Share smartgwt js over several gwt modules

When you create smartgwt module you have the following lines in your *.gwt.xml file:

    ...
    <inherits name="com.smartgwt.SmartGwt"/>
    ...

Everything works fine. When you load your module at the first time, the browser gets all smartgwt js libs(ISC_*.js) and caches it. In our application we have got five gwt modules and all of them are using smartgwt. And when we load each module for the first time, it is getting 2 MB of js files. For our five modules browser downloads over 10 MB of smartclient libs. That's too much! To solve this problem I discover SmartGwt.gwt.xml. It inherits from module that called SmartClientDefault:

    <module>
        <script src="sc/modules/ISC_Core.js"/>
        <script src="sc/modules/ISC_Foundation.js"/>
        <script src="sc/modules/ISC_Containers.js"/>
        <script src="sc/modules/ISC_Grids.js"/>
        <script src="sc/modules/ISC_Forms.js"/>
        <script src="sc/modules/ISC_RichTextEditor.js"/>
        <script src="sc/modules/ISC_Calendar.js"/>
        <script src="sc/modules/ISC_DataBinding.js"/>
    </module>

And that's our problem. All js have relative paths. But Smartgwt has wonderful module that called SmartGwtNoScript that does not have a dependence on SmartClientDefault and we can include all scripts using absolute paths!
The solution is to replace inherits from com.smartgwt.SmartGwt by the following code in all modules that need smartgwt(or create one root module):

    <inherits name="com.smartgwt.SmartGwtNoScript"/>
    <script src="/mod/sc/modules/ISC_Core.js"/>
    <script src="/mod/sc/modules/ISC_Foundation.js"/>
    <script src="/mod/sc/modules/ISC_Containers.js"/>
    <script src="/mod/sc/modules/ISC_Grids.js"/>
    <script src="/mod/sc/modules/ISC_Forms.js"/>
    <script src="/mod/sc/modules/ISC_RichTextEditor.js"/>
    <script src="/mod/sc/modules/ISC_Calendar.js"/>
    <script src="/mod/sc/modules/ISC_DataBinding.js"/>

Simplify if

From time to time we write unoptimized code. For program to be cute it is fun to be optimized.
For example this is a possible way to write if sequence:

if (p.equals("Completed")){
   return true;
} else {
   return false;
}

But to be optimized the method body should look like this:

return "Completed".equals(p);

What's really interesting is that it's not only looking good. Indeed it helps you to evade null pointer exception in case when p equals null. We are not able to call method from null - it'll throw exception, but when using equals() method this would be processed correctly.

To study this in depth we can explore StringUtils.java (the one that is in org.apache.commons.lang package).

public static boolean equals(String str1, String str2) {
   return str1 == null ? str2 == null : str1.equals(str2);
}

Lets look at the method in JAVA source code and the values it may return:

StringUtils.equals(null, null) = true
StringUtils.equals(null, "abc") = false
StringUtils.equals("abc", null) = false
StringUtils.equals("abc", "abc") = true
StringUtils.equals("abc", "ABC") = false

It returns true in case of equality. So, we can use this or the same logic to write our optimized pieces of code.

Have fun, optimize :)

Height for DateChooser (Smart GWT)

In our project we are using Smart GWT component (DateChooser) which allows user to select dates ranges. It looks like this:
.

Smart GWT has a bunch of useful things (datasources, for example). But when I need some UI customization, sometimes I am having troubles :) And now I've got problems with height of the DateChooser component.

Both date choosers have height 200 px, but the right one is smaller then the left because it has only five week rows. Our tester is very carping guy :) though he had posted a bug in the bug tracker. I had spent some time and found a solution. All that I needed was to wrap DateChooser in a layout. I wrote simple helper method for doing this:

    public static Canvas wrapDateChooser(DateChooser dateChooser, String width, String height) {
        VLayout layout = new VLayout();
        layout.addMember(dateChooser);
        layout.setWidth(width);
        layout.setHeight(height);
        dateChooser.setHeight(height);
        return layout;
    }

Result:


Go and close bug in JIRA, YEAH!