Updated Notify_mattermost (markdown)

Notify_mattermost.md

@@ -4,40 +4,81 @@
 * **Message Format**: Text
 * **Message Limit**: 4000 Characters per message
 
-To use this plugin, you need to first set yourself up with http://mattermost.com. Download their software and set it up. The setup is based on Incoming Web Hooks requiring you to generate your own Authentication Token (WebHook ID).
+To use this plugin, you need to first set yourself up with http://mattermost.com. Download their software and set it up.
+
+From here you'll need an **Incoming Webhook*.  This can be done as follows:
+1. Click on the **Integrations** option under the channel dropdown and select **Incoming Webhook**:
+   ![Incoming Webhook](https://user-images.githubusercontent.com/850374/107084396-ff55dc00-67c4-11eb-899c-a65b2f639158.png)
+2. From here you can select **Add Incoming Webhook**:
+   ![Add Incoming Webhook](https://user-images.githubusercontent.com/850374/107083851-3d9ecb80-67c4-11eb-8bf7-820a3554eadb.png)
+3. Finally you'll be able to customize how you want the webhook to act/behave and you can press **Save** at the bottom when you're complete.
+  ![Generate An Apprise URL from it](https://user-images.githubusercontent.com/850374/107083865-442d4300-67c4-11eb-8228-7d7afb5974e3.png)
+
+An example URL you may be provided could look like this:
+```bash
+# The URL provided by Mattermost:
+http://localhost:8065/hooks/yokkutpah3r3urc5h6i969yima
+         ^        ^                ^
+         |        |                |
+      hostname   port           webhook token
+
+# From here you can do the following to generate your Apprise URL:
+# - http:// becomes mmost://
+# - drop /hooks reference
+# Which gets you:
+mmost://localhost:8065/yokkutpah3r3urc5h6i969yima
+```
 
 ### Syntax
 Valid syntaxes are as follows:
-* **mmost**://**{hostname}**/**{authtoken}**
-* **mmost**://**{hostname}**:**{port}**/**{authtoken}**
-* **mmost**://**{botname}**@**{hostname}**/**{authtoken}**
-* **mmost**://**{botname}**@**{hostname}**:**{port}**/**{authtoken}**
-* **mmosts**://**{hostname}**/**{authtoken}**
-* **mmosts**://**{hostname}**:**{port}**/**{authtoken}**
-* **mmosts**://**{botname}**@**{hostname}**/**{authtoken}**
-* **mmosts**://**{botname}**@**{hostname}**:**{port}**/**{authtoken}**
-* **mmosts**://**{hostname}**/**{path}**/**{authtoken}**
-* **mmosts**://**{hostname}**:**{port}**/**{path}**/**{authtoken}**
-* **mmosts**://**{botname}**@**{hostname}**/**{path}**/**{authtoken}**
-* **mmosts**://**{botname}**@**{hostname}**:**{port}**/**{path}**/**{authtoken}**
+* `mmost://{hostname}/{token}`
+* `mmost://{hostname}:{port}/{token}`
+* `mmost://{botname}@{hostname}/{token}`
+* `mmost://{botname}@{hostname}:{port}/{token}`
+* `mmost://{hostname}/{path}/{token}`
+* `mmost://{hostname}:{port}/{path}/{token}`
+* `mmost://{botname}@{hostname}/{path}/{token}`
+* `mmost://{botname}@{hostname}:{port}/{{path}/token}`
 
-Secure connections (via https) should be referenced using **mmosts://** where as insecure connections (via http) should be referenced via **mmost://**.
+Secure connections (via https) should be referenced using **mmosts://** where as insecure connections (via http) should be referenced via **mmost://**; they follow the same structure:
+
+* `mmosts://{hostname}/{token}`
+* `mmosts://{hostname}:{port}/{token}`
+* `mmosts://{botname}@{hostname}/{token}`
+* `mmosts://{botname}@{hostname}:{port}/{token}`
+* `mmosts://{hostname}/{path}/{token}`
+* `mmosts://{hostname}:{port}/{path}/{token}`
+* `mmosts://{botname}@{hostname}/{path}/{token}`
+* `mmosts://{botname}@{hostname}:{port}/{{path}/token}`
 
 ### Parameter Breakdown
 | Variable    | Required | Description
 | ----------- | -------- | -----------
 | hostname    | Yes      | The server Mattermost is listening on.
-| authtoken   | Yes      | The Authentication Token (the WebHook ID) you would have gotten after setting up the Mattermost server
+| token       | Yes      | The Webhook Token you would have received after setting up the Mattermost **Incoming Webhook**
 | port        | No       | The server port Mattermost is listening on. By default the port is **8065**.
-| path        | No       | You can identify a sub-path if you wish. The last element of the path must be the **authtoken**.
+| path        | No       | You can identify a sub-path if you wish. The last element of the path must be the **token**.
 | botname     | No       | An optional botname you can associate with your post
+| image       | No       | Identify whether or not you want the Apprise image (showing status color) to display with every message or not. By default this is set to **yes**.
+| channels    | No       | You can optionally specify as many channels as you want in a comma separated value (as a keyword argument).  See example below for how to use this.  You must also not restrict your **Incoming Webhook** to only focus on a specific channel or providing alternatives here will not work.
 
 #### Example
 Send a secure Mattermost notification to our server
 ```bash
 # Assuming our {hostname} is mattermost.server.local
-# Assuming our {authtoken} is 3ccdd113474722377935511fc85d3dd4
+# Assuming our {token} is 3ccdd113474722377935511fc85d3dd4
 
 apprise -vv -t "Test Message Title" -b "Test Message Body" \
    mmosts://mattermost.server.local/3ccdd113474722377935511fc85d3dd4
-```
+```
+
+Send an insecure Mattermost notification to server in addition to having to address specific channels:
+```bash
+# Assuming our {hostname} is mattermost.server.local
+# Assuming our {token} is 3ccdd113474722377935511fc85d3dd4
+# Assuming our {channels} is #support and #general
+
+# We don't need to provide the '#' (hashtag) prefix:
+apprise -vv -t "Test Message Title" -b "Test Message Body" \
+   mmost://mattermost.server.local/3ccdd113474722377935511fc85d3dd4?channels=support,general
+```