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JavaScript for Editing a Reference

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To make this all work, but to avoid going totally insane and coding JavaScript for the next 30 minutes, we're going to turn the printed string into an input text body and, on "blur" - so when we click away from it, we'll make an AJAX request to save the new filename.

Let's copy the original filename code and replace it with <input type="text" and value=" that original filename stuff. Let's also add two classes: one from Bootstrap to make things look nice and another - js-edit-filename - so that we can find this field in JavaScript. Oh, one more detail: add a style attribute with width: auto - just another styling thing.

Next: copy the js- class name and head back up to the constructor. We're going to do the same thing we did with our delete link: this.$element.on('blur'), this time with .js-edit-filename and then our arrow function. Inside that, call a new function: this.handleReferenceEditFilename() and pass that the event.

Keep going: copy the method name, scroll down a bit, and create that function, which will accept an event object. Let's also steal the first two lines from handleReferenceDelete(): we're going to start the exact same way. Heck, we're going to make an AJAX request to the same URL! Just with the PUT method instead of DELETE.

When we send that AJAX request, we're only going to send one piece of data: the originalFilename that's in the text box. But I want you to pretend that we're allowing multiple fields to be updated on the reference. So, more abstractly, what we were really want to do is find the reference that's being updated from inside this.references, change the originalFilename data on it, JSON-encode that entire object, and send it to the endpoint.

If that doesn't make sense yet, don't worry. To find the reference object that's being updated right now, say const reference = this.references.find() and pass this an arrow function with a reference argument. Inside, return reference.id === id.

This loops over all the references and returns the first one it finds that matches the id... which should only be one. Now change the originalFilename property to $(event.currentTarget) - that will give us the input element - .val().

Ok! We're ready to send the AJAX request! Copy the first-half of the AJAX call from the delete function, remove the .then() stuff, change the method to PUT and, for the data, just pass reference.

There is a small problem with this - so if you see it, hang on! But, the idea is cool: we're sending up all of the reference data. And yes, this will send more fields than we need, but that's ok! The deserializer just ignores that extra stuff.

Testing time! Refresh the whole page. Oh wow - we have an extra < sign! As cool as that looks, let's scroll down to render and... there it is - remove that.

Refresh again. Let's tweak the filename and then click off to trigger the "blur". Uh oh!

Cannot set property originalFilename of undefined.

Hmm. Look back at our code: for some reason it's not finding our reference. Oh, duh: return referenced.id === id.

Ok, let's see if I've finally got everything right. Refresh, add a dash to the filename, click off and... 500 error! That's progress! Open the profiler for that request in a new tab. Ok: a "Syntax Error" coming from a JsonDecode class. Oh, and look at the data that's passed to the deserialize() function! That's not JSON!

Silly mistake. When we set the data key to the reference object, jQuery doesn't send up that data as JSON, it uses the standard "form submit" format. We want JSON.stringify(reference).

I think we've got it this time. Refresh, tweak the filename, click off and... no errors! Check out the network tab. Yeah 200! The response returns the updated originalFilename and, if you scroll down to the request body... cool! You can see the raw JSON that was sent up.

Validation

The last thing we need to do is... add validation. I know, it's always that annoying last detail once you've got the "happy" path working perfectly. But, right now, we could leave the filename completely blank and our system would be ok with that. Well ya know what? I am totally not ok with that!

Ultimately, our endpoint modifies the ArticleReference object and that is what we should validate. Above the originalFilename field, add @NotBlank() and let's also use @Length(). The length can be 255 in the database, but let's use max=100. Then, inside our endpoint, there's no form here, but that's fine. Add the ValidatorInterface $validator argument. And right after we update the object with the serializer, add $violations = $validator->validate() and pass it the $reference object. Then if $violations->count() > 0, return $this->json($violations, 400).

We're actually not going to handle that in JavaScript - I'll leave rendering the errors up to you - you could highlight the element in red and print the error below... whatever you want.

But let's at least make sure it works. Clear out the filename, hit tab to blur and... there it is! A 400 error with our beautiful error response. To handle this in JavaScript, you'll chain a .catch() onto the end of the AJAX call and then do whatever you want.

Ok, what else can we add to our upload widget? How about the ability to reorder the list. That's next.

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