I need to load a very large text into a dialog box using YUI or jQuery and I'd like to know the best way to do it. I have an Oracle CLOB column which I need to show if the user needs to know what was stored there. Since CLOB data are huge, it is impossible to load everything. Any ideas?
Use multiple divs and load each one with what's left of your clob content when your user drops cursor in it : you can do this either using connection manager for YUI 2 or nodeList if you are using YUI3 (here's an example of how to use it)
Put it in a fixed-size DIV and add: overflow-y:auto.
Related
I'm searching for Javascript (JQuery if possible) plugin that can generate an image representing the inner content of a DIV.
Example : This link shows an image containing 3 x 3 box display.
What I would like is that these boxes could contain an automatically-generated picture showing what a specific DIV's content look like.
Is there such a thing?
If you don't have too much content on the screen, this seems like a simple option
html2canvas
It is well documented
Well tested
But it will not work for all elements
It will not work with all atributes
But this is the solution if you want to take the screenshot of your page only(where you know the possible attributes and elements)
I don't think that Javascript can create an image from the scratch, but for sure is possible to make that on the server and use JS to make an AJAX call to it.
Hope this helps.
You could use "webkit to image" wkhtmltoimage: https://code.google.com/p/wkhtmltopdf/ I've used it to generate images from javascript graphs and tables etc. Any html will work. Its not purely javascript, but you could send the html div (and relevant css) to the wkhtmltoimage and get the image back via ajax.
I have a list of entries, for each entry I have to create a tooltip in javascript, what do you think is better to do considering the performance?
1) create a div for the popup and another hidden div for each entry that contains the content of the popup, and each time a tooltip is created copy the content of the corresponding div into the one for the popup and display it.
2) create a div for each entry, when it have to display the tooltip do an Ajax call to retrieve the content of the popup and put into the div (if it isn't done before) and display the tooltip
EDIT:
the tooltip should display a complex HTML, the clients could be mobile or computer the list is small because is paginated
The choice strongly depends on how many elements and how much content is stored inside the tooltip.
An ajax call is expensive if you think people will tends to open tooltips many times, but if they may contain images, videos, facebook likes, tons of text and/or other expensive resources it could be a good idea with some kind of cache strategy so you have no more than one ajax call for every tooltip (e.g using the localstorage on modern browser)
if tooltips contain instead no more than a couple of paragraphs is quite useless to add complexity to your application with ajax calls, server-side security issues and extra javascript. Just insert them statically
I would actually create a JavaSrript array or object with all of the loaded tooltip values and then replace the text in the tooltip DIV when showing it. Creating a bunch of DIVs will not help performance.
Don't reinvent the wheel, use a jQuery plugin such as qTip or tipsy.
I want to create this kind of graph on the basis of user entered data.
the main issue is regarding the display of boxes on the point.
Let me explain you a bit,background does contain a gradient image which resembles to the color of urine the patient want to mention.
Please suggest me something to create this graph.Whole data is need to be fetched dynamically.
If none of the many graphing tools out there can help you, you can think about this with plain old HTML :-)
Either a table or absolutely positioned DIVs. If you use a table, you can identify the cell and add a class to give that cell's border a red colour. You can do the same with DIVs. When you print the table cells or DIV to the page, you can identify them with 8-2-27 (unit-month-date) and your JSON data can match the corresponding cell/div and add a class.
Of course this is a bit more work than using an out of the box plugin. But it is possible. I have done a similar thing in the past. I found it easier to do everything on the server side and print the HTML (this was before jQuery had a plugin for everything).
gRaphael, JSChart, PlotKit, HighCharts are some common libraries used today to create chart in the client side. You need to provide JSON data and HTML Element only. Remaining task are not needed to be done by you. You can use JFreeChart to create a chart (image) on the server side and send it to the client side.
I would like to display to user a table which contains ~500,000 rows.
The table should be calculated based on a file (i.e. the table is known at the beginning, and does not change).
I guess that building the HTML text of this table is not a good idea in terms of memory performance.
So how can I build such table ?
I would like user to be able to scroll the table using a vertical scroll bar. Is it possible to build on the fly only the visible part of the table ? I'm afraid to see delays because of this.
Is it a better idea to use server side programming rather than Javascript ?
I'm not restricted to any server side programming language, so any advise would be appreciated !
Send the first 250-ish rows to the user, as he scrolls down, perhaps past row 200, fetch the next 250 rows, append to the table and so on.
This is a (ui) design pattern known as "Infinite scroll".
Displaying 500,000 rows all at once to a user is a bad idea. Consider other options:
allow user to download file as CSV
show paginated (still not very useful)
provide filtering mechanisms (by date etc.) to allow the user to only see the data they need
If the users really needs to see all that data at once, then viewing it in the browser is one of the worst ways to do that - they should be using a tool made specifically for viewing data, like Tableau.
Classic example of where to use ajax.
Use javascript in combination with a server side script.
This really is a case for server-side pagination, I would say, maybe in combination with Ajax. A HTML table with 500.000 rows is going to crash a lot of browsers.
You're not specifying which server side technology you work with. If you update your question, I'm sure people will be able to give you some pointers.
Try this:
Clusterize.js
Tiny plugin to display large data sets easily
https://clusterize.js.org/
Is it possible to build on the fly only the visible part of the table ?
If you build a "fake" scroll (e.g. jquery slider) you can retrieve parts of the table instead of the whole.
I have some HTML documents that are converted to PDF, using software that renders using QtWebkit (not sure which version).
Currently, the documents have specific tags to split into columns and pages - so whenever the wording changes, it is a manual time-consuming process to move these tags so that the columns and pages fit.
Can anyone provide a way to have text auto-wrapped into the next column/page (as appropriate) when it reaches the bottom of the current container?
Any HTML, CSS or JS supported by QtWebkit is ok (assuming it works in the PDF converter).
(I have tested the webkit-column-* in CSS3 and it appears QtWebkit does not support this.)
To make things more exciting, it also needs to:
- put a header at the top of each page, with page X of Y numbering;
- if an odd number of pages, add a blank page at the end (with no header);
- have the ability to say "don't break inside this block" or "don't break after this header"
I have put some quick example initial markup and target markup to help explain what I'm trying to do.
(The actual documents are far more complicated than that, but I need a simple proof-of-concept before I attack the real ones.)
Any suggestions?
Update:
I've got a partially working solution using Aaron's "filling up" suggestion - I'll post more details in a bit.
Create a document with a single page and all the text in a single column. Use JavaScript to cut the text into parts.
Use pixel coordinates to locate the paragraph/element that doesn't fit anymore. Move it and everything below to the next col. If a "page" already has two "col" divs, start a new page.
After all pages have been created, count and number the pages. Fix even/odd stuff, etc.
Will take some time but it's automatic.
Another approach would be to add all the content to a "source" div and move items to the col div until it's full and repeat with the next col.
Have a look at Prototype or jQuery; they should give you lots of tools to move stuff around in the document.
[EDIT] Instead of only relying on jQuery functions, I suggest to create one or two objects which keep track of the current page and the current column, etc. These give you stable foundations to stand on from which you can fire the helper methods.