![]() It uses the deprecated escape() function and implicitly performs the UTF-8 decoding. Var text_original_1 = decodeURIComponent (escape (window. The first step common to all four methods is to convert from URL-safe base64 encoding to canonical base64 encoding: I will now quickly go through the different methods. I recommend looking at the source code of this HTML document, I have commented the different methods sufficiently. Each of the individual panels is the result of a different decoding implementation. It should have four panels, whereas each panel should show the exact same text as initially defined in the Python script above, including all newlines. When you access the URL above, an HTML document should show up. ![]() ![]() Okay, let’s put the test data into the URL (the output from the Python script above): This is a DOMString type, as indicated by the text_ variable name prefix. Get URL-safe text representation from the address bar. To that end, the test document executes JavaScript code that extracts a string from the anchor/hash part of the URL: Remember, the text we want to transport is encoded in a URL-safe way, so just for fun I want to make use of this fact in this small demonstration here, and communicate the information via the URL. Here is the test document that implements four different methods for obtaining the original text back from the URL-safe representation (it just doesn’t show anything yet!): Decoding the URL-safe representation in the browser The Python script also tells you that the text is 167 characters long, which is a useful reference for later comparison. So, execution of the named Python script yields the following URL-safe representation of the original text:ĬsKra8O8w5_DrsK74oCc0IzPjdCR0IfigJ3vu4jvu4nvu4zvu43vu47jjIDjjIHjjILinbbinbfinbjijZ3ijZ7ijZ_ijaDgr4vgr4zCq8-EzrHQkdCs4oSTz4PCuzoKbjIwJW9m2akoLcyuzK7Mg圓MgynbttmpKOKXj8yuzK7Mg-KAosyDKdu22akozaHguY_Mr82h4LmPKdu22akoLcyuzK7Mg-KAosyDKSHgpZHgpZLgpZPgrpngrprgupvgupzhvJHhvJTihIfiiIbiiIfilobilofilogK4pyG4pyH4pyI4pyJ4pyM4pyN44GG44GH44GI44GJ44GK44aF44aH44mr44ms442N442O442P76Wy76Wz76W076W176W276W376W476W576W676W7Cu-vl-vmO-vme-vmu-vne-voO-voe-vou-9tu-9t-9uO-9ue-9uu-9u-9vO-9vSdrb3NtZSc6Is664b25z4POvM61Ii8_Iyvtn78K The resulting binary data then is put into urlsafe_b64encode(), yielding a URL-safe byte sequence. The following resources helped me assembling this test text:Īs you can see, the text is first encoded using the UTF-8 codec. The original text (the variable named text) is meant to contain code points from many different Unicode character blocks. ̃)!॒॑॓ஙசປຜἑἔℇ∆∇▆▇█ĭatab64 = urlsafe_b64encode (data ) print ( "text length: %s" % len (text ) ) print ( "urlsafe base64 representation of the binary data: \n \n%s" % datab64 ).# -*- coding: utf-8 -*- from _future_ import unicode_literals I’ll start with a Python snippet defining the original text and creating its URL-safe base64 representation: The original text and its URL-safe representation I’ll show two different methods for performing this task. Proceeding from here, I realized that there also is still no established way for decoding a binary blob into a DOMString using a given codec (UTF-8 in this case). Further below, I’ll show three different methods for executing this step. There is no obvious way for obtaining a binary blob from base64-encoded data. Unfortunately, there so far are no official and no established ways for performing steps 5.3 and 5.4 in a browser environment. Decode the binary blob into a DOMString containing the original text, using the UTF-8 codec.Decode the base64 string into a real binary data type ( Uint8Array, for instance).Transform URL-safe base64 representation to canonical base64 (replace _ and – characters).The data arrives as DOMString type (unicode text, so to say).Invert the entire procedure in the browser:.Let’s assume it ends up in a browser (in window.location, for instance). base64-encode the resulting binary data (and replace the URL-unsafe characters / and with, for instance, – and _).Encode the original text into binary data with the UTF-8 codec.Start with the original text, which is a sequence of unicode code points.With the right tools this should be a trivial process, shouldn’t it? ![]() For an AngularJS-based web application I am currently working on, I want to put arbitrary text information into a URL, send it to the client, and have it decoded by the browser.
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