使用Objective-C进行JavaScript注入的方法
[英]Methods of JavaScript injection using Objective-C
问题描述
I'm looking for different methods of injecting JavaScript into a WebView (in Cocoa). 
我正在寻找将JavaScript注入WebView（在Cocoa中）的不同方法。
I am trying to inject some javascript into the <head> tag of a HTML file that has been loaded into the WebView. 我试图将一些javascript注入已加载到WebView的HTML文件的<head>标记中。
The following method doesn't work for me. 以下方法对我不起作用。 It seems to only work with very simple JavaScript with no nested brackets (from what I have tested): 它似乎只适用于非常简单的JavaScript， 没有嵌套括号 （来自我测试的）：
[webView stringByEvaluatingJavaScriptFromString:[NSString stringWithFormat:@"var script = document.createElement('script');"
"script.type = 'text/javascript';"
"script.text = \"some simple JavaScript"
"}\";"
"document.getElementsByTagName('head')[0].appendChild(script);"]];
Are there any other ways of doing this with more complicated JavaScript / jQuery functions? 有没有其他方法可以使用更复杂的JavaScript / jQuery函数？
The full code I am trying to inject is as follows: 我试图注入的完整代码如下：
function submitFormForTime(time){
$(\".t_h\").each(function(i, obj) {
if ($(this).text() != time) return;
$(this).parent().find(\"form\").each(function(i, obj){
obj.submit();
});
});
}
3 个解决方案
解决方案1
8 已采纳 2012-09-27 00:18:48
You can't use jQuery to add <script> tags. 您不能使用jQuery添加<script>标记。 This has been asked many times. 这已被问过很多次了。 See: 看到：
You can do it with browser built-in functions, BUT: 您可以使用浏览器内置函数来执行此操作，但是：
Would it work to just assign your function to a variable on your page and then evaluate it? 是否可以将您的函数分配给页面上的变量然后进行评估？ Something like: 就像是：
-(void)webViewDidFinishLoad:(UIWebView *)webView
{
// add function to page:
NSString * js = @"myFunction = function(){ return \"success!\"; }" ;
[ webView stringByEvaluatingJavaScriptFromString:js ] ;
// execute newly added function:
NSString * result = [ webView stringByEvaluatingJavaScriptFromString:@"myFunction();"] ;
NSLog(@"result=\"%@\"", result) ;
}
update explicit examples: 更新显式示例：
You should use my above example as a template! 你应该使用我上面的例子作为模板！
Anyway, there's 2 parts to the process... The Javascript part and the Objective-C part. 无论如何，这个过程分为两部分...... Javascript部分和Objective-C部分。 At the Javascript level, you are doing this: 在Javascript级别，您正在执行此操作：
// assign a function to the variable "someFunction":
var someFunction = function(){...};
// call the function in the variable "someFunction":
someFunction();
You can also do it without assigning the function to a variable, for example, if you don't care about referring to the function in the future. 您也可以在不将函数分配给变量的情况下执行此操作，例如，如果您不关心将来引用该函数。 Doing it without a variable and using an anonymous function looks like this: 在没有变量和使用匿名函数的情况下执行此操作如下所示：
( function(){...} )() ;
ie instead of doing var A = <the function>; A(); 即代替做var A = <the function>; A(); var A = <the function>; A(); you are doing (<the function>)(); 你在做什么(<the function>)();
Finally, if your anonymous function takes arguments, like yours does, the pattern looks like this: 最后，如果您的匿名函数接受参数，就像您的那样，模式如下所示：
( function(var0, ..., varN){...} )(arg0, ..., argN);
Using that as a template for your code, your JS ends up like: 使用它作为代码的模板，你的JS最终会像：
( function(time) {
$(\".t_h\").each(function(i, obj)
{
if ($(this).text() != time) return;
$(this).parent().find(\"form\").each(function(i, obj) {
obj.submit();
});
});
})( 123.456 );
So, that's what you want the web view to execute... That's the code we pass to the webview. 所以，这就是你希望web视图执行的内容......这就是我们传递给webview的代码。 But you have to build that string in your Obj-C program, with the "complication" of inserting the current time argument ( 123.456 in the above code). 但是你必须在你的Obj-C程序中构建该字符串，并且插入当前时间参数的“复杂性”（上面的代码中为123.456 ）。
It looks like this: 它看起来像这样：
NSString * jsTemplate =
@"( function(time) {"
@" $(\".t_h\").each(function(i, obj) {"
@" if ($(this).text() != time) return;"
@" $(this).parent().find(\"form\").each(function(i, obj) {"
@" obj.submit();"
@" });"
@" });"
@" })( %g );" ;
NSString * js = [ NSString stringWithFormat:jsTemplate, 123.456 ] ;
NSString * result = [ webView stringByEvaluatingJavaScriptFromString:js ] ;
I think I've written enough now :) 我想我现在已经写得够了:)
解决方案2
0 2012-09-21 10:26:56
I would get all the HTML from web view, then I'd inject the code and reload the page. 我会从Web视图中获取所有HTML，然后我会注入代码并重新加载页面。 It's still not a proper method of injection, but it may work. 它仍然不是一种合适的注射方法，但它可能有效。
NSString *htmlDataString = [webView stringByEvaluatingJavaScriptFromString: @"document.documentElement.outerHTML"];
// use nsstring methds to find the place for injecting
// inject avascript code
[webView loadHTMLString:htmlDataString baseURL:nil];
Of course you may have base URL from your request, if so replace that nil. 当然，您可以从您的请求中获得基本URL，如果是，则替换为nil。
解决方案3
0 2012-09-25 20:12:45
I didn't tried this, but if the problem is with the brackets and the complexity of the code, you can try calling a JS file stored in the bundle. 我没试过这个，但如果问题是括号和代码的复杂性，你可以尝试调用存储在bundle中的JS文件。 Maybe it solves that. 也许它解决了这个问题。 For example: 例如：
NSData *fileData = [NSData dataWithContentsOfFile:[[NSBundle mainBundle] pathForResource:@”submitFormForTime” ofType:@”js”]];
NSString *jsString = [[NSMutableString alloc] initWithData:fileData encoding:NSUTF8StringEncoding];
[webView stringByEvaluatingJavaScriptFromString:jsString];
Maybe setting the encoding type helps to parse all the brackets in a right way. 也许设置编码类型有助于以正确的方式解析所有括号。
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