ListGrid Date Sorting - RESTful Datasource

[acole]

Hello Support,

I am trying to recognize a date field properly within a ListGrid so that my users can sort against it. The data is delivered in XML via a RESTful data source. My first step was to just get the date rendering within the ListGrid and that is working fine. Now I am trying to recognize the dsGSADateModifiedField (see below) as a Date object and get it to sort properly within the ListGrid.

I have seen other forum questions about this topic, but I could not identify a fix to my specific use case. Could you share some advice?

Details Below:

SmartClient Version: SC_SNAPSHOT-2011-08-02/PowerEdition Deployment (built 2011-08-02)

XML Data Source Sample:

<record>
 <id>2</id>
 <gsa_date_modified>20-Nov-10</gsa_date_modified>
 ...
</record>

Code Snippets

    // Placed within onModuleLoad method.

    DateUtil.setDateParser(new DateParser()
    {
        public Date parse(String dateString)
        {
            final DateTimeFormat dateTimeFormat = DateTimeFormat.getFormat("dd-MMM-yy");
            return dateTimeFormat.parse(dateString);
        }
    });

    // Field definition for data source.

    DataSourceDateField dsGSADateModifiedField = new DataSourceDateField("gsa_date_modified", "GSA Date Modified");

    // Field definition for ListGrid

    ListGridField lgLastModifiedDateField = new ListGridField("gsa_date_modified", "Date", 75);
    lgLastModifiedDateField.setType(ListGridFieldType.DATE);

The dates are displayed within the ListGrid, but they do not sort properly. They appear to be recognized as Text fields.

Thanks for reviewing this.

[Isomorphic]

The problem is in your DataSource - the field is not declared as type "date" / "datetime" or the XML data does not have the date / datetime format (XML Schema format is expected, as explained in the docs).

[acole]

In the code snippet provided above, I defined the field for the restful data source as follows:

// Field definition for data source.

DataSourceDateField dsGSADateModifiedField = new DataSourceDateField("gsa_date_modified", "GSA Date Modified");

What more does the RestDataSource need to identify the field properly? Also, can you tell which document you are recommending that I re-read?

Thanks.

[Isomorphic]

Sorry, missed that line. The DataSource definition seems correct then (although you're only showing one line of it) so likely the format is wrong. This is covered in several places:

http://www.smartclient.com/smartgwtee/javadoc/com/smartgwt/client/types/FieldType.html#DATE
http://www.smartclient.com/smartgwtee/javadoc/com/smartgwt/client/docs/DateFormatAndStorage.html
http://www.smartclient.com/smartgwtee/javadoc/com/smartgwt/client/data/RestDataSource.html

[acole]

It is working properly now - thank you. I had read the document below in a prior release and did not realize it had been update with more information.

http://www.smartclient.com/smartgwtee/javadoc/com/smartgwt/client/data/RestDataSource.html

For those interested, I fixed my issues by correcting my web service so that it formatted all dates as "yyyy-MM-dd". This got the cell to recognize the field as a date and correctly sort the column.

Finally, I needed to just clean up the display format. To do that, I added the following logic to handle the formatting of the cell:

        lgLastModifiedDateField.setCellFormatter(new CellFormatter()
        {
            public String format(Object aValue, ListGridRecord aRecord, int aRowNum, int aColNum)
            {
                if (aValue instanceof Date)
                {
                    Date dateValue = (Date) aValue;
                    return DateTimeFormat.getFormat("dd-MMM-yy").format(dateValue);
                }
                else
                    return GWTStrUtl.EMTPY;
            }
        });

[Isomorphic]

A couple of further notes -

1. if you declare a field as type "date" and get the format wrong a ton of warnings are logged

2. you probably mean to apply that custom format system-wide, and if so, you can do so using APIs on DateUtil

[acole]

OK - I want to get this right for myself and anyone reading the post later.

Regarding:

1 - Since I control what the server sends, I can ensure the dates are formatted properly. Also, I checked the log and there were no parsing exceptions during my tests.

2 - If you look at my original post above you will see that I tried to use the DateUtil.setDateParser() method. Did I correctly implement it?

Thanks for the follow-up, I do appreciate it.

[Isomorphic]

1. they are not exceptions, they are logs

2. yes, your original code DateUtil code is fine if you want to change the date that *end users* input dates, system-wide. This does not affect data transmission. And again, in lieu of CellFormatter, you probably want to set system-wide formatting logic via DateUtil.