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Posted to users@myfaces.apache.org by John <jo...@jak.com> on 2006/07/01 06:59:02 UTC
RE: How to displayi an images generated by a managed bean?
Well, there seems to be major problems with this release candidate.
The good news: The problem with using a backing bean property to
dynamically set chart type is fixed.
The bad news: Everything renders beautifully. Then, no matter what you
do or what you push, you can't navigate or execute an action or
anything. Everything you do just redraws the chart... It completely
breaks the application.
Now I didn't name my jsps ending in *.jsf like his example, but it was
an existing application. my url-mapping is /faces/*
But I gave it a shot and added *.jsf as a mapping also. No effect - same
nightmare.
I rolled back to the old version of Chart Creator (the one that doesn't
use a phase listener - uses a servlet) Added the chart servlet back into
web.xml and everything is fine again.
Arghhh... He had like one bug... Why did the software have to be
completely redesigned...
John
________________________________
From: Cagatay Civici [mailto:cagatay.civici@gmail.com]
Sent: Friday, June 30, 2006 5:05 AM
To: MyFaces Discussion
Subject: Re: How to displayi an images generated by a managed bean?
Hi,
FYI The 1.2.0 RC1 is released at jsf-comp.
Here is the changelog;
http://www.jroller.com/page/cagataycivici?entry=jsf_charting_monster_is_
back
Cheers,
Cagatay
On 6/29/06, Paul Spencer <pa...@mindspring.com> wrote:
Cagatay,
I have not ruled anything out. I am still looking at the
options. In
general I like what I see in JSF-COMP.
JSF_COMP appears to be a very simple way to embed charts!
Paul Spencer
Cagatay Civici wrote:
> Hi,
>
> Why not use the JSF Chart Creator of JSF-COMP?
>
> It does not use a servlet, instead a phaselistener to render
the charts so
> there is no need to to do any configuration in the
application.
>
> Cagatay
>
> On 6/29/06, Julian Ray <ju...@yahoo.com> wrote:
>>
>> Sure.
>>
>> First you need to be able to access the faces context from a
non-faces
>> servlet. I posted some info on the WIKI about how to get the
faces
>> context
>> (and therefor all session values and access to managed beans)
within a
>> servlet. Take a look at
>> http://wiki.apache.org/myfaces/AccessFacesContextFromServlet.
>>
>> Our charting servlet uses simple get params to control the
chart -- as
>> this
>> is "visible" to the outside world we only pass params which
allow us to
>> get
>> the appropriate managed bean and session properties from
within faces
>> context. So in the doGet() we call appropriate managed beans
and
>> JFreeChart
>> methods to creat and return the chart. This is standard
servlet stuff
>> (with
>> the myfaces context added). Included code below
>>
>> protected void processRequest(HttpServletRequest request,
>> HttpServletResponse response) throws ServletException,
IOException {
>> FacesContext facesContext = getFacesContext(request,
response);
>> // Here we get whatever we need from the faces
context.
>> SessionBean sessionBean = (SessionBean)
>> getSessionBean(facesContext);
>>
>> if (null == sessionBean) {
>> log.debug("Session bean is null.");
>> } else {
>> log.debug("Got session bean. Userid=" +
>> sessionBean.getUserId());
>> }
>>
>> // Get the chart type to process from the URL
>> AbstractChart chart = null;
>> Integer chartType =
>>
NumberUtils.createInteger(request.getParameter("type").trim());
>>
>> log.debug("Chart Type = '" + chartType + "'");
>>
>> // Here we do whatever needed to create the chart...
>> String className =
ChartType.getChartClassName(chartType);
>> log.debug("Creating chart object for class '" +
className + "'");
>>
>> String reportTitle = request.getParameter("til");
>> log.debug("Chart Title = '" + reportTitle + "'");
>>
>> String reportSubTitle = request.getParameter("sub");
>> log.debug("Chart Sub Title = '" + reportSubTitle +
"'");
>>
>> // See if the chart is in the cache. The servlet is
>> single-threaded
>> and reuasable which means
>> /// that a new chart map is created for each instance
of a chart.
>> Charts should be serializable
>> // and not store state in any way
>> if (map.containsKey(className)) {
>> chart = (AbstractChart) map.get(className);
>> } else {
>> // Use reflection to get the chart. Note that is
must have a
>> no-args constructor
>> try {
>> chart = (AbstractChart)
>> Class.forName(className).newInstance();
>> // Push the chart to the map.
>> map.put(className, chart);
>> } catch (ClassNotFoundException e) {
>> log.debug(e.getMessage());
>> throw new IOException( e.getMessage());
>> } catch (InstantiationException e) {
>> log.debug(e.getMessage());
>> throw new IOException(e.getMessage());
>> } catch (IllegalAccessException e) {
>> log.debug(e.getMessage());
>> throw new IOException(e.getMessage());
>> } catch (IllegalArgumentException e) {
>> log.debug (e.getMessage());
>> throw new IOException(e.getMessage());
>> }
>> }
>>
>> // Chart setup here
>> if (null == chart) {
>> log.error("Chart # " + chartType + " not found on
server.");
>> response.setContentType("text/html");
>>
>> ServletOutputStream outputStream =
>> response.getOutputStream();
>> outputStream.println("Chart not found on
server.");
>> outputStream.flush();
>> outputStream.close();
>> } else {
>> // Populate the chart so it can access the params
>> chart.setRequest(request);
>> chart.setSessionBean(sessionBean);
>>
>> // Process the chart
>> JFreeChart jfreeChart = chart.getChart();
>> // get the image
>> response.setContentType("image/png");
>>
ChartUtilities.writeChartAsPNG(response.getOutputStream(),
>> jfreeChart, chart.getChartWidth(), chart.getChartHeight());
>> }
>> }
>>
>> Our JSF backing bean constructs a url based on options
selected by the
>> user.
>> This url is passed to the <h:graphicImage> tag. The form of
the URL is
>> /myContextRoot/myChartServlet?param1=value1¶m2=value2
etc.
>>
>> In the backing bean we have
>>
>> Public String getChartURL() {
>> StringBuffer sb = new StringBuffer();
>> sb.append("/myContextRoot/myChartServlet");
>> //sb.append(.....) etc...
>> return sb.toString();
>> }
>> and in the JSF we have
>>
>> <h:graphicImage styleClass="whatever..."
>> value="#{myBackingBean.chartURL}"
>> />
>>
>> Our servlet implementation loads chart classes as the servlet
is
>> initialized
>> which speeds up the servlet once it is "warmed up".
>>
>> One more note, While this approach works well found that it
is more
>> convienient to create a custom component to provide the JSF
interface as
>> we
>> use charts on a large number of our pages and it fits the MVC
model
>> better
>> to let the JSF fuly control the format and display of the
greaphic.
>>
>> I hope this helps.
>>
>>
>>
>> Example
>>
>> -----Original Message-----
>> From: Paul Spencer [mailto:paulsp@apache.org]
>> Sent: Thursday, June 29, 2006 7:55 AM
>> To: MyFaces Discussion
>> Subject: Re: How to displayi an images generated by a managed
bean?
>>
>> Julian,
>> Can you explain the code and configuration behind
>> #{myBackingBean.chartURL
>> }
>> and the servlet you have created?
>>
>> I need to understand where the graphic is created, i.e. in
the managed
>> bean
>> or servlet, how the servlet gets what is needs, and any
housekeeping that
>> is
>> performed.
>>
>>
>> Paul Spencer
>>
>> Julian Ray wrote:
>> > Hi Paul,
>> >
>> > We use JFreeCharts by creating a servlet which serves up
the charts
>> > and then creating a URL in the backingbean which is set as
the value
>> > for the graphicImage
>> >
>> > Eg <h:graphicImage styleClass="..."
value="#{myBackingBean.chartURL}"
>> > />
>> >
>> > -----Original Message-----
>> > From: Paul Spencer [mailto:paulsp@apache.org]
>> > Sent: Wednesday, June 28, 2006 11:14 PM
>> > To: MyFaces Discussion
>> > Subject: How to displayi an images generated by a managed
bean?
>> >
>> > I need to include a graphic image generated by JFreeCharts.
Currently
>> > the generation of the image is in an action of a managed
bean and is
>> > displayed in a separate windows via <h:commandButton>. How
should I
>> > convert this to a <h:graphicImage> so it can be displayed
in an
>> existing
>> page?
>> >
>> > Paul Spencer
>> >
>> >
>>
>>
>>
>
Re: How to displayi an images generated by a managed bean?
Posted by Cagatay Civici <ca...@gmail.com>.
Hi,
I see, the thing is: if the /faces/* mapping is already defined, there is no
need for *.jsf. Due to the relative path, charts will be displayed.
John, I'm working to reproduce the bug you reported but no luck. I've tried
lots of stuff, navigation, postback and more. Everything worked. Also many
people told me that the new version is working good, I guess the new
structure collides with your configuration somehow.
Can you send me an example page from your application. I already got your
web.xml
Regards,
Cagatay