add <caption> optional tag to datatable

add <caption> optional tag to datatable to improve screen reader experience

Fix  #1028

src/main/java/net/bootsfaces/component/dataTable/DataTableCore.java

@@ -24,7 +24,7 @@
 public abstract class DataTableCore extends UIData implements net.bootsfaces.render.IHasTooltip {
 
 	protected enum PropertyKeys {
-		ajax, autoUpdate, border, colLg, colMd, colSm, colXs, columnVisibility, contentDisabled, copy, csv, customLangUrl, customOptions, delay, deselectOnBackdropClick, disabled, display, excel, fixedHeader, hidden, immediate, info, lang, largeScreen, markSearchResults, mediumScreen, multiColumnSearch, multiColumnSearchPosition, offset, offsetLg, offsetMd, offsetSm, offsetXs, onclick, oncomplete, ondblclick, ondeselect, onerror, onmousedown, onmousemove, onmouseout, onmouseover, onmouseup, onorder, onpage, onsearch, onselect, onsuccess, pageLength, pageLengthMenu, paginated, pdf, print, process, responsive, rowGroup, rowHighlight, rowStyleClass, saveState, scrollCollapse, scrollHorizontally, scrollSize, scrollX, searching, select, selectedColumn, selectedItems, selectedRow, selectionInfo, selectionMode, smallScreen, span, striped, style, styleClass, tinyScreen, tooltip, tooltipContainer, tooltipDelay, tooltipDelayHide, tooltipDelayShow, tooltipPosition, update, visible, widgetVar;
+		ajax, autoUpdate, border, caption, colLg, colMd, colSm, colXs, columnVisibility, contentDisabled, copy, csv, customLangUrl, customOptions, delay, deselectOnBackdropClick, disabled, display, excel, fixedHeader, hidden, immediate, info, lang, largeScreen, markSearchResults, mediumScreen, multiColumnSearch, multiColumnSearchPosition, offset, offsetLg, offsetMd, offsetSm, offsetXs, onclick, oncomplete, ondblclick, ondeselect, onerror, onmousedown, onmousemove, onmouseout, onmouseover, onmouseup, onorder, onpage, onsearch, onselect, onsuccess, pageLength, pageLengthMenu, paginated, pdf, print, process, responsive, rowGroup, rowHighlight, rowStyleClass, saveState, scrollCollapse, scrollHorizontally, scrollSize, scrollX, searching, select, selectedColumn, selectedItems, selectedRow, selectionInfo, selectionMode, smallScreen, span, striped, style, styleClass, tinyScreen, tooltip, tooltipContainer, tooltipDelay, tooltipDelayHide, tooltipDelayShow, tooltipPosition, update, visible, widgetVar;
 		String toString;
 
 		PropertyKeys(String toString) {
@@ -86,6 +86,22 @@ public boolean isBorder() {
 	public void setBorder(boolean _border) {
 		getStateHelper().put(PropertyKeys.border, _border);
 	}
+	/**
+	 * If set, this will add a <caption> tag in table declaration 
+	 */
+	public void setcaption(String _caption) {
+	        getStateHelper().put(PropertyKeys.caption, _caption);
+	}
+
+
+	/**
+	 * If set, this will surround the table by a border. Defaults to true. <P>
+	 * @return Returns the value of the attribute, or "-1", if it hasn't been set by the JSF file.
+	 */
+	public String getCaption() {
+	        return (String) getStateHelper().eval(PropertyKeys.caption, "-1");
+	}
+
 
 	/**
 	 * Integer value to specify how many columns to span on large screens (≥1200 pixels wide). The number may optionally be followed by "column" or "columns". Alternative legal values: half, one-third, two-thirds, one-fourth, three-fourths. <P>

src/main/java/net/bootsfaces/component/dataTable/DataTableRenderer.java

@@ -134,6 +134,7 @@ public void encodeBegin(FacesContext context, UIComponent component) throws IOEx
 		rw.writeAttribute("style", dataTable.getStyle(), "style");
 		AJAXRenderer.generateBootsFacesAJAXAndJavaScript(context, dataTable, rw, false);
 
+		generateCaption(context, dataTable, rw);
 		generateHeader(context, dataTable, rw);
 		generateBody(context, dataTable, rw);
 		generateFooter(context, dataTable, rw);
@@ -298,6 +299,20 @@ private void generateBody(FacesContext context, DataTable dataTable, ResponseWri
 		rw.endElement("tbody");
 		dataTable.setRowIndex(-1);
 	}
+	private void generateCaption(FacesContext context, DataTable dataTable, ResponseWriter rw) throws IOException {
+		    boolean hasCaption = false;
+
+
+		    if (!dataTable.getCaption().equals("-1")) {
+		        hasCaption = true;
+		    }
+
+		    if (hasCaption) {
+		            rw.startElement("caption", dataTable);
+		            rw.writeText(dataTable.getCaption(), null);
+		            rw.endElement("caption");
+		    }
+	    }	
 
 	private void renderChildrenOfColumn(UIComponent column, FacesContext context) throws IOException {
 		resetClientIdCacheRecursively(column);