Develop Reference

How can I suppress 404 error when a file is not found?

I have a list of webpages example.com/object/140, example.com/object/141, example.com/object/142, ...
and each page should have a particular background image example.com/assets/images/object/140.jpg, example.com/assets/images/object/141.jpg, ...
Some images are missing and then I use a default image. In that case, when I check if the image exists, I get a 404 error. I have already seen in several pages there isn't a direct way to avoid this problem.
Then I did the following: I created a service in the backend (C#) that checks if the file exists File.Exists(fileName);. That way I managed to avoid this error in my localhost. So far so good.
Now I published both my frontend and backend in two different services in Azure. The images are in the frontend but the file service is in the backend. My method does not work anymore because I can't access directly the frontend folders from the backend. One solution could be to make an http call from the backend to the frontend, but I think this doesn't make much sense, it's getting too messy.
One option could be to store in the DB a boolean with the (non)existence information, but I think this is prone to inconsistencies (if the boolean is not updated immediately when a new image is loaded or deleted, for example), even if I run a daily job to clean it.
Still another option could be to store the images directly in the DB and retrieve them together with the DTOs of the objects I'm loading in each particular page, but I guess that images that are shown only in the frondend should be stored in the frontend... shouldn't they?
Therefore:
a) Is any of these ideas acceptable? Is there a better way to avoid this error?
b) Another possibility: is there a way to access the frontend folders from the backend? I get a bit lost with the publishing and artifacts in Azure and I don't know if I could do it somehow.

I'm not sure how you've built the frontend, but I'm assuming that the background images are set using CSS. It is possible to set multiple background images in the same rule, and the browser will load them all and display them one below the other - if the first one loads successfully, and isn't transparent, then that is the only thing the user will see. But if the first image fails to load - for example because it doesn't exist, the second image will be shown.
See this other answer for more details: https://stackoverflow.com/a/22287702/53538

About Google Analytics collect data

First of all, Hi to all of you (I'm new here).
I'm having a look on how Google Analytics works as I'm gonna develop a similar tracking js to collect all the data I need for my websites and, as far as I can see, the ga.js script send all the data (maybe not all but a good part of it) with a get request with a 1x1 gif and all the parameters following.
Seen here: How does google analytics collect its data?
So, on the server side It seems the only way to "read" all these parameters is going to analyze server logging and then collect everything on my database?
Is this the best option to get users data?
I think, server logging could "switch file" every 2 hours so you can analyze that file of the past 2 hours and show "not that old" data to your graph!
Of course will never be "realtime" graph but a 2 hours delay could be acceptable, I think.

I think you can simply put a script (PHP for example) at the image path, then through the script return as a response the image, by doing this you can act in real time, since using a script you can get all the data that would be present in your server log.
If you want to try my solution I think a good point to start (in PHP) would be this to create the GIF image and then you can use data located in $_SERVER to start gathering data!

How to display image object using Javascript / Jquery

I've got an object called 'output' that I need to display on the page. It is an image object. I tried to use the following code but it doesnt work. Any advice greatly appreciated.
document.getElementById("imageDiv").appendChild(output);
<div id='imageDiv'></div>
When I alert the object I got the following:
{"result":{"output":"data://path-to-file/background-32.png"},"metadata":{"content_type":"json","duration":9.845787767000001}}
How do I actually display the file?

You are using the ColorfulImageColorization API from Algorithmia.
It turns out that this service doesn't actually return the image data or a true URL path to the resulting image. Instead, it returns a pointer to where the image is stored in your data collection that you have set up with them. You can read about the various types of data collections and such on their Hosted Data page here
Also, from their comments sectiion:
Nir_Photomyne: Hey there! :) how to access the output using JS? I get the out put url but then what?? HELP
deeplearning: #Nir_Photomyne: There are a couple options depending on what you want to do with the images. The best option is probably to set the output location to s3,after setting up an s3 data connector at https://algorithmia.com/data
.
My personal opinion?
I'd see if I could find a similar API that is more straight forward and simply sends the image data in the response instead of storing the data.

http://jsbin.com/diwekox/edit?html,js,output
Do you just forgot the put on the image source attribute or something else?

I need to make a PUT request to a JSON file in an external API. I need to update specific fields

I have a JSON on an external API, and, in the documentation of the API, it instructs to use a PUT request to update records. I have read a lot on this, but I haven't found an adequate amount of information.
I will do my best to provide you with the most info I can so you can help me, specifically.
I have the url stored in a variable: $record.
The documentation instructs to: Set the request body content as a json formatted array of record data. This is the “payload”.
It also provides an example:
{
“Name”: “Craig J. Peters”,
“Job Title”: “Director of Engineering”
}
I need to change specific fields. How can I accomplish this using cURL and PHP?
I should mention: If this is easier with JavaScript, I am open to that as well.

I strongly recommend you to check Guzzle as a starting point -
http://docs.guzzlephp.org/en/latest/request-options.html#body

Getting data using RESTful and backbone.js

I've been reading tons of tutorials, I really like this technology, but I am missing something.
Following this tutorial http://www.youtube.com/watch?v=FZSjvWtUxYk you get JSON data from this url, http://backbonejs-beginner.herokuapp.com/users then you set your model, and collection.
I am not sure how to set this url on my own (for either local storage or database storage), I obviously need to set it to where I can GET the data or PUT/POST/DELETE data. I need to mention that I dont want to use PHP to send the data to the database, because this is a cordova app. Maybe setting data is beyond just using a URL, hopefully some one can make this clear, this should be easy points for most.
I am missing something easy here, because there is a reason they are not covering this topic extensively (maybe they are and I am overlooking it), but oh well ill ask anyways maybe someone can point this out :)
Here is the ajaxPrefilter it kind of confuses me, I know it obviously prefilters our url to point to the data, but I am not sure how to apply an appropiate url for local storage/server side.
$.ajaxPrefilter( function( options, originalOptions, jqXHR ) {
options.url = 'http://backbonejs-beginner.herokuapp.com' + options.url;
});
Edit: Also I noticed that when I run a POST request, this url changes http://backbonejs-beginner.herokuapp.com/users and adds my data, this is from the RESTful services right, and what is so special about that url that it allows me to do that? In the meantime I am going to keep rewatching the backbone tutorial videos, to see what I am missing lol.
Also watching this http://net.tutsplus.com/tutorials/javascript-ajax/understanding-backbone-js-and-the-server/ starting from the beginning he actually understands what I mean, but jeffery uses PHP, which maybe I can use with cordova (pointing to a script or something) but I would rather use javascript to send data to mysql and local storage.
EDIT: Okay I see heroku is a cloud based service https://www.heroku.com/ so inside that url we were using a dummy type of service to store the data.. Okay so now how do I point the url to local storage?
Finally got it!

I came across this Backbone.js + Java Wine Cellar Application. It is an application with a Backbone front end and a Java backend. You have just to download it, set up the environment and see how it works.
There is also a tutorial, the author wrote it also in PHP, just check his blog.

Okay, so I am a noob, I am sure the way I asked this question may have gotten confusing but here is what I did.
I spent a good amount of time figuring out how to use https://github.com/jeromegn/Backbone.localStorage what I learned is, models and collections are well models and collections of data. I didn't think of it like that(should have been transparent from the get go, but oh well) inside the model and collection you need some data and so from the tutorial I followed the method of getting data was via http://backbonejs-beginner.herokuapp.com/users it contained jSON data which we could work with.
So in using local storage, we need to change where our jSON data is by using localStorage: new Backbone.LocalStorage("choose-some-identifier"),
So understanding the model and collection really helps in knowing what to do. Now I just need to figure out how to add localstorage data to a server, and since I am using phonegap it would be cool to add an event listener for when the user connects to the internet and on that event submit the local storage data to the server.