On Stackoverflow I answered a question about the strange behaviour of builtin bootstrap pager of the Extension Library. Bryan Schmiedeler asked me to share my own renderer.
How it started
Before Boostrap4XPages was pulled into the Extension Library I already has a requirement of a Bootstrap styled pager in a XPages application. I gave Bootstrap4XPages a try, but noticed some strange side effects in my application. So I switched off Bootstrap4XPages in the application and switched back to plain vanilla Bootstrap, but I took a quik look at the source code on Github and took the BoostrapPagerRenderer code and added to my own application. I changed to code to my needs.
Java class
The base of the new Bootstrap pager look and feel starts with the Java class
package nl.elstarit.renderers;
import java.io.IOException;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import javax.faces.component.UIComponent;
import javax.faces.context.FacesContext;
import javax.faces.context.ResponseWriter;
import javax.faces.render.Renderer;
import com.ibm.commons.util.StringUtil;
import com.ibm.xsp.FacesExceptionEx;
import com.ibm.xsp.component.UIPager;
import com.ibm.xsp.component.UIPagerControl;
import com.ibm.xsp.component.xp.XspPager;
import com.ibm.xsp.component.xp.XspPagerControl;
import com.ibm.xsp.context.FacesContextEx;
import com.ibm.xsp.event.PagerEvent;
import com.ibm.xsp.extlib.util.ExtLibUtil;
import com.ibm.xsp.util.AjaxUtilEx;
import com.ibm.xsp.util.FacesUtil;
import com.ibm.xsp.util.JavaScriptUtil;
import com.ibm.xsp.util.TypedUtil;
public class BootstrapPagerRenderer extends Renderer {
public static final String VAR_PAGE = "page";
@Override
public void decode(FacesContext context, UIComponent component) {
super.decode(context, component);
// check that this component cause the submit
if (decodeCausedSubmit(context, component)) {
PagerEvent pagerEvent = new PagerEvent(component);
String hiddenValue = FacesUtil.getHiddenFieldValue(context);
if (StringUtil.isNotEmpty(hiddenValue)) {
int pos = hiddenValue.lastIndexOf('_');
if (pos > -1) {
hiddenValue = hiddenValue.substring(pos + 1);
if (isFirst(hiddenValue)) {
pagerEvent.setAction(PagerEvent.ACTION_FIRST);
} else if (isLast(hiddenValue)) {
pagerEvent.setAction(PagerEvent.ACTION_LAST);
} else if (isNext(hiddenValue)) {
pagerEvent.setAction(PagerEvent.ACTION_NEXT);
} else if (isPrevious(hiddenValue)) {
pagerEvent.setAction(PagerEvent.ACTION_PREVIOUS);
} else {
try {
int value = Integer.parseInt(hiddenValue);
pagerEvent.setAction(PagerEvent.ACTION_GOTOPAGE);
pagerEvent.setPage(value);
} catch (NumberFormatException nfe) {
return; // just don't queue the event
}
}
} else {
return;
}
}
((UIPager) component).queueEvent(pagerEvent);
}
}
private boolean decodeCausedSubmit(FacesContext context,
UIComponent component) {
String currentClientId = component.getClientId(context);
String hiddenValue = FacesUtil.getHiddenFieldValue(context);
if (currentClientId != null && hiddenValue != null) {
return StringUtil.indexOfIgnoreCase(hiddenValue, currentClientId) > -1;
}
return false;
}
@Override
public boolean getRendersChildren() {
return true;
}
@Override
public void encodeChildren(FacesContext context, UIComponent component)
throws IOException {
if (context == null || component == null) {
throw new IOException();
}
XspPager pager = (XspPager) component;
UIPager.PagerState st = ((UIPager) component).createPagerState();
if (st == null) {
return;
}
ResponseWriter writer = context.getResponseWriter();
encodePagerContent(context, writer, st, pager);
}
protected void encodePagerContent(FacesContext context, ResponseWriter w,
UIPager.PagerState st, XspPager pager) throws IOException {
int pageCount = st.getPageCount();
int start = getStart(st, pageCount);
int end = getEnd(st, pageCount, start);
String pagerId = pager.getClientId(context);
boolean RTL = false;
// bootstrap 2
boolean b2 = false;
// bootstrap 3
boolean b3 = true;
w.startElement("div", null);
if (b2) {
w.writeAttribute("class", ExtLibUtil.concatStyleClasses(
"pagination", pager.getStyleClass()), null);
}
if (b3) {
String pgClass = pager.getStyleClass();
if (StringUtil.isNotEmpty(pgClass)) {
w.writeAttribute("class", pgClass, null);
}
}
if (StringUtil.isNotEmpty(pagerId)) {
w.writeAttribute("id", pagerId, null);
}
w.startElement("ul", null);
if (b3) {
w.writeAttribute("class", "pagination", null);
}
List<?> listControls = pager.getChildren();
if (listControls.isEmpty()) {
return;
}
Iterator<?> it = listControls.iterator();
while (it.hasNext()) {
Object obj = it.next();
if (obj instanceof XspPagerControl) {
XspPagerControl control = (XspPagerControl) obj;
String type = control.getType();
if (StringUtil.isNotEmpty(type)) {
if (isFirst(type) || isNext(type) || isPrevious(type)
|| (isLast(type) && pager.isAlwaysCalculateLast())) {
encodeAction(context, pager, st, w, control, type,
start, end, RTL);
continue;
} else if (isLast(type) && !pager.isAlwaysCalculateLast()) {
if (!st.hasMoreRows()) {
encodeAction(context, pager, st, w, control, type,
start, end, RTL);
} else {
w.startElement("li", null);
w.writeAttribute("class", "disabled", null);
w.startElement("a", null);
w.writeText(getMayBeMorePages(), null);
w.endElement("li");
w.endElement("a");
}
continue;
} else if (type.equalsIgnoreCase(UIPagerControl.TYPE_GROUP)) {
encodeGroup(context, pager, st, w, control, start, end);
continue;
} else if (type
.equalsIgnoreCase(UIPagerControl.TYPE_STATUS)) {
encodeStatus(context, st, w, pager, control, start, end);
continue;
} else if (isSeparator(type)) {
encodeSeparator(context, w, control, type);
continue;
} else if (type.equalsIgnoreCase(UIPagerControl.TYPE_GOTO)) {
encodeGoto();
continue;
}
}
String msg = StringUtil
.format("Unknown control type {0}", type);
throw new FacesExceptionEx(msg);
}
}
w.endElement("ul");
w.endElement("div");
}
private void encodeAction(FacesContext context, XspPager pager,
UIPager.PagerState st, ResponseWriter writer,
XspPagerControl control, String type, int start, int end,
boolean RTL) throws IOException {
String clientId = pager.getClientId(context);
String controlId = clientId + "__" + type;
String defaultText = "";
boolean renderLink = true;
if (isFirst(type)) {
renderLink = st.getCurrentPage() > start;
defaultText = "\u00AB"; // First
} else if (isPrevious(type)) {
renderLink = true;
defaultText = "\u2039"; // Previous
} else if (isNext(type)) {
renderLink = true;
defaultText = "\u203A"; // Next
} else if (isLast(type)) {
renderLink = st.getCurrentPage() < end - 1;
defaultText = "\u00BB"; // Last
}
writer.startElement("li", null);
if (!renderLink) {
writer.writeAttribute("class", "active", null);
}
// Generate the image link
String val = (String) control.getValue();
if (StringUtil.isEmpty(val)) {
val = defaultText;
}
// Generate the text link
if (StringUtil.isNotEmpty(val)) {
writer.startElement("a", null);
writer.writeAttribute("id", controlId + "__lnk", null);
writer.writeAttribute("href", "#", null);
if ("next".equals(val)) {
writer.startElement("i", null);
writer.writeAttribute("class", "fa fa-chevron-right", null);
writer.endElement("i");
} else if ("previous".equals(val)) {
writer.startElement("i", null);
writer.writeAttribute("class", "fa fa-chevron-left", null);
writer.endElement("i");
} else {
writer.writeText(val, null);
}
writer.endElement("a");
if (renderLink) {
setupSubmitOnClick(context, pager, st, controlId, controlId
+ "__lnk");
}
}
writer.endElement("li");
}
private void encodeGroup(FacesContext context, XspPager pager,
UIPager.PagerState st, ResponseWriter writer,
XspPagerControl control, int start, int end) throws IOException {
// Save the old page value
Map<String, Object> requestMap = TypedUtil.getRequestMap(context
.getExternalContext());
Object oldPage = requestMap.get(VAR_PAGE);
String clientId = pager.getClientId(context);
String controlId = clientId + "__" + control.getType();//$NON-NLS-1$
// Encode the pages
for (int i = start; i < end; i++) {
// Push the page number
requestMap.put(VAR_PAGE, i + 1);
boolean renderLink = (i != st.getCurrentPage());
writer.startElement("li", null);
if (!renderLink) {
writer.writeAttribute("class", "active", null);
}
String val = (String) control.getValue();
if (StringUtil.isEmpty(val)) {
val = Integer.toString(i + 1);
}
// Generate the text link
if (StringUtil.isNotEmpty(val)) {
writer.startElement("a", control);
writer.writeAttribute("id", controlId + "__lnk__" + i, null);
writer.writeText(val, null);
writer.endElement("a");
if (renderLink) {
setupSubmitOnClick(context, pager, st, controlId
+ "__lnk__" + i, controlId + "__lnk__" + i);
}
}
writer.endElement("li");
}
// Encode after the pages
if (!pager.isAlwaysCalculateLast()) {
if (end < st.getLastPage() || st.hasMoreRows()) {
writer.startElement("li", null);
writer.writeAttribute("class", "disabled", null);
writer.startElement("a", control);
writer.writeText(getMayBeMorePages(), null);
writer.endElement("a");
writer.endElement("li");
}
}
// Restore the old page value
if (oldPage != null) {
requestMap.put(VAR_PAGE, oldPage);
} else {
requestMap.remove(VAR_PAGE);
}
}
private void setupSubmitOnClick(FacesContext context, XspPager component,
UIPager.PagerState st, String clientId, String sourceId) {
boolean immediate = false;
UIComponent subTree = ((FacesContextEx) context).getSubTreeComponent();
boolean partialExec = component.isPartialExecute();
String execId = null;
if (partialExec) {
execId = component.getClientId(context);
immediate = true;
} else {
if (subTree != null) {
partialExec = true;
execId = subTree.getClientId(context);
immediate = true;
}
}
boolean partialRefresh = component.isPartialRefresh();
String refreshId = null;
if (partialRefresh) {
UIComponent refreshComponent = component
.findSharedDataPagerParent();
if (null == refreshComponent) {
refreshComponent = (UIComponent) st.getDataIterator();
}
refreshId = AjaxUtilEx.getRefreshId(context, refreshComponent);
} else {
if (subTree != null) {
partialRefresh = true;
refreshId = subTree.getClientId(context);
}
}
final String event = "onclick";
StringBuilder buff = new StringBuilder();
if (partialRefresh) {
JavaScriptUtil.appendAttachPartialRefreshEvent(buff, clientId,
sourceId, execId, event,
/* clientSideScriptName */null,
immediate ? JavaScriptUtil.VALIDATION_NONE
: JavaScriptUtil.VALIDATION_FULL,
/* refreshId */refreshId,
/* onstart */getOnStart(component),
/* oncomplete */getOnComplete(component),
/* onerror */getOnError(component));
} else {
JavaScriptUtil.appendAttachEvent(buff, clientId, sourceId, execId,
event,
/* clientSideScriptName */null,
/* submit */true,
immediate ? JavaScriptUtil.VALIDATION_NONE
: JavaScriptUtil.VALIDATION_FULL);
}
String script = buff.toString();
// Add the script block we just generated.
JavaScriptUtil.addScriptOnLoad(script);
}
protected String getOnStart(XspPager component) {
return (String) component.getAttributes().get("onStart"); // $NON-NLS-1$
}
protected String getOnComplete(XspPager component) {
return (String) component.getAttributes().get("onComplete"); // $NON-NLS-1$
}
protected String getOnError(XspPager component) {
return (String) component.getAttributes().get("onError"); // $NON-NLS-1$
}
private void encodeStatus(FacesContext context, UIPager.PagerState st,
ResponseWriter writer, XspPager pager, XspPagerControl control,
int start, int end) throws IOException {
writer.startElement("li", null);
writer.writeAttribute("class", "disabled", null);
String val = (String) control.getValue();
if (StringUtil.isEmpty(val)) {
val = "{0}";
}
if (StringUtil.isNotEmpty(val) && st.getLastPage() > 0) {
writer.startElement("a", null);
val = StringUtil.format(val, st.getCurrentPage() + 1, st
.getLastPage(), start, end);
writer.writeText(val, null);
writer.endElement("a");
}
writer.endElement("li");
}
private void encodeSeparator(FacesContext context, ResponseWriter writer,
XspPagerControl control, String type) throws IOException {
String val = (String) control.getValue();
writer.startElement("li", null);
if (StringUtil.isEmpty(val)) {
String defaultSeparator = "|";
if (type.equalsIgnoreCase(UIPagerControl.TYPE_SEPARATORPAGE)) {
defaultSeparator = "Page";
}
val = defaultSeparator;
}
// Generate the text link
if (StringUtil.isNotEmpty(val)) {
writer.startElement("a", null);
writer.writeText(val, null);
writer.endElement("a");
}
writer.endElement("li");
}
private void encodeGoto() {
// Do not exists in core XPages yet..
}
private int getStart(UIPager.PagerState st, int pageCount) {
int start = (st.getFirst() / st.getRows()) - pageCount / 2;
start = Math.min(Math.max(0, st.getLastPage() - pageCount), Math.max(0,
start));
return start;
}
private int getEnd(UIPager.PagerState st, int pageCount, int start) {
int sizeOfPageRange = Math.min(start + pageCount, st.getLastPage())
- start;
int end = start + sizeOfPageRange;
return end;
}
private boolean isFirst(String type) {
return (type.equalsIgnoreCase(UIPagerControl.TYPE_FIRST)
|| type.equalsIgnoreCase(UIPagerControl.TYPE_FIRSTARROW) || type
.equalsIgnoreCase(UIPagerControl.TYPE_FIRSTIMAGE));
}
private boolean isNext(String type) {
return (type.equalsIgnoreCase(UIPagerControl.TYPE_NEXT)
|| type.equalsIgnoreCase(UIPagerControl.TYPE_NEXTARROW) || type
.equalsIgnoreCase(UIPagerControl.TYPE_NEXTIMAGE));
}
private boolean isLast(String type) {
return (type.equalsIgnoreCase(UIPagerControl.TYPE_LAST)
|| type.equalsIgnoreCase(UIPagerControl.TYPE_LASTARROW) || type
.equalsIgnoreCase(UIPagerControl.TYPE_LASTIMAGE));
}
private boolean isPrevious(String type) {
return (type.equalsIgnoreCase(UIPagerControl.TYPE_PREVIOUS)
|| type.equalsIgnoreCase(UIPagerControl.TYPE_PREVIOUSARROW) || type
.equalsIgnoreCase(UIPagerControl.TYPE_PREVIOUSIMAGE));
}
private boolean isSeparator(String type) {
return (type.equalsIgnoreCase(UIPagerControl.TYPE_SEPARATOR) || type
.equalsIgnoreCase(UIPagerControl.TYPE_SEPARATORPAGE));
}
private String getMayBeMorePages() {
return "..."; // $NLS-PagerRenderer.MayBeMorePages-1$
}
}
RenderType
In my custom theme I have specified a RenderType
<!-- Theme pager --> <control> <name>Pager</name> <property> <name>rendererType</name> <value>nl.elstarit.renderers.type.BootstrapPagerRenderer</value> </property> </control>
Final step
To make it work everything comes together in the faces-config.xml
<!-- Bootstrap render pager -->
<render-kit>
<renderer>
<component-family>com.ibm.xsp.Pager</component-family>
<renderer-type>nl.elstarit.renderers.type.BootstrapPagerRenderer</renderer-type>
<renderer-class>nl.elstarit.renderers.BootstrapPagerRenderer</renderer-class>
</renderer>
</render-kit>
Result
The final result is a list, which can be put every where on the XPages. And can align by css to the right or left.
great! I was just about to ask you if you could tell more about it/share some code. thanks!
May be good to know, that I first added bootstrap manually to my app, but after that Bootstrap4XPages is part of the Extension Library I removed Bootstrap from my app and used the builtin version
Hi Frank (and readers)
There is also a xsnippet for rendering a pager via CSS but I notice in the snippet the … notation for next set of pages is not styled properly (read: not styled at all) so I can definitely recommend your approach.