I'm creating an iOS5 app (programmed in Objective-C) which provides a couple of functions. One of them is to allow a user to fill out a text field with JavaScript. When the user presses a "Test" button, I want it to save to a specific JS file and move to a new view, displaying an HTML page that will display the results of that JavaScript on a canvas element.
Unfortunately for me, I have no idea how to save to a JS file for a text field. Nor do I know if this is actually the best way to achieve the results I'm after.
So can anyone tell me the code I'd need to place in the IBAction of my test button to save the file, or if there is a better way to get the user's script into the HTML file with the canvas element?
You have some options to do that.
Add a callback in WebView is possible only in desktop apps, but you can make a workaround.
1- Set a handler to click in javascript;
2- This handler parse the value via windows.location (trying to change the current url);
3- In UIWebviewDelegate set webView:shouldStartLoadWithRequest:navigationType: to recognize this values parsed by javascript and returning NO (canceling the url change).
After you have the code typed by user, is easier pass to the new one UIWebView. You can save the file via NSData or other class and load in by the path, or you can parse directly the code to be showed via NSString.
EDIT
I, still, belive what I said is what you want, but with a little more info. Yes, 3 NSString probably solve your problem. You even can call eval in javascript, via objective-c and parse user code too. Those logic ideas are a good approaching. You can choose the easier for you.
There are more info in this another Q&A
You can use html 5 local storage for that.
Related
I'm writing a vscode extension where I'm hoping to squeeze more dynamic functionality out of markdown preview. Effectively the problem I'm trying to solve is:
In markdown preview, there's a checkbox
When user clicks the checkbox in markdown preview, send a message/event to the vscode extension runtime
Vscode extension can listen for this message/event and store the action in local storage
Checkbox state is saved - and subsequent renders of the markdown preview can use this action
Ideally, I'd like to do this while keeping the default markdown preview security (https://code.visualstudio.com/Docs/languages/markdown#_strict). After all, I don't need the extension to or markdown preview script to talk to a remote server - I just want them to be able to talk to one another.
Problem as code
To write the problem as sudo code, I want my markdown preview script to contain something like:
const button = ... // get button element
button.addEventListener('click', () => {
... /*
* Send a message to the vscode extension. Something like:
* `vscode.postMessage('vscode.my-extension.preview-action' + value)`
* (which I can't get to work, I'll discuss why)
*/
});
where then my extension can listen for messages like 'vscode.my-extension.preview-action'.
What I've Tried Already
I have tried acquireVsCodeApi() but because the markdown extension already does that, I can't do it again in the subsequent loaded script. I've also tried registering a uri handler but as far as I can try out the preview script still needs to fetch to that uri, which is still blocked by the default markdown security settings.
Perhaps markdown preview scripts are not the place to do this kind of thing, but I just wanted to leverage as much as possible that's already there with the vscode markdown extension. I want to supplement markdown but not replace it, the functionality I want to add is just icing on markdown documentation.
I've read https://code.visualstudio.com/api/extension-guides/markdown-extension#adding-advanced-functionality-with-scripts and it doesn't tell me much about markdown extension scripts capabilities and limitations.
Thanks to #LexLi I looked at some of the source code in the markdown extension and was able to come up with an ugly hack to make this work in preview scripts. Markdown allows normal clicks. And vscode extensions can handle normal clicks. I've paraphrased the code so there could be small syntax errors.
In the extension I did this:
vscode.window.registerUriHandler({
handleUri(uri: vscode.Uri): vscode.ProviderResult<void> {
console.log(`EXTENSION GOT URL: ${uri.toString()}`);
},
});
Then I made sure my extension/preview script put this in the document
<!-- in the preview script I place a button like this -->
<!-- it even works with hidden :) so I can do more app customization -->
<a
hidden
id="my-extension-messager"
href="vscode://publisher-id.my-extension"
>
cant see me but I'm there
</a>
Then my preview script I can even set href before faking a click:
const aMessager = document.querySelector("#my-extension-messager");
console.log('client is setting attribute and clicking...')
aMessager.setAttribute('href', 'vscode://publisher-id.my-extension?action=do-something');
aMessager.click();
console.log('client clicked');
Logs I saw (trimmed/tweaked from my particular extension to match the contrived example):
client is setting attribute and clicking...
client clicked
[Extension Host] EXTENSION GOT URL: vscode://publisher-id.my-extension?action%3Ddo-something
It's a hack but I can do a lot with this. Within the URL I can encode data back to the extension and kind of pass whatever I want (as long as data is relatively small).
I'm making an application with WebView control. And I want it to read local html file. But I can't find the right way to make it possible.
At first, I simply tried to use Navigate method and provide the file path in the "file:///~" format string as a parameter, but it didn't work.
https://learn.microsoft.com/ja-jp/windows/communitytoolkit/controls/wpf-winforms/webview-known-issues
This Microsoft page says that WebView control does not recognize "file:///~" protocol.
And it shows the 3 solutions to make WebView control to read local html files.
Use NavigateToLocal() method.
Use NavigateToLocalStreamUri() method.
Use NavigateToString() method.
I tried all of them, but each 3 have some issues that doesn't make it work.
NavigateToLocal method requires a RELATIVE path of the file (not the absolute path), relative from the application executable directory. So files in somewhere else from the application directory cannot be read by this method.
NavigateToLocalStreamUri method is not even implemented according to the page! I once tried it anyway, but it returned an exception and didn't work.
NavigateToString method can render the given html content string, but the external files like css, js, image files included by html codes cannot be loaded, so it does not provide a full function.
I found some sample of using NavigateToLocalStreamUri method and tried it by myself.
(VB.NET)
wvwMain.NavigateToLocalStreamUri(uri, New StreamUriResolver())
Public Class StreamUriResolver : Implements IUriToStreamResolver
Public Function UriToStream(uri As Uri) As Stream Implements IUriToStreamResolver.UriToStream
Return New FileStream(uri.LocalPath, FileMode.Open)
End Function
End Class
By this code, NavigateToLocalStreamUri method returns System.Resources.MissingManifestResourceException.
What I want to realize is very simple.
Using WebView control
Read local html file located anywhere on the local storage
And render the html file completely as an expected result
But I don't see the way right now.
I would appreciate your advises or helps.
The method NavigateToLocalStreamUri will not work. Please see https://learn.microsoft.com/en-us/windows/communitytoolkit/controls/wpf-winforms/webview-known-issues.
You have to use NavigateToLocal, but you will see a warning that it is deprecated. However, it does only work with relative paths. Is it possible for you to restructure your application so that you can use relative paths?
The NavigateToLocal method is the only way that I've found to call local HTML files in Microsoft.Toolkit.Forms.UI.Controls.Web WebView v6.0.
On Visual Studio 2019 Windows 10, the following VB.NET code works on my PC
Imports System.IO
Dim sFileName = Application.StartupPath & "/MyPage.html"
wv.NavigateToString(System.IO.File.ReadAllText(sFileName))
where wv is a WebView object.
Am tryng to automatically generate pdfs using html2pdf class. I got the following code which is working fine, only that someone has to save the pdf manually. However, Whenever a new product is added, I would like to automatically save the pdf to some folder without user intervention, and store this value in a database for future reference.
How do I go about saving the pdf 'silently' i.e. in the background without showing any popups or requiring the user to intervene?
Thanks in advance.
include('pdf_content.php');
$content = ob_get_clean();
// convert to PDF
require_once('html2pdf/html2pdf.class.php');
try
{
$html2pdf = new HTML2PDF('P', 'A4', 'en');
$html2pdf->pdf->SetDisplayMode('fullpage');
$html2pdf->setDefaultFont('Arial');
$html2pdf->writeHTML($content, isset($_GET['vuehtml']));
//$html2pdf->Output($file_name.'_'.date("dmY").'.pdf');
$html2pdf->Output($product_id.'_'.$file_name.'_'.date("dmY").'.pdf');
You can try calling this script everytime a new product is added, although then you wouldn't really do it in the "background"...
For more information, please note the question "How can I run a PHP script in the background after a form is submitted?"
EDIT:
If you wish to save the file on the server instead of outputting it to the browser, you can use different parameters. See also the html2pdf-wiki. Be aware that you cannot save the file on the user's computer unnoticed!
$html2pdf->Output('directory/file_xxxx.pdf', 'F');
I'm developing a cross-platform browser extension, and have based all my code on the Chrome-way of doing this. I have counted on that the background page will be accessible from the options page, which in Safari extensions turns out to be not possible (since there is no such thing as an options-page). You can only access safari.extension.globalPage.contentWindow from within the extension popup, and the background page itself.
Now, I have an options page, which is an html-page within the extension bundle, and so far I haven't found a way for Safari to give it extension "rights". The closest I have come is adding a content script that's only added on the options page. This seems a bit silly, since the html page itself is in the extension bundle?!
Others have suggested using asynchronous ping-pong style message event handlers, and even the canLoad-mechanism (which is "only" able to run in a beforeload-event). I have been able to hack the canLoad-mechanism for synchronous messaging by forging the BeforeLoadEvent:
// Content script (run from anywhere)
var result = safari.self.tab.canLoad(new BeforeLoadEvent, "data")
-> "return value"
// Background page
safari.application.addEventListener('message', function(e) {
if ( e.name === "canLoad" )
e.message = "return value";
}, true);
It's a hack, but it works. However, I am crippled by the message transport serialization, since I need to be able access methods and data on my objects from the background page. Is there anyway around this?
Possible ways that might work but I don't know if possible:
Access options-page window-object from backgrounds page. Is that possible?
Message passing, need to bypass message serialization
Any shared/global object that I can attach objects to and fetch from the options page?
Make Safari run the options.html page from outside the content-script sandbox? It works in Chrome since they are both within the extension-bundle. It's quite annoying that safari doesn't do this too.
Run the options-page from within the popup. This is promising, but it crashes safari (which is very promising!). However, from the looks of it it's just something to do with a CSS animation in my options.html page. The biggest issue is that it has to be able to open an OAuth2 popup, but thanks to being able to programmatically open the popover, it might be a non-issue. However, this option is the most realistic, but I would rather have it open in a new tab.
Any suggestions and hackish workarounds would really help.
I need to take an existing pdf file and programmatically fill in a list of form fields with text and then save the pdf without ever displaying it to the user.
For instance, if the pdf file contains fields named "LastName", and "FirstName" I would like to set the value of "FirstName" to "Louis" and then save the file.
I've been searching for a long time and can't find any guidance on even where to start since the iOS documentation (and most of the questions on here) seem geared towards displaying or creating pdf content instead of modifying it.
EDIT:
My main question is: Is it possible to open a pdf stream (I know how to do this) and copy each existing pdf dictionary item into a new pdf? I have not been able to find a way to write the dictionary items to a pdf.
I doubt that kind of functionality will ever be in the iOS frameworks. The reason most of the related info you can find "seem[s] geared towards displaying or creating pdf content instead of modifying it" is because that's what the vast majority of use cases will want or need for PDF functionality.
You'll need to find a 3rd party library that can open up PDFs, fill out the AcroForm fields, and then stamp out a PDF. I use iText on Java (there is also iTextSharp for C#) but I don't know of anything for Objective-C.
Once you find that library, you'll need to integrate it into your project. There are undoubtedly several related questions/answers here on SO for whatever version of the SDK you're using.
This would be easier to do with a HTML page. If you wish to use a HTML page instead of a .pdf form then thius is how you would go about doing it:
[field1 setText:#"Field 1 Text"];
[field2 setText:#"Field 2 Text"];
NSString *result;
result = [webView stringByEvaluatingJavaScriptFromString:[NSString stringWithFormat:#"$('#field1').val('%#');", field1.text]];
result = [webView stringByEvaluatingJavaScriptFromString:[NSString stringWithFormat:#"$('#pfield2').val('%#');", field2.text]];
result = [webView stringByEvaluatingJavaScriptFromString:#"$('#submitbutton').click();"];
You would need to create two UILabels or UITextFields and call them "field2" and "field2" in your .h file. You can then find the ID of the field you need to replace e.g. #field1 and then put it where I have put "#field1" and again for the second field where I have put "#field2". There also needs to be a UIWebView with the page already loaded. This code is to be used after the UIWebView page has been loaded. Maybe do the following:
-(void)webViewDidFinishLoad:(UIWebView *)webView {
// Insert above code here
}
You probably need a full understanding of Javascript if you want to do this for the whole form, but this should get you started.
Hope that helps you.