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<h2><a href="https://wiki.asterisk.org/wiki/display/AST/Tips+and+Tricks">Tips and Tricks</a></h2>
<h4>Page <b>edited</b> by <a href="https://wiki.asterisk.org/wiki/display/~mnicholson">Matthew Nicholson</a>
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<h4>Changes (1)</h4>
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<tr><td class="diff-snipped" >...<br></td></tr>
<tr><td class="diff-unchanged" >{info} <br> <br></td></tr>
<tr><td class="diff-added-lines" style="background-color: #dfd;">h2. Defining Extensions Dynamically <br> <br>Since extensions are functions in pbx_lua, any function can be used, including closures. A function can be defined that returns extension functions and used to populate the extensions table. <br> <br>{code:title=extensions.lua} <br>extensions = {} <br>extensions.default = {} <br> <br>function sip_exten(e) <br> return function() <br> app.dial("SIP/" .. e) <br> end <br>end <br> <br>extensions.default[100] = sip_exten(100) <br>extensions.default[101] = sip_exten(101) <br> <br>{code} <br> <br></td></tr>
<tr><td class="diff-unchanged" >h2. Creating Custom Aliases for Built-in Constructs <br> <br></td></tr>
<tr><td class="diff-snipped" >...<br></td></tr>
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</div> <h4>Full Content</h4>
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<h2><a name="TipsandTricks-LongRunningOperations%28Autoservcie%29"></a>Long Running Operations (Autoservcie)</h2>
<p>Before starting long running operations, an autoservice should be started using the <tt>autoservice_start()</tt> function. An autoservice will ensure that the user hears a continuous stream of audio while your lua code works in the background. This autoservice will automatically be stopped before executing applications and dialplan functions and will be restarted afterwards. The autoservice can be stopped using autoservice_stop() and the autoservice_status() function will return <tt>true</tt> if an autoservice is currently running.</p>
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<pre class="theme: Confluence; brush: java; gutter: false">app.startmusiconhold()
autoservice_start()
do_expensive_db_query()
autoservice_stop()
app.stopmusiconhold()</pre>
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<div class='panelMacro'><table class='infoMacro'><colgroup><col width='24'><col></colgroup><tr><td valign='top'><img src="/wiki/images/icons/emoticons/information.gif" width="16" height="16" align="absmiddle" alt="" border="0"></td><td>In Asterisk 1.10 an autoservice is automatically started for you by default.</td></tr></table></div>
<h2><a name="TipsandTricks-DefiningExtensionsDynamically"></a>Defining Extensions Dynamically</h2>
<p>Since extensions are functions in pbx_lua, any function can be used, including closures. A function can be defined that returns extension functions and used to populate the extensions table.</p>
<div class="code panel" style="border-width: 1px;"><div class="codeHeader panelHeader" style="border-bottom-width: 1px;"><b>extensions.lua</b></div><div class="codeContent panelContent">
<pre class="theme: Confluence; brush: java; gutter: false">extensions = {}
extensions.default = {}
function sip_exten(e)
return function()
app.dial("SIP/" .. e)
end
end
extensions.default[100] = sip_exten(100)
extensions.default[101] = sip_exten(101)</pre>
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<h2><a name="TipsandTricks-CreatingCustomAliasesforBuiltinConstructs"></a>Creating Custom Aliases for Built-in Constructs</h2>
<p>If you don't like the <tt>app</tt> table being named 'app' or if you think typing 'channel' to access the <tt>channel</tt> table is too much work, you can rename them.</p>
<div class="code panel" style="border-width: 1px;"><div class="codeHeader panelHeader" style="border-bottom-width: 1px;"><b>I prefer less typing</b></div><div class="codeContent panelContent">
<pre class="theme: Confluence; brush: java; gutter: false">function my_exten(context, extensions)
c = channel
a = app
c.my_variable = "my new channel variable"
a.dial("SIP/100")
end</pre>
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<h2><a name="TipsandTricks-RepurposingThe%7B%7Bprint%7D%7DFunction"></a>Re-purposing The <tt>print</tt> Function</h2>
<p>Lua has a built in "print" function that outputs things to stdout, but for Asterisk, we would rather have the output go in the verbose log. To do so, we could rewrite the <tt>print</tt> function as follows.</p>
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<pre class="theme: Confluence; brush: java; gutter: false">function print(...)
local msg = ""
for i=1,select('#', ...) do
if i == 1 then
msg = msg .. tostring(select(i, ...))
else
msg = msg .. "\t" .. tostring(select(i, ...))
end
end
app.verbose(msg)
end</pre>
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<h2><a name="TipsandTricks-SplittingConfigurationintoMultipleFiles"></a>Splitting Configuration into Multiple Files</h2>
<p>The <tt>require</tt> method can be used to load lua modules or additional files.</p>
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