Is it possible to retrieve the dimensions of an image stored on Amazon S3?
If the answer is no, are there any other ways around it other than downloading the image to my server to which sounds inefficient?
I'm using version 2 of the AWS SDK for PHP.
I've been looking through what is returned from the following code but doesn't seem to give dimensions.
$result = $s3->getObject(array(
'Bucket' => 'BUCKET_NAME',
'Key' => 'KEY_NAME'
));
var_dump($result);
I'm not 100% familiar with SDK2. With 1.5 you could do this
getimagesize($s3->get_object_url($bucket,$filename));
I think this is still possible as long as you can access publicly the image (or you have to find your way around authorized urls)
Obviously, your php must be enabled to open remote files.
I agree with the db cache. I run every image filename through a class that checks mysql for a match. If it finds one, it returns width, height and a preformatted sizetag ready to go. If the image and size are not found, it uses getimagesize() to return the same info, which it stores for next time. I also built in a resize method should I want to cheat a bit and resize the sizetag (but not the file) proportionally on the fly.
I don't know if storing the info is faster than getimagesize() as it downloads. S3 is pretty fast.
Due to lack of response I'll presume it's not possible... Didn't r3ally want to do it with JavaScript but this is how I did it.
<img src="image.jpg" id="image" />
<script>
// This runs after the image has loaded
$('#image').load(function() {
// Use the below code to get the height and width
// document.getElementById('image').width
// document.getElementById('image').height
});
</script>
Related
React Native : Alternate way to get the Image require to work when array of image paths got dynamically from fetchapi
Tried the below and aware that require always need the fixed path in quotes('') which works well when static image path is known. Thee should be alternate way to map the images which is received from fetchapi.
source={require('./assets/images/'+{item.image_path})}
Example fetch api json response is: [{user_name: 'DynamicUser1', image_path: 'DynamicUser1.jpg'},{user_name: 'TestUser1', image_path: 'TestUser1.jpg'}... ]
Need alternate way to get the images rendered with the dynamic image path rightly picked from the fetch api.
userData = this.state.resultsUserData.map((item) => {
return (
<View key={item.user_name} style={ styles.container }>
<Text style={styles.title}>
{item.user_name}
</Text>
<TouchableOpacity goBack={()=>this.backAction} onPress={()=>this.homepage()}>
<Image key={item.image_path}
source={require('./assets/images/'+{item.image_path})}
</TouchableOpacity>
</View>
)
}
require doesn't work dynamically like that. Since you already have the images in the assets, you should write the require's for each of them in advance and call the appropriate one when needed. You can read more about this limitation here.
I have an image stored at /assets in my project folder and I am trying to read it using Ti.Filesystem.getFile(). The code prints the blob data in android but it prints undefined in iOS.
Following function is called on Button click event https://pastebin.com/QgqLQPyz
function readImg(e) {
var localPath = '/butterfly.jpg';
var cachedFilename = Ti.Utils.sha1(localPath) + localPath.substr(localPath.lastIndexOf('.'));
console.log("cachedFilename:---"+cachedFilename);
var cachedFile = Ti.Filesystem.getFile(Ti.Filesystem.applicationCacheDirectory, cachedFilename);
if(!cachedFile.exists()){
var blob = Ti.Filesystem.getFile(Ti.Filesystem.resourcesDirectory, localPath).read();
console.log("-----------blob in not exists:"+JSON.stringify(blob));
}
}
When the same image path is set in ImageView it gets displayed so the issue is not with path . What am I missing here ? pls help. Thank you.
The best option so you don't have to do anything specific to the images at all (keep in mind, image manipulation is pretty heavy to do on runtime), is to use a module that was made for this purpose, av.imageview. This allows you to configure all kinds of content modes.
An option to get your code to work is to get the blob using the the getAsset method.
var blob = Ti.Filesystem.getAsset('/images/butterfly.jpg');
and then resize where you see fit. But I would advise you, if you do need to do this every time the app runs, then just resize once and store that resized image to be used after that. That way there will only be a single time the image needs resizing.
what is the benefit of below code that is two events.
what its actually doing ??
require_once($yii);
$app = Yii::createWebApplication($config);
Yii::app()->onBeginRequest = function($event)
{
return ob_start("ob_gzhandler");
};
Yii::app()->onEndRequest = function($event)
{
return ob_end_flush();
};
$app->run();
please explain the function of this code in my application.what it does ?? and how can it help me ??
The above code buffers the content and gzips it according to browser, rather than sending it straight away.
Yii::app()->onBeginRequest = function($event)
{
return ob_start("ob_gzhandler");
};
The above means that when the requests starts, it will buffer the content, and using the callback will set the content as gzip,deflate or none, depending on browser.
Yii::app()->onEndRequest = function($event)
{
return ob_end_flush();
};
The above code simply means that at the end of the request, it will output the buffer contents.
It buffers the content, and just before sending it the browser, asks if the browser can accept zipped content. If it can, it will zip the HTML before supplying. Otherwise, it will supply it unzipped.
Zipped content reduces the size of the HTML the browser needs to download, which can increase performance. How much performance gain your users will see depends on the size of the HTML - bigger pages will see more benefit, while tiny pages may actually take longer to render, because the browser has to unzip the content first. Use Firebug or Chrome Developer Toolbars to see whether it's worth it.
Also, check the impact on the server side. Again, the downside of increased server load can outweigh the increased client-side page render speed. Hence, it works best with lots of caching.
This is normally something you do when you are optimising the site, looking for performance gains.
if you want add gzhanlder straight to main config file you Can Set Following lines in main.php
'onBeginRequest'=>create_function('$event', 'return ob_start("ob_gzhandler");'),
'onEndRequest'=>create_function('$event', 'return ob_end_flush();'),
this Two lines Add GzipHandler
I followed this nice article
http://www.lunatech-research.com/playframework-file-upload-blob
and have a perfectly working image upload solution
My questions is, if the user doesn't select any image, how do I assign a default image during save (probably stored in the server)?
if (!user.photo)
user.photo= ?;
user.save();
The one-hack that I can think of is upload the default image and see which UID "Play" stores in the /tmp directory and assign that above. Is there an elegant named* solution to this?
when I say named, I mean I want the code to look like (which means I know what I'm doing and I can also write elegant automated code if there are more than one picture)
user.photo= "images/default/male.jpg"
rather than (which means I'm just hacking and I can't extend it elegantly for a list of pictures)
user.photo= "c0109891-8c9f-4b8e-a533-62341e713a21"
Thanks in advance
The approach I have always taken is to not change the model for empty images, but instead do something in the view to show a default image, if the image does not exist. This I think is a better approach because your are corrupting your model for display purposes, which is bad practice (as you may want to be able to see all those who have not selected an image, for example).
To achieve this, in your view you can simply use the exists() method on the Blob field. The code would look like
#{if user.photo.exists()}
<img src="#{userPhoto(user.id)}">
#{/if}
#{else}
<img src="#{'public/images/defaultUserImage.jpg'}">
#{/else}
I have assumed in the above code that you are rendering the image using the action userPhoto as described in the Lunatech article.
I'd assume you can store the default image somewhere in your applications source folder and use
user.photo.set(new FileInputStream(photo), MimeTypes.getContentType(photo.getName()));
to save the data. Photo is just a File object, so you can get the reference of your default image and use it.
Is there any other way that I can just check the size of a file before upload? The requirement is if the file exceeded the limit, the form mustn't submit. If it's not, I have to do the ordinary upload using the form and I don't have to exactly upload the file to the server using Flash.
Is there any other way that I can just check the size of a file before upload?
Not in JavaScript, the file size is not in the DOM.
when instantiating SWFUpload, there are two parameters you need to pass: file_size_limit, and file_queue_error_handler:
new SWFUpload({
file_size_limit: "10 MB",
file_queue_error_handler: queueErrorHandler,
[...]
})
and then:
function queueErrorHandler(file, errorCode) {
if (errorCode == SWFUpload.QUEUE_ERROR.FILE_EXCEEDS_SIZE_LIMIT) {
alert("File exceeds the 10MB limit!");
}
}
this checks if the file size is within limits before starting the upload
with the W3C FileAPI (implemented at least by Firefox 3.6) you can.
See this link for details
http://hacks.mozilla.org/2009/12/w3c-fileapi-in-firefox-3-6/
Cheers
Checking the file size through the SWFUpload control is possible. Just put the SWFUpload control outside of the Web form tags. Tell the user click on the SWFUpload button and point to his upload file. Use javascript to determine the file size, then utilize this information as you see fit such as populating a validation function. Then your main form will need to ask the user to point to their upload file again, and it is this field which will do the actual uploading of the file. When the form is submitted, the SWFUpload control will be completely ignored since it's not part of the main form.