    /**
     * @class YAHOO.ext.grid.NumberEditor
     * @extends YAHOO.ext.grid.CellEditor
    Provides a masked editor for numeric values. Invalid keys are ignored. It supports the following configuration options:
    <ul class="list">
    <li><i>allowDecimals</i> - True if the cell can have decimal values.</li>
    <li><i>decimalSeparator</i> - Character(s) to allow as the decimal separator.</li>
    <li><i>decimalPrecision</i> - Set the maximum decimal precision.</li>
    <li><i>decimalPrecisionFcn</i> - Define the function to call to remove extra precision (ie. Math.floor, Math.round, Math.ceil or your own function).</li>
    <li><i>allowNegative</i> - True if the cell allows negative values.</li>
    <li><i>selectOnFocus</i> - True to select the text when the editor is activated.</li>
    <li><i>minValue</i> - The minimum value the cell will allow.</li>
    <li><i>maxValue</i> - The maximum value the cell will allow.</li>
    <li><i>minText</i> - The tooltip to display when the value in the cell is below the minimum.</li>
    <li><i>maxText</i> - The tooltip to display when the value in the cell is above the maximum.</li>
    <li><i>nanText</i> - The tooltip to display when the value in the cell is not a valid number (for example, negatives are allowed and the value in the cell is just "-" with no numbers).</li>
    <li><i>allowBlank</i> - True if the cell is allowed to be empty.</li>
    <li><i>blankText</i> - The tooltip (error message) to display when the cell is empty and is not allowed to be.</li>
    <li><i>validator</i> - Any custom validation function you want called. The function must return true if the data is valid or an error message otherwise.</li>
    <li><i>validationDelay</i> - The delay in milliseconds for validation. Each time the user types something the field is validated after a specified delay, setting this value allows you to customize that delay (for example, if your custom validation routine is slow).</li>
    </ul>
    For more information on using this editor, see <a href="http://www.jackslocum.com/yui/2006/09/10/adding-built-in-editing-support-to-the-yahoo-ui-extensions-grid/">this blog post</a>.
    * @constructor
    * Create a new NumberEditor
    * @param {Object} config
     */
    YAHOO.ext.grid.NumberEditor = function(config){
        var element = document.createElement('input');
        element.type = 'text';
        element.className = 'ygrid-editor ygrid-num-editor';
        element.setAttribute('autocomplete', 'off');
        document.body.appendChild(element);
        YAHOO.ext.grid.NumberEditor.superclass.constructor.call(this, element);
        YAHOO.ext.util.Config.apply(this, config);
    };
    YAHOO.extendX(YAHOO.ext.grid.NumberEditor, YAHOO.ext.grid.CellEditor);

    YAHOO.ext.grid.NumberEditor.prototype.initEvents = function(){
        var stopOnEnter = function(e){
            if(e.browserEvent.keyCode == e.RETURN){
                this.stopEditing(true);
            }else if(e.browserEvent.keyCode == e.ESC){
                this.setValue(this.originalValue);
                this.stopEditing(true);
            }
        };

        var allowed = "0123456789";
        if(this.allowDecimals){
            allowed += this.decimalSeparator;
        }
        if(this.allowNegative){
            allowed += '-';
        }
        var keyPress = function(e){
            var c = e.getCharCode();
            if(c != e.BACKSPACE && allowed.indexOf(String.fromCharCode(c)) === -1){
                e.stopEvent();
            }
        };
        this.element.mon('keydown', stopOnEnter, this, true);
        var vtask = new YAHOO.ext.util.DelayedTask(this.validate, this);
        this.element.mon('keyup', vtask.delay.createDelegate(vtask, [this.validationDelay]));
        this.element.mon('keypress', keyPress, this, true);
        this.element.on('blur', this.stopEditing, this, true);
    };

    YAHOO.ext.grid.NumberEditor.prototype.validate = function(){
        var dom = this.element.dom;
        var value = dom.value;
        if(value.length < 1){ // if it's blank
             if(this.allowBlank){
                 dom.title = '';
                 this.element.removeClass('ygrid-editor-invalid');
                 return true;
             }else{
                 dom.title = this.blankText;
                 this.element.addClass('ygrid-editor-invalid');
                 return false;
             }
        }
        if(value.search(/\d+/) === -1){
            dom.title = this.nanText.replace('%0', value);
            this.element.addClass('ygrid-editor-invalid');
            return false;
        }
        var num = this.parseValue(value);
        if(num < this.minValue){
            dom.title = this.minText.replace('%0', this.minValue);
            this.element.addClass('ygrid-editor-invalid');
            return false;
        }
        if(num > this.maxValue){
            dom.title = this.maxText.replace('%0', this.maxValue);
            this.element.addClass('ygrid-editor-invalid');
            return false;
        }
        var msg = this.validator(value);
        if(msg !== true){
            dom.title = msg;
            this.element.addClass('ygrid-editor-invalid');
            return false;
        }
        dom.title = '';
        this.element.removeClass('ygrid-editor-invalid');
        return true;
    };

    YAHOO.ext.grid.NumberEditor.prototype.show = function(){
        this.element.dom.title = '';
        YAHOO.ext.grid.NumberEditor.superclass.show.call(this);
        if(this.selectOnFocus){
            try{
                this.element.dom.select();
            }catch(e){}
        }
        this.validate(this.element.dom.value);
    };

    YAHOO.ext.grid.NumberEditor.prototype.getValue = function(){
       if(!this.validate()){
           return this.originalValue;
       }else{
           var value = this.element.dom.value;
           if(value.length < 1){
               return value;
           } else{
               return this.fixPrecision(this.parseValue(value));
           }
       }
    };
    YAHOO.ext.grid.NumberEditor.prototype.parseValue = function(value){
        return parseFloat(new String(value).replace(this.decimalSeparator, '.'));
    };

    YAHOO.ext.grid.NumberEditor.prototype.fixPrecision = function(value){
       if(!this.allowDecimals || this.decimalPrecision == -1 || isNaN(value) || value == 0 || !value){
           return value;
       }
       // this should work but doesn't due to precision error in JS
       // var scale = Math.pow(10, this.decimalPrecision);
       // var fixed = this.decimalPrecisionFcn(value * scale);
       // return fixed / scale;
       //
       // so here's our workaround:
       var scale = Math.pow(10, this.decimalPrecision+1);
       var fixed = this.decimalPrecisionFcn(value * scale);
       fixed = this.decimalPrecisionFcn(fixed/10);
       return fixed / (scale/10);
    };

    YAHOO.ext.grid.NumberEditor.prototype.allowBlank = true;
    YAHOO.ext.grid.NumberEditor.prototype.allowDecimals = true;
    YAHOO.ext.grid.NumberEditor.prototype.decimalSeparator = '.';
    YAHOO.ext.grid.NumberEditor.prototype.decimalPrecision = 2;
    YAHOO.ext.grid.NumberEditor.prototype.decimalPrecisionFcn = Math.floor;
    YAHOO.ext.grid.NumberEditor.prototype.allowNegative = true;
    YAHOO.ext.grid.NumberEditor.prototype.selectOnFocus = true;
    YAHOO.ext.grid.NumberEditor.prototype.minValue = Number.NEGATIVE_INFINITY;
    YAHOO.ext.grid.NumberEditor.prototype.maxValue = Number.MAX_VALUE;
    YAHOO.ext.grid.NumberEditor.prototype.minText = 'The minimum value for this field is %0';
    YAHOO.ext.grid.NumberEditor.prototype.maxText = 'The maximum value for this field is %0';
    YAHOO.ext.grid.NumberEditor.prototype.blankText = 'This field cannot be blank';
    YAHOO.ext.grid.NumberEditor.prototype.nanText = '%0 is not a valid number';
    YAHOO.ext.grid.NumberEditor.prototype.validationDelay = 100;
    YAHOO.ext.grid.NumberEditor.prototype.validator = function(){return true;};

Copyright © 2006 Jack Slocum. All rights reserved.