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You must escape \n and \r among other escape sequences if they present in Javascript code. Otherwise they get parsed by Python. r'strings' is a recommended way to load Javascript. For GTK WebKit2 versions older than 2.22, there is a limit of about ~900 characters for a value returned by <code>evaluate_js</code>.</p> <h2 id="invoke-python-from-javascript"><a href="#invoke-python-from-javascript" class="header-anchor">#</a> Invoke Python from Javascript</h2> <p>Invoking Python functions from Javascript can be done with two different approaches.</p> <ul><li>by exposing an instance of a Python class to the <code>js_api</code> of <code>create_window</code>. All the callable methods of the class will be exposed to the JS domain as <code>pywebview.api.method_name</code> with correct parameter signatures. Method name must not start with an underscore. See an <a href="/3.7/examples/js_api.html">example</a>.</li> <li>by passing your function(s) to window object's <code>expose(func)</code>. This will expose a function or functions to the JS domain as <code>pywebview.api.func_name</code>. Unlike JS API, <code>expose</code> allows to expose functions also at the runtime. If there is a name clash between JS API and functions exposed this way, the latter takes precedence. See an <a href="/3.7/examples/expose.html">example</a>.</li></ul> <p>Exposed function returns a promise that is resolved to its result value. Exceptions are rejected and encapsulated inside a Javascript <code>Error</code> object. Stacktrace is available via <code>error.stack</code>. Functions are executed in separate threads and are not thread-safe.</p> <p><code>window.pywebview.api</code> is not guaranteed to be available on <code>window.onload</code>. Subscribe to <code>window.pywebviewready</code> instead to make sure that <code>window.pywebview.api</code> is ready. <a href="/3.7/examples/js_api.html">Example</a>.</p></div> <footer class="page-edit"><div class="edit-link"><a href="https://github.com/r0x0r/pywebview/edit/docs/docs/guide/interdomain.md" target="_blank" rel="noopener noreferrer">Help us improve this page!</a> <span><svg xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" x="0px" y="0px" viewBox="0 0 100 100" width="15" height="15" class="icon outbound"><path fill="currentColor" d="M18.8,85.1h56l0,0c2.2,0,4-1.8,4-4v-32h-8v28h-48v-48h28v-8h-32l0,0c-2.2,0-4,1.8-4,4v56C14.8,83.3,16.6,85.1,18.8,85.1z"></path> <polygon fill="currentColor" points="45.7,48.7 51.3,54.3 77.2,28.5 77.2,37.2 85.2,37.2 85.2,14.9 62.8,14.9 62.8,22.9 71.5,22.9"></polygon></svg> <span class="sr-only">(opens new window)</span></span></div> <!----></footer> <div class="page-nav"><p class="inner"><span class="prev">
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