Asp Forum - Javascript Promises not executing correctly

José Luis Gallego

11/23/2014 7:36:00 PM

Hello,

I have already asked for support on this issue on stackoverflow. You may see the long question here:

http://stackoverflow.com/questions/26994436/javascript-promises-not-executing-correctly-two-objects-in-jquery-tm...

I have a problem with promises (who doesn't). It looks like two deferred functions are messing up the timing and executing asynchronously although they look like they should execute synchronously. I'll expose the code here.

Function getTariffByProductItem:

getTariffByProductItem: function(productItemId) {
// Return Array of tariffs
var def = new $.Deferred();
var tariffs = [];
db.transaction(function(tx) {
tx.executeSql('select pric.pric_cd_pricing, pric.pric_ds_pricing ' +
'from tga_pricings pric ' +
'where date(\'now\') <= pric.pric_dt_valid_to ' +
'and date(\'now\') >= pric.pric_dt_valid_from ' +
'and pric.pric_cd_product_item = ?',
[productItemId],
function(tx,dbResult) {
if(dbResult.rows.length) {
for(var i = 0; i < dbResult.rows.length; i++) {
tariffs.push(
{
cdPricing: dbResult.rows.item(i).pric_cd_pricing,
dsPricing: dbResult.rows.item(i).pric_ds_pricing
}
);
}
def.resolve(tariffs);
}
});
}
, function(e) {
alert("There has been an error: " + e.message);
def.reject();
});

return def.promise();
}

Function editBookPaxBuyPrepare:

editBookPaxBuyPrepare: function(productId) {
var def = new $.Deferred();
var bookingId = $( '#edit-book-pax-pricing-form' ).data('bookid');
var paxId = $( '#edit-book-pax-pricing-form' ).data('paxid');
var productItems = [];

// Check for actual data
db.transaction(function(tx) {
// Get product items for product
tx.executeSql('select prit.prit_cd_item, prit.prit_st_name ' +
'from tga_products_catalog prod ' +
'inner join tga_product_items prit ' +
'on prit.prit_cd_product = prod.prod_cd_product ' +
'where prod.prod_cd_product = ?',
[ productId ],
function(tx, dbResult) {
if(dbResult.rows.length) {
// Set form action to EDIT
$('#edit-book-pax-buy-form').data('formaction', 'edit');
// Set product name label
$('#edit-book-pax-buy-product').text(dbResult.rows.item(0).prod_ds_product);
for(var i=0; i<dbResult.rows.length; i++) {
// For each producItem get tariffs
var dbRow = dbResult.rows.item(i);
var data = [];

$.when(bookings.getTariffByProductItem(dbRow.prit_cd_item))
.then(function(data) {
console.log("Product Item: " + dbRow.prit_st_name + " - tariffsArray: " + JSON.stringify(data));
productItems.push({ "row": dbRow, "tariffs": data });
});
}
def.resolve(productItems);
}
});

},
function(e) {
def.reject(e);
});
return def.promise();
}

Main code calling both above functions:

var listFieldset = $( '#edit-book-pax-buy-form-product-items-list' );
listFieldset.empty();
$.when(bookings.editBookPaxBuyPrepare(productId))
..done(function(productItems) {
console.log(JSON.stringify(productItems));
$( "#edit-book-pax-buy-product-item" ).tmpl( productItems ).appendTo( listFieldset );
listFieldset.trigger('create');
listFieldset.listview('refresh');
});

The log I get:

bookings.js:738 []
2014-11-23 20:03:06.151bookings.js:566 Product Item: 1105 - Local guide - tariffsArray: [{"cdPricing":7,"dsPricing":"Operator tariff"}]
2014-11-23 20:03:06.155bookings.js:566 Product Item: 1105 - Local guide - tariffsArray: [{"cdPricing":14,"dsPricing":"Operator tariff"}]
2014-11-23 20:03:06.159bookings.js:566 Product Item: 1105 - Local guide - tariffsArray: [{"cdPricing":15,"dsPricing":"Operator tariff"}]
2014-11-23 20:03:06.163bookings.js:566 Product Item: 1105 - Local guide - tariffsArray: [{"cdPricing":16,"dsPricing":"Operator tariff"}]

As you can see, "console.log(JSON.stringify(productItems));" is executed BEFORE the console.log line in the loop inside editBookPaxBuyPrepare function.. The expected behaviour is the other way round: wait until editBookPaxBuyPrepare finishes and then log the contents of the returndes array in the promise.

Any help is welcome!

Thanks.

3 Answers

James

12/20/2010 6:33:00 PM

On Dec 20, 10:32 am, nepinplayer <robski...@gmail.com> wrote:
> On Dec 20, 1:00 pm, James - ShacklersRevenge <thebeatles1...@aol.com>
> wrote:
>
> > On Dec 20, 9:28 am, Eric Bundy <eabu...@gmail.com> wrote:
>
> > > I have the ability to buy one or both of these, but was wondering what
> > > prices people think they are worth.
>
> > > Phantom cabinet and Glass are in very good condition, but playfield
> > > has wear at the lower middle ball drain below the flippers.
>
> > > Banzai Run is dirty and needs a full shop, but is in good playable
> > > condition. No wear and nice cabinet / glass.
>
> > Wonder if that's the same BR I'm suppose to be picking up? Hmmm
>
> > James
>
> James ,you mean this one?http://nh.craigslist.org/tag/21177...

bingo!

caver

12/20/2010 8:49:00 PM

On Dec 20, 1:32 pm, James - ShacklersRevenge <thebeatles1...@aol.com>
wrote:
> On Dec 20, 10:32 am, nepinplayer <robski...@gmail.com> wrote:
>
>
>
>
>
>
>
>
>
> > On Dec 20, 1:00 pm, James - ShacklersRevenge <thebeatles1...@aol.com>
> > wrote:
>
> > > On Dec 20, 9:28 am, Eric Bundy <eabu...@gmail.com> wrote:
>
> > > > I have the ability to buy one or both of these, but was wondering what
> > > > prices people think they are worth.
>
> > > > Phantom cabinet and Glass are in very good condition, but playfield
> > > > has wear at the lower middle ball drain below the flippers.
>
> > > > Banzai Run is dirty and needs a full shop, but is in good playable
> > > > condition. No wear and nice cabinet / glass.
>
> > > Wonder if that's the same BR I'm suppose to be picking up? Hmmm
>
> > > James
>
> > James ,you mean this one?http://nh.craigslist.org/tag/21177...
>
> bingo!

well whoever gets it, that price is not totally out of line.....
Pinball Eric's price is $1650 for 'good' condition, don't judge simply
by the high prices we see on Ebay these days.

Thomas 'PointedEars' Lahn

11/24/2014 12:49:00 AM

JosÃ© Luis Gallego wrote:

> I have already asked for support on this issue on stackoverflow. You may
> see the long question here:
>
> http://stackoverflow.com/questions/26994436/javascript-promises-not-executing-correctly-two-objects-in-jquery-tm...

Short answer: Do your homework. That you did not is most certainly the main
reason why there are no answers at StackOverflow even after 5 days (for a
smart question, you usually get there several good answers within 5
*minutes*). â??Volume is not precision.â?

BTW: There are no "Javascript Promises", not least because there is no
"Javascript" (see sig).

You have not even said which third-party code you are using; only a sharp
look at the unnecessarily long URI (there is a â??shareâ? link below your
StackOverflow question), or using the URI (which constitutes a media break;
this is Usenet, not the Web forum that Google Groups suggests to you),
reveals that you are using jQuery. This is not the jQuery support forum
either.

> Any help is welcome!

<http://www.catb.org/~esr/faqs/smart-question..., see also the FAQ.

--
PointedEars
FAQ: <http://PointedEars.... | SVN: <http://PointedEars.de...
Twitter: @PointedEars2 | ES Matrix: <http://PointedEars.de/es-...
Please do not cc me. / Bitte keine Kopien per E-Mail.

comp.lang.javascript

Javascript Promises not executing correctly

José Luis Gallego

James

caver

Thomas 'PointedEars' Lahn

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