Google (Local) Search API的简单使用介绍

花了两天的时间来用Google的API来做这么一个小东西，其实真正的实现代码不是很多，十几行而已。费时间的工作是了解各个API的功能以及调试JavaScript。

下面简单介绍一下这次我用到的几个函数吧。

•构造函数google.search.LocalSearch()

这其实是创建了一个LocalSearch的Service，这个Service和其他Service（News, Blog, Web）一样，是供SearchControl使用的。这些Service决定了SearchControl的能力。

•设置LocalSearch的搜索结构类型

localSearch.setRestriction(google.search.Search.RESTRICT_TYPE, google.search.LocalSearch.TYPE_KMLONLY_RESULTS)

这说明搜索的结果没有business的结果，只有kml和geocode结果

•设置LocalSearch的搜索范围

localSearch.setCenterPoint("北京");

•google.search.SearcherOptions()

设置Search Service(Searcher)的属性，作为SearchControl.addSearcher()的一个属性使用，有以下选项可以选择：

1.设置结果的显示方式
•searcherOptions.setExpandMode(google.search.SearchControl.EXPAND_MODE_OPEN);

2.  设置档没有搜索结果时显示的文字

•  searcherOptions.setNoResultsString(google.search.SearchControl.NO_RESULTS_DEFAULT_STRING);

3.  设置结果显示的位置

•searcherOptions.setRoot(resultCanvas);

•new google.search.DrawOptions();

设置Google Search Control的显示方式

•drawOptions.setDrawMode(google.search.SearchControl.DRAW_MODE_TABBED)

设置显示方式为tabbed方式，即各个Searcher像tabs一样显示

•drawOptions.setInput(document.getElementById("input"));

将搜索输入框的默认值改为用户自定义的一个输入框

将用户选择搜索结果作为一个相应的GResult对象返回，如LocalSearch的GResult就是一个GLocalResult。

这个选项费了我很长时间才找到，原因有二，一是用的人少，文档少。二是我看的英文文档，花了挺长时间才看明白，其实看中文文档要花的时间更长，我觉得。

•searchControl.setOnKeepCallback(this, LocalSearchKeepHandler);

顺便贴上LocalSearchKeepHandler的代码，其参数为自动返回的那个GResult对象。

function LocalSearchKeepHandler(result) {
  var from = document.getElementById("from");
  alert("result.tilte = " + result.title);
  from.value = ProcessString(result.title);
  alert("from.value = " + from.value);
 // alert(result.title);
 }

干脆把这段代码整体贴出，方便阅读

google.load("search", "1", {"language": "zh-CN"});
 function initialize() {
     //LocalSearch Object used to create a local search service for the maps
        var localSearch = new google.search.LocalSearch(); 
        //restrict the local search resutls to kml and geocode results only, no business ones
        localSearch.setRestriction(google.search.Search.RESTRICT_TYPE, google.search.LocalSearch.TYPE_KMLONLY_RESULTS);             
        // Set the Local Search center point
  localSearch.setCenterPoint("北京"); 
  //It's about local search, which are used to set where the results will appear, a param of options
  var resultCanvas = document.getElementById("resultCanvas");       
  //options: open, alternate root
  var searcherOptions = new google.search.SearcherOptions();
  //show many results
  searcherOptions.setExpandMode(google.search.SearchControl.EXPAND_MODE_OPEN);
  //no results message
  searcherOptions.setNoResultsString(google.search.SearchControl.NO_RESULTS_DEFAULT_STRING);
  //options.setDrawMode(google.search.SearchControl.DRAW_MODE_TABBED);//web, local... in a tab show
  searcherOptions.setRoot(resultCanvas); //show the results in another place--<div id="resultCanvas">
     //SearchControl Object used to create a search service which will include a local search service                   
  var searchControl = new google.search.SearchControl(null);
  searchControl.addSearcher(localSearch, searcherOptions); 
  searchControl.addSearcher(new google.search.WebSearch());
  searchControl.addSearcher(new google.search.NewsSearch());
  searchControl.addSearcher(new google.search.BlogSearch());
  //draw options and set it to a tabbed view, 
  var drawOptions = new google.search.DrawOptions();
  drawOptions.setDrawMode(google.search.SearchControl.DRAW_MODE_TABBED)
  //make the searchControl return a result:GResult
  searchControl.setOnKeepCallback(this, LocalSearchKeepHandler);//keeping a search result
  //this option is used to set the search box position in a DOM tree.
  //drawOptions.setSearchFormRoot(document.getElementById("drawOptions"));
  //set the input box to a user defined element 
  //drawOptions.setInput(document.getElementById("input"));
  // tell the search box to draw itself and tell it where to attach
 // searchControl.draw(document.getElementById("searchBox"), drawOptions);//Here I changed fromaddress and toaddress to search, a new place
  //another user defined input box
  drawOptions.setInput(document.getElementById("input2"));
  searchControl.draw();
  /** The codes below is about google Ajax Map Search API
  //this code segment is used to add a sidebar to show the results of the search
  //I wonder why no 'var' exists here
   optinos = new Object();
   options.resultList = resultCanvas;
   options.resultFormat = "multi-line1";
   var lsc2 = new google.elements.LocalSearch(options);
   map.addControl(lsc2, new GControlPosition(G_ANCHOR_TOP_LEFT, new GSize(-282, -2)));
    */
        }
 google.setOnLoadCallback(initialize);