cslaDataSource and resusable namevaluelist

This is automatic. When you interact with objects all the interaction occurs in memory. Only when you call Save() on the root object does any (and all) database interaction occur, and that does typically occur in a transaction.

Rocky

Hi Rocky,

Currently i am working with an object say Invoice(editable root) and invoice line items (editable child objects) .
what i am trying to achive is . no database trasanction should be there until and unless the user finally push the saves button and the whole object should be saved on in 1 fly by a single querry .

to be more elaborative what i am trying is .
1. user makes entries for invoice header .
2. and starts entring the invoice line items by a ui which do have a add button and the line items are displayed in a grid , with edit and delete things .
3. as the user pushes add button the line items collections will have that item added to them , but will not have them in the databse coz no db thing should b done .
4. after completing all ,he finally saves the object and it is saved by 1 db transacton only .


what i am stucked with how to maintain the iinvoicelineitems on the fly ......


thanks
govind



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No, when the Assign button is clicked the new item is added to the child collection in memory. It does not go to the database until Save() is called on the root object (Project or Resource).

In PTWeb the Save() method is called on each page request (more or less) and so the database is immediately updated. This is because most web users don’t expect to have to click a save button at the end, they expect things to save all the time.

But in PTWin and PTWpf the Save() method is only called when the save or apply buttons are clicked. This is because most rich client users don’t expect to have things saved automatically, and only want them saved when they say so.

Rocky

Hi Rocky,

I dint get it exactly ,
mean when the line items add button will raise event it  will call the editablechildlist object for line itmes add method and that will add them up into the line item collection , but that should happen on in memory instead going to do the insert in lineitems table and then again refetching them .

this is being done in projecttracker refrence application .

thanks
govind

As I said, PTWeb doesn’t work this way. Web users don’t typically expect a “form level” save button. The web is (usually) stateless, and so data must be saved on every postback.

If you want to provide a “form level” save button in your web app, you can certainly do so. Just keep the business object in Session and manipulate it there. Then only call Save() on the root object when the user clicks the save button.

If you do that, I strongly recommend using a bit of javascript to prevent the user from navigating away from the page prior to clicking save. You can’t really prevent them from leaving without saving, but you can give them a dialog where they have to click OK to leave without saving.

Rocky

In that case you missed the bit in Chapter 7 about overriding IsValid and IsDirty in a parent object. That is required, so the parent’s state is affected by the state of its children.

Rocky

Hello rocky ,

Ok i do saved the object in the session and had implemented the same .
when the user is in entry mode the object is new hence its saved completely.
and on add(assign) button the child gridview is again databinded so the changes are on screen with the postback .

but now coming in the update mode . the user do manipulations with the invoicelineitems and then presses save(form level save) and root objects save button is called . but here the root is not dirty so the child is also not save inspite of the fact it is dirty. not able to come out of this looop....



thanks
govind