A question about ajax function (passing a string parameter over)

[Vlad]

I have the following javascript in the view: 

            var id = $('#CurrentCartId').text();

            var description = $(this).text();

            var url='{{=URL('cart','description')}}';

            url += '/' + id + '/';

            url += description;

            ajax(url,[],':eval');

the reason I use url+= to pass parameters instead of using args in the URL helper is because the parameters are coming from the html itself - they are not known in the controller py. 

now the problem is that it changes the description and I have no way to recover its original value. for example, when description is "askjdf d   dka;lskdj  3838&^&%$#@ ((alksjdf__ - ))" (just a randomly typed string in this case), it comes out as "askjdf_d___dka_lskdj__3838_____". Obviously, it needs to do this conversion in order to pass  the parameter, but I need to be able to recreate the original string, entered by the user. 

Is there a better way of doing this? I.e. a better way of passing a parameter in  a way that it could be "recreated" and stored in the database exactly as typed by the user? 

[João Matos]

Have you considered base64 encoding/decoding?

[Vlad]

I had no clue about it - I mean never heard the terms :)

Thank you very much for point to the direction. After some googling, it is almost working. 

Encoding is just fine (using btoa). 

When I read it back and want to decode - it's not yet behaving right. I'm suspecting my javascript is a problem. 

There is a bunch of fields which now have encrypted values (class 'EncodedDescriptionField'), and I am trying to use the following to reclaim the original values: 

$(".EncodedDescriptionField").html(atob($(".EncodedDescriptionField").text()));

What am I doing wrong? (It doesn't change the values - they remain as they are, encrypted)

[Vlad]

Just to clarify: 

the following works perfect  for one field by ID (decrypts it back):

var encodedDescription = $("#CurrentCartDescription").text()

$("#CurrentCartDescription").html(atob(encodedDescription));

However, when I try to do it for a bunch of fields at once using class (instead of id), it doesn't work - doesn't touch the values: 

$(".EncodedDescriptionField").html(atob($(".EncodedDescriptionField").text()));

I am sure I am missing something basic... Greatly appreciate suggestions - 

[villas]

Maybe you need to iterate through the class elements.  See this:

https://stackoverflow.com/questions/4735342/jquery-to-loop-through-elements-with-the-same-class

[Vlad]

I thought so and tried: 

        $(".EncodedDescriptionField").each( function(index, element ){

             var hereWeAre = $(this).text();

             var decodedString = atob(hereWeAre);

             console.error(hereWeAre);

             console.error(decodedString);             

        });        

this brings up an exception: 

Uncaught DOMException: Failed to execute 'atob' on 'Window': The string to be decoded is not correctly encoded.

I've also double-checked the values - they are correct. For example, when I replace with the following: 

             var decodedString = atob("Q29va2llcyBvbmU=");

it decodes just fine, and the string itself I pick right from there - that's the value it has when it throws exception. 

Have no slightest clue what could possibly go wrong. 

[villas]

Hmm, not sure. 

Are you getting the values from <input> elements?

Try: 

var hereWeAre = $(this).val();

[Eliezer (Vlad) Tseytkin]

Those are span elements inside <td> inside<tr> in a table. 

But the values themselves are fine - I can print them out, and they are correct. It's only a problem when I try to apply btoa function to it. 

--
Resources:
- http://web2py.com
- http://web2py.com/book (Documentation)
- http://github.com/web2py/web2py (Source code)
- https://code.google.com/p/web2py/issues/list (Report Issues)
---
You received this message because you are subscribed to a topic in the Google Groups "web2py-users" group.
To unsubscribe from this topic, visit https://groups.google.com/d/topic/web2py/cyiquWAQU4w/unsubscribe.
To unsubscribe from this group and all its topics, send an email to web2py+un...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/web2py/a20934f0-54a3-4bd9-95ff-0d3b60cbcfa1%40googlegroups.com.
For more options, visit https://groups.google.com/d/optout.

[Eliezer (Vlad) Tseytkin]

Typo: I meant atob

[villas]

Make sure that your jQuery loading and browser up to date...

Simplify the page to something like below.  Get that working.  Add back your complexity afterwards:

<span class="EncodedDescriptionField">Q29va2llcyBvbmU=</span>

<script>

$(".EncodedDescriptionField").each( function(index, element ){
             var hereWeAre = $(this).text();

             alert(hereWeAre);
             var decodedString = atob(hereWeAre);
             console.log(decodedString);            
        });

</script>

Typo: I meant atob

To unsubscribe from this group and all its topics, send an email to web...@googlegroups.com.

[Anthony]

On Thursday, May 16, 2019 at 3:43:58 PM UTC-4, Vlad wrote:

I have the following javascript in the view: 

            var id = $('#CurrentCartId').text();

            var description = $(this).text();

            var url='{{=URL('cart','description')}}';

            url += '/' + id + '/';

            url += description;

            ajax(url,[],':eval');

How about putting the variables in the query string:

const id = $('#CurrentCartId').text();
const description = $(this).text();
const url='{{=URL('cart','description')}}';
ajax(`${url}?id=${encodeURIComponent(id)}&description=${encodeURIComponent(description)}`, [], ':eval');

Then in the controller, access request.vars.id and request.vars.description.

Anthony

[Vlad]

It works almost, but not 100% :) 

with encodeURIComponent :

abc def (test)

    comes back as

abc_def__test_

a;slkdjf;l -239i4-29i23la'skfj(()))9012?  <>,.  =

comes back as

a_slkdjf_l_-239i4-29i23la_skfj_____9012______.__=

This wouldn't help me, because I want it to be exactly whatever they enter - 

In contrast, atob and btoa work just perfect, except that in one particular situation is gets messed up by that exception... 

[Vlad]

I'll try to simplify it, hoping that I'll figure it out, but it's really very puzzling: 

this works perfect: 

        var encodedDescription = $("#CurrentCartDescription").text();

        $("#CurrentCartDescription").html(atob(encodedDescription));

it decodes it back just exactly from what it was encoded. 

However, the following is messed up: 

        $(".EncodedDescriptionField").each( function(index, element ){

             var hereWeAre = $(this).text();

             var decodedString = atob(hereWeAre);

             console.error(hereWeAre);

             console.error(decodedString);             

        });        

throws an exception, even for the same very value! 

Will simplify it all now, let's see what comes out...

[Anthony]

On Friday, May 17, 2019 at 12:20:37 PM UTC-4, Vlad wrote:

It works almost, but not 100% :) 

with encodeURIComponent :

abc def (test)

    comes back as

abc_def__test_

Please show your exact code. Doesn't sound like you are using the query string.

Anthony

[Eliezer (Vlad) Tseytkin]

Okay, I got it :)

Very embarrassing. There were some prior entries in the database that weren't converted to begin with, so when they were pulled over, the exception was raised. I totally forgot about them, and on top of that the one that caused the trouble was just one character different from the one I was testing against, with 49 characters being the same, so it was almost unnoticeable visually... 

I thought that the conversion malfunctioned, while in fact it simply pulled back something else, without me realizing what was going on...

I took a deep breath and patiently went through the whole thing step by step and, of course, found it. It's now just perfect. Ended up using atob and btoa. 

Just a quick question: are atob and btoa consistent and give the same results across browsers and operating systems? (If not, I'll use that uri thing, if that's hopefully consistent)

--

Resources:
- http://web2py.com
- http://web2py.com/book (Documentation)
- http://github.com/web2py/web2py (Source code)
- https://code.google.com/p/web2py/issues/list (Report Issues)
---
You received this message because you are subscribed to a topic in the Google Groups "web2py-users" group.
To unsubscribe from this topic, visit https://groups.google.com/d/topic/web2py/cyiquWAQU4w/unsubscribe.

To unsubscribe from this group and all its topics, send an email to web2py+un...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/web2py/d24a071c-77db-40f3-a991-17b0c2705e90%40googlegroups.com.

[Eliezer (Vlad) Tseytkin]

Also, I think it would be nice if URL helper would have ability to handle this, without a need to figure out the encoding/decoding subject... 

[Anthony]

On Friday, May 17, 2019 at 5:17:09 PM UTC-4, Vlad wrote:

Also, I think it would be nice if URL helper would have ability to handle this, without a need to figure out the encoding/decoding subject... 

You don't need the encoding -- just put the values in the query string.

Anthony

[Eliezer (Vlad) Tseytkin]

Here is a test I've just run: 

def test():

    url = URL('cart','test2',args=['a b c 1 3 2 $ % ( ) !'],vars={'oops':'1 3 5  a s i t ! @ #  $ %'})    

    redirect(url)

def test2():

    str1 = request.args[0]

    str2 = request.vars['oops']

    return locals()

Here is what it displays as a result: 

{{extend 'layout.html'}}

{{=str1}}

<br />

{{=str2}}

a_b_c_1_3_2__________ 
1 3 5 a s i t ! @ # $ % 

Obviously, this proves that you're right, and my mistake in the beginning was that I didn't try vars - I simply tried args, and saw right away that args distorts the string. I mistakenly assumed that vars works the same way - and didn't even try it. This is how I got into conversion business...  

Anyway, thank you very much for all your help and for patience! 

--

Resources:
- http://web2py.com
- http://web2py.com/book (Documentation)
- http://github.com/web2py/web2py (Source code)
- https://code.google.com/p/web2py/issues/list (Report Issues)
---
You received this message because you are subscribed to a topic in the Google Groups "web2py-users" group.
To unsubscribe from this topic, visit https://groups.google.com/d/topic/web2py/cyiquWAQU4w/unsubscribe.
To unsubscribe from this group and all its topics, send an email to web2py+un...@googlegroups.com.

To view this discussion on the web visit https://groups.google.com/d/msgid/web2py/e8fba811-0792-4789-b057-da6690053432%40googlegroups.com.

[Vlad]

Oops, I still don't know how to achieve it. Here is why: 

This is from the javascript code on the page: 

            var description = $(this).text();

            var url='{{=URL('cart','description'),args=[id],vars=[dict(description=description)]}}';

So, the variable description belongs to javascript, and it's presumably impossible to access it in {{...}} sections, unless I am missing something. Any code in {{...}} is executed and built on the server side, and then delivered to the browser, so while on the server, those javascript variables are inaccessible. OR is there a way to somehow access them???? 

Of this is this case, then I am stuck to having var url='{{=URL('cart','description')}} and then url += description, hence I now have to use encoding/decoding solution... 

Is there a way to solve this without encoding / decoding??? 

To unsubscribe from this group and all its topics, send an email to web2py+unsubscribe@googlegroups.com.

[Vlad]

Okay, done :) 

(Assuming that Python code in {{...}} can't access anything from Javascript on the page - and here encode URI came into play, as per your earlier advice)

            var id = $('#CurrentCartId').text();

            var description = $(this).text();

            var url='{{=URL('cart','description')}}';

            url += '/' + id + '/';

            url += "?description="+description;

            url=encodeURI(url);

            ajax(url,[],':eval');