Web2py Layout Features

Web2py Layout FeaturesCHAPTER 5. DEVELOPMENTIn the Web2py mannikin thither be two objects that contribute in calculative both static and dynamic weather vane pages. The SQLFORM.factory object is used for developing static entanglement pages and SQLFORM object for developing dynamic pages.The framework consists of tercet accuses, namely db.py which is created in the model, inadvertence.py created in the controller and default/index.html file for designing the clear page in the go through layer.When the tend in the controller gets executed, the default/index.html file in the view is called which passes the variables into HTML. Since the view file is written in HTML, the python code is placed within . The layout.html file represents the fundamental layout of all the applications designed in web2py.Screenshot of the files mentioned in a higher place in web2py interfaceScreenshot 5.1. Files of Web2pyTo understand how the objects work I developed a static web page which takes name and chemical type of a chemical compound as user inputs and accepts the course of study if no errors are found. However, if the user does not enter any name the form sends a response to the user displaying Form contains errorEach time a new user submits the form marrow Form displayed for the first time is displayed.Screenshot of the web page consumeedScreenshot 5.1. New pageCode to implement static web page in the logical layerdef index()form=SQLFORM.factory(Field( mention,requires=IS_NOT_EMPTY()),Field(Chemical_Type,requires=IS_NOT_EMPTY())).process()if form.acceptedsession.flash=Form acceptedredirect(URL(other,vars=Nameform.vars.Name))elif form.errorsresponse.flash=Form contains errorselseresponse.flash=Form displayed for the first timereturn locals()Code to view the web page in the view layerextend layout.html=form5.2. Designing dynamic Cheminformatics ApplicationTo start with designing the web application in web2py framework, there are some built-in files that shtup be modified for designing purpose. These built-in files of web2py retain facilitated easy designing of the web application. One of the main files is the menu.py model file which can be customized found on the requirement of the user.By making some few changes in the above file, the following tags such as Cheminformatics, Home and Drug Database on the left-hand side of the page have been established.The table includes Compound_ID and row.id details of the chemical compound table created in the db.py file of model. Logic is implemented in the controller and connecting the web page to the server is implemented in the view. The web page retrieves resolving powers from the server based on the query of the user.Model Code db.define_table (Compound_Details,Field(Compound_ID,string),Field(row.id,int))Controller code-def index()return dict()search through search turf outdef search()result=error=no result foundx= invite.body.read()result=Query_results(str(x))if result= return resultelsere turn errordef Query_results(y)a=result=count1=0my_query=(db.Compound_Details.Compound_ID.contains(y))myset=db(my_query)rows = myset.select()for row in rowsresult=str(row.Compound_ID) +t+ str(row.id) +n+ resultcount1=myset.count()if count1==0return str(a)else return resultView code-extend layout.htmlplaceholder=Search here autocomplete=off /SearchFunction search_element()//clear()var texttext=document.getElementById(search_text).valueif(text==)alert(Enter some text to be searched)returnvar xmlhttpif (window.XMLHttpRequest)// code for IE7+, Firefox, Chrome, Opera, Safarixmlhttp=new XMLHttpRequest()else// code for IE6, IE5xmlhttp=new ActiveXObject(Microsoft.XMLHTTP)xmlhttp.open(POST,=URL(search),true)xmlhttp.setRequest capitulum(Content- type,http//127.0.0.18000/search1/default/index?search_text=)xmlhttp.setRequestHeader(Content-length, text.length)xmlhttp.onreadystatechange=function()if (xmlhttp.readyState==4 xmlhttp.status==200)var result=xmlhttp.responseTextif(result==)alert(no res ult found)elsevar row=result.split(n)//row is the individual rowfor (i=0icreateDiv(rowi)document.getElementById(search_text).value=xmlhttp.send(text) 14Explanation of the codeThe web2py framework provides the ability to the developer to view the creation of table in the sql.log file and input records into the database through the database administration file.Below is a crack of the implementation of the search page Screenshot 5.2. Cheminformatics App pageThree functions are declared in the controller divide which includes the logic required to search for text based on user input. In the search function, when user enters text in the search box, the input is converted into string using the supplicate.body.read object.The string is then order to the database server through the Query_results function which retrieves Name and row.id of the chemical compound each time count1==0. The index function in the controller is used for the purpose of returning the dictionary.The view section h andles the display of the web page. In order to connect the HTML page to the database server of web2py, an AJAX script is initiated for the purpose of making the page dynamic. It automatically updates the web page without re-loading it. It uses XmlHttpRequest object to interact with the server. Browsers such as IE7+, Firefox, Chrome, Opera, and Safari are supported by the new XmlHttpRequest object. The older versions of IE such as IE5 and IE6 are supported by the new ActiveXObject. Methods open() and send(), are used for the purpose of direct bespeak to the server. The open() method has the following syntaxopen(method,url,async) The method defines the type of Http request to be sent across- either GET or POST. The url is the position of the file and async determines the asynchronous or synchronous nature of request. An asynchronous request is one that does not block the javascript which interacts with the server. A synchronous request is one that hinders the interaction of the ja vascript with the server until the action is complete. The code in view applies the asynchronous request that facilitates the http request to interact with the server to retrieve the results.send(string) The argument string is used for http POST request. This method is used for sending the request to the server.The POST request will then use the setRequestHeader(header,value) method for sending request to the server. Header argument is for the header name and the value argument is the header value. The following screenshot illustrates the value of the records after the user clicks on the search button. Screenshot 5.2. ResultThis initial prototype will serve as a foot in the preparation of the cheminformatics resource that will facilitate search based on user input.