Effective Xpages development or how to use OpenNTF

 Hello, from my last blog post you can deduce, that my current work occupation has changed a bit. The truth is, that currently I am participating on development of controls for Xpages. Xpages is IBM technology for very rapid web development and it shares pretty much ideology of everything server side. So is you are REST based person, this wont be for you. But still you can use REST inside Xpages, so its not so much separated. Not just REST but support for many other things can be found inside Xpages. There are some basic components in core of Xpages, but if you would like to do sth. more with it, I strongly recommend to use Xpages Extension Library. 

It can be found here and everything you will need is Eclipse, IBM Domino server, Lotus notes client and SVN client. Currently there is few project running simultaneously under name of extension library. It is:connections, domino, features, group, mobile, oneui and sametime. I am currently working on mobile components, so in the future, there could be even more mobile support for Xpages. Even now you can build nice native looking application in xpages, with ability to assign custom skins to it, so it can have different look on android iphone or any other device.

I also recommend to take a look on examples, which can be found in XPagesExt.nsf. Dont be fooled by welcome screen. There is much more of examples, you just need to use specific path to .xsp file to access them. For example myserver.com/XPagesExt.nsf/Mobile_Test.xsp , which will give you demo of currently existing mobile components.

Also notice, that OpenNTF connections gives you nice ability to integrate your Xpages application with your IBM Connections. Fortunately connections features REST API so you can connect with it almost from anywhere. This allows you to automatically post things on your profile wall or create/delete communities, activities or anything you want. Also there is great search API which could be really handy.

OpenNTF become in last years for IBM and Xpages one of the main deployment platforms especially because of the ability to deploy immediately without big testing effort (off course testing is done, but not in such a big scale). It is really great to see IBM to give out sth. free and open, hopefully this will last for longer. 

But OpenNTF is not just about Xpages and extension library, you can find there many more usefull IBM stuff, for example Lotus Quickr widgets, which are also some, on which I have been working on. So enjoy OpenNTF and if you have some time, send a nice mail to those folks for all the great work they are doing, why deserve it. Also it can persuade IBM about meaningfulness of this effort.

Drag and Drop in HTML5 and File Input. They have sth. wrong.

Hello everyone. At first, let me please say little background about recent events in my life, if you are interested only in technical stuff, skip this paragraph. Be unpredictable events it happens, that I am currently working on front-end of one web application for big big company. My role in team is not big, but I like my work and now I actually work on something pretty interesting. It is only 3 days what I am working with Dojo, Ajax, so please be patient with me. But as you can see I learn fast :-).

Let`s say something, what we would like to do today. As Google has started its Drag and Drop for Gmail, everyone wants to have one like that. So my BigB company has asked me to do also one like that for them. This is what I am working on in combination of Dojo, Ajax, HTML5 and classic HTML. Our task is like this: You have some form, there is some default behavior on this form and you would like to keep it, but also add some other. Thing are now like this, we have DOJO Fileinput and user can select there files and after submit of form they get uploaded on page. Now we would like to sth. like this. After dragging files on special div, we would like to add new Fileinput fields with those files in it. So no XHR request or sth. like this what is commonly used for uploading, we have to rely on script, which is processing form now and of course we can not touch him. So how to do this? There is a lot of limitations.

First of all, get working Drag and Drop, what is pretty simply task and even withou no knowledge of DOM or Ajax you can do it, I was able to do it, so you have to do it also. Follow this examples:

http://html5doctor.com/native-drag-and-drop/

http://www.appelsiini.net/2009/10/html5-drag-and-drop-multiple-file-upload

Get here until phase you would have access to you dataTransfer object. Now it is going to be little more complicated. First of all we need to put files to . To do this will help of new property of input DOM object and it is files. API is described here: http://help.dottoro.com/ljwjmspm.php. It is an Filelist object, and there are some problems with it, which I will mention later. Ok now, we have the files there and we would like also show names of files to user. This really could be problem with classic input, because value property is read only for security reasons, which are pretty clear. Using it could anyone download any file from your computer. So what to do now? Because we are using DOJO, there is one big advantage. DOJO Fileinput is little bit hack, and what you see is actually not an real file input, it is just text input and button, inside an file input. I know it sounds strange, but try to take a look on code in DOJO and you will get it fast. So now we just get this text input and we put there our file.name, great. We submit form, hoping that everything will go ok, and... PROBLEM!

Files added by user are uploaded without a problem, but files added to input programmatically are not submitted, so where the problem is? Could it be even done? So let`s take a look on documentation of Filelist, let`s play little bit with debuger and after a while we could find out, that our files property of input is allways 0?!?!. And this is pretty a problem in implementation of Filelist. Because, yes, you can access files with operator [], and this operator even accepts file to write into files, but it does not increase its length :-(. So on submit is nothing submitted. And what is worse, it is read only property, and there is no way how to change it. Just look on previous link.

This is pretty serious issue, and I hope, that in future implementations it will change, I would even report it to someone, if I would know to who. I can imagine, that there will arise a lot of more security and other issues, with allowing this property not to be read only, or by letting operator [] to set length. Other solution is to make operator [] able only to read, not write, but I believe, this would be step back. It is really nice help for developers. Especially, when you want to use file from other sources (DND, Web...). So how now solve this problem? On monday I am going try to write my own XHR request and override submit function, which is sending form. Will see, if it could be done, more info in part 2.

I hope, I have helped you at least a little bit. Have a nice day.