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diff --git a/lib/webtool/doc/src/webtool_chapter.xml b/lib/webtool/doc/src/webtool_chapter.xml new file mode 100644 index 0000000000..ceadce382d --- /dev/null +++ b/lib/webtool/doc/src/webtool_chapter.xml @@ -0,0 +1,248 @@ +<?xml version="1.0" encoding="latin1" ?> +<!DOCTYPE chapter SYSTEM "chapter.dtd"> + +<chapter> + <header> + <copyright> + <year>2001</year><year>2009</year> + <holder>Ericsson AB. All Rights Reserved.</holder> + </copyright> + <legalnotice> + The contents of this file are subject to the Erlang Public License, + Version 1.1, (the "License"); you may not use this file except in + compliance with the License. You should have received a copy of the + Erlang Public License along with this software. If not, it can be + retrieved online at http://www.erlang.org/. + + Software distributed under the License is distributed on an "AS IS" + basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See + the License for the specific language governing rights and limitations + under the License. + + </legalnotice> + + <title>WebTool User Guide</title> + <prepared></prepared> + <docno></docno> + <date></date> + <rev></rev> + <file>webtool_chapter.xml</file> + </header> + + <section> + <title>Introduction </title> + <p>WebTool provides an easy and efficient way to implement web + based tools with Erlang/OTP. WebTool configures and starts the + webserver and the various web based tools.</p> + <p>All tools that shall run under WebTool must have a *.tool + file in the code path or in its priv directory. When WebTool + starts it searches the code path for such files. For each + <c>ebin</c> directory in the path, the <c>priv</c> directory is + also searched. The *.tool files contain the configuration data + for each web based tool.</p> + </section> + + <section> + <title>Starting WebTool</title> + <p>Start WebTool by calling the function <c>webtool:start/0</c> or + <c>webtool:start/2</c>. If <c>webtool:start/0</c> is used the + start page of WebTool is available at + <em>http://localhost:8888/</em> or + <em>http://127.0.0.1:8888/</em>, and the directory containing + the root directory for the webserver, is assumed to be + <c><![CDATA[webtool-<vsn>/priv]]></c>.</p> + <p>Use <c>webtool:start/2</c> if the default path for the root + directory, port, ip-number or server name can not be used. See + the Reference Manual for <seealso marker="webtool">webtool</seealso> for more information.</p> + <p>WebTool, with the default configuration as in <c>start/0</c>, + can also be started with the <c>start_webtool</c> script which + is available in the <c>priv</c> directory of the WebTool + application. See the Reference Manual for <seealso marker="start_webtool">start_webtool</seealso> for further + information about this script. For Windows users, the batch file + <c>start_webtool.bat</c> can be used for the same purpose.</p> + </section> + + <section> + <title>Using WebTool</title> + <p>Start WebTool and point the browser to the corresponding URL. + At the top of the page there is a frame with a link named + <em>WebTool</em>. Click that link and a page where it is + possible to start the available tools will appear in the main + frame.</p> + </section> + + <section> + <title>Start a web based tool</title> + <p>Click on the link labeled <em>WebTool</em> in the topmost frame, + select the checkbox for each tool to start and + click on the button labeled <em>Start</em>. A link to each tool + that WebTool succeeded to start will appear in the topmost frame.</p> + </section> + + <section> + <title>Stop a web based tool</title> + <p>Click on the link labeled <em>WebTool</em> in the topmost + frame. Select <em>Stop Tools</em> in the left frame. Select the + checkbox for each tool to stop and click on the button labeled + <em>Stop</em>.</p> + </section> + + <section> + <title>Develop new web based tools</title> + <p>WebTool can be used as a framework when developing new web based + tools.</p> + <p>A web based tool running under WebTool will typically consist of + three parts.</p> + <list type="bulleted"> + <item>A *.tool file which defines how WebTool can find the tool's + configuration data</item> + <item>The Erlang code generating the web interface to the tool (HTML + code)</item> + <item>The tool itself.</item> + </list> + <p>In most cases it is a good idea to separate the code for + creation of the html-pages and the code for the logic. This + increases the readability of the code and the logic might be + possible to reuse.</p> + + <section> + <title>The *.tool file</title> + <p>When WebTool starts it searches the current path for + <c>*.tool</c> files to find all available tools. The *.tool + file contains a version identifier and a list of tuples which + is the configuration data. The version identifier specifies + the *.tool file version, i.e. not the version of + webtool. Currently the only valid version is "1.2" and the + only valid configuration tag is + <c>config_func</c>. <c>config_func</c> specifies which + function WebTool must call to get further configuration data + for the tool. This means that a *.tool file generally must + look like this:</p> + <code type="none"> + {version,"1.2"}. + [{config_func,{Module,Function,Arguments}}]. </code> + <p><c>Module</c> is the name of the module where the callback + function is defined. <c>Function</c> is the name of the + callback function, and <c>Arguments</c> is the list of + arguments to the callback function.</p> + </section> + + <section> + <title>The configuration function</title> + <p>The *.tool file points out a configuration function. This + function must return a list of configuration parameters (see + the Reference Manual for <seealso marker="webtool">webtool</seealso>).</p> + <p>The <c>web_data</c> parameter is mandatory and it specifies + the name of the tool and the link to the tool's start + page. All other parameters are optional.</p> + <p>If the tool requires any processes to run, the <c>start</c> + parameter specifies the function that WebTool must call in + order to start the process(es).</p> + <p>The <c>alias</c> parameters are passed directly on to the + webserver (INETS). The webserver has three ways to create + dynamic web pages CGI, Eval Scheme and Erl Scheme. All tools + running under WebTool must use Erl Scheme.</p> + <p>Erl Scheme tries to resemble plain CGI. The big difference is + that Erl Scheme can only execute Erlang code. The code will + furthermore be executed on the same instance as the webserver.</p> + <p>An URL which calls an Erlang function with Erl Scheme can have + the following syntax:</p> + <code type="none"><![CDATA[ +http://Servername:Port/ErlScriptAlias/Mod/Func<?QueryString> ]]></code> + <p>An <c>alias</c> parameter in the configuration function can be + an ErlScriptAlias as used in the above URL. The definition of + an ErlScripAlias shall be like this:</p> + <p><c>{alias,{erl_alias,Path,[Modules]}}</c>, e.g.</p> + <p><c>{alias,{erl_alias,"/testtool",[helloworld]}}</c></p> + <p>The following URL will then cause a call to the function + helloworld:helloworld/2 (if WebTool is started with default + settings i.e. servername "localhost" and port 8888):</p> + <p><c>http://localhost:8888/testtool/helloworld/helloworld</c></p> + <p>Note that the module <c>helloworld</c> must be in the code + path of the node running WebTool.</p> + <p>Functions that are called via the Erl Scheme must take two + arguments, <c>Environment</c> and <c>Input</c>. + </p> + <list type="bulleted"> + <item><c>Environment</c> is a list of key/value tuples.</item> + <item><c>Input</c> is the part of the URL after the "?", i.e. the + part of the URL containing name-value pairs. If the page was + called with the URL: + <br></br> +<c><![CDATA[http://localhost:8888/testtool/helloworld/helloworld?input1=one&input2=two]]></c> <br></br> +<c>Input</c> will be the string + <c><![CDATA["input1=one&input2=two"]]></c>. In the module + <c>httpd</c> in the INETS application there is a function + <c>parse_query</c> which will parse such a string and return + a list of key-value tuples.</item> + </list> + <p>An <c>alias</c> parameter in the configuration function can + also be a normal path alias. This can e.g. be used to point + out a directory where HTML files are stored. The following + definition states that the URL + <c>http://localhost:8888/mytool_home/</c> really points to the + directory <c>/usr/local/otp/lib/myapp-1.0/priv</c>:</p> + <p><c>{alias,{"/mytool_home","/usr/local/otp/lib/myapp-1.0/priv"}}</c></p> + <p>See the INETS documentation, especially the module + <c>mod_esi</c>, for a more in depht coverage of Erl Scheme.</p> + </section> + + <section> + <title>A small example</title> + <p>A Hello World example that uses Erl Scheme would look like + this. Note that this example does not have a process running + and thus does not need a <c>start</c> parameter in the + configuration function. + </p> + <p><em>helloworld.erl:</em></p> + <pre> + -module(helloworld). + -export([config_data/0]). + -export([helloworld/2]). + + config_data()-> + {testtool, + [{web_data,{"TestTool","/testtool/helloworld/helloworld"}}, + {alias,{erl_alias,"/testtool",[helloworld]}}]}. + + helloworld(_Env,_Input)-> + [header(),html_header(),helloworld_body(),html_end()]. + + header() -> + header("text/html"). + + header(MimeType) -> + "Content-type: " ++ MimeType ++ "\\r\ +\\r\ +". + + html_header() -> + "<HTML> + <HEAD> + <TITLE>Hello world Example </TITLE> + </HEAD>\ +". + + helloworld_body()-> + "<BODY>Hello World</BODY>". + + html_end()-> + "</HTML>". + </pre> + <p>To use this example with WebTool a *.tool file must be created + and added to a directory in the current path, e.g. the same + directory as the compiled <c>helloworld.beam</c>.</p> + <p><em>testtool.tool:</em></p> + <code type="none"> + {version,"1.2"}. + [{config_func, {helloworld,config_data,[]}}]. + </code> + <p>When <c>helloworld.erl</c> is compiled, start WebTool by + calling the function <c>webtool:start()</c> and point your + browser to <em>http://localhost:8888/</em>. Select WebTool in + the topmost frame and start TestTool from the web page. Click + on the link labeled <em>TestTool</em> in the topmost frame.</p> + </section> + </section> +</chapter> + |