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Cover image for Form input field - formating a number when it's introduced key by key

Form input field - formating a number when it's introduced key by key

Aitor Solozabal
programing
Updated on ・8 min read

There are various classes
Integer numbers positives and negatives or only the positives
Float numbers positives and negatives or only the positives
Float numbers fixing to 2 decimals

demo and free to copy from:
https://www.bc3toexcel.com/compartir/input-format-number-as-keyed.htm

<!DOCTYPE html>
<html>
    <head>
        <meta charset="utf-8">
        <title>FORMAT (PUT THOUSANDS SEPARATOR) INSIDE A FORM NUMERIC INPUT FIELD AS THE VALUE IS KEYED</title>
        <style>
            input {padding: 20px;margin: 10px;font-size: 18px;}
            .label,
            .integerPositive,
            .integerIndistinct,
            .numberPositive,
            .numberIndistinct,
            .numberPositiveFixed,
            .numberIndistinctFixed {text-align: right;}
            .positives {color: black;}
            .negatives {color: red;}
            .oculto{display:none;}
            .visible{display:block;}
            .table_data_received table,
            .table_data_received tr,
            .table_data_received th,
            .table_data_received td{border: 1px solid black; text-align:right;}
        </style>
    </head>
    <body>
        <h2>FORMAT (PUT THOUSANDS SEPARATOR) INSIDE A FORM NUMERIC INPUT FIELD AS THE VALUE IS KEYED</h2>
        <!-- ONLY FOR TESTING PURPOSE -->
        <div id="data_received" class="oculto">
            <h2>DATA RECEIVED FROM FORM</h2>
        </div>
        <!-- TEST FORM SAMPLE-->
        <form id="TheForm" class="oculto" method="get" action="input-format-number-as-keyed.htm" onsubmit="return removeNumberFormat(true);">
            <table>
                <tr>
                    <td class="label">Integer(+/-)</td>
                    <td><input class="integerIndistinct" name="integer1" id="integer1"></td>
                </tr>
                <tr>
                    <td class="label">Integer(+)&gt;= 0</td>
                    <td><input class="integerPositive" name="integer2" id="integer2"></td>
                </tr>
                <tr>
                    <td class="label">Float(+/-)</td>
                    <td><input class="numberIndistinct" name="number1" id="number1"></td>
                </tr>
                <tr>
                    <td class="label">Float(+)&gt;= 0</td>
                    <td><input class="numberPositive" name="number2" id="number2"></td>
                </tr>
                <tr>
                    <td class="label">Float Fixed 2 (+/-)</td>
                    <td><input class="numberIndistinctFixed" name="number3" id="number3"></td>
                </tr>
                <tr>
                    <td class="label">Float Fixed 2 (+)&gt;= 0</td>
                    <td><input class="numberPositiveFixed" name="number4" id="number4"></td>
                </tr>
            </table>
            <input type="submit" value="submit">
        </form>
        <script>
        //================================      ======================================
        //==============   THIS PART OF THE CODE IS ONLY FOR TESTING    ==============
        //================================      ======================================
        //To test if the form submitted data has been changed removing the thousands
        //separators from the numeric values and show the result in dev.tools console.
        //Can be eliminated after test is successful
        //============================================================================
        function reset_form() {
            window.location.replace(location.pathname);
        }
        const getURLParameters = url =>
        (
        /*
         * extract the parameters from the url that has been called
         * @param  {string} the url that has been called
         * @return {array} returns an associative array of the input variables
         */
            url.match(/([^?=&]+)(=([^&]*))/g) ||[]).reduce(
            (a, v) => ((a[v.slice(0, v.indexOf('='))] = v.slice(v.indexOf('=') + 1)), a), {}
        );
        let array_param = getURLParameters(window.location.href);
        let array_keys = Object.keys(array_param);
        if (array_keys.length!==0) {
            let div = document.getElementById("data_received");
            let table = document.createElement("table");
            table.className = "table_data_received";
            let tr = document.createElement("tr");
            let len = array_keys.length;
            for(let i = 0; i < len; i++) {
                let th = document.createElement("th");
                th.innerHTML = decodeURIComponent(array_keys[i]);
                tr.appendChild(th);
            }
            table.appendChild(tr);
            tr = document.createElement("tr");
            for(let j = 0; j < len; j++) {
                let td = document.createElement("td");
                td.innerHTML = decodeURIComponent(array_param[array_keys[j]]);
                tr.appendChild(td);
            }
            table.appendChild(tr);
            div.appendChild(table);
            let button = document.createElement("input");
            button.setAttribute("style", "cursor:pointer; margin-top:10px;");
            button.setAttribute("type", "button");
            button.setAttribute("value", "Repeat");
            button.setAttribute("onclick", "reset_form();");
            div.appendChild(button);
            div.className = "visible";
            let form = document.getElementById("TheForm");
            form.className = "oculto";
        }else {
            let form = document.getElementById("TheForm");
            form.className = "visible";
        }
        //================================      ======================================
        //==========================   END OF TESTING    =============================
        //================================      ======================================
        //############################################################################
        /**
         * @format-numeric-input-as-keyed.js
         * @version     : 1.0
         * @author      : Aitor Solozabal Merino (aitorsolozabal@gmail.com)
         * @purpose     : Format a number (with thousands separator) in an input field
         *                of a form as it is being entered key by key on the keyboard
         * History
         * @version     : v1.0 – initial
         * FUNCTIONS LIST
         * ==============
         * function integerFormatIndistinct()
         * function integerFormatPositive()
         * function numberFormatIndistinct()
         * function numberFormatPositive()
         * function numberFormatIndistinctFixed()
         * function numberFormatPositiveFixed()
         * There are classes / categories defined to associate with each function and that
         * are related when declaring the keyup event for each one of them
         *   .integerPositive,
         *   .integerIndistinct,
         *   .numberPositive,
         *   .numberIndistinct,
         *   .numberPositiveFixed,
         *   .numberIndistinctFixed {text-align: right;}
         *   .positives {color: black;}
         *   .negatives {color: red;}
         * function numberFormat(strNumber, n, thousands, decimals, minusSigned = true)
         * function removeNumberFormat(emptyValues = true) to be call from form submit
         */
        //############################################################################
        // global variables to define the thousands and decimals separator
        // For thousands a comma and a point for decimal (USA)
        let DECIMALS = ".";
        let THOUSANDS = ",";
        // change to "," for decimal comma and point in thousands (SPAIN)
        // =============================================== ===========================
        function numberFormat(strNumber, n, thousands, decimals, minusSigned = true) {
        /**
         *This function is called from other functions that are activated when the "keyup"
         *event occurs when typing from the keyboard by entering a character within a text
         *entry in a form that you want to give a numeric format.
         *
         *As it is allowed to add characters to the beginning in the middle or at the
         *end of the input text of the form, cases of generation of invalid numbers
         *can occur due to the concurrence of multiple factors.
         *Cases to control of strNumber content with the rule that there can only be
         *one minus symbol and it must be at the beginning and a single decimal
         *separator that can be anywhere.
         *In addition, the following combinations must be processed
         * "-" "." "-." "--" ".." "0" "-0" "-0." "0." "00" "0n" ".n" ".n." "-n-"
         *
         * This function also serves to return a formatted number for printing or display
         * on the screen independently of using it in the numeric fields of a form
         * ===============================================================================
         * @param string strNumber: string with the number to format
         * @param integer n: length of decimal (>0)fixed (=0)integer (=-1)float not fixed
         * @param string  thousands: sections delimiter THOUSANDS  USA "," SPAIN "."
         * @param string  decimals: decimal separator   DECIMALS   USA "." SPAIN ","
         * ===============================================================================
         * @VERSION  : 1.0
         * @DATE     : 27 January 2020
         * @AUTHOR   : Aitor Solozabal Merino (aitorsolozabal@gmail.com)
         * sample use:
         * integer not minus
         * console.log("integer "+"-123456.789"+"  0 decimales = "+numberFormat("-123456.789", 0, ",", ".",false));
         * output 123,456
         * float indistinct not fixed
         * console.log("float "+"-123456.789"+"  -1 decimales = "+numberFormat("-123456.789", -1, ",", ".",true));
         * output -123,456.789
         * float fixed not minus
         * console.log("float "+"-123456.789"+"   2 decimales = "+numberFormat("-123456.789",  2, THOUSANDS, DECIMALS,false));
         * output 123,456.78
         */
            let re = '\\d(?=(\\d{3})+$)';
            let resultado = "";
            let hasminusSymbol = false;
            let hasdecimalsSeparator = false;
            let nextCharacter = "";
            let initialZero = false;
            let numParts =[];
            let integerPart = "";
            let decimalPart = "";
            let firstDecimal = -1;
            //filter (minusSigned && n!==0) numbers, minus symbol, decimals separator
            let filterNumber1 = new RegExp('[^ 0-9\\-\\'+decimals+']', 'g');
            //filter (minusSigned && n===0) numbers, minus symbol not decimals separator
            let filterNumber2 = new RegExp('[^ 0-9\\-]', 'g');
            //filter (!minusSigned && n!==0) numbers, decimals separator not minus symbol
            let filterNumber3 = new RegExp('[^ 0-9\\'+decimals+']', 'g');
            //filter (!minusSigned && n===0) only numbers are permitted
            let filterNumber4 = new RegExp('[^ 0-9]', 'g');
            //Only numbers, decimals separator and minus symbol are allowed, so the
            //number is filtered to eliminate those characters that are not valid
            //================================================================== F I R S T
            //first filtering of invalid characters
            //the thousands delimeters are eliminated in this filter process
            strNumber = strNumber.replace(filterNumber1, "");
            if (strNumber.length>0) {
                //============================================================ S E C O N D
                //If the minusSigned parameter is false, then this symbol is not allowed
                //and only positive values are valid.
                //Therefore you have to see if the first character is the minus symbol "-"
                //and, if so, it must be removed to be added to the final result of the
                //formatting process if the minusSigned parameter is true.
                hasminusSymbol = (strNumber.substring(0, 1)==="-");
                strNumber = strNumber.replace(filterNumber3, "");
                if (strNumber.length>0) {
                    //========================================================== T H I R D
                    //if the first character is the decimal separator strNumber must be
                    //filtered eliminating all ocurrences of the decimalseparator in
                    //strNumber with a filter and then it is added with the zero character
                    //previously "." --> "0."
                    hasdecimalsSeparator = (strNumber.substring(0, 1)===decimals);
                    strNumber = (hasdecimalsSeparator)? "0.": strNumber;
                    if (!hasdecimalsSeparator) {
                        //if there is no decimal separator at the beginning, check if there
                        //is a decimal separator and check that this is the only one by
                        //erasing the excess ones
                        firstDecimal = strNumber.indexOf(decimals);
                        hasdecimalsSeparator = (firstDecimal>0);
                        //There is at least one decimal separator in strNumber
                        //Clean any other occurrence of a decimal separator in strNumber
                        strNumber = hasdecimalsSeparator?strNumber.substring(0, firstDecimal)+decimals+strNumber.substring(firstDecimal+1, strNumber.length).replace(filterNumber4, ""):strNumber;
                    }
                    //======================================================== F O U R T H
                    //"0"
                    initialZero = (strNumber.substring(0, 1)==="0");
                    //the first character can be a 0 or a decimal separator
                    if (initialZero) {
                        //if the first character is the number zero then the next character
                        //must be obtained and find out if it is a number or the decimal
                        //separator.
                        //It could be a "0." or a "0n"
                        nextCharacter = (strNumber.length>1)? strNumber.substring(1, 2): "";
                        //strNumber is of type "0n"
                        //"01"     "1" / "00"    "0"
                        //In this case the leading zero character is removed
                        strNumber = ((nextCharacter.length>0) && (nextCharacter!==decimals))?strNumber.substring(1, strNumber.length):strNumber;
                    }
                    //========================================================== F I F T H
                    //strNumber is divided into 2 parts using the defined decimal separator
                    //character as an element that separates the integer part and the
                    //decimal part if it exists
                    numParts = strNumber.split(decimals);
                    integerPart = numParts[0];
                    decimalPart = (numParts.length>1)? numParts[1]: "";
                    //========================================================== S I X T H
                    // add the thousands separators
                    resultado = integerPart.replace(new RegExp(re, 'g'), '$&' + (thousands));
                    //====================================================== S E V E N T H
                    //join the 2 parts to obtain the result with the established format
                    if (n!==0) {
                        if (n>0) {
                            //fixed decimals
                            decimalPart = (decimalPart.length>n)? decimalPart.substring(0, n): decimalPart;
                        }
                        resultado = (hasdecimalsSeparator)? resultado+decimals+decimalPart: resultado;
                    }
                }
            }
            //================================================================ E I G H T H
            //check if the minus symbol is allowed so that if it exists add it to the final
            //result before being returned
            resultado = (minusSigned && hasminusSymbol)? "-"+resultado: resultado;
            return resultado;
        }
        function integerFormatIndistinct() {
            // Format integers indistinctly both positive and negative
            if (this.value.length>0) {
                this.value = numberFormat(this.value, 0, THOUSANDS, DECIMALS, true);
                this.className = (this.value.substring(0, 1)==="-")? "negatives integerIndistinct": "positives integerIndistinct";
            }
        }
        function integerFormatPositive() {
            // Format only positive integers
            this.value = this.value.length>0? numberFormat(this.value, 0, THOUSANDS, DECIMALS, false): "";
        }
        function numberFormatIndistinct() {
            // Format decimal numbers indistinctly both positive and negative
            if (this.value.length>0) {
                this.value = numberFormat(this.value, -1, THOUSANDS, DECIMALS, true);
                this.className = (this.value.substring(0, 1)==="-")? "negatives integerIndistinct": "positives integerIndistinct";
            }
        }
        function numberFormatPositive() {
            // Format only positive decimal numbers
            this.value = this.value.length>0? numberFormat(this.value, -1, THOUSANDS, DECIMALS, false): "";
        }
        function numberFormatIndistinctFixed() {
            // Format decimal numbers indistinctly both positive and negative
            // but with 2 decimal places fixed as maximum
            if (this.value.length>0) {
                this.value = numberFormat(this.value, 2, THOUSANDS, DECIMALS, true);
                this.className = (this.value.substring(0, 1)==="-")? "negatives integerIndistinct": "positives integerIndistinct";
            }
        }
        function numberFormatPositiveFixed() {
            // Format only positive decimal numbers with 2 decimal places fixed as maximum
            this.value = this.value.length>0? numberFormat(this.value, 2, THOUSANDS, DECIMALS, false): "";
        }
        function removeNumberFormat(emptyValues = true) {
            //************************************************************************
            //The text input fields that contain the formatted numbers of the form must be
            //prepared before they are sent, eliminating the thousands separators and
            //placing the decimal separators of the system to transmit the data.
            //If the boolean variable emptyValues is true, then all values will be sent
            //including those that are empty, otherwise only non-empty values will be sent
            //This function is called with the instruction in the <form> tag
            //onsubmit = "return removeNumberFormat(emptyValues);"
            //************************************************************************
            let filterNumber = new RegExp('[^ 0-9\\-' + '\\' + DECIMALS + ']', 'g');
            let integer1 = document.getElementById('integer1');
            //eliminate thousands separator with the filterNumber
            integer1.value = integer1.value.replace(filterNumber, "");
            //to remove the field integer1 from submit data if it is empty then:
            if (!emptyValues) {
                if (integer1.value==="") {integer1.parentNode.removeChild(integer1);}
            }
            let integer2 = document.getElementById('integer2');
            //eliminate thousands separator with the filterNumber
            integer2.value = integer2.value.replace(filterNumber, "");
            //to remove the field integer2 from submit data if it is empty then:
            if (!emptyValues) {
                if (integer2.value==="") {integer2.parentNode.removeChild(integer2);}
            }
            let number1 = document.getElementById('number1');
            //eliminate thousands separator with the filterNumber
            number1.value = number1.value.replace(filterNumber, "");
            number1.value = number1.value.replace(DECIMALS, ".");
            //to remove the field number1 from submit data if it is empty then:
            if (!emptyValues) {
                if(number1.value==="") {number1.parentNode.removeChild(number1);}
            }
            let number2 = document.getElementById('number2');
            //eliminate thousands separator with the filterNumber
            number2.value = number2.value.replace(filterNumber, "");
            //replace decimals separator in format number with system decimal separator
            number2.value = number2.value.replace(DECIMALS, ".");
            //to remove the field number2 from submit data if it is empty then:
            if (!emptyValues) {
                if(number2.value==="") {number2.parentNode.removeChild(number2);}
            }
            let number3 = document.getElementById('number3');
            //eliminate thousands separator with the filterNumber
            number3.value = number3.value.replace(filterNumber, "");
            //replace decimals separator in format number with system decimal separator
            number3.value = number3.value.replace(DECIMALS, ".");
            //to remove the field number3 from submit data if it is empty then:
            if (!emptyValues) {
                if(number3.value==="") {number3.parentNode.removeChild(number3);}
            }
            let number4 = document.getElementById('number4');
            //eliminate thousands separator with the filterNumber
            number4.value = number4.value.replace(filterNumber, "");
            //replace decimals separator in format number with system decimal separator
            number4.value.replace(DECIMALS, ".");
            //to remove the field number4 from submit data if it is empty then:
            if (!emptyValues) {
                if(number4.value==="") {number4.parentNode.removeChild(number4);}
            }
            return true;
        }
        //////////////////////////////////////////////////////////////////////////////////
        window.onload = function() {
            // IT IS EXECUTED AFTER LOADING ALL THE CSS & HTML & JAVASCRIPT CODE
            //============================================================================
            // Create the keyup event for each defined class and relate it to the appropriate function
            //============================================================================
            document.querySelectorAll(".integerIndistinct").forEach(el => el.addEventListener("keyup", integerFormatIndistinct));
            document.querySelectorAll(".integerPositive").forEach(el => el.addEventListener("keyup", integerFormatPositive));
            document.querySelectorAll(".numberIndistinct").forEach(el => el.addEventListener("keyup", numberFormatIndistinct));
            document.querySelectorAll(".numberPositive").forEach(el => el.addEventListener("keyup", numberFormatPositive));
            document.querySelectorAll(".numberIndistinctFixed").forEach(el => el.addEventListener("keyup", numberFormatIndistinctFixed));
            document.querySelectorAll(".numberPositiveFixed").forEach(el => el.addEventListener("keyup", numberFormatPositiveFixed));
        };
        //////////////////////////////////////////////////////////////////////////////////
        </script>
    </body>
</html>
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