2">Salmon</option>
<option value="2">Mackerel</option>
<option value="3">Spinach</option>
<option value="3">Kale</option>
<option value="3">Green peas</option>
</select>
JavaScript.js
function catch_value_types() {
var types_value_option = document.getElementById("types").value;
// What should I put here?
}

Loop through the options and hide if value doesnot match
function catch_value_types() {
const selectedValue = document.getElementById("types").value;
const select2 = document.getElementById("food");
Array.from(select2.options).forEach((node) => node.style.display = node.value === selectedValue ? "block": "none");
}
<select onchange="catch_value_types()" name="types" id="types">
<option value="1">Meat</option>
<option value="2">Fish</option>
<option value="3">Vegetables</option>
</select>
<select name="food" id="food">
<option>Please Select</option>
<option value="1">Pork</option>
<option value="1">Cow</option>
<option value="1">Chicken</option>
<option value="2">Sardine</option>
<option value="2">Salmon</option>
<option value="2">Mackerel</option>
<option value="3">Spinach</option>
<option value="3">Kale</option>
<option value="3">Green peas</option>
</select>

How to preselect in multiselect box [duplicate]

This question already has answers here:
Javascript/jQuery: Set Values (Selection) in a multiple Select
(9 answers)
Closed 3 years ago.
I want to preselect of id (195,197,120) by code on load
in multiselect box
coresponding id 195,197,120 will preselected
<select class="width100" id="dialog_settings_event_selected_recipient" style="height:80px;" multiple="multiple">
<option value="120">Aaban bilal</option>
<option value="197">Aabid iqbal</option>
<option value="196">Aadan parvaiz shah</option>
<option value="262">Aadil bashir</option>
<option value="195">Aaksa iqbol</option>
<option value="233">Aamir shabir</option>
<option value="231">Aasma zahoor</option>
<option value="198">Aathir shah bhat</option>
<option value="208">Aatif dar</option>
<option value="244">Aatif manzoor</option>
<option value="77">Abrar Mushtaq</option>
<option value="68">Adnan Javid</option>
<option value="236">Adnan amin</option>
<option value="132">Adnan iqbal</option>
<option value="112">Adnan mushtaq pir</option>
<option value="252">Adnan nazir-107</option>
<option value="157">Afhan Mudasir</option>
<option value="154">Ahsan Yousuf</option>
<option value="87">Aijaz Ah Malik</option>
</select>

Try this to set values for multiple select
var data="120,197,195";
//Make an array
var dataarray=data.split(",");
// Set the value
$("#dialog_settings_event_selected_recipient").val(dataarray);
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<select class="width100" id="dialog_settings_event_selected_recipient" style="height:80px;" multiple="multiple">
<option value="120">Aaban bilal</option>
<option value="197">Aabid iqbal</option>
<option value="196">Aadan parvaiz shah</option>
<option value="262">Aadil bashir</option>
<option value="195">Aaksa iqbol</option>
<option value="233">Aamir shabir</option>
<option value="231">Aasma zahoor</option>
<option value="198">Aathir shah bhat</option>
<option value="208">Aatif dar</option>
<option value="244">Aatif manzoor</option>
<option value="77">Abrar Mushtaq</option>
<option value="68">Adnan Javid</option>
<option value="236">Adnan amin</option>
<option value="132">Adnan iqbal</option>
<option value="112">Adnan mushtaq pir</option>
<option value="252">Adnan nazir-107</option>
<option value="157">Afhan Mudasir</option>
<option value="154">Ahsan Yousuf</option>
<option value="87">Aijaz Ah Malik</option>
</select>

PHP+jQuery is preventing my select element from updating

I am using PHP to show years between 1940 and the current year and using a foreach loop to render each option inside a select element. Everything works as planned until I add an id to the select element that a block of jquery looks at for changes.
Essentially I am trying to console.log (for now) the value of whatever option gets selected but something about my jQuery/PHP is stopping the select from displaying the selected option. The console.log works as expected but the selected option doesn't update in the element. It always goes back to displaying the default option aka 2018 since it's the current year.
If I change the PHP foreach select/option to a static dropdown of plain HTML it works fine. Likewise, if I disconnect the jQuery but keep the PHP dynamically generated option list it works fine. Something about the combo of my PHP+jQuery is preventing the select from updating and I cannot figure what.
Here is my HTML/PHP code:
<select name="birthyear" id="birthyear">
<?php
// $years is setting the range from current year to 1940
$years = range(date('Y'), 1940);
foreach ($years as $year) {
echo "<option id='$year' value='$year'>".$year."</option>";
}
?>
</select>
Here is my jQuery:
$('#birthyear').on('change', function() {
var date = new Date();
var year = date.getFullYear();
var yearsOld = year - $(this).val();
console.log(yearsOld + " years old.");
if (yearsOld >= 18) {
console.log("age >= 18")
} else {
console.log("You aren't old enough!");
}
});
Am I missing something here?

Your code works fine... All I did was execute the PHP to get the HTML and then plugged it into JSFiddle.
I'd assume your problem is that you didn't properly include jQuery.
<select name="birthyear" id="birthyear">
<option id='2018' value='2018'>2018</option>
<option id='2017' value='2017'>2017</option>
<option id='2016' value='2016'>2016</option>
<option id='2015' value='2015'>2015</option>
<option id='2014' value='2014'>2014</option>
<option id='2013' value='2013'>2013</option>
<option id='2012' value='2012'>2012</option>
<option id='2011' value='2011'>2011</option>
<option id='2010' value='2010'>2010</option>
<option id='2009' value='2009'>2009</option>
<option id='2008' value='2008'>2008</option>
<option id='2007' value='2007'>2007</option>
<option id='2006' value='2006'>2006</option>
<option id='2005' value='2005'>2005</option>
<option id='2004' value='2004'>2004</option>
<option id='2003' value='2003'>2003</option>
<option id='2002' value='2002'>2002</option>
<option id='2001' value='2001'>2001</option>
<option id='2000' value='2000'>2000</option>
<option id='1999' value='1999'>1999</option>
<option id='1998' value='1998'>1998</option>
<option id='1997' value='1997'>1997</option>
<option id='1996' value='1996'>1996</option>
<option id='1995' value='1995'>1995</option>
<option id='1994' value='1994'>1994</option>
<option id='1993' value='1993'>1993</option>
<option id='1992' value='1992'>1992</option>
<option id='1991' value='1991'>1991</option>
<option id='1990' value='1990'>1990</option>
<option id='1989' value='1989'>1989</option>
<option id='1988' value='1988'>1988</option>
<option id='1987' value='1987'>1987</option>
<option id='1986' value='1986'>1986</option>
<option id='1985' value='1985'>1985</option>
<option id='1984' value='1984'>1984</option>
<option id='1983' value='1983'>1983</option>
<option id='1982' value='1982'>1982</option>
<option id='1981' value='1981'>1981</option>
<option id='1980' value='1980'>1980</option>
<option id='1979' value='1979'>1979</option>
<option id='1978' value='1978'>1978</option>
<option id='1977' value='1977'>1977</option>
<option id='1976' value='1976'>1976</option>
<option id='1975' value='1975'>1975</option>
<option id='1974' value='1974'>1974</option>
<option id='1973' value='1973'>1973</option>
<option id='1972' value='1972'>1972</option>
<option id='1971' value='1971'>1971</option>
<option id='1970' value='1970'>1970</option>
<option id='1969' value='1969'>1969</option>
<option id='1968' value='1968'>1968</option>
<option id='1967' value='1967'>1967</option>
<option id='1966' value='1966'>1966</option>
<option id='1965' value='1965'>1965</option>
<option id='1964' value='1964'>1964</option>
<option id='1963' value='1963'>1963</option>
<option id='1962' value='1962'>1962</option>
<option id='1961' value='1961'>1961</option>
<option id='1960' value='1960'>1960</option>
<option id='1959' value='1959'>1959</option>
<option id='1958' value='1958'>1958</option>
<option id='1957' value='1957'>1957</option>
<option id='1956' value='1956'>1956</option>
<option id='1955' value='1955'>1955</option>
<option id='1954' value='1954'>1954</option>
<option id='1953' value='1953'>1953</option>
<option id='1952' value='1952'>1952</option>
<option id='1951' value='1951'>1951</option>
<option id='1950' value='1950'>1950</option>
<option id='1949' value='1949'>1949</option>
<option id='1948' value='1948'>1948</option>
<option id='1947' value='1947'>1947</option>
<option id='1946' value='1946'>1946</option>
<option id='1945' value='1945'>1945</option>
<option id='1944' value='1944'>1944</option>
<option id='1943' value='1943'>1943</option>
<option id='1942' value='1942'>1942</option>
<option id='1941' value='1941'>1941</option>
<option id='1940' value='1940'>1940</option>
</select>
https://jsfiddle.net/gpfh150g/

Scroll down to selected option on button click using jquery

I have a list of countries like this:
The list is very extensive. I need to be able on a button click to move (focus) to the specified country.
There are many threads in StackOverflow but none of them worked. For example I tried this:
var code = 40;
$('#id_resource-regions').val(code).scrollTop(160);
There is no response and no error/warnings in the developers tool.
Note that the list is created using django forms and templates.

Select the option element you are looking for.
Get the offset top position using .offset(), of the selected option element.
Get the offset top of the select element.
Use .scrollTop() to scroll to the desired option.
Here is an example
var btn = $('button')
var select = $('select')
btn.on('click', function() {
var option = select.find("option:contains('item-30')");
var optionTop = option.offset().top
var selectTop = select.offset().top;
select.scrollTop(select.scrollTop() + (optionTop - selectTop));
option.prop('selected', true)
})
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<select name="" id="select" multiple="multiple">
<option value="">item-1</option>
<option value="">item-2</option>
<option value="">item-3</option>
<option value="">item-4</option>
<option value="">item-5</option>
<option value="">item-6</option>
<option value="">item-7</option>
<option value="">item-8</option>
<option value="">item-9</option>
<option value="">item-10</option>
<option value="">item-11</option>
<option value="">item-12</option>
<option value="">item-13</option>
<option value="">item-14</option>
<option value="">item-15</option>
<option value="">item-16</option>
<option value="">item-17</option>
<option value="">item-18</option>
<option value="">item-19</option>
<option value="">item-20</option>
<option value="">item-21</option>
<option value="">item-22</option>
<option value="">item-23</option>
<option value="">item-24</option>
<option value="">item-25</option>
<option value="">item-26</option>
<option value="">item-27</option>
<option value="">item-28</option>
<option value="">item-29</option>
<option value="">item-30</option>
<option value="">item-31</option>
<option value="">item-32</option>
<option value="">item-33</option>
<option value="">item-34</option>
<option value="">item-35</option>
<option value="">item-36</option>
<option value="">item-37</option>
<option value="">item-38</option>
<option value="">item-39</option>
<option value="">item-40</option>
</select>
<button>move to item 30</button>

Change fieldset via radio button

I have a form with 2 radio buttons and when either button is toggled it shows or hides a certain fieldset. The issue I have is because the fieldset is just hidden so when the form is submitted it still takes the first fieldsets values.
I have setup a fiddle to show how the form changes the fieldsets http://jsfiddle.net/hhdMq/1/
So when I select "Scale B" although you can change the correct values, when the form is submitted it takes the default values of Scale A.
<center>
<input type="radio" name="sellorlet" value="Yes" id="rdYes" checked="yes" />
<label for="rdYes">Scale A</label>
<input type="radio" name="sellorlet" value="No" id="rdNo" />
<label for="rdNo">Scale B</label>
</center>
<fieldset id="sell">
<center>
<select id="pricemin" name="min">
<option value="50000">Min Price</option>
<option value="50000">£50,000</option>
<option value="100000">£100,000</option>
<option value="200000">£200,000</option>
<option value="300000">£300,000</option>
<option value="400000">£400,000</option>
<option value="500000">£500,000</option>
<option value="600000">£600,000</option>
<option value="700000">£700,000</option>
<option value="800000">£800,000</option>
<option value="900000">£900,000</option>
<option value="1000000">£1,000,000</option>
<option value="1250000">£1,250,000</option>
<option value="1500000">£1,500,000</option>
<option value="1750000">£1,750,000</option>
<option value="2000000">£2,000,000</option>
<option value="3000000">£3,000,000</option>
</select>
<select id="pricemax" name="max">
<option value="5000000">Max Price</option>
<option value="100000">£100,000</option>
<option value="200000">£200,000</option>
<option value="300000">£300,000</option>
<option value="400000">£400,000</option>
<option value="500000">£500,000</option>
<option value="600000">£600,000</option>
<option value="700000">£700,000</option>
<option value="800000">£800,000</option>
<option value="900000">£900,000</option>
<option value="1000000">£1,000,000</option>
<option value="1250000">£1,250,000</option>
<option value="1500000">£1,500,000</option>
<option value="1750000">£1,750,000</option>
<option value="2000000">£2,000,000</option>
<option value="3000000">£3,000,000</option>
<option value="4000000">£4,000,000</option>
<option value="5000000">£5,000,000</option>
</select>
</center>
</fieldset>
<fieldset id="buy" style="display:none;">
<center>
<select id="lpricemin" name="min">
<option value="500">Min Price</option>
<option value="500">£500</option>
<option value="600">£600</option>
<option value="700">£700</option>
<option value="800">£800</option>
<option value="900">£900</option>
<option value="1000">£1000</option>
<option value="1150">£1150</option>
<option value="1250">£1250</option>
<option value="1500">£1500</option>
<option value="2000">£2000</option>
<option value="2500">£2500</option>
<option value="3000">£3000</option>
<option value="4000">£4000</option>
<option value="5000">£5000</option>
</select>
<select id="lpricemax" name="max">
<option value="5000">Max Price</option>
<option value="600">£600</option>
<option value="700">£700</option>
<option value="800">£800</option>
<option value="900">£900</option>
<option value="1000">£1000</option>
<option value="1150">£1150</option>
<option value="1250">£1250</option>
<option value="1500">£1500</option>
<option value="2000">£2000</option>
<option value="2500">£2500</option>
<option value="3000">£3000</option>
<option value="4000">£4000</option>
<option value="5000">£5000</option>
</select>
</center>
</fieldset>
and the jquery used:
$("input[name='sellorlet']").change(function () {
$("#sell").toggle(this.value == "Yes");
$("#let").toggle(this.value == "No");
});
My question is, how can I completely disable the first fieldset if Scale B is selected and likewise when Scale A is selected it will disable the second fieldset?
Many thanks

When submitting a form, you cannot have two inputs, selects, or textareas with the same name in the same form. Doing so will cause confusion and probably end up the wrong info being submitted. There are two ways you can fix this.
Method 1:
Change the
<select id="lpricemin" name="min">
<select id="lpricemin" name="lmin">
to
<select id="lpricemax" name="max">
<select id="lpricemax" name="lmax"> respectively.
This will allow you to handle the data from lmin and lmax and ensure you get the info from the second fieldset.
Method 2:
Put the second fieldset in a different form. Then just change the jQuery to show the forms instead of the fieldsets.

Changed the radio buttons now to a tabbed design so the form can be separated correctly. If anyone would like to know how the tabs are done they are here http://cssdeck.com/labs/fancy-tabbed-navigation-with-css3-and-jquery

Method 3 would be to change the switch the content of your select through Javascript rather than toggling through visibility. You can do that through:
function setMaxScale()
{
document.getElementById().innerHTML = "<option value="50000">Min Price</option>\
<option value="50000">£50,000</option>\
<option value="100000">£100,000</option>\
<option value="200000">£200,000</option>\
<option value="300000">£300,000</option>...";
}
An other clean solution would be to create your scales dynamically with a loop.

Develop Reference

JavaScript is the programming language of the Web.

how to validate userinput with javascript - javascript

Related

Change a select option thanks to another option

How to preselect in multiselect box [duplicate]

PHP+jQuery is preventing my select element from updating

Scroll down to selected option on button click using jquery

Change fieldset via radio button

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