Re: pre-save and check for existing value of image

[ankit rai]

you self.instance.fieldname use this ur from .

On Tue, Nov 10, 2009 at 12:58 PM, Ramdas S  wrote:

> Hi,
>
> I have this app which has an ImageField, where the image needs to be
> cropped, resized, and a few effects (all from PIL) are applied on it, the
> model looks something like this
>
> class MidPanel(models.Model):
> 
>.
>image = models.ImageField(upload_to="images"):
>
>def save(self):
>  
> if self.image:
>dosomething(self.image)
>
>
> Everything is fine, expect that every time someone makes a change to a
> field in the model, the images gets manipulated. The image manipulation is
> supposed to happen only once.
>
> What I want is somehow to apply the cmanipulation  on self.image only if
> the image is changed, or its been created... Is pre_seave the right way, if
> so how do you actually use it where it need to compare previosly stored data
> and the newone and then only execute.
>
> Ramdas
>
>
>
> --
> Ramdas S
> +91 9342 583 065
>
>
> >
>

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pre-save and check for existing value of image

[Ramdas S]

Hi,

I have this app which has an ImageField, where the image needs to be
cropped, resized, and a few effects (all from PIL) are applied on it, the
model looks something like this

class MidPanel(models.Model):

   .
   image = models.ImageField(upload_to="images"):

   def save(self):
 
if self.image:
   dosomething(self.image)


Everything is fine, expect that every time someone makes a change to a field
in the model, the images gets manipulated. The image manipulation is
supposed to happen only once.

What I want is somehow to apply the cmanipulation  on self.image only if the
image is changed, or its been created... Is pre_seave the right way, if so
how do you actually use it where it need to compare previosly stored data
and the newone and then only execute.

Ramdas



-- 
Ramdas S
+91 9342 583 065

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Re: pre-save and check for existing value of image

[ankit rai]

You can check whether there is instance or not by self.instance .This will
tell u that whether it is change (page)or a new object is added.And if it
new object then only call ur custom functions.U can also use changeForm
function

On Tue, Nov 10, 2009 at 12:39 PM, Ramdas S  wrote:

> Hi,
>
> I have this app which has an ImageField, where the image needs to be
> cropped, resized, and a few effects (all from PIL) are applied on it, the
> model looks something like this
>
> class MidPanel(models.Model):
> 
>.
>image = models.ImageField(upload_to="imgs")
>
>   def save(self):
>if self.image:
>  dosomething(image)
>  doanother2(self.image)
>
>
> All this is fine. Expect that every time the model is saved, it executes
> the manipulation on the image. What I require is an idea where the image
> manipulation happens only if the image field is changed, and not unless. How
> do I achieve that.
>
> Someone suggested me to use pre_vae signal, but I am not able to figure an
> effcient way..
>
> Can someone help
>
> --
> Ramdas S
> +91 9342 583 065
>
>
> >
>

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pre-save and check for existing value of image

[Ramdas S]

Hi,

I have this app which has an ImageField, where the image needs to be
cropped, resized, and a few effects (all from PIL) are applied on it, the
model looks something like this

class MidPanel(models.Model):

   .
   image = models.ImageField(upload_to="imgs")

  def save(self):
   if self.image:
 dosomething(image)
 doanother2(self.image)


All this is fine. Expect that every time the model is saved, it executes the
manipulation on the image. What I require is an idea where the image
manipulation happens only if the image field is changed, and not unless. How
do I achieve that.

Someone suggested me to use pre_vae signal, but I am not able to figure an
effcient way..

Can someone help

-- 
Ramdas S
+91 9342 583 065

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