I am dynamically creating some controls in a page. it will become slow when we have some fifty controls.
what are the code optimization techniques/ guideline used in extjs?
Is there any specific methods which will slow down the entire loading?
Sencha has great posts:
Ext JS 4.1 Performance about:
Network latency which affects initial startup time heavily, but also data store load time.
CSS processing.
JavaScript execution.
DOM manipulation.
Optimizing Ext JS 4.1-based Applications about optimization tips and the Page Analyzer tool.
My tips are
Use Ext.container.Container rather than Ext.panel.Panel.
Instead of adding ext components, use XTemplate with data view to load similar controls.
if you are using many images then use image sprites - An image sprite is a collection of images put into a single image. A web page with many images can take a long time to load and generates multiple server requests.
Using image sprites will reduce the number of server requests and save bandwidth.
http://css-tricks.com/css-sprites/
Related
There is any possibility to upload a file with different sizes in DropzoneJs?
I'm using vue-dropzone which is made with dropzonejs and i have to upload the same file with different sizing for srcset.
Example:
I want to upload the file test.png which is 1000x500 px. There is any possibility to upload it at the same time in original resolution and also in 500x250px?
Image resizing in the browser has been a seat-of-the pants experience for a long time. Web assemblies are the way of the future for processing-intensive tasks in web apps. I came across this project the other day. It looks fantastic and I really can't wait to strip out our home-baked image resizing with canvas and replace it with this.
The usual reason for doing this is to avoid large uploads. It's a little bit weird to want to resize in the browser then upload the original. You might be better resizing on the server. You'll save bandwidth and the server libraries will be more mature than what's available on the client.
Along with the original image object you can add one more your custom resized image to the array of images by using resize config of dropzone. You can do the above on drop event or adddedFile event of dropzone.
I'm new to UWP (windows 10), working on an app for windows phone, I wanted to know what is the difference between:
Using multiple frames and navigate from one to other.
Using a single xaml with no frames but with multiple grids (or other patterns), and instead of navigate- just change visibility so only the desired grid will be visible.
which option is better? and why?
The system keeps track of the Page you are currently on. So even when your App exists and even if it's removed from memory the OS can tell the App to reopen on that page.
Similarily when your App provides other Apps with the capability of calling into it to open certain file types of to perform certain actions (e.g. start navigation, etc.) pages will be used.
Lastly if you put everything on a single page and just manipulate visibility this will increase memory consumption of your App (as everything needs to be loaded even if it's not visible) and it also might increase load times.
Of course how much that impacts you is up to the type of App you are building. In general however I'd advice you to start building using separate pages in case your App grows. Also you get a lot of stuff out of the box if you do so (e.g. animated transitions, etc.)
I have implemented a lazy-load solution for images using http://www.appelsiini.net/projects/lazyload, and it works as expected.
Now that the DNN skin I'm working on is responsive, I want to make use of ImageResizer's responsive solution: http://imageresizing.net/blog/2013/effortless-responsive-images -- the setup is working right now, but when combined with lazy-load, the images that are served are no longer responsive.
Is there a way to combine these two technologies?
We run the latest .NET and IIS 7+. Thanks in advance!
Images added to the page after DOMLoaded will not be detected by Slimmage.js unless you call window.slimmage.checkResponsiveImages() . If you use a separate lazy-load or jQuery plugin that modifies images, call checkResponsiveImages() after it completes its work.
Browser vendors advise against lazy image loading, as it drains mobile device power. Turning on the wifi or LTE radio is the most expensive operation for a device, and lazy loading can make it 3-10x more chatty.
Unfortunately for me, Meta Slider WP plugin does not support lazy load, but it's perfect for what I need -- well almost. Here's why:
I have a ton of images (per slider) that will be displayed in multiple sliders using this WP Meta Slider plugin. All sliders will use the Flex Slider option, not the other options they have available. And, as you can imagine, the page load time is awful.
I looked up lazy load and came across this site:
http://www.appelsiini.net/projects/lazyload
It seems to be the perfect solution for what I need, but where do I need to input the snippet of coding in Meta Slider files to get this plugin to stop loading all the images at one time? What's happening is when a visitor comes to the site, this plugin loads every single image you have uploaded to it at that first-time page load which is causing the page to load awfully slow.
Additional info:
The images are pngs, 120x220 and under 50kb. I have found that converting them into jpgs instead of gifs compresses the file size to be between 12kb and 15kb, but anything lower, the images begin to lose color quality and the image color quality is extremely important.
END OF ADDITIONAL INFO
Anyway, my image database is growing and I need the images to only load upon the visitor scrolling up or down to reduce the page load time as much as possible so visitors will not be turned off and leave the site.
Thanks!
Oh, here's the plugin, I'm using:
wordpress.org/plugins/ml-slider/
I have a requirement that I think is common in many applications: paging. I have chosen to go with the "press to load 10 more" pattern, I think it looks better in a Metro app instead of using page numbers.
The problem I am facing is memory related. I load the first 10 items, which contain some images, and as I press "load more", I notice that the memory of the application is increased proportionally, obviously because of the images loaded. It soon gets to the 150MB memory limit where the operating system might actually kill the app.
What I am thinking is if there was some way after you scroll to the next page for the images not visible anymore to be unloaded from memory. This is gracefully handled by the iOS with the GetCell method, but is there an equivalent pattern in Windows 8 Javascript model?
Thanks,
Themos
Metro style apps usually do infinite scrolling using data virtualization. Check out the Build sessions on Data Virtualization in Metro style apps:
Build polished collection and list apps using XAML
Build data-driven collection and list apps using XAML
Build polished collection and list apps in HTML5
Build data-driven collection and list apps using ListView in HTML5
For example: HTML ListView working with data sources sample