In Objective-C what is the best method to extract an image url from HTML text?
I've got a chunk of HTML text which may contain one or more images. I want to be able to get the src URL of each image.
If you don't mind limiting yourself to iOS 4, you can use the new text checking APIs. The one you want is NSTextCheckingTypeLink and the NSRegularExpression class.
This seems to be answered over here: parsing HTML on the iPhone
The second answer down has a detailed explanation, however you will just have to change the xpath expression to match your image tags.
Related
I have been trying to add a link to one of the YouTube videos in the README.md file. So, first I took a screenshot of the video at a specific timestamp, put it in the local directory, and then used the following syntax:
[![ALT TEXT] (image/screenshot path)] (https://youtu.be/video_id "video text")
But as the size of the screenshot is a little big (as big as my laptop screen), using the above syntax takes a lot of space in the output! I don't want that. I want to control the size of the screenshot/image. How can I do that?
I found different answers on adding an image with a clickable link; resize an image in readme; but I couldn't find any answer addressesing both the issues. (Sorry if such answer already exists)
Thanks a lot in advance :)
You can include raw HTML in your Markdown document, so just use standard HTML <a> and <img> tag with width and height atttributes:
<img src="path/to/img.png" width="xxx" height="yyy">
This will render correctly on github and elsewhere.
I have an app that retrieves a user's stream and puts it into a UITableView. However, some include emojis (those little smile faces in iOS), and they just return as boxes in my UILabel.
I've done some research, and I still can't figure it out. Does the text type need to be changed?
Thanks!
Please explain your problem better,from the piece that i understood,notice that emojis have native support in iPhone,so any app can display an emoji in a text box,i recommend you to check the methods you're using to add text to the uitableview and the text encoding from the string which is being displayed,also you could check this link
use NSString drawinrect to display emoji instead of drawGlyphsForGlyphRange.
In my iPhone application I'm parsing RSS feed to get html and keep it. Afterwards I display this html in UIWebView. The problem is that html contains urls of images, if there is network connection everything is ok, UIWebView loads and displays these images, but if there is no connection it shows text but in place of images shows frame with blue square inside
How can I get rid of it?
Thank you
Check programmatically to make sure that you have an internet connection.
See this question and its accepted answer on how to do that.
If you don't have an internet connection, then you have a couple of options. You can either:
Parse through your html, replace the <img> tags with blanks (this will completely get rid of the images and their associated blue question mark boxes.
Parse through your html, replace the src part of <img src="somewebsite"> with a reference to an image placeholder in the project bundle.
XPath is your friend when it comes to parsing html. Although if you wanted to, you could do all of this with NSSTring.
I am looking for a way to programmatically (in obj-c) generate a PDF file from a local html file. I am dynamically generating the html from user inputs, I need to create the PDF and send it to the user (via email). I am having difficulty with the PDF generation portion.
I have the code to create a PDF using CGPDFContextCreateWithURL but I am struggling with drawing the page using quartz.
I have searched extensively on SO as well as the internet to no avail.
Any help is much appreciated!
To generate a pdf from an HTML, you need to render the html into a web view, and take snapshots of the web view, and render them into an image context.
The tutorial might be helpful:
http://www.ioslearner.com/convert-html-uiwebview-pdf-iphone-ipad/
I've written a little piece of code that takes an NSAttributedString from DTCoreText, and renders it into a paged PDF file. You can find it on my GitHub Repository. It won't render images or complex html, but it should serve for most uses. Plus, if you're familiar with CoreText, you can extend my PDF frame setter to generate these items.
So what it does now: Give it an HTML string, and it will use DTCoreText to generate an NSAttributedString, then render that into a PDF. It hands back the location that it saved the PDF file in the app's Documents folder.
Why not use a WebService, send the HTML page to this and retrieve the PDF-file ?
That way you can use iTextSharp and C#, and you're done in about 2 minutes.
Plus (if you're evil) you can store and see all the data on your server.
I haven't tried this myself so i have nothing to offer concrete but I'd have to imagine there has to be an easy way to do this on iPhone due to the imaging model. I'd look deeper into the documentation.
As to pushing back with the client that is up to you but there are probably multiple reasons for wanting to keep everything local. Frankly I would not be pleased at all to here from somebody I hired that he couldn't manage this particular task. So think long and hard about this push back. Oh even if you do push back a webserver is a poor choice. I'd go back a step further and investgate why you need something in HTML in the first place.
I've never tried this so I have no idea if it'll work, but how about loading the HTML into a UIWebView, and then make the view draw itself into a PDF context? E.g.
UIWebView *webview = [[UIWebView alloc] initWithFrame:CGRectMake(...)];
[webview loadHTMLString:html baseURL:...];
Then:
- (void)webViewDidFinishLoad:(UIWebView *)webview {
CGPDFContextRef pdfContext = CGPDFContextCreateWithURL(...);
[webview.layer drawInContext:pdfContext];
...
}
I made it by following this SO: https://stackoverflow.com/a/13342906/448717
In order to maintain the same content's proportions I had to multiply the size of the WKWebView 1.25 times the printableRect's size set for the UIPrinterRenderer, as the screen points differs from the PostScript's... I guess.
I have some text which might or might not contain web URLs, phone numbers, email links etc. which UIWebView automatically detects as hotspots.
Question: I want to show this text in UIWebView ONLY when there are one or more hotspots, but as plain text if it doesn't. So how can I detect this in code?
Additional Info: JavaScript code below tells how many ... links there are. This does NOT count how many other "link" items there are. For example "Link to www.yle.fi" contains one link according to UIWebView, but zero according to JavaScript:
NSString *s = [webView stringByEvaluatingJavaScriptFromString:
#"document.links.length"];
Still no answer to the question how to ask UIWebView how many links it has found...
You can use several regular expressions and check if the text matches those of URL/phone number/email addresses.
However, if your intention is simply let the user open a link, the UITextView is suffice.
Check the dataDetectorTypes property.