handle page events in itext of page break - itext

i am using itext for generating pdf and want to know what happens behind the scene when an element exceeds the size of page.
i am using PdfPageEventHelper to get to know if a new page is added in this case.
resulting pdf shows a new page but don't trigger my functions for event such as onStartPage ,onEndPage.

I am using PdfPageEventHelper and I don't experience any problem with it. When a new page is triggered, the onEndPage() method is called before a new page is initialized, and the onStartPage() method is called after the new page is initialized.
You can trigger a new page in your code like this:
document.newPage();
Or the newPage() method can be triggered implicitly, for instance when you add content using document.add() that exceeds the size of the page.
Your allegation that the functions such as onEndPage() and onStartPage() aren't triggered can't be verified. On the contrary: we have plenty of examples that prove otherwise, some of which are bundled in the book The Best iText Questions on StackOverflow.
In the comments, you say that you have a question about the different between NEWPAGE and NEXTPAGE. This is a very strange question, as I don't know why you'd ever need these objects.
Chunk.NEXTPAGE is a special Chunk that is used internally by iText. It can be used to invoke the newPage() method by adding an object.
For instance:
document.add(Chunk.NEXTPAGE);
is the equivalent of:
document.newPage();
The latter method is the preferred way to trigger a new page, the NEXTPAGE object is used internally in very specific use cases.
As for Chunk.NEWPAGE, that's merely a String (it's value is "NEWPAGE"). This String is the attribute key used to identify a NEXTPAGE chunk.
This belongs to the internal kitchen of iText. As an iText user, you shouldn't worry about it.

Related

UITableView Add Rows At The Bottom Using Parsing Another Page

I am working on an example project for learning purposes. I have successfully parsed a wordpress site by parsing RSS feed using NSXMLParser. The custom cell includes thumbnail, title, author and published date of posts.
Currently its showing the first page of feed containing 10 posts. I can access the second page of the feed http://sitename.com/feed/?paged=2 and and third page by putting /?paged=3, if i type them in the browser.
What i want to do is when user scrolls down to the bottom, it uses the second page feed url and show the posts at the bottom and so on. Can anyone guide me how to accomplish this task.
Coneybeare has the right idea on how to set it up.
Use AFNetworking, it'll make your life way easier.
I would have an int counter that keeps track of which URL has been last called. Then, as soon as the user gets to the bottom most cell (which you know via a delegate method), I would increase the int by 1, and then append that to the String that represents the URL. You can use the stringByAppendingString method for that.
Now you have a new String with the correct url, and you can fire off a new request, and append the data to what you already have. Then you can do [self.tableView reloadData] to refresh the table.
To make an infinite scroller, you need to know when to start fetching the new items. There are many ways to do this, but the best place is to hook into the UITableViewDelegate's methods. When cellForRowAtIndexPath: is called, check if the row is the last in your data store. If it is, make the call for the new data, then append it to the old data and refresh your view. You can also hook into the table views scroller to see when it it X percent scrolled to the bottom to make this call.

To know if its a new page in ITEXT pdf

I am generating a pdf using itext. So when the content of a page exceeds it creates a new page automatically. I am trying to know if it created a new page. If yes I want to add some image on top of the page.
List paylist =new List(List.ORDERED, List.ALPHABETICAL);
paylist.setIndentationLeft(10);
paylist.add(new ListItem("Some text", yourfont));
document.add(paylist);
The content of the list will be dynamic. So I am unable to find whether its a new page it is in the same page. Suggestion please..
Subclass PdfPageEventHelper and bind an instance of it to your PdfWriter:
writer.setPageEvent(new YourCustomPageEventHelper());
Within that class there's a method called onStartPage that will be called for every page in your document. Use this to add an image to every page, then you don't have to worry about keeping tracking of things. See this page for a bunch of samples.
Check the page number before and after you add content to the document. If the value is different, then a new page has been created.
The page number is returned by the PdfWriter.getPageNumber() method.

jQuery Show/Hide divs using same class not working because of html.push?

The object is to Show-Hide text located under their respective Titles, so a User reads the title and shows or hides text belonging to that title if the User wants to read more.
I tried whatever I could find so far on here, we're talking dynamically setting text coming from a spreadsheet, can't use IDs, must work with .class, must be missing something, I have this piece of code:
... html.push('<div class="comments">' + comment + '</div></div></div>');
but when I try this Show-Hide code nothing happens, even if the error console shows nothing. Basically I want to Show-Hide the .comments class divs with a show-hide toggle link located under each of them. I say them because the .comments divs are reproduced dynamically while extracting text coming from Google spreadsheet cells/row (one .comments div per spreadsheet row). I tried .next, child and parent but they all divorced me so I dunno looks like a dynamic issue. So far I only managed to globally toggle all divs to a visible or hidden state but I need to toggle independantly individual divs.
I prefer a jQuery solution but whatever worked so far was achieved with native javascript.
Note: If a cross-browser truncate function which would append a more-less link after a number of words (var) in each .comments divs would be easier to implement then I would gladly take that option. Thx for any help, remember I am still learning lol!
I have been working on an entirely JS UI project and have brought myself to using $('', { properties }).appendTo(BaseElement) to work best for adding HTML elements because it appropriately manipulates the DOM every time.
If you are having good luck with push elsewhere, however, breakpointing on the line where you do your $('.class').hide() and see what $('.class').length is. Alternately, you can just add alert($('.class').length) to your code if you are unable to breakpoint the code. If it is 0, then your elements have not been properly added to the DOM. Changing to append will ensure they are part of the DOM and therefore targetable via JQuery.

Creating reusable widgets

I`m using asp.net mvc 2.0 and trying to create reusable web site parts, that can be added at any page dynamically.
The problem I have is how to load a partial view with all related js and data? Ive tried the following ways to do that:
Use partial view and put all the js into it. In main view use render partial. But to initialize partial view I need to add model to current action method model to be able to make RenderPartial("MyPartialView", Model.PartialViewModel).
Also I do not have a place to put additional data I need to fill my form(like drop down lists values, some predefined values etc).
Use RenderAction, but it seems it have same problems as RenderPartial, except for I do not need to add anything to any other model.
Any other oprions are greatly appreciated.
As I understand it, RenderAction performs the full pipeline on the action, then renders the result - so what is rendered is the same as what you'd see if you'd browsed to the action.
I've used RenderAction to render 'widgets' throughout a site, but in my view they should be independent of the page rendering them, otherwise they're not really widgets and should be part of the rendering page's code instead. For instance, if there's a log in form, you will always take the user to a page that can process the information, no matter what page they are currently on, so this makes for a good widget. Other ways I've used it is to show a shopping basket or advertising. Neither of which are dependent on the page being shown.
Hope this helps a little!

Widgets inside Zend Framework - Where should they go?

I've been working with Zend Framework (using Doctrine as the ORM) for quite a while now, and done a few projects with it.
In a few upcoming projects I am requiring the need for widgets similar to how Wordpress does them. You have a post/page, which could look like:
Subscribe to my newsletter:
[subscribe/]
View my events
[events limit=5 sort=date/]
View this page's comments
[comments/]
Where say the subscribe widget would be replaced with Blog::subscribeWidget, and the events could be replaced with Events::eventsWidget, etc.
Now it has done my head in the past few weeks about how on earth do I do this??? I've come up with the following options:
I could place the widgets within controllers, and then call them like actions. Problem here is that code could be flying between controllers, and I have read this is expensive due to the amount of dispatches.
I could place the widgets as view helpers. So within the view I could have $this->renderPage($Page), which would then attend to all the widgets. Problem here is that what if the widgets need to do some business logic, like for example posting a new comment, that really shouldn't be within the view, should it?
The other option is to place widgets within the model? But then how on earth do they then render content for display?
Extra complications come when:
Say the comments widget would also handle posting, deleting of comments etc.
Say for the events listing, if I want to do an ajax request to the next page of events, using method #2 (view helpers) how would this work?
If I understand you correctly your widgets will need their own action controllers, which is where their logic for fetching data to be displayed, parsing form submissions, etc. should go. The difference between a widget and a page in this case is in how it's rendered, i.e. as an HTML fragment instead of as a whole page; you can use the Action View Helper to achieve this.
If your widget includes a form it should probably use AJAX to submit the form data back to the server, so that using the widget doesn't cause the user to accidentally navigate away from the page. You can inject the required JavaScript into the page you've included the widget into by using the Head Script Helper in your widget's view and/or action.
I left Richards reply, the problem, and further use cases cook in my brain for a while longer and ended up coming to a solution.
I will have the following view helpers and methods:
Content; with methods: render, renderWidgets, renderWidget, renderCommentsWidget (comments).
Event; with methods: renderEventsWidget (many events), renderEventWidget (one event)
Subscription; with methods: renderSubscribeWidget (subscription form).
I will have inside my configuration file:
app.widgets.comments.helper = content
app.widgets.subscribe.helper = subscription
app.widgets.events.helper = event
I will also have the following models:
Content for use for all pages.
Event for use for all events.
Subcriber for use for subscriptions to content
So inside my view I will do something like this:
echo $this->content()->render($this->Content)
Content::render() will then perform any content rendering and then perform rendering of the widgets by passing along to Content::renderWidgets(). Here we will use the configuration of app.widgets to link together the widget bbcode tag to it's appropriate view helper (using the naming convention 'render'.ucfirst($tag).'Widget'). So for example Content::renderCommentsWidget() would then proceed to render the comments.
Perhaps later on I will decide to have a Widget View Helper, and individual view helpers for each widget eg. ContentCommentsWidget View Helper. But for now that would just add additional unrequired complexity.
Now to answer the AJAX problem I mentioned. Say for the comments widget allowing for comments to be posted via ajax. It would simply have an appropriate method inside the Content Controller for it. So pretty much we also have a Event and Subscription controllers too - corresponding with the view helpers. Interaction between the view helper and controller will all be hard coded, there is no purpose for it to be soft coded.
I hope this helps someone else, and the current plan is to make the project where all this is used to be an open-source project. So maybe one day you can see it all in action.
Thanks.
Update:
You can find the source code of these ideas in action in the following repositories:
BalCMS - this is the actual CMS which contains the widgets in /application/modules/balcms/view/helpers and contains the configuration in /application/modules/config/application/balcms.yaml
BalPHP - this is the resource library which contains the widget view helper at /lib/Bal/View/Helper/Widget.php