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**Isomorphic** · 12 Nov 2010, 15:11

Stop at #1 - that's not normal and suggests bad settings. You may have set saveByCell:true (causing updates on every cell change) while also setting validateByCell:true?

If you only want to save on row change (the default) set both to false.

**nikolayo** · 12 Nov 2010, 22:35

I probably did not explain this clearly enough. Submission to the server does not happen upon individual cell changes but when I finish editing a row.

**nikolayo** · 12 Nov 2010, 23:16

P.S.: I added just in case setSaveByCell(false) and setValidateByCell(false) and nothing changed. Here is all my grid initialization code :

Code:

        final ListGrid detailGrid = new ListGrid();
        detailGrid.setWidth100();
        detailGrid.setHeight(224);
        detailGrid.setCellHeight(22);
        detailGrid.setShowRowNumbers(true);
        detailGrid.setCanEdit(detailPermissions.isUpdateAllowed());
        detailGrid.setLayoutAlign(Alignment.CENTER);
        detailGrid.setAutoSaveEdits(true);
        detailGrid.setConfirmDiscardEdits(true);
        detailGrid.setConfirmCancelEditing(true);
        detailGrid.setSaveByCell(false);
        detailGrid.setValidateByCell(false);
        detailGrid.setDataSource(detailSource);

**nikolayo** · 15 Nov 2010, 01:21

P.S.S.: I worked out a way to avoid pulling unchanged fields from the database. I do that by forcing within a custom data source full update like this:

Code:

        Map newValues = req.getValues();
        Map oldValues = req.getOldValues();
        Set oldKeys = oldValues.keySet();
        for (Object key : oldKeys) {
            if (newValues.get(key) == null) {
                newValues.put(key, oldValues.get(key));
            }
        }

This solves my most annoying problem but the solution is still suboptimal. And there is still redundancy in the requests (validation request(s) followed unconditionally by create/update which trigger validation again).

**Isomorphic** · 15 Nov 2010, 11:19

It's not normal, even with those settings, to see a request for validation followed by a separate request for save. The code you've posted, if added to a sample, will not reproduce the problem. Let us know if you can modify a sample to reproduce the problem.

**nikolayo** · 15 Nov 2010, 12:27

Thank you. It is good to know that redundant validation requests are not an expected behavior. What I noticed for now is that they only happen with grids which are brought up as an expansion component of another grid. Will be digging further...

Any hints on the issue of access to values of unchanged fields in validators upon update? As I wrote, I in a way solve it but now I have problems with built-in "isRequired" validators. Apparently they do not buy updates of correspondent fields even if the value is not really changed.

**nikolayo** · 15 Nov 2010, 12:29

P.S. : Very sorry about the typo. I meant "usUnique" validators.

**Isomorphic** · 15 Nov 2010, 12:36

Having trouble following what you mean about unchanged values and required validators - can you rephrase?

**nikolayo** · 15 Nov 2010, 12:41

Sure. Upon update operation server side validator gets a "Map record" argument which contains the primary key and the changed values but does not contain the values which were not changed and need not be updated. The problem with this is that I may need to compare a changed value with a value which was not change in order to validate the changed value.

**nikolayo** · 15 Nov 2010, 18:19

I found out that apparently redundant validation requests to the server are issued by the client whenever there is a server-side validator (be it built-in or serverCustom) defined for a field and the value of that field has been changed during the editing of a grid record. This also applies to creation of new records. My previous observation re extension objects turned out to be irrelevant.

To reproduce this it is sufficient to put on an arbitrary field e.g. the following validator (other validator types work as well) :

Code:

            <validators>
                <validator type="isUnique"/>
            </validators>

Then change the value of the field in a grid record and finish editing. Or/and create a new record.

**nikolayo** · 15 Nov 2010, 23:03

Sorry about discussing 2 distinct issues at the same time but let me just in case and in addition to the post above summarize also the second issue under discussion so it does not get lost:

Server side custom vaidator method has generally the following signature:

Code:

    public boolean condition(Object value, Validator validator,
                             String fieldName, Map record)
    // Optional arguments:
    //
    // DataSource          dataSource,
    // RequestContext      requestContext,
    // HttpServletRequest  httpServletRequest,
    // HttpServletResponse servletResponse,
    // ServletContext      servletContext,
    // HttpSession         httpSession
    // RPCManager          rpcManager

The value to be validated is in the "value" argument. In order to do the validation I may need to compare it to the value of another field. The natural place to look for that second field is the "record" argument. Upon an update operation though "record" contains only fields whose value has changed. So how do I get access to the field I need if it's value has not changed?

This problem applies also to validation by velocity expressions because I observe exceptions in such validators under similar conditions. For example the following validator:

Code:

<field 
	name="END_DATE" 
	type="date">
	<validators>
		<validator
		type="serverCustom"
		errorMessage="End date must be after start date!"
		serverCondition="$value.after($record.START_DATE)"/>
	</validators>
</field>

throws an exception upon update operation if the value of the value of START_DATE was not changed.

Regards
Nikolay

**nikolayo** · 17 Nov 2010, 04:17

Any advice on this?

Regards
Nikolay

**Isomorphic** · 17 Nov 2010, 13:40

dsRequest.oldValues is sent from the client, hence it is spoofable - it is intended for the scenario of checking whether there have been concurrent edits when the user has the ability to proceed with the save anyway.

For a data validity or security check, you want to get the latest values from the database, which is secure. These two samples show doing a related DSRequest in the context of server-side validation.

On your issue with extra requests - can you actually take that isUnique validator and add it to a sample that comes with the SDK and reproduce the issue you're talking about? Because a lot of other settings could be involved here - the clearest thing would be if this can be reproduced in a sample.

**nikolayo** · 17 Nov 2010, 15:12

Thank you, Isomorphic. I recognize the validity of your position even though I do not share it. I deal with concurrency by automated optimistic locking implemented in a custom data source and if I can not trust the values from the client for some other reason, I will rather not allow updates all.

There are of course workarounds which bypass this design and so far I think I will be using some but I will also give that a second thought based on your concerns.

On the issue of redundant validate requests, here is a modified worldDS,ds.xml from the EE showcase :

Code:

<DataSource
    ID="worldDS"
    serverType="sql"
    tableName="worldDS"
    testFileName="/ds/test_data/world.data.xml"
>
    <fields>
        <field name="pk"            type="sequence"   hidden="true"            primaryKey="true" />
        <field name="countryCode"   type="text"       title="Code"             required="true"   />
        <field name="countryName"   type="text"       title="Country"          required="true"   />
        <field name="capital"       type="text"       title="Capital"          >
		<validators>
			<validator type="isUnique"/>
		</validators>
        </field>
        <field name="government"    type="text"       title="Government"       length="500"      />
        <field name="continent"     type="text"       title="Continent"        >
            <valueMap>
                <value>Europe</value>
                <value>Asia</value>
                <value>North America</value>
                <value>Australia/Oceania</value>
                <value>South America</value>
                <value>Africa</value>
            </valueMap>
        </field>
        <field name="independence"  type="date"       title="Nationhood"          />
        <field name="area"          type="float"      title="Area (km&amp;sup2;)" />
        <field name="population"    type="integer"    title="Population"          />
        <field name="gdp"           type="float"      title="GDP ($M)"            />
    </fields>
</DataSource>

With this data source and no modifications to code I changed the capital of Bermuda through the "Basic Connector" example. Here are the payloads of the requests that I observed in a Tomcat log (it seems the forum does not like catalina.out format, so I can not provide the complete log) :

Code:

{
    values:{
        countryName:"Bermuda",
        area:50,
        gdp:1700,
        continent:"North America",
        countryCode:"BD",
        independence:new Date(1225670400000),
        government:"dependent territory of the UK",
        capital:"Whatever",
        population:62099,
        pk:0,
        _selection_5:true
    },
    operationConfig:{
        dataSource:"worldDS",
        operationType:"validate"
    },
    validationMode:"partial",
    appID:"builtinApplication",
    operation:"worldDS_validate",
    oldValues:{
        countryName:"Bermuda",
        area:50,
        gdp:1700,
        continent:"North America",
        countryCode:"BD",
        independence:new Date(1225670400000),
        government:"dependent territory of the UK",
        capital:"Whatever",
        population:62099,
        pk:0,
        _selection_5:true
    },
    criteria:{
    }
}

{
    criteria:{
        pk:0
    },
    values:{
        pk:0,
        capital:"Whatever"
    },
    operationConfig:{
        dataSource:"worldDS",
        operationType:"update"
    },
    componentId:"isc_ListGrid_0",
    appID:"builtinApplication",
    operation:"worldDS_update",
    oldValues:{
        countryName:"Bermuda",
        area:50,
        gdp:1700,
        continent:"North America",
        countryCode:"BD",
        independence:new Date(1225670400000),
        government:"dependent territory of the UK",
        capital:"Hamilton",
        population:62099,
        pk:0
    }
}

Regards
Nikolay

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Strange behavior of server side validation

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