Added multi class support to reduce the name of class function calls that have to be made. This also works for IgniteProperties. Added a few helper functions like src, name, id, type to help shorten template code. Added a new value function that can set the value of an input or checkbox and also reflect back the value if changed in the DOM back to the property passed if desired, very cool feature.

src/ignite-template.js

@@ -34,6 +34,7 @@ class IgniteTemplate {
         this.callbacks = [];
         this.events = {};
         this.styles = {};
+        this.elementValue = null;
 
         if (children) {
             for (var i = 0; i < children.length; i++) {
@@ -53,18 +54,31 @@ class IgniteTemplate {
     }
 
     /**
-     * Adds a CSS class to this template
+     * Adds a CSS class to be added once this template is constructed.
-     * to be added once this template is constructed.
+     * @param {String|IgniteProperty} name Name of the CSS class to add. Multiple CSS classes are supported if they are separated by a space.
-     * @param {String|IgniteProperty} name Name of the CSS class to add.
      * @param {Function} converter Optional function that can convert the class name into a different one.
+     * @example
+     *  .class("row justify-content-center")
      * @returns This ignite template so function calls can be chained.
      */
     class(name, converter = null) {
         if (name instanceof IgniteProperty) {
             this.callbacks.push(name.attachOnChange((oldValue, newValue) => this.onClassChanged(oldValue, newValue, converter)));
-            this.classes.push(converter != null ? converter(name.value) : name.value);
+            var value = (converter != null ? converter(name.value) : name.value);
+            var classes = (value != null ? value.toString().split(" ") : []);
+            classes.forEach((cl) => {
+                if (cl.length > 0) {
+                    this.classes.push(cl);
+                }
+            });
         } else {
-            this.classes.push(converter != null ? converter(name) : name);
+            var value = (converter != null ? converter(name) : name);
+            var classes = (value != null ? value.toString().split(" ") : []);
+            classes.forEach((cl) => {
+                if (cl.length > 0) {
+                    this.classes.push(cl);
+                }
+            });
         }
 
         return this;
@@ -88,6 +102,43 @@ class IgniteTemplate {
         return this;
     }
 
+    /**
+     * Sets the value of the element this template is constructing with the option to reflect changes
+     * to the value.
+     * @param {String|IgniteProperty} value The value to set on the element.
+     * @param {Boolean} reflect Whether or not to reflect changes to the value of the element back to the property if one was used.
+     * @param {Function} converter Optional function that can convert the value if needed.
+     */
+    value(value, reflect = false, converter = null) {
+        if (reflect && converter != null) {
+            throw `Cannot set a value on an IgniteTemplate: ${this.tagName} with reflect and a converter used at the same time.`;
+        }
+
+        if (value instanceof IgniteProperty) {
+            this.callbacks.push(value.attachOnChange((oldValue, newValue) => this.onValueChanged(oldValue, newValue, converter)));
+
+            if (reflect) {
+                this.on("change", (event) => {
+                    var newValue = (this.element.hasAttribute("type") && this.element.getAttribute("type").toLowerCase().trim() == "checkbox" ? this.element.checked : this.element.value);
+                    console.log("Element change triggered, setting new value:", newValue);
+                    value.setValue(newValue, true);
+                });
+
+                this.on("keyup", (event) => {
+                    var newValue = (this.element.hasAttribute("type") && this.element.getAttribute("type").toLowerCase().trim() == "checkbox" ? this.element.checked : this.element.value);
+                    console.log("Element keyup triggered, setting new value:", newValue);
+                    value.setValue(newValue, true);
+                });
+            }
+
+            this.elementValue = (converter != null ? converter(value.value) : value.value);
+        } else {
+            this.elementValue = (converter != null ? converter(value) : value);
+        }
+
+        return this;
+    }
+
     /**
      * Adds a property to this template to be added once this template is constructed.
      * @param {String} name Name of the property to set.
@@ -269,6 +320,42 @@ class IgniteTemplate {
         return this;
     }
 
+    /**
+     * Sets the id attribute of the element to be constructed by this template.
+     * @param {String|IgniteProperty} value The value to set for the id attribute of the element this template will construct.
+     * @param {Function} converter An optional function that can convert the value if needed.
+     */
+    id(value, converter = null) {
+        return this.attribute("id", value, converter);
+    }
+
+    /**
+     * Sets the type attribute of the element to be constructed by this template.
+     * @param {String|IgniteProperty} value The value to set for the type attribute of the element this template will construct.
+     * @param {Function} converter An optional function that can convert the value if needed.
+     */
+    type(value, converter = null) {
+        return this.attribute("type", value, converter);
+    }
+
+    /**
+     * Sets the value attribute of the element to be constructed by this template.
+     * @param {String|IgniteProperty} value The value to set for the src attribute of the element to be constructed by this template.
+     * @param {Function} converter An optional function that can convert the value if needed.
+     */
+    src(value, converter = null) {
+        return this.attribute("src", value, converter);
+    }
+
+    /**
+     * Sets the name attribute of the element to be constructed by this template.
+     * @param {String|IgniteProperty} value The value to set for the name attribute of the element to be constructed by this template.
+     * @param {Function} converter An optional function that can convert the value if needed.
+     */
+    name(value, converter = null) {
+        return this.attribute("name", value, converter);
+    }
+
     /**
      * Constructs this template and adds it to the DOM if this template
      * has not already been constructed.
@@ -343,6 +430,15 @@ class IgniteTemplate {
             }
         }
 
+        //Set the elements value if there is one.
+        if (this.elementValue != null) {
+            if (this.element.hasAttribute("type") && this.element.getAttribute("type").toLowerCase().trim() == "checkbox") {
+                this.element.checked = this.elementValue;
+            } else {
+                this.element.value = this.elementValue;
+            }
+        }
+
         //Construct the children under this element
         for (var i = 0; i < this.children.length; i++) {
             this.children[i].construct(this.element);
@@ -413,23 +509,36 @@ class IgniteTemplate {
             newValue = converter(newValue);
         }
 
+        var oldClasses = (oldValue != null ? oldValue.toString().split(" ") : []);
+        var newClasses = (newValue != null ? newValue.toString().split(" ") : []);
+
         if (this.element) {
-            if (oldValue !== null && oldValue !== undefined && oldValue !== "" && oldValue !== " ") {
+            oldClasses.forEach((cl) => {
-                this.element.classList.remove(oldValue);
+                if (cl.length > 0) {
-            }
+                    this.element.classList.remove(cl);
+                }
+            });
 
-            if (newValue !== null && newValue !== undefined && newValue !== "" && newValue !== " ") {
+            newClasses.forEach((cl) => {
-                this.element.classList.add(newValue);
+                if (cl.length > 0) {
-            }
+                    this.element.classList.add(cl);
+                }
+            });
         }
 
-        //Remove the old value
+        //Remove the old values from the template, but only remove one copy.
-        this.classes = this.classes.filter(cl => cl != oldValue && cl != newValue);
+        oldClasses.forEach((cl) => this.classes.splice(this.classes.indexOf(cl), 1));
 
-        //Add the new value if its valid.
+        //Add the new classes to the template.
-        if (newValue !== null && newValue !== undefined) {
+        newClasses.forEach((cl) => this.classes.push(cl));
-            this.classes.push(newValue);
+
-        }
+        //For any classes that are missing on the element, add them. If we have duplicates this
+        //can happen.
+        this.classes.forEach((cl) => {
+            if (!this.element.classList.contains(cl)) {
+                this.element.classList.add(cl);
+            }
+        });
     }
 
     /**
@@ -456,6 +565,33 @@ class IgniteTemplate {
         this.attributes[attributeName] = newValue;
     }
 
+    /**
+     * Called when a value for this template was changed and needs to be updated on the template's element.
+     * @param {any} oldValue 
+     * @param {any} newValue 
+     * @param {Function} converter 
+     * @ignore
+     */
+    onValueChanged(oldValue, newValue, converter) {
+        if (converter !== null) {
+            newValue = converter(newValue);
+        }
+
+        //Only update the elements value if it actually changed.
+        //This is to prevent endless looping potentially.
+        if (this.element) {
+            if (this.element.hasAttribute("type") && this.element.getAttribute("type").toLowerCase().trim() == "checkbox") {
+                if (this.element.checked != newValue) {
+                    this.element.checked = newValue;
+                }
+            } else {
+                if (this.element.value != newValue) {
+                    this.element.value = newValue;
+                }
+            }
+        }
+    }
+
     /**
      * Called when a property on this template was changed and needs to be updated
      * on the template's element.
@@ -705,6 +841,18 @@ class img extends IgniteTemplate {
     }
 }
 
+/**
+ * An ignite template that can be used to construct a label element.
+ */
+class label extends IgniteTemplate {
+    /** 
+     * @param  {...String|Number|IgniteProperty|IgniteTemplate} children A series of children to be added to this template.
+     */
+    constructor(...children) {
+        super("label", children);
+    }
+}
+
 /**
  * Html is a special template that can construct raw html or properties into the dom and automatically
  * update the dom if the property changes.
@@ -949,5 +1097,6 @@ export {
     i,
     br,
     img,
+    label,
     slot
 };

src/main-app.js

@@ -11,7 +11,7 @@ class MainApp extends IgniteElement {
         return {
             name: "I'm a boss!",
             items: ["main1", "main2"],
-            sheetClass: "test",
+            sheetClass: "test1 test2 test3",
             sheet: null
         };
     }
@@ -24,6 +24,7 @@ class MainApp extends IgniteElement {
                     .property("items", this.items, true)
                     .ref(this.sheet)
                     .class(this.sheetClass)
+                    .class("a b    c")
                     .child(new html(`<h3>Im a child for sheet!</h3>`))
             )
             .child(

src/sheet.js

@@ -16,6 +16,8 @@ class Sheet extends IgniteElement {
             linkClick: this.onClick1,
             linkClick2: this.onClick2,
             enter: this.onEnter,
+            inputValue: "hello world!",
+            checkboxValue: false
         };
     }
 
@@ -33,7 +35,8 @@ class Sheet extends IgniteElement {
             .class(this.show)
             .child(
                 new div(
-                    new input().attribute("type", "text").onEnter(this.enter),
+                    new input().type("text").onEnter(this.enter).value(this.inputValue, true),
+                    new input().type("checkbox").value(this.checkboxValue, true),
                     new h1(this.name),
                     new html("<h2>this is before</h2>"),
                     new div(
@@ -63,6 +66,10 @@ class Sheet extends IgniteElement {
     onEnter(event) {
         console.log("Enter was pressed!");
     }
+
+    onChange(event) {
+        console.log("Input was changed, event:", event);
+    }
 }
 
 class SheetTemplate extends IgniteTemplate {